Merge pull request #937 from mhils/single-repo

Combine mitmproxy, pathod and netlib in a single repo.

34 files changed, 5688 insertions, 0 deletions

diff --git a/netlib/MANIFEST.in b/netlib/MANIFEST.in
new file mode 100644
index 00000000..db0e2ed6
--- /dev/null
+++ b/netlib/MANIFEST.in
@@ -0,0 +1,4 @@
+include LICENSE CONTRIBUTORS README.rst
+graft test
+prune test/tools
+recursive-exclude * *.pyc *.pyo *.swo *.swp
\ No newline at end of file
diff --git a/netlib/README.rst b/netlib/README.rst
new file mode 100644
index 00000000..16bd65a7
--- /dev/null
+++ b/netlib/README.rst
@@ -0,0 +1,35 @@
+|travis| |coveralls| |downloads| |latest_release| |python_versions|
+
+Netlib is a collection of network utility classes, used by the pathod and
+mitmproxy projects. It differs from other projects in some fundamental
+respects, because both pathod and mitmproxy often need to violate standards.
+This means that protocols are implemented as small, well-contained and flexible
+functions, and are designed to allow misbehaviour when needed.
+
+
+Development
+-----------
+
+If you'd like to work on netlib, check out the instructions in mitmproxy's README_.
+
+.. |travis| image:: https://shields.mitmproxy.org/travis/mitmproxy/netlib/master.svg
+    :target: https://travis-ci.org/mitmproxy/netlib
+    :alt: Build Status
+
+.. |coveralls| image:: https://shields.mitmproxy.org/coveralls/mitmproxy/netlib/master.svg
+    :target: https://coveralls.io/r/mitmproxy/netlib
+    :alt: Coverage Status
+
+.. |downloads| image:: https://shields.mitmproxy.org/pypi/dm/netlib.svg?color=orange
+    :target: https://pypi.python.org/pypi/netlib
+    :alt: Downloads
+
+.. |latest_release| image:: https://shields.mitmproxy.org/pypi/v/netlib.svg
+    :target: https://pypi.python.org/pypi/netlib
+    :alt: Latest Version
+
+.. |python_versions| image:: https://shields.mitmproxy.org/pypi/pyversions/netlib.svg
+    :target: https://pypi.python.org/pypi/netlib
+    :alt: Supported Python versions
+
+.. _README: https://github.com/mitmproxy/mitmproxy#hacking
\ No newline at end of file
diff --git a/netlib/netlib/__init__.py b/netlib/netlib/__init__.py
new file mode 100644
index 00000000..9b4faa33
--- /dev/null
+++ b/netlib/netlib/__init__.py
@@ -0,0 +1 @@
+from __future__ import (absolute_import, print_function, division)
diff --git a/netlib/netlib/certutils.py b/netlib/netlib/certutils.py
new file mode 100644
index 00000000..616a778e
--- /dev/null
+++ b/netlib/netlib/certutils.py
@@ -0,0 +1,472 @@
+from __future__ import (absolute_import, print_function, division)
+import os
+import ssl
+import time
+import datetime
+from six.moves import filter
+import ipaddress
+
+import sys
+from pyasn1.type import univ, constraint, char, namedtype, tag
+from pyasn1.codec.der.decoder import decode
+from pyasn1.error import PyAsn1Error
+import OpenSSL
+
+from .utils import Serializable
+
+# Default expiry must not be too long: https://github.com/mitmproxy/mitmproxy/issues/815
+
+DEFAULT_EXP = 94608000  # = 24 * 60 * 60 * 365 * 3
+# Generated with "openssl dhparam". It's too slow to generate this on startup.
+DEFAULT_DHPARAM = b"""
+-----BEGIN DH PARAMETERS-----
+MIICCAKCAgEAyT6LzpwVFS3gryIo29J5icvgxCnCebcdSe/NHMkD8dKJf8suFCg3
+O2+dguLakSVif/t6dhImxInJk230HmfC8q93hdcg/j8rLGJYDKu3ik6H//BAHKIv
+j5O9yjU3rXCfmVJQic2Nne39sg3CreAepEts2TvYHhVv3TEAzEqCtOuTjgDv0ntJ
+Gwpj+BJBRQGG9NvprX1YGJ7WOFBP/hWU7d6tgvE6Xa7T/u9QIKpYHMIkcN/l3ZFB
+chZEqVlyrcngtSXCROTPcDOQ6Q8QzhaBJS+Z6rcsd7X+haiQqvoFcmaJ08Ks6LQC
+ZIL2EtYJw8V8z7C0igVEBIADZBI6OTbuuhDwRw//zU1uq52Oc48CIZlGxTYG/Evq
+o9EWAXUYVzWkDSTeBH1r4z/qLPE2cnhtMxbFxuvK53jGB0emy2y1Ei6IhKshJ5qX
+IB/aE7SSHyQ3MDHHkCmQJCsOd4Mo26YX61NZ+n501XjqpCBQ2+DfZCBh8Va2wDyv
+A2Ryg9SUz8j0AXViRNMJgJrr446yro/FuJZwnQcO3WQnXeqSBnURqKjmqkeFP+d8
+6mk2tqJaY507lRNqtGlLnj7f5RNoBFJDCLBNurVgfvq9TCVWKDIFD4vZRjCrnl6I
+rD693XKIHUCWOjMh1if6omGXKHH40QuME2gNa50+YPn1iYDl88uDbbMCAQI=
+-----END DH PARAMETERS-----
+"""
+
+
+def create_ca(o, cn, exp):
+    key = OpenSSL.crypto.PKey()
+    key.generate_key(OpenSSL.crypto.TYPE_RSA, 2048)
+    cert = OpenSSL.crypto.X509()
+    cert.set_serial_number(int(time.time() * 10000))
+    cert.set_version(2)
+    cert.get_subject().CN = cn
+    cert.get_subject().O = o
+    cert.gmtime_adj_notBefore(-3600 * 48)
+    cert.gmtime_adj_notAfter(exp)
+    cert.set_issuer(cert.get_subject())
+    cert.set_pubkey(key)
+    cert.add_extensions([
+        OpenSSL.crypto.X509Extension(
+            b"basicConstraints",
+            True,
+            b"CA:TRUE"
+        ),
+        OpenSSL.crypto.X509Extension(
+            b"nsCertType",
+            False,
+            b"sslCA"
+        ),
+        OpenSSL.crypto.X509Extension(
+            b"extendedKeyUsage",
+            False,
+            b"serverAuth,clientAuth,emailProtection,timeStamping,msCodeInd,msCodeCom,msCTLSign,msSGC,msEFS,nsSGC"
+        ),
+        OpenSSL.crypto.X509Extension(
+            b"keyUsage",
+            True,
+            b"keyCertSign, cRLSign"
+        ),
+        OpenSSL.crypto.X509Extension(
+            b"subjectKeyIdentifier",
+            False,
+            b"hash",
+            subject=cert
+        ),
+    ])
+    cert.sign(key, "sha256")
+    return key, cert
+
+
+def dummy_cert(privkey, cacert, commonname, sans):
+    """
+        Generates a dummy certificate.
+
+        privkey: CA private key
+        cacert: CA certificate
+        commonname: Common name for the generated certificate.
+        sans: A list of Subject Alternate Names.
+
+        Returns cert if operation succeeded, None if not.
+    """
+    ss = []
+    for i in sans:
+        try:
+            ipaddress.ip_address(i.decode("ascii"))
+        except ValueError:
+            ss.append(b"DNS: %s" % i)
+        else:
+            ss.append(b"IP: %s" % i)
+    ss = b", ".join(ss)
+
+    cert = OpenSSL.crypto.X509()
+    cert.gmtime_adj_notBefore(-3600 * 48)
+    cert.gmtime_adj_notAfter(DEFAULT_EXP)
+    cert.set_issuer(cacert.get_subject())
+    if commonname is not None:
+        cert.get_subject().CN = commonname
+    cert.set_serial_number(int(time.time() * 10000))
+    if ss:
+        cert.set_version(2)
+        cert.add_extensions(
+            [OpenSSL.crypto.X509Extension(b"subjectAltName", False, ss)])
+    cert.set_pubkey(cacert.get_pubkey())
+    cert.sign(privkey, "sha256")
+    return SSLCert(cert)
+
+
+# DNTree did not pass TestCertStore.test_sans_change and is temporarily replaced by a simple dict.
+#
+# class _Node(UserDict.UserDict):
+#     def __init__(self):
+#         UserDict.UserDict.__init__(self)
+#         self.value = None
+#
+#
+# class DNTree:
+#     """
+#         Domain store that knows about wildcards. DNS wildcards are very
+#         restricted - the only valid variety is an asterisk on the left-most
+#         domain component, i.e.:
+#
+#             *.foo.com
+#     """
+#     def __init__(self):
+#         self.d = _Node()
+#
+#     def add(self, dn, cert):
+#         parts = dn.split(".")
+#         parts.reverse()
+#         current = self.d
+#         for i in parts:
+#             current = current.setdefault(i, _Node())
+#         current.value = cert
+#
+#     def get(self, dn):
+#         parts = dn.split(".")
+#         current = self.d
+#         for i in reversed(parts):
+#             if i in current:
+#                 current = current[i]
+#             elif "*" in current:
+#                 return current["*"].value
+#             else:
+#                 return None
+#         return current.value
+
+
+class CertStoreEntry(object):
+
+    def __init__(self, cert, privatekey, chain_file):
+        self.cert = cert
+        self.privatekey = privatekey
+        self.chain_file = chain_file
+
+
+class CertStore(object):
+
+    """
+        Implements an in-memory certificate store.
+    """
+
+    def __init__(
+            self,
+            default_privatekey,
+            default_ca,
+            default_chain_file,
+            dhparams):
+        self.default_privatekey = default_privatekey
+        self.default_ca = default_ca
+        self.default_chain_file = default_chain_file
+        self.dhparams = dhparams
+        self.certs = dict()
+
+    @staticmethod
+    def load_dhparam(path):
+
+        # netlib<=0.10 doesn't generate a dhparam file.
+        # Create it now if neccessary.
+        if not os.path.exists(path):
+            with open(path, "wb") as f:
+                f.write(DEFAULT_DHPARAM)
+
+        bio = OpenSSL.SSL._lib.BIO_new_file(path.encode(sys.getfilesystemencoding()), b"r")
+        if bio != OpenSSL.SSL._ffi.NULL:
+            bio = OpenSSL.SSL._ffi.gc(bio, OpenSSL.SSL._lib.BIO_free)
+            dh = OpenSSL.SSL._lib.PEM_read_bio_DHparams(
+                bio,
+                OpenSSL.SSL._ffi.NULL,
+                OpenSSL.SSL._ffi.NULL,
+                OpenSSL.SSL._ffi.NULL)
+            dh = OpenSSL.SSL._ffi.gc(dh, OpenSSL.SSL._lib.DH_free)
+            return dh
+
+    @classmethod
+    def from_store(cls, path, basename):
+        ca_path = os.path.join(path, basename + "-ca.pem")
+        if not os.path.exists(ca_path):
+            key, ca = cls.create_store(path, basename)
+        else:
+            with open(ca_path, "rb") as f:
+                raw = f.read()
+            ca = OpenSSL.crypto.load_certificate(
+                OpenSSL.crypto.FILETYPE_PEM,
+                raw)
+            key = OpenSSL.crypto.load_privatekey(
+                OpenSSL.crypto.FILETYPE_PEM,
+                raw)
+        dh_path = os.path.join(path, basename + "-dhparam.pem")
+        dh = cls.load_dhparam(dh_path)
+        return cls(key, ca, ca_path, dh)
+
+    @staticmethod
+    def create_store(path, basename, o=None, cn=None, expiry=DEFAULT_EXP):
+        if not os.path.exists(path):
+            os.makedirs(path)
+
+        o = o or basename
+        cn = cn or basename
+
+        key, ca = create_ca(o=o, cn=cn, exp=expiry)
+        # Dump the CA plus private key
+        with open(os.path.join(path, basename + "-ca.pem"), "wb") as f:
+            f.write(
+                OpenSSL.crypto.dump_privatekey(
+                    OpenSSL.crypto.FILETYPE_PEM,
+                    key))
+            f.write(
+                OpenSSL.crypto.dump_certificate(
+                    OpenSSL.crypto.FILETYPE_PEM,
+                    ca))
+
+        # Dump the certificate in PEM format
+        with open(os.path.join(path, basename + "-ca-cert.pem"), "wb") as f:
+            f.write(
+                OpenSSL.crypto.dump_certificate(
+                    OpenSSL.crypto.FILETYPE_PEM,
+                    ca))
+
+        # Create a .cer file with the same contents for Android
+        with open(os.path.join(path, basename + "-ca-cert.cer"), "wb") as f:
+            f.write(
+                OpenSSL.crypto.dump_certificate(
+                    OpenSSL.crypto.FILETYPE_PEM,
+                    ca))
+
+        # Dump the certificate in PKCS12 format for Windows devices
+        with open(os.path.join(path, basename + "-ca-cert.p12"), "wb") as f:
+            p12 = OpenSSL.crypto.PKCS12()
+            p12.set_certificate(ca)
+            p12.set_privatekey(key)
+            f.write(p12.export())
+
+        with open(os.path.join(path, basename + "-dhparam.pem"), "wb") as f:
+            f.write(DEFAULT_DHPARAM)
+
+        return key, ca
+
+    def add_cert_file(self, spec, path):
+        with open(path, "rb") as f:
+            raw = f.read()
+        cert = SSLCert(
+            OpenSSL.crypto.load_certificate(
+                OpenSSL.crypto.FILETYPE_PEM,
+                raw))
+        try:
+            privatekey = OpenSSL.crypto.load_privatekey(
+                OpenSSL.crypto.FILETYPE_PEM,
+                raw)
+        except Exception:
+            privatekey = self.default_privatekey
+        self.add_cert(
+            CertStoreEntry(cert, privatekey, path),
+            spec
+        )
+
+    def add_cert(self, entry, *names):
+        """
+            Adds a cert to the certstore. We register the CN in the cert plus
+            any SANs, and also the list of names provided as an argument.
+        """
+        if entry.cert.cn:
+            self.certs[entry.cert.cn] = entry
+        for i in entry.cert.altnames:
+            self.certs[i] = entry
+        for i in names:
+            self.certs[i] = entry
+
+    @staticmethod
+    def asterisk_forms(dn):
+        if dn is None:
+            return []
+        parts = dn.split(b".")
+        parts.reverse()
+        curr_dn = b""
+        dn_forms = [b"*"]
+        for part in parts[:-1]:
+            curr_dn = b"." + part + curr_dn  # .example.com
+            dn_forms.append(b"*" + curr_dn)   # *.example.com
+        if parts[-1] != b"*":
+            dn_forms.append(parts[-1] + curr_dn)
+        return dn_forms
+
+    def get_cert(self, commonname, sans):
+        """
+            Returns an (cert, privkey, cert_chain) tuple.
+
+            commonname: Common name for the generated certificate. Must be a
+            valid, plain-ASCII, IDNA-encoded domain name.
+
+            sans: A list of Subject Alternate Names.
+        """
+
+        potential_keys = self.asterisk_forms(commonname)
+        for s in sans:
+            potential_keys.extend(self.asterisk_forms(s))
+        potential_keys.append((commonname, tuple(sans)))
+
+        name = next(
+            filter(lambda key: key in self.certs, potential_keys),
+            None
+        )
+        if name:
+            entry = self.certs[name]
+        else:
+            entry = CertStoreEntry(
+                cert=dummy_cert(
+                    self.default_privatekey,
+                    self.default_ca,
+                    commonname,
+                    sans),
+                privatekey=self.default_privatekey,
+                chain_file=self.default_chain_file)
+            self.certs[(commonname, tuple(sans))] = entry
+
+        return entry.cert, entry.privatekey, entry.chain_file
+
+
+class _GeneralName(univ.Choice):
+    # We are only interested in dNSNames. We use a default handler to ignore
+    # other types.
+    # TODO: We should also handle iPAddresses.
+    componentType = namedtype.NamedTypes(
+        namedtype.NamedType('dNSName', char.IA5String().subtype(
+            implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 2)
+        )
+        ),
+    )
+
+
+class _GeneralNames(univ.SequenceOf):
+    componentType = _GeneralName()
+    sizeSpec = univ.SequenceOf.sizeSpec + \
+        constraint.ValueSizeConstraint(1, 1024)
+
+
+class SSLCert(Serializable):
+
+    def __init__(self, cert):
+        """
+            Returns a (common name, [subject alternative names]) tuple.
+        """
+        self.x509 = cert
+
+    def __eq__(self, other):
+        return self.digest("sha256") == other.digest("sha256")
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def get_state(self):
+        return self.to_pem()
+
+    def set_state(self, state):
+        self.x509 = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, state)
+
+    @classmethod
+    def from_state(cls, state):
+        cls.from_pem(state)
+
+    @classmethod
+    def from_pem(cls, txt):
+        x509 = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, txt)
+        return cls(x509)
+
+    @classmethod
+    def from_der(cls, der):
+        pem = ssl.DER_cert_to_PEM_cert(der)
+        return cls.from_pem(pem)
+
+    def to_pem(self):
+        return OpenSSL.crypto.dump_certificate(
+            OpenSSL.crypto.FILETYPE_PEM,
+            self.x509)
+
+    def digest(self, name):
+        return self.x509.digest(name)
+
+    @property
+    def issuer(self):
+        return self.x509.get_issuer().get_components()
+
+    @property
+    def notbefore(self):
+        t = self.x509.get_notBefore()
+        return datetime.datetime.strptime(t.decode("ascii"), "%Y%m%d%H%M%SZ")
+
+    @property
+    def notafter(self):
+        t = self.x509.get_notAfter()
+        return datetime.datetime.strptime(t.decode("ascii"), "%Y%m%d%H%M%SZ")
+
+    @property
+    def has_expired(self):
+        return self.x509.has_expired()
+
+    @property
+    def subject(self):
+        return self.x509.get_subject().get_components()
+
+    @property
+    def serial(self):
+        return self.x509.get_serial_number()
+
+    @property
+    def keyinfo(self):
+        pk = self.x509.get_pubkey()
+        types = {
+            OpenSSL.crypto.TYPE_RSA: "RSA",
+            OpenSSL.crypto.TYPE_DSA: "DSA",
+        }
+        return (
+            types.get(pk.type(), "UNKNOWN"),
+            pk.bits()
+        )
+
+    @property
+    def cn(self):
+        c = None
+        for i in self.subject:
+            if i[0] == b"CN":
+                c = i[1]
+        return c
+
+    @property
+    def altnames(self):
+        """
+        Returns:
+            All DNS altnames.
+        """
+        # tcp.TCPClient.convert_to_ssl assumes that this property only contains DNS altnames for hostname verification.
+        altnames = []
+        for i in range(self.x509.get_extension_count()):
+            ext = self.x509.get_extension(i)
+            if ext.get_short_name() == b"subjectAltName":
+                try:
+                    dec = decode(ext.get_data(), asn1Spec=_GeneralNames())
+                except PyAsn1Error:
+                    continue
+                for i in dec[0]:
+                    altnames.append(i[0].asOctets())
+        return altnames
diff --git a/netlib/netlib/encoding.py b/netlib/netlib/encoding.py
new file mode 100644
index 00000000..14479e00
--- /dev/null
+++ b/netlib/netlib/encoding.py
@@ -0,0 +1,88 @@
+"""
+    Utility functions for decoding response bodies.
+"""
+from __future__ import absolute_import
+from io import BytesIO
+import gzip
+import zlib
+from .utils import always_byte_args
+
+
+ENCODINGS = {"identity", "gzip", "deflate"}
+
+
+def decode(e, content):
+    if not isinstance(content, bytes):
+        return None
+    encoding_map = {
+        "identity": identity,
+        "gzip": decode_gzip,
+        "deflate": decode_deflate,
+    }
+    if e not in encoding_map:
+        return None
+    return encoding_map[e](content)
+
+
+def encode(e, content):
+    if not isinstance(content, bytes):
+        return None
+    encoding_map = {
+        "identity": identity,
+        "gzip": encode_gzip,
+        "deflate": encode_deflate,
+    }
+    if e not in encoding_map:
+        return None
+    return encoding_map[e](content)
+
+
+def identity(content):
+    """
+        Returns content unchanged. Identity is the default value of
+        Accept-Encoding headers.
+    """
+    return content
+
+
+def decode_gzip(content):
+    gfile = gzip.GzipFile(fileobj=BytesIO(content))
+    try:
+        return gfile.read()
+    except (IOError, EOFError):
+        return None
+
+
+def encode_gzip(content):
+    s = BytesIO()
+    gf = gzip.GzipFile(fileobj=s, mode='wb')
+    gf.write(content)
+    gf.close()
+    return s.getvalue()
+
+
+def decode_deflate(content):
+    """
+        Returns decompressed data for DEFLATE. Some servers may respond with
+        compressed data without a zlib header or checksum. An undocumented
+        feature of zlib permits the lenient decompression of data missing both
+        values.
+
+        http://bugs.python.org/issue5784
+    """
+    try:
+        try:
+            return zlib.decompress(content)
+        except zlib.error:
+            return zlib.decompress(content, -15)
+    except zlib.error:
+        return None
+
+
+def encode_deflate(content):
+    """
+        Returns compressed content, always including zlib header and checksum.
+    """
+    return zlib.compress(content)
+
+__all__ = ["ENCODINGS", "encode", "decode"]
diff --git a/netlib/netlib/exceptions.py b/netlib/netlib/exceptions.py
new file mode 100644
index 00000000..05f1054b
--- /dev/null
+++ b/netlib/netlib/exceptions.py
@@ -0,0 +1,56 @@
+"""
+We try to be very hygienic regarding the exceptions we throw:
+Every Exception netlib raises shall be a subclass of NetlibException.
+
+
+See also: http://lucumr.pocoo.org/2014/10/16/on-error-handling/
+"""
+from __future__ import absolute_import, print_function, division
+
+
+class NetlibException(Exception):
+    """
+    Base class for all exceptions thrown by netlib.
+    """
+    def __init__(self, message=None):
+        super(NetlibException, self).__init__(message)
+
+
+class Disconnect(object):
+    """Immediate EOF"""
+
+
+class HttpException(NetlibException):
+    pass
+
+
+class HttpReadDisconnect(HttpException, Disconnect):
+    pass
+
+
+class HttpSyntaxException(HttpException):
+    pass
+
+
+class TcpException(NetlibException):
+    pass
+
+
+class TcpDisconnect(TcpException, Disconnect):
+    pass
+
+
+class TcpReadIncomplete(TcpException):
+    pass
+
+
+class TcpTimeout(TcpException):
+    pass
+
+
+class TlsException(NetlibException):
+    pass
+
+
+class InvalidCertificateException(TlsException):
+    pass
diff --git a/netlib/netlib/http/__init__.py b/netlib/netlib/http/__init__.py
new file mode 100644
index 00000000..fd632cd5
--- /dev/null
+++ b/netlib/netlib/http/__init__.py
@@ -0,0 +1,14 @@
+from __future__ import absolute_import, print_function, division
+from .request import Request
+from .response import Response
+from .headers import Headers
+from .message import decoded, CONTENT_MISSING
+from . import http1, http2
+
+__all__ = [
+    "Request",
+    "Response",
+    "Headers",
+    "decoded", "CONTENT_MISSING",
+    "http1", "http2",
+]
diff --git a/netlib/netlib/http/authentication.py b/netlib/netlib/http/authentication.py
new file mode 100644
index 00000000..d769abe5
--- /dev/null
+++ b/netlib/netlib/http/authentication.py
@@ -0,0 +1,167 @@
+from __future__ import (absolute_import, print_function, division)
+from argparse import Action, ArgumentTypeError
+import binascii
+
+
+def parse_http_basic_auth(s):
+    words = s.split()
+    if len(words) != 2:
+        return None
+    scheme = words[0]
+    try:
+        user = binascii.a2b_base64(words[1]).decode("utf8", "replace")
+    except binascii.Error:
+        return None
+    parts = user.split(':')
+    if len(parts) != 2:
+        return None
+    return scheme, parts[0], parts[1]
+
+
+def assemble_http_basic_auth(scheme, username, password):
+    v = binascii.b2a_base64((username + ":" + password).encode("utf8")).decode("ascii")
+    return scheme + " " + v
+
+
+class NullProxyAuth(object):
+
+    """
+        No proxy auth at all (returns empty challange headers)
+    """
+
+    def __init__(self, password_manager):
+        self.password_manager = password_manager
+
+    def clean(self, headers_):
+        """
+            Clean up authentication headers, so they're not passed upstream.
+        """
+
+    def authenticate(self, headers_):
+        """
+            Tests that the user is allowed to use the proxy
+        """
+        return True
+
+    def auth_challenge_headers(self):
+        """
+            Returns a dictionary containing the headers require to challenge the user
+        """
+        return {}
+
+
+class BasicProxyAuth(NullProxyAuth):
+    CHALLENGE_HEADER = 'Proxy-Authenticate'
+    AUTH_HEADER = 'Proxy-Authorization'
+
+    def __init__(self, password_manager, realm):
+        NullProxyAuth.__init__(self, password_manager)
+        self.realm = realm
+
+    def clean(self, headers):
+        del headers[self.AUTH_HEADER]
+
+    def authenticate(self, headers):
+        auth_value = headers.get(self.AUTH_HEADER)
+        if not auth_value:
+            return False
+        parts = parse_http_basic_auth(auth_value)
+        if not parts:
+            return False
+        scheme, username, password = parts
+        if scheme.lower() != 'basic':
+            return False
+        if not self.password_manager.test(username, password):
+            return False
+        self.username = username
+        return True
+
+    def auth_challenge_headers(self):
+        return {self.CHALLENGE_HEADER: 'Basic realm="%s"' % self.realm}
+
+
+class PassMan(object):
+
+    def test(self, username_, password_token_):
+        return False
+
+
+class PassManNonAnon(PassMan):
+
+    """
+        Ensure the user specifies a username, accept any password.
+    """
+
+    def test(self, username, password_token_):
+        if username:
+            return True
+        return False
+
+
+class PassManHtpasswd(PassMan):
+
+    """
+        Read usernames and passwords from an htpasswd file
+    """
+
+    def __init__(self, path):
+        """
+            Raises ValueError if htpasswd file is invalid.
+        """
+        import passlib.apache
+        self.htpasswd = passlib.apache.HtpasswdFile(path)
+
+    def test(self, username, password_token):
+        return bool(self.htpasswd.check_password(username, password_token))
+
+
+class PassManSingleUser(PassMan):
+
+    def __init__(self, username, password):
+        self.username, self.password = username, password
+
+    def test(self, username, password_token):
+        return self.username == username and self.password == password_token
+
+
+class AuthAction(Action):
+
+    """
+    Helper class to allow seamless integration int argparse. Example usage:
+    parser.add_argument(
+        "--nonanonymous",
+        action=NonanonymousAuthAction, nargs=0,
+        help="Allow access to any user long as a credentials are specified."
+    )
+    """
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        passman = self.getPasswordManager(values)
+        authenticator = BasicProxyAuth(passman, "mitmproxy")
+        setattr(namespace, self.dest, authenticator)
+
+    def getPasswordManager(self, s):  # pragma: nocover
+        raise NotImplementedError()
+
+
+class SingleuserAuthAction(AuthAction):
+
+    def getPasswordManager(self, s):
+        if len(s.split(':')) != 2:
+            raise ArgumentTypeError(
+                "Invalid single-user specification. Please use the format username:password"
+            )
+        username, password = s.split(':')
+        return PassManSingleUser(username, password)
+
+
+class NonanonymousAuthAction(AuthAction):
+
+    def getPasswordManager(self, s):
+        return PassManNonAnon()
+
+
+class HtpasswdAuthAction(AuthAction):
+
+    def getPasswordManager(self, s):
+        return PassManHtpasswd(s)
diff --git a/netlib/netlib/http/cookies.py b/netlib/netlib/http/cookies.py
new file mode 100644
index 00000000..18544b5e
--- /dev/null
+++ b/netlib/netlib/http/cookies.py
@@ -0,0 +1,193 @@
+import re
+
+from .. import odict
+
+"""
+A flexible module for cookie parsing and manipulation.
+
+This module differs from usual standards-compliant cookie modules in a number
+of ways. We try to be as permissive as possible, and to retain even mal-formed
+information. Duplicate cookies are preserved in parsing, and can be set in
+formatting. We do attempt to escape and quote values where needed, but will not
+reject data that violate the specs.
+
+Parsing accepts the formats in RFC6265 and partially RFC2109 and RFC2965. We do
+not parse the comma-separated variant of Set-Cookie that allows multiple
+cookies to be set in a single header. Technically this should be feasible, but
+it turns out that violations of RFC6265 that makes the parsing problem
+indeterminate are much more common than genuine occurences of the multi-cookie
+variants. Serialization follows RFC6265.
+
+    http://tools.ietf.org/html/rfc6265
+    http://tools.ietf.org/html/rfc2109
+    http://tools.ietf.org/html/rfc2965
+"""
+
+# TODO: Disallow LHS-only Cookie values
+
+
+def _read_until(s, start, term):
+    """
+        Read until one of the characters in term is reached.
+    """
+    if start == len(s):
+        return "", start + 1
+    for i in range(start, len(s)):
+        if s[i] in term:
+            return s[start:i], i
+    return s[start:i + 1], i + 1
+
+
+def _read_token(s, start):
+    """
+        Read a token - the LHS of a token/value pair in a cookie.
+    """
+    return _read_until(s, start, ";=")
+
+
+def _read_quoted_string(s, start):
+    """
+        start: offset to the first quote of the string to be read
+
+        A sort of loose super-set of the various quoted string specifications.
+
+        RFC6265 disallows backslashes or double quotes within quoted strings.
+        Prior RFCs use backslashes to escape. This leaves us free to apply
+        backslash escaping by default and be compatible with everything.
+    """
+    escaping = False
+    ret = []
+    # Skip the first quote
+    i = start  # initialize in case the loop doesn't run.
+    for i in range(start + 1, len(s)):
+        if escaping:
+            ret.append(s[i])
+            escaping = False
+        elif s[i] == '"':
+            break
+        elif s[i] == "\\":
+            escaping = True
+        else:
+            ret.append(s[i])
+    return "".join(ret), i + 1
+
+
+def _read_value(s, start, delims):
+    """
+        Reads a value - the RHS of a token/value pair in a cookie.
+
+        special: If the value is special, commas are premitted. Else comma
+        terminates. This helps us support old and new style values.
+    """
+    if start >= len(s):
+        return "", start
+    elif s[start] == '"':
+        return _read_quoted_string(s, start)
+    else:
+        return _read_until(s, start, delims)
+
+
+def _read_pairs(s, off=0):
+    """
+        Read pairs of lhs=rhs values.
+
+        off: start offset
+        specials: a lower-cased list of keys that may contain commas
+    """
+    vals = []
+    while True:
+        lhs, off = _read_token(s, off)
+        lhs = lhs.lstrip()
+        if lhs:
+            rhs = None
+            if off < len(s):
+                if s[off] == "=":
+                    rhs, off = _read_value(s, off + 1, ";")
+            vals.append([lhs, rhs])
+        off += 1
+        if not off < len(s):
+            break
+    return vals, off
+
+
+def _has_special(s):
+    for i in s:
+        if i in '",;\\':
+            return True
+        o = ord(i)
+        if o < 0x21 or o > 0x7e:
+            return True
+    return False
+
+
+ESCAPE = re.compile(r"([\"\\])")
+
+
+def _format_pairs(lst, specials=(), sep="; "):
+    """
+        specials: A lower-cased list of keys that will not be quoted.
+    """
+    vals = []
+    for k, v in lst:
+        if v is None:
+            vals.append(k)
+        else:
+            if k.lower() not in specials and _has_special(v):
+                v = ESCAPE.sub(r"\\\1", v)
+                v = '"%s"' % v
+            vals.append("%s=%s" % (k, v))
+    return sep.join(vals)
+
+
+def _format_set_cookie_pairs(lst):
+    return _format_pairs(
+        lst,
+        specials=("expires", "path")
+    )
+
+
+def _parse_set_cookie_pairs(s):
+    """
+        For Set-Cookie, we support multiple cookies as described in RFC2109.
+        This function therefore returns a list of lists.
+    """
+    pairs, off_ = _read_pairs(s)
+    return pairs
+
+
+def parse_set_cookie_header(line):
+    """
+        Parse a Set-Cookie header value
+
+        Returns a (name, value, attrs) tuple, or None, where attrs is an
+        ODictCaseless set of attributes. No attempt is made to parse attribute
+        values - they are treated purely as strings.
+    """
+    pairs = _parse_set_cookie_pairs(line)
+    if pairs:
+        return pairs[0][0], pairs[0][1], odict.ODictCaseless(pairs[1:])
+
+
+def format_set_cookie_header(name, value, attrs):
+    """
+        Formats a Set-Cookie header value.
+    """
+    pairs = [[name, value]]
+    pairs.extend(attrs.lst)
+    return _format_set_cookie_pairs(pairs)
+
+
+def parse_cookie_header(line):
+    """
+        Parse a Cookie header value.
+        Returns a (possibly empty) ODict object.
+    """
+    pairs, off_ = _read_pairs(line)
+    return odict.ODict(pairs)
+
+
+def format_cookie_header(od):
+    """
+        Formats a Cookie header value.
+    """
+    return _format_pairs(od.lst)
diff --git a/netlib/netlib/http/headers.py b/netlib/netlib/http/headers.py
new file mode 100644
index 00000000..78404796
--- /dev/null
+++ b/netlib/netlib/http/headers.py
@@ -0,0 +1,204 @@
+"""
+
+Unicode Handling
+----------------
+See also: http://lucumr.pocoo.org/2013/7/2/the-updated-guide-to-unicode/
+"""
+from __future__ import absolute_import, print_function, division
+import copy
+try:
+    from collections.abc import MutableMapping
+except ImportError:  # pragma: nocover
+    from collections import MutableMapping  # Workaround for Python < 3.3
+
+
+import six
+
+from netlib.utils import always_byte_args, always_bytes, Serializable
+
+if six.PY2:  # pragma: nocover
+    _native = lambda x: x
+    _always_bytes = lambda x: x
+    _always_byte_args = lambda x: x
+else:
+    # While headers _should_ be ASCII, it's not uncommon for certain headers to be utf-8 encoded.
+    _native = lambda x: x.decode("utf-8", "surrogateescape")
+    _always_bytes = lambda x: always_bytes(x, "utf-8", "surrogateescape")
+    _always_byte_args = always_byte_args("utf-8", "surrogateescape")
+
+
+class Headers(MutableMapping, Serializable):
+    """
+    Header class which allows both convenient access to individual headers as well as
+    direct access to the underlying raw data. Provides a full dictionary interface.
+
+    Example:
+
+    .. code-block:: python
+
+        # Create headers with keyword arguments
+        >>> h = Headers(host="example.com", content_type="application/xml")
+
+        # Headers mostly behave like a normal dict.
+        >>> h["Host"]
+        "example.com"
+
+        # HTTP Headers are case insensitive
+        >>> h["host"]
+        "example.com"
+
+        # Headers can also be creatd from a list of raw (header_name, header_value) byte tuples
+        >>> h = Headers([
+            [b"Host",b"example.com"],
+            [b"Accept",b"text/html"],
+            [b"accept",b"application/xml"]
+        ])
+
+        # Multiple headers are folded into a single header as per RFC7230
+        >>> h["Accept"]
+        "text/html, application/xml"
+
+        # Setting a header removes all existing headers with the same name.
+        >>> h["Accept"] = "application/text"
+        >>> h["Accept"]
+        "application/text"
+
+        # bytes(h) returns a HTTP1 header block.
+        >>> print(bytes(h))
+        Host: example.com
+        Accept: application/text
+
+        # For full control, the raw header fields can be accessed
+        >>> h.fields
+
+    Caveats:
+        For use with the "Set-Cookie" header, see :py:meth:`get_all`.
+    """
+
+    @_always_byte_args
+    def __init__(self, fields=None, **headers):
+        """
+        Args:
+            fields: (optional) list of ``(name, value)`` header byte tuples,
+                e.g. ``[(b"Host", b"example.com")]``. All names and values must be bytes.
+            **headers: Additional headers to set. Will overwrite existing values from `fields`.
+                For convenience, underscores in header names will be transformed to dashes -
+                this behaviour does not extend to other methods.
+                If ``**headers`` contains multiple keys that have equal ``.lower()`` s,
+                the behavior is undefined.
+        """
+        self.fields = fields or []
+
+        for name, value in self.fields:
+            if not isinstance(name, bytes) or not isinstance(value, bytes):
+                raise ValueError("Headers passed as fields must be bytes.")
+
+        # content_type -> content-type
+        headers = {
+            _always_bytes(name).replace(b"_", b"-"): value
+            for name, value in six.iteritems(headers)
+            }
+        self.update(headers)
+
+    def __bytes__(self):
+        if self.fields:
+            return b"\r\n".join(b": ".join(field) for field in self.fields) + b"\r\n"
+        else:
+            return b""
+
+    if six.PY2:  # pragma: nocover
+        __str__ = __bytes__
+
+    @_always_byte_args
+    def __getitem__(self, name):
+        values = self.get_all(name)
+        if not values:
+            raise KeyError(name)
+        return ", ".join(values)
+
+    @_always_byte_args
+    def __setitem__(self, name, value):
+        idx = self._index(name)
+
+        # To please the human eye, we insert at the same position the first existing header occured.
+        if idx is not None:
+            del self[name]
+            self.fields.insert(idx, [name, value])
+        else:
+            self.fields.append([name, value])
+
+    @_always_byte_args
+    def __delitem__(self, name):
+        if name not in self:
+            raise KeyError(name)
+        name = name.lower()
+        self.fields = [
+            field for field in self.fields
+            if name != field[0].lower()
+        ]
+
+    def __iter__(self):
+        seen = set()
+        for name, _ in self.fields:
+            name_lower = name.lower()
+            if name_lower not in seen:
+                seen.add(name_lower)
+                yield _native(name)
+
+    def __len__(self):
+        return len(set(name.lower() for name, _ in self.fields))
+
+    # __hash__ = object.__hash__
+
+    def _index(self, name):
+        name = name.lower()
+        for i, field in enumerate(self.fields):
+            if field[0].lower() == name:
+                return i
+        return None
+
+    def __eq__(self, other):
+        if isinstance(other, Headers):
+            return self.fields == other.fields
+        return False
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    @_always_byte_args
+    def get_all(self, name):
+        """
+        Like :py:meth:`get`, but does not fold multiple headers into a single one.
+        This is useful for Set-Cookie headers, which do not support folding.
+
+        See also: https://tools.ietf.org/html/rfc7230#section-3.2.2
+        """
+        name_lower = name.lower()
+        values = [_native(value) for n, value in self.fields if n.lower() == name_lower]
+        return values
+
+    @_always_byte_args
+    def set_all(self, name, values):
+        """
+        Explicitly set multiple headers for the given key.
+        See: :py:meth:`get_all`
+        """
+        values = map(_always_bytes, values)  # _always_byte_args does not fix lists
+        if name in self:
+            del self[name]
+        self.fields.extend(
+            [name, value] for value in values
+        )
+
+    def copy(self):
+        return Headers(copy.copy(self.fields))
+
+    def get_state(self):
+        return tuple(tuple(field) for field in self.fields)
+
+    def set_state(self, state):
+        self.fields = [list(field) for field in state]
+
+    @classmethod
+    def from_state(cls, state):
+        return cls([list(field) for field in state])
\ No newline at end of file
diff --git a/netlib/netlib/http/http1/__init__.py b/netlib/netlib/http/http1/__init__.py
new file mode 100644
index 00000000..2aa7e26a
--- /dev/null
+++ b/netlib/netlib/http/http1/__init__.py
@@ -0,0 +1,25 @@
+from __future__ import absolute_import, print_function, division
+from .read import (
+    read_request, read_request_head,
+    read_response, read_response_head,
+    read_body,
+    connection_close,
+    expected_http_body_size,
+)
+from .assemble import (
+    assemble_request, assemble_request_head,
+    assemble_response, assemble_response_head,
+    assemble_body,
+)
+
+
+__all__ = [
+    "read_request", "read_request_head",
+    "read_response", "read_response_head",
+    "read_body",
+    "connection_close",
+    "expected_http_body_size",
+    "assemble_request", "assemble_request_head",
+    "assemble_response", "assemble_response_head",
+    "assemble_body",
+]
diff --git a/netlib/netlib/http/http1/assemble.py b/netlib/netlib/http/http1/assemble.py
new file mode 100644
index 00000000..785ee8d3
--- /dev/null
+++ b/netlib/netlib/http/http1/assemble.py
@@ -0,0 +1,104 @@
+from __future__ import absolute_import, print_function, division
+
+from ... import utils
+import itertools
+from ...exceptions import HttpException
+from .. import CONTENT_MISSING
+
+
+def assemble_request(request):
+    if request.content == CONTENT_MISSING:
+        raise HttpException("Cannot assemble flow with CONTENT_MISSING")
+    head = assemble_request_head(request)
+    body = b"".join(assemble_body(request.data.headers, [request.data.content]))
+    return head + body
+
+
+def assemble_request_head(request):
+    first_line = _assemble_request_line(request.data)
+    headers = _assemble_request_headers(request.data)
+    return b"%s\r\n%s\r\n" % (first_line, headers)
+
+
+def assemble_response(response):
+    if response.content == CONTENT_MISSING:
+        raise HttpException("Cannot assemble flow with CONTENT_MISSING")
+    head = assemble_response_head(response)
+    body = b"".join(assemble_body(response.data.headers, [response.data.content]))
+    return head + body
+
+
+def assemble_response_head(response):
+    first_line = _assemble_response_line(response.data)
+    headers = _assemble_response_headers(response.data)
+    return b"%s\r\n%s\r\n" % (first_line, headers)
+
+
+def assemble_body(headers, body_chunks):
+    if "chunked" in headers.get("transfer-encoding", "").lower():
+        for chunk in body_chunks:
+            if chunk:
+                yield b"%x\r\n%s\r\n" % (len(chunk), chunk)
+        yield b"0\r\n\r\n"
+    else:
+        for chunk in body_chunks:
+            yield chunk
+
+
+def _assemble_request_line(request_data):
+    """
+    Args:
+        request_data (netlib.http.request.RequestData)
+    """
+    form = request_data.first_line_format
+    if form == "relative":
+        return b"%s %s %s" % (
+            request_data.method,
+            request_data.path,
+            request_data.http_version
+        )
+    elif form == "authority":
+        return b"%s %s:%d %s" % (
+            request_data.method,
+            request_data.host,
+            request_data.port,
+            request_data.http_version
+        )
+    elif form == "absolute":
+        return b"%s %s://%s:%d%s %s" % (
+            request_data.method,
+            request_data.scheme,
+            request_data.host,
+            request_data.port,
+            request_data.path,
+            request_data.http_version
+        )
+    else:
+        raise RuntimeError("Invalid request form")
+
+
+def _assemble_request_headers(request_data):
+    """
+    Args:
+        request_data (netlib.http.request.RequestData)
+    """
+    headers = request_data.headers.copy()
+    if "host" not in headers and request_data.scheme and request_data.host and request_data.port:
+        headers["host"] = utils.hostport(
+            request_data.scheme,
+            request_data.host,
+            request_data.port
+        )
+    return bytes(headers)
+
+
+def _assemble_response_line(response_data):
+    return b"%s %d %s" % (
+        response_data.http_version,
+        response_data.status_code,
+        response_data.reason,
+    )
+
+
+def _assemble_response_headers(response):
+    return bytes(response.headers)
diff --git a/netlib/netlib/http/http1/read.py b/netlib/netlib/http/http1/read.py
new file mode 100644
index 00000000..6e3a1b93
--- /dev/null
+++ b/netlib/netlib/http/http1/read.py
@@ -0,0 +1,362 @@
+from __future__ import absolute_import, print_function, division
+import time
+import sys
+import re
+
+from ... import utils
+from ...exceptions import HttpReadDisconnect, HttpSyntaxException, HttpException, TcpDisconnect
+from .. import Request, Response, Headers
+
+
+def read_request(rfile, body_size_limit=None):
+    request = read_request_head(rfile)
+    expected_body_size = expected_http_body_size(request)
+    request.data.content = b"".join(read_body(rfile, expected_body_size, limit=body_size_limit))
+    request.timestamp_end = time.time()
+    return request
+
+
+def read_request_head(rfile):
+    """
+    Parse an HTTP request head (request line + headers) from an input stream
+
+    Args:
+        rfile: The input stream
+
+    Returns:
+        The HTTP request object (without body)
+
+    Raises:
+        HttpReadDisconnect: No bytes can be read from rfile.
+        HttpSyntaxException: The input is malformed HTTP.
+        HttpException: Any other error occured.
+    """
+    timestamp_start = time.time()
+    if hasattr(rfile, "reset_timestamps"):
+        rfile.reset_timestamps()
+
+    form, method, scheme, host, port, path, http_version = _read_request_line(rfile)
+    headers = _read_headers(rfile)
+
+    if hasattr(rfile, "first_byte_timestamp"):
+        # more accurate timestamp_start
+        timestamp_start = rfile.first_byte_timestamp
+
+    return Request(
+        form, method, scheme, host, port, path, http_version, headers, None, timestamp_start
+    )
+
+
+def read_response(rfile, request, body_size_limit=None):
+    response = read_response_head(rfile)
+    expected_body_size = expected_http_body_size(request, response)
+    response.data.content = b"".join(read_body(rfile, expected_body_size, body_size_limit))
+    response.timestamp_end = time.time()
+    return response
+
+
+def read_response_head(rfile):
+    """
+    Parse an HTTP response head (response line + headers) from an input stream
+
+    Args:
+        rfile: The input stream
+
+    Returns:
+        The HTTP request object (without body)
+
+    Raises:
+        HttpReadDisconnect: No bytes can be read from rfile.
+        HttpSyntaxException: The input is malformed HTTP.
+        HttpException: Any other error occured.
+    """
+
+    timestamp_start = time.time()
+    if hasattr(rfile, "reset_timestamps"):
+        rfile.reset_timestamps()
+
+    http_version, status_code, message = _read_response_line(rfile)
+    headers = _read_headers(rfile)
+
+    if hasattr(rfile, "first_byte_timestamp"):
+        # more accurate timestamp_start
+        timestamp_start = rfile.first_byte_timestamp
+
+    return Response(http_version, status_code, message, headers, None, timestamp_start)
+
+
+def read_body(rfile, expected_size, limit=None, max_chunk_size=4096):
+    """
+        Read an HTTP message body
+
+        Args:
+            rfile: The input stream
+            expected_size: The expected body size (see :py:meth:`expected_body_size`)
+            limit: Maximum body size
+            max_chunk_size: Maximium chunk size that gets yielded
+
+        Returns:
+            A generator that yields byte chunks of the content.
+
+        Raises:
+            HttpException, if an error occurs
+
+        Caveats:
+            max_chunk_size is not considered if the transfer encoding is chunked.
+    """
+    if not limit or limit < 0:
+        limit = sys.maxsize
+    if not max_chunk_size:
+        max_chunk_size = limit
+
+    if expected_size is None:
+        for x in _read_chunked(rfile, limit):
+            yield x
+    elif expected_size >= 0:
+        if limit is not None and expected_size > limit:
+            raise HttpException(
+                "HTTP Body too large. "
+                "Limit is {}, content length was advertised as {}".format(limit, expected_size)
+            )
+        bytes_left = expected_size
+        while bytes_left:
+            chunk_size = min(bytes_left, max_chunk_size)
+            content = rfile.read(chunk_size)
+            if len(content) < chunk_size:
+                raise HttpException("Unexpected EOF")
+            yield content
+            bytes_left -= chunk_size
+    else:
+        bytes_left = limit
+        while bytes_left:
+            chunk_size = min(bytes_left, max_chunk_size)
+            content = rfile.read(chunk_size)
+            if not content:
+                return
+            yield content
+            bytes_left -= chunk_size
+        not_done = rfile.read(1)
+        if not_done:
+            raise HttpException("HTTP body too large. Limit is {}.".format(limit))
+
+
+def connection_close(http_version, headers):
+    """
+        Checks the message to see if the client connection should be closed
+        according to RFC 2616 Section 8.1.
+    """
+    # At first, check if we have an explicit Connection header.
+    if "connection" in headers:
+        tokens = utils.get_header_tokens(headers, "connection")
+        if "close" in tokens:
+            return True
+        elif "keep-alive" in tokens:
+            return False
+
+    # If we don't have a Connection header, HTTP 1.1 connections are assumed to
+    # be persistent
+    return http_version != "HTTP/1.1" and http_version != b"HTTP/1.1"  # FIXME: Remove one case.
+
+
+def expected_http_body_size(request, response=None):
+    """
+        Returns:
+            The expected body length:
+            - a positive integer, if the size is known in advance
+            - None, if the size in unknown in advance (chunked encoding)
+            - -1, if all data should be read until end of stream.
+
+        Raises:
+            HttpSyntaxException, if the content length header is invalid
+    """
+    # Determine response size according to
+    # http://tools.ietf.org/html/rfc7230#section-3.3
+    if not response:
+        headers = request.headers
+        response_code = None
+        is_request = True
+    else:
+        headers = response.headers
+        response_code = response.status_code
+        is_request = False
+
+    if is_request:
+        if headers.get("expect", "").lower() == "100-continue":
+            return 0
+    else:
+        if request.method.upper() == "HEAD":
+            return 0
+        if 100 <= response_code <= 199:
+            return 0
+        if response_code == 200 and request.method.upper() == "CONNECT":
+            return 0
+        if response_code in (204, 304):
+            return 0
+
+    if "chunked" in headers.get("transfer-encoding", "").lower():
+        return None
+    if "content-length" in headers:
+        try:
+            size = int(headers["content-length"])
+            if size < 0:
+                raise ValueError()
+            return size
+        except ValueError:
+            raise HttpSyntaxException("Unparseable Content Length")
+    if is_request:
+        return 0
+    return -1
+
+
+def _get_first_line(rfile):
+    try:
+        line = rfile.readline()
+        if line == b"\r\n" or line == b"\n":
+            # Possible leftover from previous message
+            line = rfile.readline()
+    except TcpDisconnect:
+        raise HttpReadDisconnect("Remote disconnected")
+    if not line:
+        raise HttpReadDisconnect("Remote disconnected")
+    return line.strip()
+
+
+def _read_request_line(rfile):
+    try:
+        line = _get_first_line(rfile)
+    except HttpReadDisconnect:
+        # We want to provide a better error message.
+        raise HttpReadDisconnect("Client disconnected")
+
+    try:
+        method, path, http_version = line.split(b" ")
+
+        if path == b"*" or path.startswith(b"/"):
+            form = "relative"
+            scheme, host, port = None, None, None
+        elif method == b"CONNECT":
+            form = "authority"
+            host, port = _parse_authority_form(path)
+            scheme, path = None, None
+        else:
+            form = "absolute"
+            scheme, host, port, path = utils.parse_url(path)
+
+        _check_http_version(http_version)
+    except ValueError:
+        raise HttpSyntaxException("Bad HTTP request line: {}".format(line))
+
+    return form, method, scheme, host, port, path, http_version
+
+
+def _parse_authority_form(hostport):
+    """
+        Returns (host, port) if hostport is a valid authority-form host specification.
+        http://tools.ietf.org/html/draft-luotonen-web-proxy-tunneling-01 section 3.1
+
+        Raises:
+            ValueError, if the input is malformed
+    """
+    try:
+        host, port = hostport.split(b":")
+        port = int(port)
+        if not utils.is_valid_host(host) or not utils.is_valid_port(port):
+            raise ValueError()
+    except ValueError:
+        raise HttpSyntaxException("Invalid host specification: {}".format(hostport))
+
+    return host, port
+
+
+def _read_response_line(rfile):
+    try:
+        line = _get_first_line(rfile)
+    except HttpReadDisconnect:
+        # We want to provide a better error message.
+        raise HttpReadDisconnect("Server disconnected")
+
+    try:
+
+        parts = line.split(b" ", 2)
+        if len(parts) == 2:  # handle missing message gracefully
+            parts.append(b"")
+
+        http_version, status_code, message = parts
+        status_code = int(status_code)
+        _check_http_version(http_version)
+
+    except ValueError:
+        raise HttpSyntaxException("Bad HTTP response line: {}".format(line))
+
+    return http_version, status_code, message
+
+
+def _check_http_version(http_version):
+    if not re.match(br"^HTTP/\d\.\d$", http_version):
+        raise HttpSyntaxException("Unknown HTTP version: {}".format(http_version))
+
+
+def _read_headers(rfile):
+    """
+        Read a set of headers.
+        Stop once a blank line is reached.
+
+        Returns:
+            A headers object
+
+        Raises:
+            HttpSyntaxException
+    """
+    ret = []
+    while True:
+        line = rfile.readline()
+        if not line or line == b"\r\n" or line == b"\n":
+            break
+        if line[0] in b" \t":
+            if not ret:
+                raise HttpSyntaxException("Invalid headers")
+            # continued header
+            ret[-1][1] = ret[-1][1] + b'\r\n ' + line.strip()
+        else:
+            try:
+                name, value = line.split(b":", 1)
+                value = value.strip()
+                if not name:
+                    raise ValueError()
+                ret.append([name, value])
+            except ValueError:
+                raise HttpSyntaxException("Invalid headers")
+    return Headers(ret)
+
+
+def _read_chunked(rfile, limit=sys.maxsize):
+    """
+    Read a HTTP body with chunked transfer encoding.
+
+    Args:
+        rfile: the input file
+        limit: A positive integer
+    """
+    total = 0
+    while True:
+        line = rfile.readline(128)
+        if line == b"":
+            raise HttpException("Connection closed prematurely")
+        if line != b"\r\n" and line != b"\n":
+            try:
+                length = int(line, 16)
+            except ValueError:
+                raise HttpSyntaxException("Invalid chunked encoding length: {}".format(line))
+            total += length
+            if total > limit:
+                raise HttpException(
+                    "HTTP Body too large. Limit is {}, "
+                    "chunked content longer than {}".format(limit, total)
+                )
+            chunk = rfile.read(length)
+            suffix = rfile.readline(5)
+            if suffix != b"\r\n":
+                raise HttpSyntaxException("Malformed chunked body")
+            if length == 0:
+                return
+            yield chunk
diff --git a/netlib/netlib/http/http2/__init__.py b/netlib/netlib/http/http2/__init__.py
new file mode 100644
index 00000000..7043d36f
--- /dev/null
+++ b/netlib/netlib/http/http2/__init__.py
@@ -0,0 +1,6 @@
+from __future__ import absolute_import, print_function, division
+from .connections import HTTP2Protocol
+
+__all__ = [
+    "HTTP2Protocol"
+]
diff --git a/netlib/netlib/http/http2/connections.py b/netlib/netlib/http/http2/connections.py
new file mode 100644
index 00000000..52fa7193
--- /dev/null
+++ b/netlib/netlib/http/http2/connections.py
@@ -0,0 +1,426 @@
+from __future__ import (absolute_import, print_function, division)
+import itertools
+import time
+
+from hpack.hpack import Encoder, Decoder
+from ... import utils
+from .. import Headers, Response, Request
+
+from hyperframe import frame
+
+
+class TCPHandler(object):
+
+    def __init__(self, rfile, wfile=None):
+        self.rfile = rfile
+        self.wfile = wfile
+
+
+class HTTP2Protocol(object):
+
+    ERROR_CODES = utils.BiDi(
+        NO_ERROR=0x0,
+        PROTOCOL_ERROR=0x1,
+        INTERNAL_ERROR=0x2,
+        FLOW_CONTROL_ERROR=0x3,
+        SETTINGS_TIMEOUT=0x4,
+        STREAM_CLOSED=0x5,
+        FRAME_SIZE_ERROR=0x6,
+        REFUSED_STREAM=0x7,
+        CANCEL=0x8,
+        COMPRESSION_ERROR=0x9,
+        CONNECT_ERROR=0xa,
+        ENHANCE_YOUR_CALM=0xb,
+        INADEQUATE_SECURITY=0xc,
+        HTTP_1_1_REQUIRED=0xd
+    )
+
+    CLIENT_CONNECTION_PREFACE = b'PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n'
+
+    HTTP2_DEFAULT_SETTINGS = {
+        frame.SettingsFrame.HEADER_TABLE_SIZE: 4096,
+        frame.SettingsFrame.ENABLE_PUSH: 1,
+        frame.SettingsFrame.MAX_CONCURRENT_STREAMS: None,
+        frame.SettingsFrame.INITIAL_WINDOW_SIZE: 2 ** 16 - 1,
+        frame.SettingsFrame.MAX_FRAME_SIZE: 2 ** 14,
+        frame.SettingsFrame.MAX_HEADER_LIST_SIZE: None,
+    }
+
+    def __init__(
+        self,
+        tcp_handler=None,
+        rfile=None,
+        wfile=None,
+        is_server=False,
+        dump_frames=False,
+        encoder=None,
+        decoder=None,
+        unhandled_frame_cb=None,
+    ):
+        self.tcp_handler = tcp_handler or TCPHandler(rfile, wfile)
+        self.is_server = is_server
+        self.dump_frames = dump_frames
+        self.encoder = encoder or Encoder()
+        self.decoder = decoder or Decoder()
+        self.unhandled_frame_cb = unhandled_frame_cb
+
+        self.http2_settings = self.HTTP2_DEFAULT_SETTINGS.copy()
+        self.current_stream_id = None
+        self.connection_preface_performed = False
+
+    def read_request(
+        self,
+        __rfile,
+        include_body=True,
+        body_size_limit=None,
+        allow_empty=False,
+    ):
+        if body_size_limit is not None:
+            raise NotImplementedError()
+
+        self.perform_connection_preface()
+
+        timestamp_start = time.time()
+        if hasattr(self.tcp_handler.rfile, "reset_timestamps"):
+            self.tcp_handler.rfile.reset_timestamps()
+
+        stream_id, headers, body = self._receive_transmission(
+            include_body=include_body,
+        )
+
+        if hasattr(self.tcp_handler.rfile, "first_byte_timestamp"):
+            # more accurate timestamp_start
+            timestamp_start = self.tcp_handler.rfile.first_byte_timestamp
+
+        timestamp_end = time.time()
+
+        authority = headers.get(':authority', b'')
+        method = headers.get(':method', 'GET')
+        scheme = headers.get(':scheme', 'https')
+        path = headers.get(':path', '/')
+        host = None
+        port = None
+
+        if path == '*' or path.startswith("/"):
+            form_in = "relative"
+        elif method == 'CONNECT':
+            form_in = "authority"
+            if ":" in authority:
+                host, port = authority.split(":", 1)
+            else:
+                host = authority
+        else:
+            form_in = "absolute"
+            # FIXME: verify if path or :host contains what we need
+            scheme, host, port, _ = utils.parse_url(path)
+            scheme = scheme.decode('ascii')
+            host = host.decode('ascii')
+
+        if host is None:
+            host = 'localhost'
+        if port is None:
+            port = 80 if scheme == 'http' else 443
+        port = int(port)
+
+        request = Request(
+            form_in,
+            method.encode('ascii'),
+            scheme.encode('ascii'),
+            host.encode('ascii'),
+            port,
+            path.encode('ascii'),
+            b"HTTP/2.0",
+            headers,
+            body,
+            timestamp_start,
+            timestamp_end,
+        )
+        request.stream_id = stream_id
+
+        return request
+
+    def read_response(
+        self,
+        __rfile,
+        request_method=b'',
+        body_size_limit=None,
+        include_body=True,
+        stream_id=None,
+    ):
+        if body_size_limit is not None:
+            raise NotImplementedError()
+
+        self.perform_connection_preface()
+
+        timestamp_start = time.time()
+        if hasattr(self.tcp_handler.rfile, "reset_timestamps"):
+            self.tcp_handler.rfile.reset_timestamps()
+
+        stream_id, headers, body = self._receive_transmission(
+            stream_id=stream_id,
+            include_body=include_body,
+        )
+
+        if hasattr(self.tcp_handler.rfile, "first_byte_timestamp"):
+            # more accurate timestamp_start
+            timestamp_start = self.tcp_handler.rfile.first_byte_timestamp
+
+        if include_body:
+            timestamp_end = time.time()
+        else:
+            timestamp_end = None
+
+        response = Response(
+            b"HTTP/2.0",
+            int(headers.get(':status', 502)),
+            b'',
+            headers,
+            body,
+            timestamp_start=timestamp_start,
+            timestamp_end=timestamp_end,
+        )
+        response.stream_id = stream_id
+
+        return response
+
+    def assemble(self, message):
+        if isinstance(message, Request):
+            return self.assemble_request(message)
+        elif isinstance(message, Response):
+            return self.assemble_response(message)
+        else:
+            raise ValueError("HTTP message not supported.")
+
+    def assemble_request(self, request):
+        assert isinstance(request, Request)
+
+        authority = self.tcp_handler.sni if self.tcp_handler.sni else self.tcp_handler.address.host
+        if self.tcp_handler.address.port != 443:
+            authority += ":%d" % self.tcp_handler.address.port
+
+        headers = request.headers.copy()
+
+        if ':authority' not in headers:
+            headers.fields.insert(0, (b':authority', authority.encode('ascii')))
+        if ':scheme' not in headers:
+            headers.fields.insert(0, (b':scheme', request.scheme.encode('ascii')))
+        if ':path' not in headers:
+            headers.fields.insert(0, (b':path', request.path.encode('ascii')))
+        if ':method' not in headers:
+            headers.fields.insert(0, (b':method', request.method.encode('ascii')))
+
+        if hasattr(request, 'stream_id'):
+            stream_id = request.stream_id
+        else:
+            stream_id = self._next_stream_id()
+
+        return list(itertools.chain(
+            self._create_headers(headers, stream_id, end_stream=(request.body is None or len(request.body) == 0)),
+            self._create_body(request.body, stream_id)))
+
+    def assemble_response(self, response):
+        assert isinstance(response, Response)
+
+        headers = response.headers.copy()
+
+        if ':status' not in headers:
+            headers.fields.insert(0, (b':status', str(response.status_code).encode('ascii')))
+
+        if hasattr(response, 'stream_id'):
+            stream_id = response.stream_id
+        else:
+            stream_id = self._next_stream_id()
+
+        return list(itertools.chain(
+            self._create_headers(headers, stream_id, end_stream=(response.body is None or len(response.body) == 0)),
+            self._create_body(response.body, stream_id),
+        ))
+
+    def perform_connection_preface(self, force=False):
+        if force or not self.connection_preface_performed:
+            if self.is_server:
+                self.perform_server_connection_preface(force)
+            else:
+                self.perform_client_connection_preface(force)
+
+    def perform_server_connection_preface(self, force=False):
+        if force or not self.connection_preface_performed:
+            self.connection_preface_performed = True
+
+            magic_length = len(self.CLIENT_CONNECTION_PREFACE)
+            magic = self.tcp_handler.rfile.safe_read(magic_length)
+            assert magic == self.CLIENT_CONNECTION_PREFACE
+
+            frm = frame.SettingsFrame(settings={
+                frame.SettingsFrame.ENABLE_PUSH: 0,
+                frame.SettingsFrame.MAX_CONCURRENT_STREAMS: 1,
+            })
+            self.send_frame(frm, hide=True)
+            self._receive_settings(hide=True)
+
+    def perform_client_connection_preface(self, force=False):
+        if force or not self.connection_preface_performed:
+            self.connection_preface_performed = True
+
+            self.tcp_handler.wfile.write(self.CLIENT_CONNECTION_PREFACE)
+
+            self.send_frame(frame.SettingsFrame(), hide=True)
+            self._receive_settings(hide=True)  # server announces own settings
+            self._receive_settings(hide=True)  # server acks my settings
+
+    def send_frame(self, frm, hide=False):
+        raw_bytes = frm.serialize()
+        self.tcp_handler.wfile.write(raw_bytes)
+        self.tcp_handler.wfile.flush()
+        if not hide and self.dump_frames:  # pragma no cover
+            print(frm.human_readable(">>"))
+
+    def read_frame(self, hide=False):
+        while True:
+            frm = utils.http2_read_frame(self.tcp_handler.rfile)
+            if not hide and self.dump_frames:  # pragma no cover
+                print(frm.human_readable("<<"))
+
+            if isinstance(frm, frame.PingFrame):
+                raw_bytes = frame.PingFrame(flags=['ACK'], payload=frm.payload).serialize()
+                self.tcp_handler.wfile.write(raw_bytes)
+                self.tcp_handler.wfile.flush()
+                continue
+            if isinstance(frm, frame.SettingsFrame) and 'ACK' not in frm.flags:
+                self._apply_settings(frm.settings, hide)
+            if isinstance(frm, frame.DataFrame) and frm.flow_controlled_length > 0:
+                self._update_flow_control_window(frm.stream_id, frm.flow_controlled_length)
+            return frm
+
+    def check_alpn(self):
+        alp = self.tcp_handler.get_alpn_proto_negotiated()
+        if alp != b'h2':
+            raise NotImplementedError(
+                "HTTP2Protocol can not handle unknown ALP: %s" % alp)
+        return True
+
+    def _handle_unexpected_frame(self, frm):
+        if isinstance(frm, frame.SettingsFrame):
+            return
+        if self.unhandled_frame_cb:
+            self.unhandled_frame_cb(frm)
+
+    def _receive_settings(self, hide=False):
+        while True:
+            frm = self.read_frame(hide)
+            if isinstance(frm, frame.SettingsFrame):
+                break
+            else:
+                self._handle_unexpected_frame(frm)
+
+    def _next_stream_id(self):
+        if self.current_stream_id is None:
+            if self.is_server:
+                # servers must use even stream ids
+                self.current_stream_id = 2
+            else:
+                # clients must use odd stream ids
+                self.current_stream_id = 1
+        else:
+            self.current_stream_id += 2
+        return self.current_stream_id
+
+    def _apply_settings(self, settings, hide=False):
+        for setting, value in settings.items():
+            old_value = self.http2_settings[setting]
+            if not old_value:
+                old_value = '-'
+            self.http2_settings[setting] = value
+
+        frm = frame.SettingsFrame(flags=['ACK'])
+        self.send_frame(frm, hide)
+
+    def _update_flow_control_window(self, stream_id, increment):
+        frm = frame.WindowUpdateFrame(stream_id=0, window_increment=increment)
+        self.send_frame(frm)
+        frm = frame.WindowUpdateFrame(stream_id=stream_id, window_increment=increment)
+        self.send_frame(frm)
+
+    def _create_headers(self, headers, stream_id, end_stream=True):
+        def frame_cls(chunks):
+            for i in chunks:
+                if i == 0:
+                    yield frame.HeadersFrame, i
+                else:
+                    yield frame.ContinuationFrame, i
+
+        header_block_fragment = self.encoder.encode(headers.fields)
+
+        chunk_size = self.http2_settings[frame.SettingsFrame.MAX_FRAME_SIZE]
+        chunks = range(0, len(header_block_fragment), chunk_size)
+        frms = [frm_cls(
+            flags=[],
+            stream_id=stream_id,
+            data=header_block_fragment[i:i+chunk_size]) for frm_cls, i in frame_cls(chunks)]
+
+        frms[-1].flags.add('END_HEADERS')
+        if end_stream:
+            frms[0].flags.add('END_STREAM')
+
+        if self.dump_frames:  # pragma no cover
+            for frm in frms:
+                print(frm.human_readable(">>"))
+
+        return [frm.serialize() for frm in frms]
+
+    def _create_body(self, body, stream_id):
+        if body is None or len(body) == 0:
+            return b''
+
+        chunk_size = self.http2_settings[frame.SettingsFrame.MAX_FRAME_SIZE]
+        chunks = range(0, len(body), chunk_size)
+        frms = [frame.DataFrame(
+            flags=[],
+            stream_id=stream_id,
+            data=body[i:i+chunk_size]) for i in chunks]
+        frms[-1].flags.add('END_STREAM')
+
+        if self.dump_frames:  # pragma no cover
+            for frm in frms:
+                print(frm.human_readable(">>"))
+
+        return [frm.serialize() for frm in frms]
+
+    def _receive_transmission(self, stream_id=None, include_body=True):
+        if not include_body:
+            raise NotImplementedError()
+
+        body_expected = True
+
+        header_blocks = b''
+        body = b''
+
+        while True:
+            frm = self.read_frame()
+            if (
+                (isinstance(frm, frame.HeadersFrame) or isinstance(frm, frame.ContinuationFrame)) and
+                (stream_id is None or frm.stream_id == stream_id)
+            ):
+                stream_id = frm.stream_id
+                header_blocks += frm.data
+                if 'END_STREAM' in frm.flags:
+                    body_expected = False
+                if 'END_HEADERS' in frm.flags:
+                    break
+            else:
+                self._handle_unexpected_frame(frm)
+
+        while body_expected:
+            frm = self.read_frame()
+            if isinstance(frm, frame.DataFrame) and frm.stream_id == stream_id:
+                body += frm.data
+                if 'END_STREAM' in frm.flags:
+                    break
+            else:
+                self._handle_unexpected_frame(frm)
+
+        headers = Headers(
+            [[k.encode('ascii'), v.encode('ascii')] for k, v in self.decoder.decode(header_blocks)]
+        )
+
+        return stream_id, headers, body
diff --git a/netlib/netlib/http/message.py b/netlib/netlib/http/message.py
new file mode 100644
index 00000000..e3d8ce37
--- /dev/null
+++ b/netlib/netlib/http/message.py
@@ -0,0 +1,222 @@
+from __future__ import absolute_import, print_function, division
+
+import warnings
+
+import six
+
+from .headers import Headers
+from .. import encoding, utils
+
+CONTENT_MISSING = 0
+
+if six.PY2:  # pragma: nocover
+    _native = lambda x: x
+    _always_bytes = lambda x: x
+else:
+    # While the HTTP head _should_ be ASCII, it's not uncommon for certain headers to be utf-8 encoded.
+    _native = lambda x: x.decode("utf-8", "surrogateescape")
+    _always_bytes = lambda x: utils.always_bytes(x, "utf-8", "surrogateescape")
+
+
+class MessageData(utils.Serializable):
+    def __eq__(self, other):
+        if isinstance(other, MessageData):
+            return self.__dict__ == other.__dict__
+        return False
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def set_state(self, state):
+        for k, v in state.items():
+            if k == "headers":
+                v = Headers.from_state(v)
+            setattr(self, k, v)
+
+    def get_state(self):
+        state = vars(self).copy()
+        state["headers"] = state["headers"].get_state()
+        return state
+
+    @classmethod
+    def from_state(cls, state):
+        state["headers"] = Headers.from_state(state["headers"])
+        return cls(**state)
+
+
+class Message(utils.Serializable):
+    def __init__(self, data):
+        self.data = data
+
+    def __eq__(self, other):
+        if isinstance(other, Message):
+            return self.data == other.data
+        return False
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def get_state(self):
+        return self.data.get_state()
+
+    def set_state(self, state):
+        self.data.set_state(state)
+
+    @classmethod
+    def from_state(cls, state):
+        return cls(**state)
+
+    @property
+    def headers(self):
+        """
+        Message headers object
+
+        Returns:
+            netlib.http.Headers
+        """
+        return self.data.headers
+
+    @headers.setter
+    def headers(self, h):
+        self.data.headers = h
+
+    @property
+    def content(self):
+        """
+        The raw (encoded) HTTP message body
+
+        See also: :py:attr:`text`
+        """
+        return self.data.content
+
+    @content.setter
+    def content(self, content):
+        self.data.content = content
+        if isinstance(content, bytes):
+            self.headers["content-length"] = str(len(content))
+
+    @property
+    def http_version(self):
+        """
+        Version string, e.g. "HTTP/1.1"
+        """
+        return _native(self.data.http_version)
+
+    @http_version.setter
+    def http_version(self, http_version):
+        self.data.http_version = _always_bytes(http_version)
+
+    @property
+    def timestamp_start(self):
+        """
+        First byte timestamp
+        """
+        return self.data.timestamp_start
+
+    @timestamp_start.setter
+    def timestamp_start(self, timestamp_start):
+        self.data.timestamp_start = timestamp_start
+
+    @property
+    def timestamp_end(self):
+        """
+        Last byte timestamp
+        """
+        return self.data.timestamp_end
+
+    @timestamp_end.setter
+    def timestamp_end(self, timestamp_end):
+        self.data.timestamp_end = timestamp_end
+
+    @property
+    def text(self):
+        """
+        The decoded HTTP message body.
+        Decoded contents are not cached, so accessing this attribute repeatedly is relatively expensive.
+
+        .. note::
+            This is not implemented yet.
+
+        See also: :py:attr:`content`, :py:class:`decoded`
+        """
+        # This attribute should be called text, because that's what requests does.
+        raise NotImplementedError()
+
+    @text.setter
+    def text(self, text):
+        raise NotImplementedError()
+
+    def decode(self):
+        """
+            Decodes body based on the current Content-Encoding header, then
+            removes the header. If there is no Content-Encoding header, no
+            action is taken.
+
+            Returns:
+                True, if decoding succeeded.
+                False, otherwise.
+        """
+        ce = self.headers.get("content-encoding")
+        data = encoding.decode(ce, self.content)
+        if data is None:
+            return False
+        self.content = data
+        self.headers.pop("content-encoding", None)
+        return True
+
+    def encode(self, e):
+        """
+            Encodes body with the encoding e, where e is "gzip", "deflate" or "identity".
+
+            Returns:
+                True, if decoding succeeded.
+                False, otherwise.
+        """
+        data = encoding.encode(e, self.content)
+        if data is None:
+            return False
+        self.content = data
+        self.headers["content-encoding"] = e
+        return True
+
+    # Legacy
+
+    @property
+    def body(self):  # pragma: nocover
+        warnings.warn(".body is deprecated, use .content instead.", DeprecationWarning)
+        return self.content
+
+    @body.setter
+    def body(self, body):  # pragma: nocover
+        warnings.warn(".body is deprecated, use .content instead.", DeprecationWarning)
+        self.content = body
+
+
+class decoded(object):
+    """
+    A context manager that decodes a request or response, and then
+    re-encodes it with the same encoding after execution of the block.
+
+    Example:
+
+    .. code-block:: python
+
+        with decoded(request):
+            request.content = request.content.replace("foo", "bar")
+    """
+
+    def __init__(self, message):
+        self.message = message
+        ce = message.headers.get("content-encoding")
+        if ce in encoding.ENCODINGS:
+            self.ce = ce
+        else:
+            self.ce = None
+
+    def __enter__(self):
+        if self.ce:
+            self.message.decode()
+
+    def __exit__(self, type, value, tb):
+        if self.ce:
+            self.message.encode(self.ce)
diff --git a/netlib/netlib/http/request.py b/netlib/netlib/http/request.py
new file mode 100644
index 00000000..0e0f88ce
--- /dev/null
+++ b/netlib/netlib/http/request.py
@@ -0,0 +1,353 @@
+from __future__ import absolute_import, print_function, division
+
+import warnings
+
+import six
+from six.moves import urllib
+
+from netlib import utils
+from netlib.http import cookies
+from netlib.odict import ODict
+from .. import encoding
+from .headers import Headers
+from .message import Message, _native, _always_bytes, MessageData
+
+
+class RequestData(MessageData):
+    def __init__(self, first_line_format, method, scheme, host, port, path, http_version, headers=None, content=None,
+                 timestamp_start=None, timestamp_end=None):
+        if not isinstance(headers, Headers):
+            headers = Headers(headers)
+
+        self.first_line_format = first_line_format
+        self.method = method
+        self.scheme = scheme
+        self.host = host
+        self.port = port
+        self.path = path
+        self.http_version = http_version
+        self.headers = headers
+        self.content = content
+        self.timestamp_start = timestamp_start
+        self.timestamp_end = timestamp_end
+
+
+class Request(Message):
+    """
+    An HTTP request.
+    """
+    def __init__(self, *args, **kwargs):
+        data = RequestData(*args, **kwargs)
+        super(Request, self).__init__(data)
+
+    def __repr__(self):
+        if self.host and self.port:
+            hostport = "{}:{}".format(self.host, self.port)
+        else:
+            hostport = ""
+        path = self.path or ""
+        return "Request({} {}{})".format(
+            self.method, hostport, path
+        )
+
+    @property
+    def first_line_format(self):
+        """
+        HTTP request form as defined in `RFC7230 <https://tools.ietf.org/html/rfc7230#section-5.3>`_.
+
+        origin-form and asterisk-form are subsumed as "relative".
+        """
+        return self.data.first_line_format
+
+    @first_line_format.setter
+    def first_line_format(self, first_line_format):
+        self.data.first_line_format = first_line_format
+
+    @property
+    def method(self):
+        """
+        HTTP request method, e.g. "GET".
+        """
+        return _native(self.data.method).upper()
+
+    @method.setter
+    def method(self, method):
+        self.data.method = _always_bytes(method)
+
+    @property
+    def scheme(self):
+        """
+        HTTP request scheme, which should be "http" or "https".
+        """
+        return _native(self.data.scheme)
+
+    @scheme.setter
+    def scheme(self, scheme):
+        self.data.scheme = _always_bytes(scheme)
+
+    @property
+    def host(self):
+        """
+        Target host. This may be parsed from the raw request
+        (e.g. from a ``GET http://example.com/ HTTP/1.1`` request line)
+        or inferred from the proxy mode (e.g. an IP in transparent mode).
+
+        Setting the host attribute also updates the host header, if present.
+        """
+
+        if six.PY2:  # pragma: nocover
+            return self.data.host
+
+        if not self.data.host:
+            return self.data.host
+        try:
+            return self.data.host.decode("idna")
+        except UnicodeError:
+            return self.data.host.decode("utf8", "surrogateescape")
+
+    @host.setter
+    def host(self, host):
+        if isinstance(host, six.text_type):
+            try:
+                # There's no non-strict mode for IDNA encoding.
+                # We don't want this operation to fail though, so we try
+                # utf8 as a last resort.
+                host = host.encode("idna", "strict")
+            except UnicodeError:
+                host = host.encode("utf8", "surrogateescape")
+
+        self.data.host = host
+
+        # Update host header
+        if "host" in self.headers:
+            if host:
+                self.headers["host"] = host
+            else:
+                self.headers.pop("host")
+
+    @property
+    def port(self):
+        """
+        Target port
+        """
+        return self.data.port
+
+    @port.setter
+    def port(self, port):
+        self.data.port = port
+
+    @property
+    def path(self):
+        """
+        HTTP request path, e.g. "/index.html".
+        Guaranteed to start with a slash.
+        """
+        return _native(self.data.path)
+
+    @path.setter
+    def path(self, path):
+        self.data.path = _always_bytes(path)
+
+    @property
+    def url(self):
+        """
+        The URL string, constructed from the request's URL components
+        """
+        return utils.unparse_url(self.scheme, self.host, self.port, self.path)
+
+    @url.setter
+    def url(self, url):
+        self.scheme, self.host, self.port, self.path = utils.parse_url(url)
+
+    @property
+    def pretty_host(self):
+        """
+        Similar to :py:attr:`host`, but using the Host headers as an additional preferred data source.
+        This is useful in transparent mode where :py:attr:`host` is only an IP address,
+        but may not reflect the actual destination as the Host header could be spoofed.
+        """
+        return self.headers.get("host", self.host)
+
+    @property
+    def pretty_url(self):
+        """
+        Like :py:attr:`url`, but using :py:attr:`pretty_host` instead of :py:attr:`host`.
+        """
+        if self.first_line_format == "authority":
+            return "%s:%d" % (self.pretty_host, self.port)
+        return utils.unparse_url(self.scheme, self.pretty_host, self.port, self.path)
+
+    @property
+    def query(self):
+        """
+        The request query string as an :py:class:`ODict` object.
+        None, if there is no query.
+        """
+        _, _, _, _, query, _ = urllib.parse.urlparse(self.url)
+        if query:
+            return ODict(utils.urldecode(query))
+        return None
+
+    @query.setter
+    def query(self, odict):
+        query = utils.urlencode(odict.lst)
+        scheme, netloc, path, params, _, fragment = urllib.parse.urlparse(self.url)
+        self.url = urllib.parse.urlunparse([scheme, netloc, path, params, query, fragment])
+
+    @property
+    def cookies(self):
+        """
+        The request cookies.
+        An empty :py:class:`ODict` object if the cookie monster ate them all.
+        """
+        ret = ODict()
+        for i in self.headers.get_all("Cookie"):
+            ret.extend(cookies.parse_cookie_header(i))
+        return ret
+
+    @cookies.setter
+    def cookies(self, odict):
+        self.headers["cookie"] = cookies.format_cookie_header(odict)
+
+    @property
+    def path_components(self):
+        """
+        The URL's path components as a list of strings.
+        Components are unquoted.
+        """
+        _, _, path, _, _, _ = urllib.parse.urlparse(self.url)
+        return [urllib.parse.unquote(i) for i in path.split("/") if i]
+
+    @path_components.setter
+    def path_components(self, components):
+        components = map(lambda x: urllib.parse.quote(x, safe=""), components)
+        path = "/" + "/".join(components)
+        scheme, netloc, _, params, query, fragment = urllib.parse.urlparse(self.url)
+        self.url = urllib.parse.urlunparse([scheme, netloc, path, params, query, fragment])
+
+    def anticache(self):
+        """
+        Modifies this request to remove headers that might produce a cached
+        response. That is, we remove ETags and If-Modified-Since headers.
+        """
+        delheaders = [
+            "if-modified-since",
+            "if-none-match",
+        ]
+        for i in delheaders:
+            self.headers.pop(i, None)
+
+    def anticomp(self):
+        """
+        Modifies this request to remove headers that will compress the
+        resource's data.
+        """
+        self.headers["accept-encoding"] = "identity"
+
+    def constrain_encoding(self):
+        """
+        Limits the permissible Accept-Encoding values, based on what we can
+        decode appropriately.
+        """
+        accept_encoding = self.headers.get("accept-encoding")
+        if accept_encoding:
+            self.headers["accept-encoding"] = (
+                ', '.join(
+                    e
+                    for e in encoding.ENCODINGS
+                    if e in accept_encoding
+                )
+            )
+
+    @property
+    def urlencoded_form(self):
+        """
+        The URL-encoded form data as an :py:class:`ODict` object.
+        None if there is no data or the content-type indicates non-form data.
+        """
+        is_valid_content_type = "application/x-www-form-urlencoded" in self.headers.get("content-type", "").lower()
+        if self.content and is_valid_content_type:
+            return ODict(utils.urldecode(self.content))
+        return None
+
+    @urlencoded_form.setter
+    def urlencoded_form(self, odict):
+        """
+        Sets the body to the URL-encoded form data, and adds the appropriate content-type header.
+        This will overwrite the existing content if there is one.
+        """
+        self.headers["content-type"] = "application/x-www-form-urlencoded"
+        self.content = utils.urlencode(odict.lst)
+
+    @property
+    def multipart_form(self):
+        """
+        The multipart form data as an :py:class:`ODict` object.
+        None if there is no data or the content-type indicates non-form data.
+        """
+        is_valid_content_type = "multipart/form-data" in self.headers.get("content-type", "").lower()
+        if self.content and is_valid_content_type:
+            return ODict(utils.multipartdecode(self.headers,self.content))
+        return None
+
+    @multipart_form.setter
+    def multipart_form(self, value):
+        raise NotImplementedError()
+
+    # Legacy
+
+    def get_cookies(self):  # pragma: nocover
+        warnings.warn(".get_cookies is deprecated, use .cookies instead.", DeprecationWarning)
+        return self.cookies
+
+    def set_cookies(self, odict):  # pragma: nocover
+        warnings.warn(".set_cookies is deprecated, use .cookies instead.", DeprecationWarning)
+        self.cookies = odict
+
+    def get_query(self):  # pragma: nocover
+        warnings.warn(".get_query is deprecated, use .query instead.", DeprecationWarning)
+        return self.query or ODict([])
+
+    def set_query(self, odict):  # pragma: nocover
+        warnings.warn(".set_query is deprecated, use .query instead.", DeprecationWarning)
+        self.query = odict
+
+    def get_path_components(self):  # pragma: nocover
+        warnings.warn(".get_path_components is deprecated, use .path_components instead.", DeprecationWarning)
+        return self.path_components
+
+    def set_path_components(self, lst):  # pragma: nocover
+        warnings.warn(".set_path_components is deprecated, use .path_components instead.", DeprecationWarning)
+        self.path_components = lst
+
+    def get_form_urlencoded(self):  # pragma: nocover
+        warnings.warn(".get_form_urlencoded is deprecated, use .urlencoded_form instead.", DeprecationWarning)
+        return self.urlencoded_form or ODict([])
+
+    def set_form_urlencoded(self, odict):  # pragma: nocover
+        warnings.warn(".set_form_urlencoded is deprecated, use .urlencoded_form instead.", DeprecationWarning)
+        self.urlencoded_form = odict
+
+    def get_form_multipart(self):  # pragma: nocover
+        warnings.warn(".get_form_multipart is deprecated, use .multipart_form instead.", DeprecationWarning)
+        return self.multipart_form or ODict([])
+
+    @property
+    def form_in(self):  # pragma: nocover
+        warnings.warn(".form_in is deprecated, use .first_line_format instead.", DeprecationWarning)
+        return self.first_line_format
+
+    @form_in.setter
+    def form_in(self, form_in):  # pragma: nocover
+        warnings.warn(".form_in is deprecated, use .first_line_format instead.", DeprecationWarning)
+        self.first_line_format = form_in
+
+    @property
+    def form_out(self):  # pragma: nocover
+        warnings.warn(".form_out is deprecated, use .first_line_format instead.", DeprecationWarning)
+        return self.first_line_format
+
+    @form_out.setter
+    def form_out(self, form_out):  # pragma: nocover
+        warnings.warn(".form_out is deprecated, use .first_line_format instead.", DeprecationWarning)
+        self.first_line_format = form_out
\ No newline at end of file
diff --git a/netlib/netlib/http/response.py b/netlib/netlib/http/response.py
new file mode 100644
index 00000000..8f4d6215
--- /dev/null
+++ b/netlib/netlib/http/response.py
@@ -0,0 +1,116 @@
+from __future__ import absolute_import, print_function, division
+
+import warnings
+
+from . import cookies
+from .headers import Headers
+from .message import Message, _native, _always_bytes, MessageData
+from .. import utils
+from ..odict import ODict
+
+
+class ResponseData(MessageData):
+    def __init__(self, http_version, status_code, reason=None, headers=None, content=None,
+                 timestamp_start=None, timestamp_end=None):
+        if not isinstance(headers, Headers):
+            headers = Headers(headers)
+
+        self.http_version = http_version
+        self.status_code = status_code
+        self.reason = reason
+        self.headers = headers
+        self.content = content
+        self.timestamp_start = timestamp_start
+        self.timestamp_end = timestamp_end
+
+
+class Response(Message):
+    """
+    An HTTP response.
+    """
+    def __init__(self, *args, **kwargs):
+        data = ResponseData(*args, **kwargs)
+        super(Response, self).__init__(data)
+
+    def __repr__(self):
+        if self.content:
+            details = "{}, {}".format(
+                self.headers.get("content-type", "unknown content type"),
+                utils.pretty_size(len(self.content))
+            )
+        else:
+            details = "no content"
+        return "Response({status_code} {reason}, {details})".format(
+            status_code=self.status_code,
+            reason=self.reason,
+            details=details
+        )
+
+    @property
+    def status_code(self):
+        """
+        HTTP Status Code, e.g. ``200``.
+        """
+        return self.data.status_code
+
+    @status_code.setter
+    def status_code(self, status_code):
+        self.data.status_code = status_code
+
+    @property
+    def reason(self):
+        """
+        HTTP Reason Phrase, e.g. "Not Found".
+        This is always :py:obj:`None` for HTTP2 requests, because HTTP2 responses do not contain a reason phrase.
+        """
+        return _native(self.data.reason)
+
+    @reason.setter
+    def reason(self, reason):
+        self.data.reason = _always_bytes(reason)
+
+    @property
+    def cookies(self):
+        """
+        Get the contents of all Set-Cookie headers.
+
+        A possibly empty :py:class:`ODict`, where keys are cookie name strings,
+        and values are [value, attr] lists. Value is a string, and attr is
+        an ODictCaseless containing cookie attributes. Within attrs, unary
+        attributes (e.g. HTTPOnly) are indicated by a Null value.
+        """
+        ret = []
+        for header in self.headers.get_all("set-cookie"):
+            v = cookies.parse_set_cookie_header(header)
+            if v:
+                name, value, attrs = v
+                ret.append([name, [value, attrs]])
+        return ODict(ret)
+
+    @cookies.setter
+    def cookies(self, odict):
+        values = []
+        for i in odict.lst:
+            header = cookies.format_set_cookie_header(i[0], i[1][0], i[1][1])
+            values.append(header)
+        self.headers.set_all("set-cookie", values)
+
+    # Legacy
+
+    def get_cookies(self):  # pragma: nocover
+        warnings.warn(".get_cookies is deprecated, use .cookies instead.", DeprecationWarning)
+        return self.cookies
+
+    def set_cookies(self, odict):  # pragma: nocover
+        warnings.warn(".set_cookies is deprecated, use .cookies instead.", DeprecationWarning)
+        self.cookies = odict
+
+    @property
+    def msg(self):  # pragma: nocover
+        warnings.warn(".msg is deprecated, use .reason instead.", DeprecationWarning)
+        return self.reason
+
+    @msg.setter
+    def msg(self, reason):  # pragma: nocover
+        warnings.warn(".msg is deprecated, use .reason instead.", DeprecationWarning)
+        self.reason = reason
diff --git a/netlib/netlib/http/status_codes.py b/netlib/netlib/http/status_codes.py
new file mode 100644
index 00000000..8a4dc1f5
--- /dev/null
+++ b/netlib/netlib/http/status_codes.py
@@ -0,0 +1,106 @@
+from __future__ import absolute_import, print_function, division
+
+CONTINUE = 100
+SWITCHING = 101
+OK = 200
+CREATED = 201
+ACCEPTED = 202
+NON_AUTHORITATIVE_INFORMATION = 203
+NO_CONTENT = 204
+RESET_CONTENT = 205
+PARTIAL_CONTENT = 206
+MULTI_STATUS = 207
+
+MULTIPLE_CHOICE = 300
+MOVED_PERMANENTLY = 301
+FOUND = 302
+SEE_OTHER = 303
+NOT_MODIFIED = 304
+USE_PROXY = 305
+TEMPORARY_REDIRECT = 307
+
+BAD_REQUEST = 400
+UNAUTHORIZED = 401
+PAYMENT_REQUIRED = 402
+FORBIDDEN = 403
+NOT_FOUND = 404
+NOT_ALLOWED = 405
+NOT_ACCEPTABLE = 406
+PROXY_AUTH_REQUIRED = 407
+REQUEST_TIMEOUT = 408
+CONFLICT = 409
+GONE = 410
+LENGTH_REQUIRED = 411
+PRECONDITION_FAILED = 412
+REQUEST_ENTITY_TOO_LARGE = 413
+REQUEST_URI_TOO_LONG = 414
+UNSUPPORTED_MEDIA_TYPE = 415
+REQUESTED_RANGE_NOT_SATISFIABLE = 416
+EXPECTATION_FAILED = 417
+IM_A_TEAPOT = 418
+
+INTERNAL_SERVER_ERROR = 500
+NOT_IMPLEMENTED = 501
+BAD_GATEWAY = 502
+SERVICE_UNAVAILABLE = 503
+GATEWAY_TIMEOUT = 504
+HTTP_VERSION_NOT_SUPPORTED = 505
+INSUFFICIENT_STORAGE_SPACE = 507
+NOT_EXTENDED = 510
+
+RESPONSES = {
+    # 100
+    CONTINUE: "Continue",
+    SWITCHING: "Switching Protocols",
+
+    # 200
+    OK: "OK",
+    CREATED: "Created",
+    ACCEPTED: "Accepted",
+    NON_AUTHORITATIVE_INFORMATION: "Non-Authoritative Information",
+    NO_CONTENT: "No Content",
+    RESET_CONTENT: "Reset Content.",
+    PARTIAL_CONTENT: "Partial Content",
+    MULTI_STATUS: "Multi-Status",
+
+    # 300
+    MULTIPLE_CHOICE: "Multiple Choices",
+    MOVED_PERMANENTLY: "Moved Permanently",
+    FOUND: "Found",
+    SEE_OTHER: "See Other",
+    NOT_MODIFIED: "Not Modified",
+    USE_PROXY: "Use Proxy",
+    # 306 not defined??
+    TEMPORARY_REDIRECT: "Temporary Redirect",
+
+    # 400
+    BAD_REQUEST: "Bad Request",
+    UNAUTHORIZED: "Unauthorized",
+    PAYMENT_REQUIRED: "Payment Required",
+    FORBIDDEN: "Forbidden",
+    NOT_FOUND: "Not Found",
+    NOT_ALLOWED: "Method Not Allowed",
+    NOT_ACCEPTABLE: "Not Acceptable",
+    PROXY_AUTH_REQUIRED: "Proxy Authentication Required",
+    REQUEST_TIMEOUT: "Request Time-out",
+    CONFLICT: "Conflict",
+    GONE: "Gone",
+    LENGTH_REQUIRED: "Length Required",
+    PRECONDITION_FAILED: "Precondition Failed",
+    REQUEST_ENTITY_TOO_LARGE: "Request Entity Too Large",
+    REQUEST_URI_TOO_LONG: "Request-URI Too Long",
+    UNSUPPORTED_MEDIA_TYPE: "Unsupported Media Type",
+    REQUESTED_RANGE_NOT_SATISFIABLE: "Requested Range not satisfiable",
+    EXPECTATION_FAILED: "Expectation Failed",
+    IM_A_TEAPOT: "I'm a teapot",
+
+    # 500
+    INTERNAL_SERVER_ERROR: "Internal Server Error",
+    NOT_IMPLEMENTED: "Not Implemented",
+    BAD_GATEWAY: "Bad Gateway",
+    SERVICE_UNAVAILABLE: "Service Unavailable",
+    GATEWAY_TIMEOUT: "Gateway Time-out",
+    HTTP_VERSION_NOT_SUPPORTED: "HTTP Version not supported",
+    INSUFFICIENT_STORAGE_SPACE: "Insufficient Storage Space",
+    NOT_EXTENDED: "Not Extended"
+}
diff --git a/netlib/netlib/http/user_agents.py b/netlib/netlib/http/user_agents.py
new file mode 100644
index 00000000..e8681908
--- /dev/null
+++ b/netlib/netlib/http/user_agents.py
@@ -0,0 +1,52 @@
+from __future__ import (absolute_import, print_function, division)
+
+"""
+    A small collection of useful user-agent header strings. These should be
+    kept reasonably current to reflect common usage.
+"""
+
+# pylint: line-too-long
+
+# A collection of (name, shortcut, string) tuples.
+
+UASTRINGS = [
+    ("android",
+     "a",
+     "Mozilla/5.0 (Linux; U; Android 4.1.1; en-gb; Nexus 7 Build/JRO03D) AFL/01.04.02"),  # noqa
+    ("blackberry",
+     "l",
+     "Mozilla/5.0 (BlackBerry; U; BlackBerry 9900; en) AppleWebKit/534.11+ (KHTML, like Gecko) Version/7.1.0.346 Mobile Safari/534.11+"),  # noqa
+    ("bingbot",
+     "b",
+     "Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)"),  # noqa
+    ("chrome",
+     "c",
+     "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/22.0.1207.1 Safari/537.1"),  # noqa
+    ("firefox",
+     "f",
+     "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:14.0) Gecko/20120405 Firefox/14.0a1"),  # noqa
+    ("googlebot",
+     "g",
+     "Googlebot/2.1 (+http://www.googlebot.com/bot.html)"),  # noqa
+    ("ie9",
+     "i",
+     "Mozilla/5.0 (Windows; U; MSIE 9.0; WIndows NT 9.0; en-US)"),  # noqa
+    ("ipad",
+     "p",
+     "Mozilla/5.0 (iPad; CPU OS 5_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B176 Safari/7534.48.3"),  # noqa
+    ("iphone",
+     "h",
+     "Mozilla/5.0 (iPhone; CPU iPhone OS 4_2_1 like Mac OS X) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148a Safari/6533.18.5"),  # noqa
+    ("safari",
+     "s",
+     "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_3) AppleWebKit/534.55.3 (KHTML, like Gecko) Version/5.1.3 Safari/534.53.10"),  # noqa
+]
+
+
+def get_by_shortcut(s):
+    """
+        Retrieve a user agent entry by shortcut.
+    """
+    for i in UASTRINGS:
+        if s == i[1]:
+            return i
diff --git a/netlib/netlib/odict.py b/netlib/netlib/odict.py
new file mode 100644
index 00000000..1e6e381a
--- /dev/null
+++ b/netlib/netlib/odict.py
@@ -0,0 +1,193 @@
+from __future__ import (absolute_import, print_function, division)
+import re
+import copy
+import six
+
+from .utils import Serializable
+
+
+def safe_subn(pattern, repl, target, *args, **kwargs):
+    """
+        There are Unicode conversion problems with re.subn. We try to smooth
+        that over by casting the pattern and replacement to strings. We really
+        need a better solution that is aware of the actual content ecoding.
+    """
+    return re.subn(str(pattern), str(repl), target, *args, **kwargs)
+
+
+class ODict(Serializable):
+
+    """
+        A dictionary-like object for managing ordered (key, value) data. Think
+        about it as a convenient interface to a list of (key, value) tuples.
+    """
+
+    def __init__(self, lst=None):
+        self.lst = lst or []
+
+    def _kconv(self, s):
+        return s
+
+    def __eq__(self, other):
+        return self.lst == other.lst
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __iter__(self):
+        return self.lst.__iter__()
+
+    def __getitem__(self, k):
+        """
+            Returns a list of values matching key.
+        """
+        ret = []
+        k = self._kconv(k)
+        for i in self.lst:
+            if self._kconv(i[0]) == k:
+                ret.append(i[1])
+        return ret
+
+    def keys(self):
+        return list(set([self._kconv(i[0]) for i in self.lst]))
+
+    def _filter_lst(self, k, lst):
+        k = self._kconv(k)
+        new = []
+        for i in lst:
+            if self._kconv(i[0]) != k:
+                new.append(i)
+        return new
+
+    def __len__(self):
+        """
+            Total number of (key, value) pairs.
+        """
+        return len(self.lst)
+
+    def __setitem__(self, k, valuelist):
+        """
+            Sets the values for key k. If there are existing values for this
+            key, they are cleared.
+        """
+        if isinstance(valuelist, six.text_type) or isinstance(valuelist, six.binary_type):
+            raise ValueError(
+                "Expected list of values instead of string. "
+                "Example: odict[b'Host'] = [b'www.example.com']"
+            )
+        kc = self._kconv(k)
+        new = []
+        for i in self.lst:
+            if self._kconv(i[0]) == kc:
+                if valuelist:
+                    new.append([k, valuelist.pop(0)])
+            else:
+                new.append(i)
+        while valuelist:
+            new.append([k, valuelist.pop(0)])
+        self.lst = new
+
+    def __delitem__(self, k):
+        """
+            Delete all items matching k.
+        """
+        self.lst = self._filter_lst(k, self.lst)
+
+    def __contains__(self, k):
+        k = self._kconv(k)
+        for i in self.lst:
+            if self._kconv(i[0]) == k:
+                return True
+        return False
+
+    def add(self, key, value, prepend=False):
+        if prepend:
+            self.lst.insert(0, [key, value])
+        else:
+            self.lst.append([key, value])
+
+    def get(self, k, d=None):
+        if k in self:
+            return self[k]
+        else:
+            return d
+
+    def get_first(self, k, d=None):
+        if k in self:
+            return self[k][0]
+        else:
+            return d
+
+    def items(self):
+        return self.lst[:]
+
+    def copy(self):
+        """
+            Returns a copy of this object.
+        """
+        lst = copy.deepcopy(self.lst)
+        return self.__class__(lst)
+
+    def extend(self, other):
+        """
+            Add the contents of other, preserving any duplicates.
+        """
+        self.lst.extend(other.lst)
+
+    def __repr__(self):
+        return repr(self.lst)
+
+    def in_any(self, key, value, caseless=False):
+        """
+            Do any of the values matching key contain value?
+
+            If caseless is true, value comparison is case-insensitive.
+        """
+        if caseless:
+            value = value.lower()
+        for i in self[key]:
+            if caseless:
+                i = i.lower()
+            if value in i:
+                return True
+        return False
+
+    def replace(self, pattern, repl, *args, **kwargs):
+        """
+            Replaces a regular expression pattern with repl in both keys and
+            values. Encoded content will be decoded before replacement, and
+            re-encoded afterwards.
+
+            Returns the number of replacements made.
+        """
+        nlst, count = [], 0
+        for i in self.lst:
+            k, c = safe_subn(pattern, repl, i[0], *args, **kwargs)
+            count += c
+            v, c = safe_subn(pattern, repl, i[1], *args, **kwargs)
+            count += c
+            nlst.append([k, v])
+        self.lst = nlst
+        return count
+
+    # Implement the StateObject protocol from mitmproxy
+    def get_state(self):
+        return [tuple(i) for i in self.lst]
+
+    def set_state(self, state):
+        self.lst = [list(i) for i in state]
+
+    @classmethod
+    def from_state(cls, state):
+        return cls([list(i) for i in state])
+
+
+class ODictCaseless(ODict):
+
+    """
+        A variant of ODict with "caseless" keys. This version _preserves_ key
+        case, but does not consider case when setting or getting items.
+    """
+
+    def _kconv(self, s):
+        return s.lower()
diff --git a/netlib/netlib/socks.py b/netlib/netlib/socks.py
new file mode 100644
index 00000000..51ad1c63
--- /dev/null
+++ b/netlib/netlib/socks.py
@@ -0,0 +1,176 @@
+from __future__ import (absolute_import, print_function, division)
+import struct
+import array
+import ipaddress
+from . import tcp, utils
+
+
+class SocksError(Exception):
+    def __init__(self, code, message):
+        super(SocksError, self).__init__(message)
+        self.code = code
+
+
+VERSION = utils.BiDi(
+    SOCKS4=0x04,
+    SOCKS5=0x05
+)
+
+CMD = utils.BiDi(
+    CONNECT=0x01,
+    BIND=0x02,
+    UDP_ASSOCIATE=0x03
+)
+
+ATYP = utils.BiDi(
+    IPV4_ADDRESS=0x01,
+    DOMAINNAME=0x03,
+    IPV6_ADDRESS=0x04
+)
+
+REP = utils.BiDi(
+    SUCCEEDED=0x00,
+    GENERAL_SOCKS_SERVER_FAILURE=0x01,
+    CONNECTION_NOT_ALLOWED_BY_RULESET=0x02,
+    NETWORK_UNREACHABLE=0x03,
+    HOST_UNREACHABLE=0x04,
+    CONNECTION_REFUSED=0x05,
+    TTL_EXPIRED=0x06,
+    COMMAND_NOT_SUPPORTED=0x07,
+    ADDRESS_TYPE_NOT_SUPPORTED=0x08,
+)
+
+METHOD = utils.BiDi(
+    NO_AUTHENTICATION_REQUIRED=0x00,
+    GSSAPI=0x01,
+    USERNAME_PASSWORD=0x02,
+    NO_ACCEPTABLE_METHODS=0xFF
+)
+
+
+class ClientGreeting(object):
+    __slots__ = ("ver", "methods")
+
+    def __init__(self, ver, methods):
+        self.ver = ver
+        self.methods = array.array("B")
+        self.methods.extend(methods)
+
+    def assert_socks5(self):
+        if self.ver != VERSION.SOCKS5:
+            if self.ver == ord("G") and len(self.methods) == ord("E"):
+                guess = "Probably not a SOCKS request but a regular HTTP request. "
+            else:
+                guess = ""
+
+            raise SocksError(
+                REP.GENERAL_SOCKS_SERVER_FAILURE,
+                guess + "Invalid SOCKS version. Expected 0x05, got 0x%x" % self.ver
+            )
+
+    @classmethod
+    def from_file(cls, f, fail_early=False):
+        """
+        :param fail_early: If true, a SocksError will be raised if the first byte does not indicate socks5.
+        """
+        ver, nmethods = struct.unpack("!BB", f.safe_read(2))
+        client_greeting = cls(ver, [])
+        if fail_early:
+            client_greeting.assert_socks5()
+        client_greeting.methods.fromstring(f.safe_read(nmethods))
+        return client_greeting
+
+    def to_file(self, f):
+        f.write(struct.pack("!BB", self.ver, len(self.methods)))
+        f.write(self.methods.tostring())
+
+
+class ServerGreeting(object):
+    __slots__ = ("ver", "method")
+
+    def __init__(self, ver, method):
+        self.ver = ver
+        self.method = method
+
+    def assert_socks5(self):
+        if self.ver != VERSION.SOCKS5:
+            if self.ver == ord("H") and self.method == ord("T"):
+                guess = "Probably not a SOCKS request but a regular HTTP response. "
+            else:
+                guess = ""
+
+            raise SocksError(
+                REP.GENERAL_SOCKS_SERVER_FAILURE,
+                guess + "Invalid SOCKS version. Expected 0x05, got 0x%x" % self.ver
+            )
+
+    @classmethod
+    def from_file(cls, f):
+        ver, method = struct.unpack("!BB", f.safe_read(2))
+        return cls(ver, method)
+
+    def to_file(self, f):
+        f.write(struct.pack("!BB", self.ver, self.method))
+
+
+class Message(object):
+    __slots__ = ("ver", "msg", "atyp", "addr")
+
+    def __init__(self, ver, msg, atyp, addr):
+        self.ver = ver
+        self.msg = msg
+        self.atyp = atyp
+        self.addr = tcp.Address.wrap(addr)
+
+    def assert_socks5(self):
+        if self.ver != VERSION.SOCKS5:
+            raise SocksError(
+                REP.GENERAL_SOCKS_SERVER_FAILURE,
+                "Invalid SOCKS version. Expected 0x05, got 0x%x" % self.ver
+            )
+
+    @classmethod
+    def from_file(cls, f):
+        ver, msg, rsv, atyp = struct.unpack("!BBBB", f.safe_read(4))
+        if rsv != 0x00:
+            raise SocksError(
+                REP.GENERAL_SOCKS_SERVER_FAILURE,
+                "Socks Request: Invalid reserved byte: %s" % rsv
+            )
+        if atyp == ATYP.IPV4_ADDRESS:
+            # We use tnoa here as ntop is not commonly available on Windows.
+            host = ipaddress.IPv4Address(f.safe_read(4)).compressed
+            use_ipv6 = False
+        elif atyp == ATYP.IPV6_ADDRESS:
+            host = ipaddress.IPv6Address(f.safe_read(16)).compressed
+            use_ipv6 = True
+        elif atyp == ATYP.DOMAINNAME:
+            length, = struct.unpack("!B", f.safe_read(1))
+            host = f.safe_read(length)
+            if not utils.is_valid_host(host):
+                raise SocksError(REP.GENERAL_SOCKS_SERVER_FAILURE, "Invalid hostname: %s" % host)
+            host = host.decode("idna")
+            use_ipv6 = False
+        else:
+            raise SocksError(REP.ADDRESS_TYPE_NOT_SUPPORTED,
+                             "Socks Request: Unknown ATYP: %s" % atyp)
+
+        port, = struct.unpack("!H", f.safe_read(2))
+        addr = tcp.Address((host, port), use_ipv6=use_ipv6)
+        return cls(ver, msg, atyp, addr)
+
+    def to_file(self, f):
+        f.write(struct.pack("!BBBB", self.ver, self.msg, 0x00, self.atyp))
+        if self.atyp == ATYP.IPV4_ADDRESS:
+            f.write(ipaddress.IPv4Address(self.addr.host).packed)
+        elif self.atyp == ATYP.IPV6_ADDRESS:
+            f.write(ipaddress.IPv6Address(self.addr.host).packed)
+        elif self.atyp == ATYP.DOMAINNAME:
+            f.write(struct.pack("!B", len(self.addr.host)))
+            f.write(self.addr.host.encode("idna"))
+        else:
+            raise SocksError(
+                REP.ADDRESS_TYPE_NOT_SUPPORTED,
+                "Unknown ATYP: %s" % self.atyp
+            )
+        f.write(struct.pack("!H", self.addr.port))
diff --git a/netlib/netlib/tcp.py b/netlib/netlib/tcp.py
new file mode 100644
index 00000000..61b41cdc
--- /dev/null
+++ b/netlib/netlib/tcp.py
@@ -0,0 +1,911 @@
+from __future__ import (absolute_import, print_function, division)
+import os
+import select
+import socket
+import sys
+import threading
+import time
+import traceback
+
+import binascii
+from six.moves import range
+
+import certifi
+from backports import ssl_match_hostname
+import six
+import OpenSSL
+from OpenSSL import SSL
+
+from . import certutils, version_check, utils
+
+# This is a rather hackish way to make sure that
+# the latest version of pyOpenSSL is actually installed.
+from netlib.exceptions import InvalidCertificateException, TcpReadIncomplete, TlsException, \
+    TcpTimeout, TcpDisconnect, TcpException
+
+version_check.check_pyopenssl_version()
+
+if six.PY2:
+    socket_fileobject = socket._fileobject
+else:
+    socket_fileobject = socket.SocketIO
+
+EINTR = 4
+if os.environ.get("NO_ALPN"):
+    HAS_ALPN = False
+else:
+    HAS_ALPN = OpenSSL._util.lib.Cryptography_HAS_ALPN
+
+# To enable all SSL methods use: SSLv23
+# then add options to disable certain methods
+# https://bugs.launchpad.net/pyopenssl/+bug/1020632/comments/3
+SSL_BASIC_OPTIONS = (
+    SSL.OP_CIPHER_SERVER_PREFERENCE
+)
+if hasattr(SSL, "OP_NO_COMPRESSION"):
+    SSL_BASIC_OPTIONS |= SSL.OP_NO_COMPRESSION
+
+SSL_DEFAULT_METHOD = SSL.SSLv23_METHOD
+SSL_DEFAULT_OPTIONS = (
+    SSL.OP_NO_SSLv2 |
+    SSL.OP_NO_SSLv3 |
+    SSL_BASIC_OPTIONS
+)
+if hasattr(SSL, "OP_NO_COMPRESSION"):
+    SSL_DEFAULT_OPTIONS |= SSL.OP_NO_COMPRESSION
+
+"""
+Map a reasonable SSL version specification into the format OpenSSL expects.
+Don't ask...
+https://bugs.launchpad.net/pyopenssl/+bug/1020632/comments/3
+"""
+sslversion_choices = {
+    "all": (SSL.SSLv23_METHOD, SSL_BASIC_OPTIONS),
+    # SSLv23_METHOD + NO_SSLv2 + NO_SSLv3 == TLS 1.0+
+    # TLSv1_METHOD would be TLS 1.0 only
+    "secure": (SSL.SSLv23_METHOD, (SSL.OP_NO_SSLv2 | SSL.OP_NO_SSLv3 | SSL_BASIC_OPTIONS)),
+    "SSLv2": (SSL.SSLv2_METHOD, SSL_BASIC_OPTIONS),
+    "SSLv3": (SSL.SSLv3_METHOD, SSL_BASIC_OPTIONS),
+    "TLSv1": (SSL.TLSv1_METHOD, SSL_BASIC_OPTIONS),
+    "TLSv1_1": (SSL.TLSv1_1_METHOD, SSL_BASIC_OPTIONS),
+    "TLSv1_2": (SSL.TLSv1_2_METHOD, SSL_BASIC_OPTIONS),
+}
+
+class SSLKeyLogger(object):
+
+    def __init__(self, filename):
+        self.filename = filename
+        self.f = None
+        self.lock = threading.Lock()
+
+    # required for functools.wraps, which pyOpenSSL uses.
+    __name__ = "SSLKeyLogger"
+
+    def __call__(self, connection, where, ret):
+        if where == SSL.SSL_CB_HANDSHAKE_DONE and ret == 1:
+            with self.lock:
+                if not self.f:
+                    d = os.path.dirname(self.filename)
+                    if not os.path.isdir(d):
+                        os.makedirs(d)
+                    self.f = open(self.filename, "ab")
+                    self.f.write(b"\r\n")
+                client_random = binascii.hexlify(connection.client_random())
+                masterkey = binascii.hexlify(connection.master_key())
+                self.f.write(b"CLIENT_RANDOM %s %s\r\n" % (client_random, masterkey))
+                self.f.flush()
+
+    def close(self):
+        with self.lock:
+            if self.f:
+                self.f.close()
+
+    @staticmethod
+    def create_logfun(filename):
+        if filename:
+            return SSLKeyLogger(filename)
+        return False
+
+log_ssl_key = SSLKeyLogger.create_logfun(
+    os.getenv("MITMPROXY_SSLKEYLOGFILE") or os.getenv("SSLKEYLOGFILE"))
+
+
+class _FileLike(object):
+    BLOCKSIZE = 1024 * 32
+
+    def __init__(self, o):
+        self.o = o
+        self._log = None
+        self.first_byte_timestamp = None
+
+    def set_descriptor(self, o):
+        self.o = o
+
+    def __getattr__(self, attr):
+        return getattr(self.o, attr)
+
+    def start_log(self):
+        """
+            Starts or resets the log.
+
+            This will store all bytes read or written.
+        """
+        self._log = []
+
+    def stop_log(self):
+        """
+            Stops the log.
+        """
+        self._log = None
+
+    def is_logging(self):
+        return self._log is not None
+
+    def get_log(self):
+        """
+            Returns the log as a string.
+        """
+        if not self.is_logging():
+            raise ValueError("Not logging!")
+        return b"".join(self._log)
+
+    def add_log(self, v):
+        if self.is_logging():
+            self._log.append(v)
+
+    def reset_timestamps(self):
+        self.first_byte_timestamp = None
+
+
+class Writer(_FileLike):
+
+    def flush(self):
+        """
+            May raise TcpDisconnect
+        """
+        if hasattr(self.o, "flush"):
+            try:
+                self.o.flush()
+            except (socket.error, IOError) as v:
+                raise TcpDisconnect(str(v))
+
+    def write(self, v):
+        """
+            May raise TcpDisconnect
+        """
+        if v:
+            self.first_byte_timestamp = self.first_byte_timestamp or time.time()
+            try:
+                if hasattr(self.o, "sendall"):
+                    self.add_log(v)
+                    return self.o.sendall(v)
+                else:
+                    r = self.o.write(v)
+                    self.add_log(v[:r])
+                    return r
+            except (SSL.Error, socket.error) as e:
+                raise TcpDisconnect(str(e))
+
+
+class Reader(_FileLike):
+
+    def read(self, length):
+        """
+            If length is -1, we read until connection closes.
+        """
+        result = b''
+        start = time.time()
+        while length == -1 or length > 0:
+            if length == -1 or length > self.BLOCKSIZE:
+                rlen = self.BLOCKSIZE
+            else:
+                rlen = length
+            try:
+                data = self.o.read(rlen)
+            except SSL.ZeroReturnError:
+                # TLS connection was shut down cleanly
+                break
+            except (SSL.WantWriteError, SSL.WantReadError):
+                # From the OpenSSL docs:
+                # If the underlying BIO is non-blocking, SSL_read() will also return when the
+                # underlying BIO could not satisfy the needs of SSL_read() to continue the
+                # operation. In this case a call to SSL_get_error with the return value of
+                # SSL_read() will yield SSL_ERROR_WANT_READ or SSL_ERROR_WANT_WRITE.
+                if (time.time() - start) < self.o.gettimeout():
+                    time.sleep(0.1)
+                    continue
+                else:
+                    raise TcpTimeout()
+            except socket.timeout:
+                raise TcpTimeout()
+            except socket.error as e:
+                raise TcpDisconnect(str(e))
+            except SSL.SysCallError as e:
+                if e.args == (-1, 'Unexpected EOF'):
+                    break
+                raise TlsException(str(e))
+            except SSL.Error as e:
+                raise TlsException(str(e))
+            self.first_byte_timestamp = self.first_byte_timestamp or time.time()
+            if not data:
+                break
+            result += data
+            if length != -1:
+                length -= len(data)
+        self.add_log(result)
+        return result
+
+    def readline(self, size=None):
+        result = b''
+        bytes_read = 0
+        while True:
+            if size is not None and bytes_read >= size:
+                break
+            ch = self.read(1)
+            bytes_read += 1
+            if not ch:
+                break
+            else:
+                result += ch
+                if ch == b'\n':
+                    break
+        return result
+
+    def safe_read(self, length):
+        """
+            Like .read, but is guaranteed to either return length bytes, or
+            raise an exception.
+        """
+        result = self.read(length)
+        if length != -1 and len(result) != length:
+            if not result:
+                raise TcpDisconnect()
+            else:
+                raise TcpReadIncomplete(
+                    "Expected %s bytes, got %s" % (length, len(result))
+                )
+        return result
+
+    def peek(self, length):
+        """
+        Tries to peek into the underlying file object.
+
+        Returns:
+            Up to the next N bytes if peeking is successful.
+
+        Raises:
+            TcpException if there was an error with the socket
+            TlsException if there was an error with pyOpenSSL.
+            NotImplementedError if the underlying file object is not a [pyOpenSSL] socket
+        """
+        if isinstance(self.o, socket_fileobject):
+            try:
+                return self.o._sock.recv(length, socket.MSG_PEEK)
+            except socket.error as e:
+                raise TcpException(repr(e))
+        elif isinstance(self.o, SSL.Connection):
+            try:
+                if tuple(int(x) for x in OpenSSL.__version__.split(".")[:2]) > (0, 15):
+                    return self.o.recv(length, socket.MSG_PEEK)
+                else:
+                    # TODO: remove once a new version is released
+                    # Polyfill for pyOpenSSL <= 0.15.1
+                    # Taken from https://github.com/pyca/pyopenssl/commit/1d95dea7fea03c7c0df345a5ea30c12d8a0378d2
+                    buf = SSL._ffi.new("char[]", length)
+                    result = SSL._lib.SSL_peek(self.o._ssl, buf, length)
+                    self.o._raise_ssl_error(self.o._ssl, result)
+                    return SSL._ffi.buffer(buf, result)[:]
+            except SSL.Error as e:
+                six.reraise(TlsException, TlsException(str(e)), sys.exc_info()[2])
+        else:
+            raise NotImplementedError("Can only peek into (pyOpenSSL) sockets")
+
+
+class Address(utils.Serializable):
+
+    """
+        This class wraps an IPv4/IPv6 tuple to provide named attributes and
+        ipv6 information.
+    """
+
+    def __init__(self, address, use_ipv6=False):
+        self.address = tuple(address)
+        self.use_ipv6 = use_ipv6
+
+    def get_state(self):
+        return {
+            "address": self.address,
+            "use_ipv6": self.use_ipv6
+        }
+
+    def set_state(self, state):
+        self.address = state["address"]
+        self.use_ipv6 = state["use_ipv6"]
+
+    @classmethod
+    def from_state(cls, state):
+        return Address(**state)
+
+    @classmethod
+    def wrap(cls, t):
+        if isinstance(t, cls):
+            return t
+        else:
+            return cls(t)
+
+    def __call__(self):
+        return self.address
+
+    @property
+    def host(self):
+        return self.address[0]
+
+    @property
+    def port(self):
+        return self.address[1]
+
+    @property
+    def use_ipv6(self):
+        return self.family == socket.AF_INET6
+
+    @use_ipv6.setter
+    def use_ipv6(self, b):
+        self.family = socket.AF_INET6 if b else socket.AF_INET
+
+    def __repr__(self):
+        return "{}:{}".format(self.host, self.port)
+
+    def __str__(self):
+        return str(self.address)
+
+    def __eq__(self, other):
+        if not other:
+            return False
+        other = Address.wrap(other)
+        return (self.address, self.family) == (other.address, other.family)
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __hash__(self):
+        return hash(self.address) ^ 42  # different hash than the tuple alone.
+
+
+def ssl_read_select(rlist, timeout):
+    """
+    This is a wrapper around select.select() which also works for SSL.Connections
+    by taking ssl_connection.pending() into account.
+
+    Caveats:
+        If .pending() > 0 for any of the connections in rlist, we avoid the select syscall
+        and **will not include any other connections which may or may not be ready**.
+
+    Args:
+        rlist: wait until ready for reading
+
+    Returns:
+        subset of rlist which is ready for reading.
+    """
+    return [
+        conn for conn in rlist
+        if isinstance(conn, SSL.Connection) and conn.pending() > 0
+    ] or select.select(rlist, (), (), timeout)[0]
+
+
+def close_socket(sock):
+    """
+    Does a hard close of a socket, without emitting a RST.
+    """
+    try:
+        # We already indicate that we close our end.
+        # may raise "Transport endpoint is not connected" on Linux
+        sock.shutdown(socket.SHUT_WR)
+
+        # Section 4.2.2.13 of RFC 1122 tells us that a close() with any pending
+        # readable data could lead to an immediate RST being sent (which is the
+        # case on Windows).
+        # http://ia600609.us.archive.org/22/items/TheUltimateSo_lingerPageOrWhyIsMyTcpNotReliable/the-ultimate-so_linger-page-or-why-is-my-tcp-not-reliable.html
+        #
+        # This in turn results in the following issue: If we send an error page
+        # to the client and then close the socket, the RST may be received by
+        # the client before the error page and the users sees a connection
+        # error rather than the error page. Thus, we try to empty the read
+        # buffer on Windows first. (see
+        # https://github.com/mitmproxy/mitmproxy/issues/527#issuecomment-93782988)
+        #
+
+        if os.name == "nt":  # pragma: no cover
+            # We cannot rely on the shutdown()-followed-by-read()-eof technique
+            # proposed by the page above: Some remote machines just don't send
+            # a TCP FIN, which would leave us in the unfortunate situation that
+            # recv() would block infinitely. As a workaround, we set a timeout
+            # here even if we are in blocking mode.
+            sock.settimeout(sock.gettimeout() or 20)
+
+            # limit at a megabyte so that we don't read infinitely
+            for _ in range(1024 ** 3 // 4096):
+                # may raise a timeout/disconnect exception.
+                if not sock.recv(4096):
+                    break
+
+        # Now we can close the other half as well.
+        sock.shutdown(socket.SHUT_RD)
+
+    except socket.error:
+        pass
+
+    sock.close()
+
+
+class _Connection(object):
+
+    rbufsize = -1
+    wbufsize = -1
+
+    def _makefile(self):
+        """
+        Set up .rfile and .wfile attributes from .connection
+        """
+        # Ideally, we would use the Buffered IO in Python 3 by default.
+        # Unfortunately, the implementation of .peek() is broken for n>1 bytes,
+        # as it may just return what's left in the buffer and not all the bytes we want.
+        # As a workaround, we just use unbuffered sockets directly.
+        # https://mail.python.org/pipermail/python-dev/2009-June/089986.html
+        if six.PY2:
+            self.rfile = Reader(self.connection.makefile('rb', self.rbufsize))
+            self.wfile = Writer(self.connection.makefile('wb', self.wbufsize))
+        else:
+            self.rfile = Reader(socket.SocketIO(self.connection, "rb"))
+            self.wfile = Writer(socket.SocketIO(self.connection, "wb"))
+
+    def __init__(self, connection):
+        if connection:
+            self.connection = connection
+            self._makefile()
+        else:
+            self.connection = None
+            self.rfile = None
+            self.wfile = None
+
+        self.ssl_established = False
+        self.finished = False
+
+    def get_current_cipher(self):
+        if not self.ssl_established:
+            return None
+
+        name = self.connection.get_cipher_name()
+        bits = self.connection.get_cipher_bits()
+        version = self.connection.get_cipher_version()
+        return name, bits, version
+
+    def finish(self):
+        self.finished = True
+        # If we have an SSL connection, wfile.close == connection.close
+        # (We call _FileLike.set_descriptor(conn))
+        # Closing the socket is not our task, therefore we don't call close
+        # then.
+        if not isinstance(self.connection, SSL.Connection):
+            if not getattr(self.wfile, "closed", False):
+                try:
+                    self.wfile.flush()
+                    self.wfile.close()
+                except TcpDisconnect:
+                    pass
+
+            self.rfile.close()
+        else:
+            try:
+                self.connection.shutdown()
+            except SSL.Error:
+                pass
+
+    def _create_ssl_context(self,
+                            method=SSL_DEFAULT_METHOD,
+                            options=SSL_DEFAULT_OPTIONS,
+                            verify_options=SSL.VERIFY_NONE,
+                            ca_path=None,
+                            ca_pemfile=None,
+                            cipher_list=None,
+                            alpn_protos=None,
+                            alpn_select=None,
+                            alpn_select_callback=None,
+                            ):
+        """
+        Creates an SSL Context.
+
+        :param method: One of SSLv2_METHOD, SSLv3_METHOD, SSLv23_METHOD, TLSv1_METHOD, TLSv1_1_METHOD, or TLSv1_2_METHOD
+        :param options: A bit field consisting of OpenSSL.SSL.OP_* values
+        :param verify_options: A bit field consisting of OpenSSL.SSL.VERIFY_* values
+        :param ca_path: Path to a directory of trusted CA certificates prepared using the c_rehash tool
+        :param ca_pemfile: Path to a PEM formatted trusted CA certificate
+        :param cipher_list: A textual OpenSSL cipher list, see https://www.openssl.org/docs/apps/ciphers.html
+        :rtype : SSL.Context
+        """
+        context = SSL.Context(method)
+        # Options (NO_SSLv2/3)
+        if options is not None:
+            context.set_options(options)
+
+        # Verify Options (NONE/PEER and trusted CAs)
+        if verify_options is not None:
+            def verify_cert(conn, x509, errno, err_depth, is_cert_verified):
+                if not is_cert_verified:
+                    self.ssl_verification_error = dict(errno=errno,
+                                                       depth=err_depth)
+                return is_cert_verified
+
+            context.set_verify(verify_options, verify_cert)
+            if ca_path is None and ca_pemfile is None:
+                ca_pemfile = certifi.where()
+            context.load_verify_locations(ca_pemfile, ca_path)
+
+        # Workaround for
+        # https://github.com/pyca/pyopenssl/issues/190
+        # https://github.com/mitmproxy/mitmproxy/issues/472
+        # Options already set before are not cleared.
+        context.set_mode(SSL._lib.SSL_MODE_AUTO_RETRY)
+
+        # Cipher List
+        if cipher_list:
+            try:
+                context.set_cipher_list(cipher_list)
+
+                # TODO: maybe change this to with newer pyOpenSSL APIs
+                context.set_tmp_ecdh(OpenSSL.crypto.get_elliptic_curve('prime256v1'))
+            except SSL.Error as v:
+                raise TlsException("SSL cipher specification error: %s" % str(v))
+
+        # SSLKEYLOGFILE
+        if log_ssl_key:
+            context.set_info_callback(log_ssl_key)
+
+        if HAS_ALPN:
+            if alpn_protos is not None:
+                # advertise application layer protocols
+                context.set_alpn_protos(alpn_protos)
+            elif alpn_select is not None and alpn_select_callback is None:
+                # select application layer protocol
+                def alpn_select_callback(conn_, options):
+                    if alpn_select in options:
+                        return bytes(alpn_select)
+                    else:  # pragma no cover
+                        return options[0]
+                context.set_alpn_select_callback(alpn_select_callback)
+            elif alpn_select_callback is not None and alpn_select is None:
+                context.set_alpn_select_callback(alpn_select_callback)
+            elif alpn_select_callback is not None and alpn_select is not None:
+                raise TlsException("ALPN error: only define alpn_select (string) OR alpn_select_callback (method).")
+
+        return context
+
+
+class TCPClient(_Connection):
+
+    def __init__(self, address, source_address=None):
+        super(TCPClient, self).__init__(None)
+        self.address = address
+        self.source_address = source_address
+        self.cert = None
+        self.ssl_verification_error = None
+        self.sni = None
+
+    @property
+    def address(self):
+        return self.__address
+
+    @address.setter
+    def address(self, address):
+        if address:
+            self.__address = Address.wrap(address)
+        else:
+            self.__address = None
+
+    @property
+    def source_address(self):
+        return self.__source_address
+
+    @source_address.setter
+    def source_address(self, source_address):
+        if source_address:
+            self.__source_address = Address.wrap(source_address)
+        else:
+            self.__source_address = None
+
+    def close(self):
+        # Make sure to close the real socket, not the SSL proxy.
+        # OpenSSL is really good at screwing up, i.e. when trying to recv from a failed connection,
+        # it tries to renegotiate...
+        if isinstance(self.connection, SSL.Connection):
+            close_socket(self.connection._socket)
+        else:
+            close_socket(self.connection)
+
+    def create_ssl_context(self, cert=None, alpn_protos=None, **sslctx_kwargs):
+        context = self._create_ssl_context(
+            alpn_protos=alpn_protos,
+            **sslctx_kwargs)
+        # Client Certs
+        if cert:
+            try:
+                context.use_privatekey_file(cert)
+                context.use_certificate_file(cert)
+            except SSL.Error as v:
+                raise TlsException("SSL client certificate error: %s" % str(v))
+        return context
+
+    def convert_to_ssl(self, sni=None, alpn_protos=None, **sslctx_kwargs):
+        """
+            cert: Path to a file containing both client cert and private key.
+
+            options: A bit field consisting of OpenSSL.SSL.OP_* values
+            verify_options: A bit field consisting of OpenSSL.SSL.VERIFY_* values
+            ca_path: Path to a directory of trusted CA certificates prepared using the c_rehash tool
+            ca_pemfile: Path to a PEM formatted trusted CA certificate
+        """
+        verification_mode = sslctx_kwargs.get('verify_options', None)
+        if verification_mode == SSL.VERIFY_PEER and not sni:
+            raise TlsException("Cannot validate certificate hostname without SNI")
+
+        context = self.create_ssl_context(
+            alpn_protos=alpn_protos,
+            **sslctx_kwargs
+        )
+        self.connection = SSL.Connection(context, self.connection)
+        if sni:
+            self.sni = sni
+            self.connection.set_tlsext_host_name(sni)
+        self.connection.set_connect_state()
+        try:
+            self.connection.do_handshake()
+        except SSL.Error as v:
+            if self.ssl_verification_error:
+                raise InvalidCertificateException("SSL handshake error: %s" % repr(v))
+            else:
+                raise TlsException("SSL handshake error: %s" % repr(v))
+        else:
+            # Fix for pre v1.0 OpenSSL, which doesn't throw an exception on
+            # certificate validation failure
+            if verification_mode == SSL.VERIFY_PEER and self.ssl_verification_error is not None:
+                raise InvalidCertificateException("SSL handshake error: certificate verify failed")
+
+        self.cert = certutils.SSLCert(self.connection.get_peer_certificate())
+
+        # Validate TLS Hostname
+        try:
+            crt = dict(
+                subjectAltName=[("DNS", x.decode("ascii", "strict")) for x in self.cert.altnames]
+            )
+            if self.cert.cn:
+                crt["subject"] = [[["commonName", self.cert.cn.decode("ascii", "strict")]]]
+            if sni:
+                hostname = sni.decode("ascii", "strict")
+            else:
+                hostname = "no-hostname"
+            ssl_match_hostname.match_hostname(crt, hostname)
+        except (ValueError, ssl_match_hostname.CertificateError) as e:
+            self.ssl_verification_error = dict(depth=0, errno="Invalid Hostname")
+            if verification_mode == SSL.VERIFY_PEER:
+                raise InvalidCertificateException("Presented certificate for {} is not valid: {}".format(sni, str(e)))
+
+        self.ssl_established = True
+        self.rfile.set_descriptor(self.connection)
+        self.wfile.set_descriptor(self.connection)
+
+    def connect(self):
+        try:
+            connection = socket.socket(self.address.family, socket.SOCK_STREAM)
+            if self.source_address:
+                connection.bind(self.source_address())
+            connection.connect(self.address())
+            if not self.source_address:
+                self.source_address = Address(connection.getsockname())
+        except (socket.error, IOError) as err:
+            raise TcpException(
+                'Error connecting to "%s": %s' %
+                (self.address.host, err))
+        self.connection = connection
+        self._makefile()
+
+    def settimeout(self, n):
+        self.connection.settimeout(n)
+
+    def gettimeout(self):
+        return self.connection.gettimeout()
+
+    def get_alpn_proto_negotiated(self):
+        if HAS_ALPN and self.ssl_established:
+            return self.connection.get_alpn_proto_negotiated()
+        else:
+            return b""
+
+
+class BaseHandler(_Connection):
+
+    """
+        The instantiator is expected to call the handle() and finish() methods.
+    """
+
+    def __init__(self, connection, address, server):
+        super(BaseHandler, self).__init__(connection)
+        self.address = Address.wrap(address)
+        self.server = server
+        self.clientcert = None
+
+    def create_ssl_context(self,
+                           cert, key,
+                           handle_sni=None,
+                           request_client_cert=None,
+                           chain_file=None,
+                           dhparams=None,
+                           **sslctx_kwargs):
+        """
+            cert: A certutils.SSLCert object or the path to a certificate
+            chain file.
+
+            handle_sni: SNI handler, should take a connection object. Server
+            name can be retrieved like this:
+
+                    connection.get_servername()
+
+            And you can specify the connection keys as follows:
+
+                    new_context = Context(TLSv1_METHOD)
+                    new_context.use_privatekey(key)
+                    new_context.use_certificate(cert)
+                    connection.set_context(new_context)
+
+            The request_client_cert argument requires some explanation. We're
+            supposed to be able to do this with no negative effects - if the
+            client has no cert to present, we're notified and proceed as usual.
+            Unfortunately, Android seems to have a bug (tested on 4.2.2) - when
+            an Android client is asked to present a certificate it does not
+            have, it hangs up, which is frankly bogus. Some time down the track
+            we may be able to make the proper behaviour the default again, but
+            until then we're conservative.
+        """
+
+        context = self._create_ssl_context(**sslctx_kwargs)
+
+        context.use_privatekey(key)
+        if isinstance(cert, certutils.SSLCert):
+            context.use_certificate(cert.x509)
+        else:
+            context.use_certificate_chain_file(cert)
+
+        if handle_sni:
+            # SNI callback happens during do_handshake()
+            context.set_tlsext_servername_callback(handle_sni)
+
+        if request_client_cert:
+            def save_cert(conn_, cert, errno_, depth_, preverify_ok_):
+                self.clientcert = certutils.SSLCert(cert)
+                # Return true to prevent cert verification error
+                return True
+            context.set_verify(SSL.VERIFY_PEER, save_cert)
+
+        # Cert Verify
+        if chain_file:
+            context.load_verify_locations(chain_file)
+
+        if dhparams:
+            SSL._lib.SSL_CTX_set_tmp_dh(context._context, dhparams)
+
+        return context
+
+    def convert_to_ssl(self, cert, key, **sslctx_kwargs):
+        """
+        Convert connection to SSL.
+        For a list of parameters, see BaseHandler._create_ssl_context(...)
+        """
+
+        context = self.create_ssl_context(
+            cert,
+            key,
+            **sslctx_kwargs)
+        self.connection = SSL.Connection(context, self.connection)
+        self.connection.set_accept_state()
+        try:
+            self.connection.do_handshake()
+        except SSL.Error as v:
+            raise TlsException("SSL handshake error: %s" % repr(v))
+        self.ssl_established = True
+        self.rfile.set_descriptor(self.connection)
+        self.wfile.set_descriptor(self.connection)
+
+    def handle(self):  # pragma: no cover
+        raise NotImplementedError
+
+    def settimeout(self, n):
+        self.connection.settimeout(n)
+
+    def get_alpn_proto_negotiated(self):
+        if HAS_ALPN and self.ssl_established:
+            return self.connection.get_alpn_proto_negotiated()
+        else:
+            return b""
+
+
+class TCPServer(object):
+    request_queue_size = 20
+
+    def __init__(self, address):
+        self.address = Address.wrap(address)
+        self.__is_shut_down = threading.Event()
+        self.__shutdown_request = False
+        self.socket = socket.socket(self.address.family, socket.SOCK_STREAM)
+        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        self.socket.bind(self.address())
+        self.address = Address.wrap(self.socket.getsockname())
+        self.socket.listen(self.request_queue_size)
+
+    def connection_thread(self, connection, client_address):
+        client_address = Address(client_address)
+        try:
+            self.handle_client_connection(connection, client_address)
+        except:
+            self.handle_error(connection, client_address)
+        finally:
+            close_socket(connection)
+
+    def serve_forever(self, poll_interval=0.1):
+        self.__is_shut_down.clear()
+        try:
+            while not self.__shutdown_request:
+                try:
+                    r, w_, e_ = select.select(
+                        [self.socket], [], [], poll_interval)
+                except select.error as ex:  # pragma: no cover
+                    if ex[0] == EINTR:
+                        continue
+                    else:
+                        raise
+                if self.socket in r:
+                    connection, client_address = self.socket.accept()
+                    t = threading.Thread(
+                        target=self.connection_thread,
+                        args=(connection, client_address),
+                        name="ConnectionThread (%s:%s -> %s:%s)" %
+                             (client_address[0], client_address[1],
+                              self.address.host, self.address.port)
+                    )
+                    t.setDaemon(1)
+                    try:
+                        t.start()
+                    except threading.ThreadError:
+                        self.handle_error(connection, Address(client_address))
+                        connection.close()
+        finally:
+            self.__shutdown_request = False
+            self.__is_shut_down.set()
+
+    def shutdown(self):
+        self.__shutdown_request = True
+        self.__is_shut_down.wait()
+        self.socket.close()
+        self.handle_shutdown()
+
+    def handle_error(self, connection_, client_address, fp=sys.stderr):
+        """
+            Called when handle_client_connection raises an exception.
+        """
+        # If a thread has persisted after interpreter exit, the module might be
+        # none.
+        if traceback:
+            exc = six.text_type(traceback.format_exc())
+            print(u'-' * 40, file=fp)
+            print(
+                u"Error in processing of request from %s" % repr(client_address), file=fp)
+            print(exc, file=fp)
+            print(u'-' * 40, file=fp)
+
+    def handle_client_connection(self, conn, client_address):  # pragma: no cover
+        """
+            Called after client connection.
+        """
+        raise NotImplementedError
+
+    def handle_shutdown(self):
+        """
+            Called after server shutdown.
+        """
diff --git a/netlib/netlib/tservers.py b/netlib/netlib/tservers.py
new file mode 100644
index 00000000..44ef8063
--- /dev/null
+++ b/netlib/netlib/tservers.py
@@ -0,0 +1,109 @@
+from __future__ import (absolute_import, print_function, division)
+
+import threading
+from six.moves import queue
+from io import StringIO
+import OpenSSL
+
+from netlib import tcp
+from netlib import tutils
+
+
+class ServerThread(threading.Thread):
+
+    def __init__(self, server):
+        self.server = server
+        threading.Thread.__init__(self)
+
+    def run(self):
+        self.server.serve_forever()
+
+    def shutdown(self):
+        self.server.shutdown()
+
+
+class ServerTestBase(object):
+    ssl = None
+    handler = None
+    addr = ("localhost", 0)
+
+    @classmethod
+    def setup_class(cls):
+        cls.q = queue.Queue()
+        s = cls.makeserver()
+        cls.port = s.address.port
+        cls.server = ServerThread(s)
+        cls.server.start()
+
+    @classmethod
+    def makeserver(cls):
+        return TServer(cls.ssl, cls.q, cls.handler, cls.addr)
+
+    @classmethod
+    def teardown_class(cls):
+        cls.server.shutdown()
+
+    @property
+    def last_handler(self):
+        return self.server.server.last_handler
+
+
+class TServer(tcp.TCPServer):
+
+    def __init__(self, ssl, q, handler_klass, addr):
+        """
+            ssl: A dictionary of SSL parameters:
+
+                    cert, key, request_client_cert, cipher_list,
+                    dhparams, v3_only
+        """
+        tcp.TCPServer.__init__(self, addr)
+
+        if ssl is True:
+            self.ssl = dict()
+        elif isinstance(ssl, dict):
+            self.ssl = ssl
+        else:
+            self.ssl = None
+
+        self.q = q
+        self.handler_klass = handler_klass
+        self.last_handler = None
+
+    def handle_client_connection(self, request, client_address):
+        h = self.handler_klass(request, client_address, self)
+        self.last_handler = h
+        if self.ssl is not None:
+            cert = self.ssl.get(
+                "cert",
+                tutils.test_data.path("data/server.crt"))
+            raw_key = self.ssl.get(
+                "key",
+                tutils.test_data.path("data/server.key"))
+            key = OpenSSL.crypto.load_privatekey(
+                OpenSSL.crypto.FILETYPE_PEM,
+                open(raw_key, "rb").read())
+            if self.ssl.get("v3_only", False):
+                method = OpenSSL.SSL.SSLv3_METHOD
+                options = OpenSSL.SSL.OP_NO_SSLv2 | OpenSSL.SSL.OP_NO_TLSv1
+            else:
+                method = OpenSSL.SSL.SSLv23_METHOD
+                options = None
+            h.convert_to_ssl(
+                cert, key,
+                method=method,
+                options=options,
+                handle_sni=getattr(h, "handle_sni", None),
+                request_client_cert=self.ssl.get("request_client_cert", None),
+                cipher_list=self.ssl.get("cipher_list", None),
+                dhparams=self.ssl.get("dhparams", None),
+                chain_file=self.ssl.get("chain_file", None),
+                alpn_select=self.ssl.get("alpn_select", None)
+            )
+        h.handle()
+        h.finish()
+
+    def handle_error(self, connection, client_address, fp=None):
+        s = StringIO()
+        tcp.TCPServer.handle_error(self, connection, client_address, s)
+        self.q.put(s.getvalue())
diff --git a/netlib/netlib/tutils.py b/netlib/netlib/tutils.py
new file mode 100644
index 00000000..f6ce8e0a
--- /dev/null
+++ b/netlib/netlib/tutils.py
@@ -0,0 +1,133 @@
+from io import BytesIO
+import tempfile
+import os
+import time
+import shutil
+from contextlib import contextmanager
+import six
+import sys
+
+from . import utils, tcp
+from .http import Request, Response, Headers
+
+
+def treader(bytes):
+    """
+        Construct a tcp.Read object from bytes.
+    """
+    fp = BytesIO(bytes)
+    return tcp.Reader(fp)
+
+
+@contextmanager
+def tmpdir(*args, **kwargs):
+    orig_workdir = os.getcwd()
+    temp_workdir = tempfile.mkdtemp(*args, **kwargs)
+    os.chdir(temp_workdir)
+
+    yield temp_workdir
+
+    os.chdir(orig_workdir)
+    shutil.rmtree(temp_workdir)
+
+
+def _check_exception(expected, actual, exc_tb):
+    if isinstance(expected, six.string_types):
+        if expected.lower() not in str(actual).lower():
+            six.reraise(AssertionError, AssertionError(
+                "Expected %s, but caught %s" % (
+                    repr(expected), repr(actual)
+                )
+            ), exc_tb)
+    else:
+        if not isinstance(actual, expected):
+            six.reraise(AssertionError, AssertionError(
+                "Expected %s, but caught %s %s" % (
+                    expected.__name__, actual.__class__.__name__, repr(actual)
+                )
+            ), exc_tb)
+
+
+def raises(expected_exception, obj=None, *args, **kwargs):
+    """
+        Assert that a callable raises a specified exception.
+
+        :exc An exception class or a string. If a class, assert that an
+        exception of this type is raised. If a string, assert that the string
+        occurs in the string representation of the exception, based on a
+        case-insenstivie match.
+
+        :obj A callable object.
+
+        :args Arguments to be passsed to the callable.
+
+        :kwargs Arguments to be passed to the callable.
+    """
+    if obj is None:
+        return RaisesContext(expected_exception)
+    else:
+        try:
+            ret = obj(*args, **kwargs)
+        except Exception as actual:
+            _check_exception(expected_exception, actual, sys.exc_info()[2])
+        else:
+            raise AssertionError("No exception raised. Return value: {}".format(ret))
+
+
+class RaisesContext(object):
+    def __init__(self, expected_exception):
+        self.expected_exception = expected_exception
+
+    def __enter__(self):
+        return
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if not exc_type:
+            raise AssertionError("No exception raised.")
+        else:
+            _check_exception(self.expected_exception, exc_val, exc_tb)
+        return True
+
+
+test_data = utils.Data(__name__)
+# FIXME: Temporary workaround during repo merge.
+import os
+test_data.dirname = os.path.join(test_data.dirname,"..","..","test","netlib")
+
+
+def treq(**kwargs):
+    """
+    Returns:
+        netlib.http.Request
+    """
+    default = dict(
+        first_line_format="relative",
+        method=b"GET",
+        scheme=b"http",
+        host=b"address",
+        port=22,
+        path=b"/path",
+        http_version=b"HTTP/1.1",
+        headers=Headers(header="qvalue", content_length="7"),
+        content=b"content"
+    )
+    default.update(kwargs)
+    return Request(**default)
+
+
+def tresp(**kwargs):
+    """
+    Returns:
+        netlib.http.Response
+    """
+    default = dict(
+        http_version=b"HTTP/1.1",
+        status_code=200,
+        reason=b"OK",
+        headers=Headers(header_response="svalue", content_length="7"),
+        content=b"message",
+        timestamp_start=time.time(),
+        timestamp_end=time.time(),
+    )
+    default.update(kwargs)
+    return Response(**default)
diff --git a/netlib/netlib/utils.py b/netlib/netlib/utils.py
new file mode 100644
index 00000000..f7bb5c4b
--- /dev/null
+++ b/netlib/netlib/utils.py
@@ -0,0 +1,418 @@
+from __future__ import absolute_import, print_function, division
+import os.path
+import re
+import codecs
+import unicodedata
+from abc import ABCMeta, abstractmethod
+import importlib
+import inspect
+
+import six
+
+from six.moves import urllib
+import hyperframe
+
+
+@six.add_metaclass(ABCMeta)
+class Serializable(object):
+    """
+    Abstract Base Class that defines an API to save an object's state and restore it later on.
+    """
+
+    @classmethod
+    @abstractmethod
+    def from_state(cls, state):
+        """
+        Create a new object from the given state.
+        """
+        raise NotImplementedError()
+
+    @abstractmethod
+    def get_state(self):
+        """
+        Retrieve object state.
+        """
+        raise NotImplementedError()
+
+    @abstractmethod
+    def set_state(self, state):
+        """
+        Set object state to the given state.
+        """
+        raise NotImplementedError()
+
+
+def always_bytes(unicode_or_bytes, *encode_args):
+    if isinstance(unicode_or_bytes, six.text_type):
+        return unicode_or_bytes.encode(*encode_args)
+    return unicode_or_bytes
+
+
+def always_byte_args(*encode_args):
+    """Decorator that transparently encodes all arguments passed as unicode"""
+    def decorator(fun):
+        def _fun(*args, **kwargs):
+            args = [always_bytes(arg, *encode_args) for arg in args]
+            kwargs = {k: always_bytes(v, *encode_args) for k, v in six.iteritems(kwargs)}
+            return fun(*args, **kwargs)
+        return _fun
+    return decorator
+
+
+def native(s, *encoding_opts):
+    """
+    Convert :py:class:`bytes` or :py:class:`unicode` to the native
+    :py:class:`str` type, using latin1 encoding if conversion is necessary.
+
+    https://www.python.org/dev/peps/pep-3333/#a-note-on-string-types
+    """
+    if not isinstance(s, (six.binary_type, six.text_type)):
+        raise TypeError("%r is neither bytes nor unicode" % s)
+    if six.PY3:
+        if isinstance(s, six.binary_type):
+            return s.decode(*encoding_opts)
+    else:
+        if isinstance(s, six.text_type):
+            return s.encode(*encoding_opts)
+    return s
+
+
+def isascii(bytes):
+    try:
+        bytes.decode("ascii")
+    except ValueError:
+        return False
+    return True
+
+
+def clean_bin(s, keep_spacing=True):
+    """
+        Cleans binary data to make it safe to display.
+
+        Args:
+            keep_spacing: If False, tabs and newlines will also be replaced.
+    """
+    if isinstance(s, six.text_type):
+        if keep_spacing:
+            keep = u" \n\r\t"
+        else:
+            keep = u" "
+        return u"".join(
+            ch if (unicodedata.category(ch)[0] not in "CZ" or ch in keep) else u"."
+            for ch in s
+        )
+    else:
+        if keep_spacing:
+            keep = (9, 10, 13)  # \t, \n, \r,
+        else:
+            keep = ()
+        return b"".join(
+            six.int2byte(ch) if (31 < ch < 127 or ch in keep) else b"."
+            for ch in six.iterbytes(s)
+        )
+
+
+def hexdump(s):
+    """
+        Returns:
+            A generator of (offset, hex, str) tuples
+    """
+    for i in range(0, len(s), 16):
+        offset = "{:0=10x}".format(i).encode()
+        part = s[i:i + 16]
+        x = b" ".join("{:0=2x}".format(i).encode() for i in six.iterbytes(part))
+        x = x.ljust(47)  # 16*2 + 15
+        yield (offset, x, clean_bin(part, False))
+
+
+def setbit(byte, offset, value):
+    """
+        Set a bit in a byte to 1 if value is truthy, 0 if not.
+    """
+    if value:
+        return byte | (1 << offset)
+    else:
+        return byte & ~(1 << offset)
+
+
+def getbit(byte, offset):
+    mask = 1 << offset
+    return bool(byte & mask)
+
+
+class BiDi(object):
+
+    """
+        A wee utility class for keeping bi-directional mappings, like field
+        constants in protocols. Names are attributes on the object, dict-like
+        access maps values to names:
+
+        CONST = BiDi(a=1, b=2)
+        assert CONST.a == 1
+        assert CONST.get_name(1) == "a"
+    """
+
+    def __init__(self, **kwargs):
+        self.names = kwargs
+        self.values = {}
+        for k, v in kwargs.items():
+            self.values[v] = k
+        if len(self.names) != len(self.values):
+            raise ValueError("Duplicate values not allowed.")
+
+    def __getattr__(self, k):
+        if k in self.names:
+            return self.names[k]
+        raise AttributeError("No such attribute: %s", k)
+
+    def get_name(self, n, default=None):
+        return self.values.get(n, default)
+
+
+def pretty_size(size):
+    suffixes = [
+        ("B", 2 ** 10),
+        ("kB", 2 ** 20),
+        ("MB", 2 ** 30),
+    ]
+    for suf, lim in suffixes:
+        if size >= lim:
+            continue
+        else:
+            x = round(size / float(lim / 2 ** 10), 2)
+            if x == int(x):
+                x = int(x)
+            return str(x) + suf
+
+
+class Data(object):
+
+    def __init__(self, name):
+        m = importlib.import_module(name)
+        dirname = os.path.dirname(inspect.getsourcefile(m))
+        self.dirname = os.path.abspath(dirname)
+
+    def path(self, path):
+        """
+            Returns a path to the package data housed at 'path' under this
+            module.Path can be a path to a file, or to a directory.
+
+            This function will raise ValueError if the path does not exist.
+        """
+        fullpath = os.path.join(self.dirname, path)
+        if not os.path.exists(fullpath):
+            raise ValueError("dataPath: %s does not exist." % fullpath)
+        return fullpath
+
+
+_label_valid = re.compile(b"(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
+
+
+def is_valid_host(host):
+    """
+    Checks if a hostname is valid.
+
+    Args:
+      host (bytes): The hostname
+    """
+    try:
+        host.decode("idna")
+    except ValueError:
+        return False
+    if len(host) > 255:
+        return False
+    if host[-1] == b".":
+        host = host[:-1]
+    return all(_label_valid.match(x) for x in host.split(b"."))
+
+
+def is_valid_port(port):
+    return 0 <= port <= 65535
+
+
+# PY2 workaround
+def decode_parse_result(result, enc):
+    if hasattr(result, "decode"):
+        return result.decode(enc)
+    else:
+        return urllib.parse.ParseResult(*[x.decode(enc) for x in result])
+
+
+# PY2 workaround
+def encode_parse_result(result, enc):
+    if hasattr(result, "encode"):
+        return result.encode(enc)
+    else:
+        return urllib.parse.ParseResult(*[x.encode(enc) for x in result])
+
+
+def parse_url(url):
+    """
+        URL-parsing function that checks that
+            - port is an integer 0-65535
+            - host is a valid IDNA-encoded hostname with no null-bytes
+            - path is valid ASCII
+
+        Args:
+            A URL (as bytes or as unicode)
+
+        Returns:
+            A (scheme, host, port, path) tuple
+
+        Raises:
+            ValueError, if the URL is not properly formatted.
+    """
+    parsed = urllib.parse.urlparse(url)
+
+    if not parsed.hostname:
+        raise ValueError("No hostname given")
+
+    if isinstance(url, six.binary_type):
+        host = parsed.hostname
+
+        # this should not raise a ValueError,
+        # but we try to be very forgiving here and accept just everything.
+        # decode_parse_result(parsed, "ascii")
+    else:
+        host = parsed.hostname.encode("idna")
+        parsed = encode_parse_result(parsed, "ascii")
+
+    port = parsed.port
+    if not port:
+        port = 443 if parsed.scheme == b"https" else 80
+
+    full_path = urllib.parse.urlunparse(
+        (b"", b"", parsed.path, parsed.params, parsed.query, parsed.fragment)
+    )
+    if not full_path.startswith(b"/"):
+        full_path = b"/" + full_path
+
+    if not is_valid_host(host):
+        raise ValueError("Invalid Host")
+    if not is_valid_port(port):
+        raise ValueError("Invalid Port")
+
+    return parsed.scheme, host, port, full_path
+
+
+def get_header_tokens(headers, key):
+    """
+        Retrieve all tokens for a header key. A number of different headers
+        follow a pattern where each header line can containe comma-separated
+        tokens, and headers can be set multiple times.
+    """
+    if key not in headers:
+        return []
+    tokens = headers[key].split(",")
+    return [token.strip() for token in tokens]
+
+
+def hostport(scheme, host, port):
+    """
+        Returns the host component, with a port specifcation if needed.
+    """
+    if (port, scheme) in [(80, "http"), (443, "https"), (80, b"http"), (443, b"https")]:
+        return host
+    else:
+        if isinstance(host, six.binary_type):
+            return b"%s:%d" % (host, port)
+        else:
+            return "%s:%d" % (host, port)
+
+
+def unparse_url(scheme, host, port, path=""):
+    """
+    Returns a URL string, constructed from the specified components.
+
+    Args:
+        All args must be str.
+    """
+    return "%s://%s%s" % (scheme, hostport(scheme, host, port), path)
+
+
+def urlencode(s):
+    """
+        Takes a list of (key, value) tuples and returns a urlencoded string.
+    """
+    s = [tuple(i) for i in s]
+    return urllib.parse.urlencode(s, False)
+
+
+def urldecode(s):
+    """
+        Takes a urlencoded string and returns a list of (key, value) tuples.
+    """
+    return urllib.parse.parse_qsl(s, keep_blank_values=True)
+
+
+def parse_content_type(c):
+    """
+        A simple parser for content-type values. Returns a (type, subtype,
+        parameters) tuple, where type and subtype are strings, and parameters
+        is a dict. If the string could not be parsed, return None.
+
+        E.g. the following string:
+
+            text/html; charset=UTF-8
+
+        Returns:
+
+            ("text", "html", {"charset": "UTF-8"})
+    """
+    parts = c.split(";", 1)
+    ts = parts[0].split("/", 1)
+    if len(ts) != 2:
+        return None
+    d = {}
+    if len(parts) == 2:
+        for i in parts[1].split(";"):
+            clause = i.split("=", 1)
+            if len(clause) == 2:
+                d[clause[0].strip()] = clause[1].strip()
+    return ts[0].lower(), ts[1].lower(), d
+
+
+def multipartdecode(headers, content):
+    """
+        Takes a multipart boundary encoded string and returns list of (key, value) tuples.
+    """
+    v = headers.get("content-type")
+    if v:
+        v = parse_content_type(v)
+        if not v:
+            return []
+        try:
+            boundary = v[2]["boundary"].encode("ascii")
+        except (KeyError, UnicodeError):
+            return []
+
+        rx = re.compile(br'\bname="([^"]+)"')
+        r = []
+
+        for i in content.split(b"--" + boundary):
+            parts = i.splitlines()
+            if len(parts) > 1 and parts[0][0:2] != b"--":
+                match = rx.search(parts[1])
+                if match:
+                    key = match.group(1)
+                    value = b"".join(parts[3 + parts[2:].index(b""):])
+                    r.append((key, value))
+        return r
+    return []
+
+
+def http2_read_raw_frame(rfile):
+    header = rfile.safe_read(9)
+    length = int(codecs.encode(header[:3], 'hex_codec'), 16)
+
+    if length == 4740180:
+        raise ValueError("Length field looks more like HTTP/1.1: %s" % rfile.peek(20))
+
+    body = rfile.safe_read(length)
+    return [header, body]
+
+def http2_read_frame(rfile):
+    header, body = http2_read_raw_frame(rfile)
+    frame, length = hyperframe.frame.Frame.parse_frame_header(header)
+    frame.parse_body(memoryview(body))
+    return frame
diff --git a/netlib/netlib/version.py b/netlib/netlib/version.py
new file mode 100644
index 00000000..bc35c30f
--- /dev/null
+++ b/netlib/netlib/version.py
@@ -0,0 +1,11 @@
+from __future__ import (absolute_import, print_function, division)
+
+IVERSION = (0, 17)
+VERSION = ".".join(str(i) for i in IVERSION)
+MINORVERSION = ".".join(str(i) for i in IVERSION[:2])
+NAME = "netlib"
+NAMEVERSION = NAME + " " + VERSION
+
+NEXT_MINORVERSION = list(IVERSION)
+NEXT_MINORVERSION[1] += 1
+NEXT_MINORVERSION = ".".join(str(i) for i in NEXT_MINORVERSION[:2])
diff --git a/netlib/netlib/version_check.py b/netlib/netlib/version_check.py
new file mode 100644
index 00000000..9cf27eea
--- /dev/null
+++ b/netlib/netlib/version_check.py
@@ -0,0 +1,60 @@
+"""
+Having installed a wrong version of pyOpenSSL or netlib is unfortunately a
+very common source of error. Check before every start that both versions
+are somewhat okay.
+"""
+from __future__ import division, absolute_import, print_function
+import sys
+import inspect
+import os.path
+import six
+
+import OpenSSL
+from . import version
+
+PYOPENSSL_MIN_VERSION = (0, 15)
+
+
+def check_mitmproxy_version(mitmproxy_version, fp=sys.stderr):
+    # We don't introduce backward-incompatible changes in patch versions. Only
+    # consider major and minor version.
+    if version.IVERSION[:2] != mitmproxy_version[:2]:
+        print(
+            u"You are using mitmproxy %s with netlib %s. "
+            u"Most likely, that won't work - please upgrade!" % (
+                mitmproxy_version, version.VERSION
+            ),
+            file=fp
+        )
+        sys.exit(1)
+
+
+def check_pyopenssl_version(min_version=PYOPENSSL_MIN_VERSION, fp=sys.stderr):
+    min_version_str = u".".join(six.text_type(x) for x in min_version)
+    try:
+        v = tuple(int(x) for x in OpenSSL.__version__.split(".")[:2])
+    except ValueError:
+        print(
+            u"Cannot parse pyOpenSSL version: {}"
+            u"mitmproxy requires pyOpenSSL {} or greater.".format(
+                OpenSSL.__version__, min_version_str
+            ),
+            file=fp
+        )
+        return
+    if v < min_version:
+        print(
+            u"You are using an outdated version of pyOpenSSL: "
+            u"mitmproxy requires pyOpenSSL {} or greater.".format(min_version_str),
+            file=fp
+        )
+        # Some users apparently have multiple versions of pyOpenSSL installed.
+        # Report which one we got.
+        pyopenssl_path = os.path.dirname(inspect.getfile(OpenSSL))
+        print(
+            u"Your pyOpenSSL {} installation is located at {}".format(
+                OpenSSL.__version__, pyopenssl_path
+            ),
+            file=fp
+        )
+        sys.exit(1)
diff --git a/netlib/netlib/websockets/__init__.py b/netlib/netlib/websockets/__init__.py
new file mode 100644
index 00000000..1c143919
--- /dev/null
+++ b/netlib/netlib/websockets/__init__.py
@@ -0,0 +1,2 @@
+from .frame import *
+from .protocol import *
diff --git a/netlib/netlib/websockets/frame.py b/netlib/netlib/websockets/frame.py
new file mode 100644
index 00000000..fce2c9d3
--- /dev/null
+++ b/netlib/netlib/websockets/frame.py
@@ -0,0 +1,316 @@
+from __future__ import absolute_import
+import os
+import struct
+import io
+import warnings
+
+import six
+
+from .protocol import Masker
+from netlib import tcp
+from netlib import utils
+
+
+MAX_16_BIT_INT = (1 << 16)
+MAX_64_BIT_INT = (1 << 64)
+
+DEFAULT=object()
+
+OPCODE = utils.BiDi(
+    CONTINUE=0x00,
+    TEXT=0x01,
+    BINARY=0x02,
+    CLOSE=0x08,
+    PING=0x09,
+    PONG=0x0a
+)
+
+
+class FrameHeader(object):
+
+    def __init__(
+        self,
+        opcode=OPCODE.TEXT,
+        payload_length=0,
+        fin=False,
+        rsv1=False,
+        rsv2=False,
+        rsv3=False,
+        masking_key=DEFAULT,
+        mask=DEFAULT,
+        length_code=DEFAULT
+    ):
+        if not 0 <= opcode < 2 ** 4:
+            raise ValueError("opcode must be 0-16")
+        self.opcode = opcode
+        self.payload_length = payload_length
+        self.fin = fin
+        self.rsv1 = rsv1
+        self.rsv2 = rsv2
+        self.rsv3 = rsv3
+
+        if length_code is DEFAULT:
+            self.length_code = self._make_length_code(self.payload_length)
+        else:
+            self.length_code = length_code
+
+        if mask is DEFAULT and masking_key is DEFAULT:
+            self.mask = False
+            self.masking_key = b""
+        elif mask is DEFAULT:
+            self.mask = 1
+            self.masking_key = masking_key
+        elif masking_key is DEFAULT:
+            self.mask = mask
+            self.masking_key = os.urandom(4)
+        else:
+            self.mask = mask
+            self.masking_key = masking_key
+
+        if self.masking_key and len(self.masking_key) != 4:
+            raise ValueError("Masking key must be 4 bytes.")
+
+    @classmethod
+    def _make_length_code(self, length):
+        """
+         A websockets frame contains an initial length_code, and an optional
+         extended length code to represent the actual length if length code is
+         larger than 125
+        """
+        if length <= 125:
+            return length
+        elif length >= 126 and length <= 65535:
+            return 126
+        else:
+            return 127
+
+    def __repr__(self):
+        vals = [
+            "ws frame:",
+            OPCODE.get_name(self.opcode, hex(self.opcode)).lower()
+        ]
+        flags = []
+        for i in ["fin", "rsv1", "rsv2", "rsv3", "mask"]:
+            if getattr(self, i):
+                flags.append(i)
+        if flags:
+            vals.extend([":", "|".join(flags)])
+        if self.masking_key:
+            vals.append(":key=%s" % repr(self.masking_key))
+        if self.payload_length:
+            vals.append(" %s" % utils.pretty_size(self.payload_length))
+        return "".join(vals)
+
+    def human_readable(self):
+        warnings.warn("FrameHeader.to_bytes is deprecated, use bytes(frame_header) instead.", DeprecationWarning)
+        return repr(self)
+
+    def __bytes__(self):
+        first_byte = utils.setbit(0, 7, self.fin)
+        first_byte = utils.setbit(first_byte, 6, self.rsv1)
+        first_byte = utils.setbit(first_byte, 5, self.rsv2)
+        first_byte = utils.setbit(first_byte, 4, self.rsv3)
+        first_byte = first_byte | self.opcode
+
+        second_byte = utils.setbit(self.length_code, 7, self.mask)
+
+        b = six.int2byte(first_byte) + six.int2byte(second_byte)
+
+        if self.payload_length < 126:
+            pass
+        elif self.payload_length < MAX_16_BIT_INT:
+            # '!H' pack as 16 bit unsigned short
+            # add 2 byte extended payload length
+            b += struct.pack('!H', self.payload_length)
+        elif self.payload_length < MAX_64_BIT_INT:
+            # '!Q' = pack as 64 bit unsigned long long
+            # add 8 bytes extended payload length
+            b += struct.pack('!Q', self.payload_length)
+        if self.masking_key:
+            b += self.masking_key
+        return b
+
+    if six.PY2:
+        __str__ = __bytes__
+
+    def to_bytes(self):
+        warnings.warn("FrameHeader.to_bytes is deprecated, use bytes(frame_header) instead.", DeprecationWarning)
+        return bytes(self)
+
+    @classmethod
+    def from_file(cls, fp):
+        """
+          read a websockets frame header
+        """
+        first_byte = six.byte2int(fp.safe_read(1))
+        second_byte = six.byte2int(fp.safe_read(1))
+
+        fin = utils.getbit(first_byte, 7)
+        rsv1 = utils.getbit(first_byte, 6)
+        rsv2 = utils.getbit(first_byte, 5)
+        rsv3 = utils.getbit(first_byte, 4)
+        # grab right-most 4 bits
+        opcode = first_byte & 15
+        mask_bit = utils.getbit(second_byte, 7)
+        # grab the next 7 bits
+        length_code = second_byte & 127
+
+        # payload_lengthy > 125 indicates you need to read more bytes
+        # to get the actual payload length
+        if length_code <= 125:
+            payload_length = length_code
+        elif length_code == 126:
+            payload_length, = struct.unpack("!H", fp.safe_read(2))
+        elif length_code == 127:
+            payload_length, = struct.unpack("!Q", fp.safe_read(8))
+
+        # masking key only present if mask bit set
+        if mask_bit == 1:
+            masking_key = fp.safe_read(4)
+        else:
+            masking_key = None
+
+        return cls(
+            fin=fin,
+            rsv1=rsv1,
+            rsv2=rsv2,
+            rsv3=rsv3,
+            opcode=opcode,
+            mask=mask_bit,
+            length_code=length_code,
+            payload_length=payload_length,
+            masking_key=masking_key,
+        )
+
+    def __eq__(self, other):
+        if isinstance(other, FrameHeader):
+            return bytes(self) == bytes(other)
+        return False
+
+
+class Frame(object):
+
+    """
+        Represents one websockets frame.
+        Constructor takes human readable forms of the frame components
+        from_bytes() is also avaliable.
+
+        WebSockets Frame as defined in RFC6455
+
+          0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+         +-+-+-+-+-------+-+-------------+-------------------------------+
+         |F|R|R|R| opcode|M| Payload len |    Extended payload length    |
+         |I|S|S|S|  (4)  |A|     (7)     |             (16/64)           |
+         |N|V|V|V|       |S|             |   (if payload len==126/127)   |
+         | |1|2|3|       |K|             |                               |
+         +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
+         |     Extended payload length continued, if payload len == 127  |
+         + - - - - - - - - - - - - - - - +-------------------------------+
+         |                               |Masking-key, if MASK set to 1  |
+         +-------------------------------+-------------------------------+
+         | Masking-key (continued)       |          Payload Data         |
+         +-------------------------------- - - - - - - - - - - - - - - - +
+         :                     Payload Data continued ...                :
+         + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
+         |                     Payload Data continued ...                |
+         +---------------------------------------------------------------+
+    """
+
+    def __init__(self, payload=b"", **kwargs):
+        self.payload = payload
+        kwargs["payload_length"] = kwargs.get("payload_length", len(payload))
+        self.header = FrameHeader(**kwargs)
+
+    @classmethod
+    def default(cls, message, from_client=False):
+        """
+          Construct a basic websocket frame from some default values.
+          Creates a non-fragmented text frame.
+        """
+        if from_client:
+            mask_bit = 1
+            masking_key = os.urandom(4)
+        else:
+            mask_bit = 0
+            masking_key = None
+
+        return cls(
+            message,
+            fin=1,  # final frame
+            opcode=OPCODE.TEXT,  # text
+            mask=mask_bit,
+            masking_key=masking_key,
+        )
+
+    @classmethod
+    def from_bytes(cls, bytestring):
+        """
+          Construct a websocket frame from an in-memory bytestring
+          to construct a frame from a stream of bytes, use from_file() directly
+        """
+        return cls.from_file(tcp.Reader(io.BytesIO(bytestring)))
+
+    def __repr__(self):
+        ret = repr(self.header)
+        if self.payload:
+            ret = ret + "\nPayload:\n" + utils.clean_bin(self.payload).decode("ascii")
+        return ret
+
+    def human_readable(self):
+        warnings.warn("Frame.to_bytes is deprecated, use bytes(frame) instead.", DeprecationWarning)
+        return repr(self)
+
+    def __bytes__(self):
+        """
+            Serialize the frame to wire format. Returns a string.
+        """
+        b = bytes(self.header)
+        if self.header.masking_key:
+            b += Masker(self.header.masking_key)(self.payload)
+        else:
+            b += self.payload
+        return b
+
+    if six.PY2:
+        __str__ = __bytes__
+
+    def to_bytes(self):
+        warnings.warn("FrameHeader.to_bytes is deprecated, use bytes(frame_header) instead.", DeprecationWarning)
+        return bytes(self)
+
+    def to_file(self, writer):
+        warnings.warn("Frame.to_file is deprecated, use wfile.write(bytes(frame)) instead.", DeprecationWarning)
+        writer.write(bytes(self))
+        writer.flush()
+
+    @classmethod
+    def from_file(cls, fp):
+        """
+          read a websockets frame sent by a server or client
+
+          fp is a "file like" object that could be backed by a network
+          stream or a disk or an in memory stream reader
+        """
+        header = FrameHeader.from_file(fp)
+        payload = fp.safe_read(header.payload_length)
+
+        if header.mask == 1 and header.masking_key:
+            payload = Masker(header.masking_key)(payload)
+
+        return cls(
+            payload,
+            fin=header.fin,
+            opcode=header.opcode,
+            mask=header.mask,
+            payload_length=header.payload_length,
+            masking_key=header.masking_key,
+            rsv1=header.rsv1,
+            rsv2=header.rsv2,
+            rsv3=header.rsv3,
+            length_code=header.length_code
+        )
+
+    def __eq__(self, other):
+        if isinstance(other, Frame):
+            return bytes(self) == bytes(other)
+        return False
diff --git a/netlib/netlib/websockets/protocol.py b/netlib/netlib/websockets/protocol.py
new file mode 100644
index 00000000..1e95fa1c
--- /dev/null
+++ b/netlib/netlib/websockets/protocol.py
@@ -0,0 +1,115 @@
+
+
+
+# Colleciton of utility functions that implement small portions of the RFC6455
+# WebSockets Protocol Useful for building WebSocket clients and servers.
+#
+# Emphassis is on readabilty, simplicity and modularity, not performance or
+# completeness
+#
+# This is a work in progress and does not yet contain all the utilites need to
+# create fully complient client/servers #
+# Spec: https://tools.ietf.org/html/rfc6455
+
+# The magic sha that websocket servers must know to prove they understand
+# RFC6455
+from __future__ import absolute_import
+import base64
+import hashlib
+import os
+
+import binascii
+import six
+from ..http import Headers
+
+websockets_magic = b'258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
+VERSION = "13"
+
+
+class Masker(object):
+
+    """
+        Data sent from the server must be masked to prevent malicious clients
+        from sending data over the wire in predictable patterns
+
+        Servers do not have to mask data they send to the client.
+        https://tools.ietf.org/html/rfc6455#section-5.3
+    """
+
+    def __init__(self, key):
+        self.key = key
+        self.offset = 0
+
+    def mask(self, offset, data):
+        result = bytearray(data)
+        if six.PY2:
+            for i in range(len(data)):
+                result[i] ^= ord(self.key[offset % 4])
+                offset += 1
+            result = str(result)
+        else:
+
+            for i in range(len(data)):
+                result[i] ^= self.key[offset % 4]
+                offset += 1
+            result = bytes(result)
+        return result
+
+    def __call__(self, data):
+        ret = self.mask(self.offset, data)
+        self.offset += len(ret)
+        return ret
+
+
+class WebsocketsProtocol(object):
+
+    def __init__(self):
+        pass
+
+    @classmethod
+    def client_handshake_headers(self, key=None, version=VERSION):
+        """
+            Create the headers for a valid HTTP upgrade request. If Key is not
+            specified, it is generated, and can be found in sec-websocket-key in
+            the returned header set.
+
+            Returns an instance of Headers
+        """
+        if not key:
+            key = base64.b64encode(os.urandom(16)).decode('ascii')
+        return Headers(
+            sec_websocket_key=key,
+            sec_websocket_version=version,
+            connection="Upgrade",
+            upgrade="websocket",
+        )
+
+    @classmethod
+    def server_handshake_headers(self, key):
+        """
+          The server response is a valid HTTP 101 response.
+        """
+        return Headers(
+            sec_websocket_accept=self.create_server_nonce(key),
+            connection="Upgrade",
+            upgrade="websocket"
+        )
+
+
+    @classmethod
+    def check_client_handshake(self, headers):
+        if headers.get("upgrade") != "websocket":
+            return
+        return headers.get("sec-websocket-key")
+
+
+    @classmethod
+    def check_server_handshake(self, headers):
+        if headers.get("upgrade") != "websocket":
+            return
+        return headers.get("sec-websocket-accept")
+
+
+    @classmethod
+    def create_server_nonce(self, client_nonce):
+        return base64.b64encode(hashlib.sha1(client_nonce + websockets_magic).digest())
diff --git a/netlib/netlib/wsgi.py b/netlib/netlib/wsgi.py
new file mode 100644
index 00000000..d6dfae5d
--- /dev/null
+++ b/netlib/netlib/wsgi.py
@@ -0,0 +1,164 @@
+from __future__ import (absolute_import, print_function, division)
+from io import BytesIO, StringIO
+import urllib
+import time
+import traceback
+
+import six
+from six.moves import urllib
+
+from netlib.utils import always_bytes, native
+from . import http, tcp
+
+class ClientConn(object):
+
+    def __init__(self, address):
+        self.address = tcp.Address.wrap(address)
+
+
+class Flow(object):
+
+    def __init__(self, address, request):
+        self.client_conn = ClientConn(address)
+        self.request = request
+
+
+class Request(object):
+
+    def __init__(self, scheme, method, path, http_version, headers, content):
+        self.scheme, self.method, self.path = scheme, method, path
+        self.headers, self.content = headers, content
+        self.http_version = http_version
+
+
+def date_time_string():
+    """Return the current date and time formatted for a message header."""
+    WEEKS = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
+    MONTHS = [
+        None,
+        'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
+        'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'
+    ]
+    now = time.time()
+    year, month, day, hh, mm, ss, wd, y_, z_ = time.gmtime(now)
+    s = "%s, %02d %3s %4d %02d:%02d:%02d GMT" % (
+        WEEKS[wd],
+        day, MONTHS[month], year,
+        hh, mm, ss
+    )
+    return s
+
+
+class WSGIAdaptor(object):
+
+    def __init__(self, app, domain, port, sversion):
+        self.app, self.domain, self.port, self.sversion = app, domain, port, sversion
+
+    def make_environ(self, flow, errsoc, **extra):
+        path = native(flow.request.path, "latin-1")
+        if '?' in path:
+            path_info, query = native(path, "latin-1").split('?', 1)
+        else:
+            path_info = path
+            query = ''
+        environ = {
+            'wsgi.version': (1, 0),
+            'wsgi.url_scheme': native(flow.request.scheme, "latin-1"),
+            'wsgi.input': BytesIO(flow.request.content or b""),
+            'wsgi.errors': errsoc,
+            'wsgi.multithread': True,
+            'wsgi.multiprocess': False,
+            'wsgi.run_once': False,
+            'SERVER_SOFTWARE': self.sversion,
+            'REQUEST_METHOD': native(flow.request.method, "latin-1"),
+            'SCRIPT_NAME': '',
+            'PATH_INFO': urllib.parse.unquote(path_info),
+            'QUERY_STRING': query,
+            'CONTENT_TYPE': native(flow.request.headers.get('Content-Type', ''), "latin-1"),
+            'CONTENT_LENGTH': native(flow.request.headers.get('Content-Length', ''), "latin-1"),
+            'SERVER_NAME': self.domain,
+            'SERVER_PORT': str(self.port),
+            'SERVER_PROTOCOL': native(flow.request.http_version, "latin-1"),
+        }
+        environ.update(extra)
+        if flow.client_conn.address:
+            environ["REMOTE_ADDR"] = native(flow.client_conn.address.host, "latin-1")
+            environ["REMOTE_PORT"] = flow.client_conn.address.port
+
+        for key, value in flow.request.headers.items():
+            key = 'HTTP_' + native(key, "latin-1").upper().replace('-', '_')
+            if key not in ('HTTP_CONTENT_TYPE', 'HTTP_CONTENT_LENGTH'):
+                environ[key] = value
+        return environ
+
+    def error_page(self, soc, headers_sent, s):
+        """
+            Make a best-effort attempt to write an error page. If headers are
+            already sent, we just bung the error into the page.
+        """
+        c = """
+            <html>
+                <h1>Internal Server Error</h1>
+                <pre>{err}"</pre>
+            </html>
+        """.format(err=s).strip().encode()
+
+        if not headers_sent:
+            soc.write(b"HTTP/1.1 500 Internal Server Error\r\n")
+            soc.write(b"Content-Type: text/html\r\n")
+            soc.write("Content-Length: {length}\r\n".format(length=len(c)).encode())
+            soc.write(b"\r\n")
+        soc.write(c)
+
+    def serve(self, request, soc, **env):
+        state = dict(
+            response_started=False,
+            headers_sent=False,
+            status=None,
+            headers=None
+        )
+
+        def write(data):
+            if not state["headers_sent"]:
+                soc.write("HTTP/1.1 {status}\r\n".format(status=state["status"]).encode())
+                headers = state["headers"]
+                if 'server' not in headers:
+                    headers["Server"] = self.sversion
+                if 'date' not in headers:
+                    headers["Date"] = date_time_string()
+                soc.write(bytes(headers))
+                soc.write(b"\r\n")
+                state["headers_sent"] = True
+            if data:
+                soc.write(data)
+            soc.flush()
+
+        def start_response(status, headers, exc_info=None):
+            if exc_info:
+                if state["headers_sent"]:
+                    six.reraise(*exc_info)
+            elif state["status"]:
+                raise AssertionError('Response already started')
+            state["status"] = status
+            state["headers"] = http.Headers([[always_bytes(k), always_bytes(v)] for k,v in headers])
+            if exc_info:
+                self.error_page(soc, state["headers_sent"], traceback.format_tb(exc_info[2]))
+                state["headers_sent"] = True
+
+        errs = six.BytesIO()
+        try:
+            dataiter = self.app(
+                self.make_environ(request, errs, **env), start_response
+            )
+            for i in dataiter:
+                write(i)
+            if not state["headers_sent"]:
+                write(b"")
+        except Exception as e:
+            try:
+                s = traceback.format_exc()
+                errs.write(s.encode("utf-8", "replace"))
+                self.error_page(soc, state["headers_sent"], s)
+            except Exception:    # pragma: no cover
+                pass
+        return errs.getvalue()
diff --git a/netlib/setup.cfg b/netlib/setup.cfg
new file mode 100644
index 00000000..3480374b
--- /dev/null
+++ b/netlib/setup.cfg
@@ -0,0 +1,2 @@
+[bdist_wheel]
+universal=1
\ No newline at end of file
diff --git a/netlib/setup.py b/netlib/setup.py
new file mode 100644
index 00000000..bcaecad4
--- /dev/null
+++ b/netlib/setup.py
@@ -0,0 +1,72 @@
+from setuptools import setup, find_packages
+from codecs import open
+import os
+import sys
+
+from netlib import version
+
+# Based on https://github.com/pypa/sampleproject/blob/master/setup.py
+# and https://python-packaging-user-guide.readthedocs.org/
+# and https://caremad.io/2014/11/distributing-a-cffi-project/
+
+here = os.path.abspath(os.path.dirname(__file__))
+
+with open(os.path.join(here, 'README.rst'), encoding='utf-8') as f:
+    long_description = f.read()
+
+setup(
+    name="netlib",
+    version=version.VERSION,
+    description="A collection of network utilities used by pathod and mitmproxy.",
+    long_description=long_description,
+    url="http://github.com/mitmproxy/netlib",
+    author="Aldo Cortesi",
+    author_email="aldo@corte.si",
+    license="MIT",
+    classifiers=[
+        "License :: OSI Approved :: MIT License",
+        "Development Status :: 3 - Alpha",
+        "Operating System :: POSIX",
+        "Programming Language :: Python",
+        "Programming Language :: Python :: 2",
+        "Programming Language :: Python :: 2.7",
+        "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.5",
+        "Programming Language :: Python :: Implementation :: CPython",
+        "Programming Language :: Python :: Implementation :: PyPy",
+        "Topic :: Internet",
+        "Topic :: Internet :: WWW/HTTP",
+        "Topic :: Internet :: WWW/HTTP :: HTTP Servers",
+        "Topic :: Software Development :: Testing",
+        "Topic :: Software Development :: Testing :: Traffic Generation",
+    ],
+    packages=find_packages(exclude=["test", "test.*"]),
+    include_package_data=True,
+    zip_safe=False,
+    install_requires=[
+        "pyasn1>=0.1.9, <0.2",
+        "pyOpenSSL>=0.15.1, <0.16",
+        "cryptography>=1.2.2, <1.3",
+        "passlib>=1.6.5, <1.7",
+        "hpack>=2.1.0, <3.0",
+        "hyperframe>=3.2.0, <4.0",
+        "six>=1.10.0, <1.11",
+        "certifi>=2015.11.20.1",  # no semver here - this should always be on the last release!
+        "backports.ssl_match_hostname>=3.5.0.1, <3.6",
+    ],
+    extras_require={
+        # Do not use a range operator here: https://bitbucket.org/pypa/setuptools/issues/380
+        # Ubuntu Trusty and other still ship with setuptools < 17.1
+        ':python_version == "2.7"': [
+            "ipaddress>=1.0.15, <1.1",
+        ],
+        'dev': [
+            "mock>=1.3.0, <1.4",
+            "pytest>=2.8.7, <2.9",
+            "pytest-xdist>=1.14, <1.15",
+            "pytest-cov>=2.2.1, <2.3",
+            "pytest-timeout>=1.0.0, <1.1",
+            "coveralls>=1.1, <1.2"
+        ]
+    },
+)