Merge pull request #83 from rouli/master

Adding some basic proxy authentication code

1 files changed, 95 insertions, 0 deletions

diff --git a/libmproxy/authentication.py b/libmproxy/authentication.py
new file mode 100644
index 00000000..e5383f5a
--- /dev/null
+++ b/libmproxy/authentication.py
@@ -0,0 +1,95 @@
+import binascii
+import contrib.md5crypt as md5crypt
+
+class NullProxyAuth():
+    """ No proxy auth at all (returns empty challange headers) """
+    def __init__(self, password_manager=None):
+        self.password_manager = password_manager
+        self.username = ""
+
+    def authenticate(self, auth_value):
+        """ Tests that the specified user is allowed to use the proxy (stub) """
+        return True
+
+    def auth_challenge_headers(self):
+        """ Returns a dictionary containing the headers require to challenge the user """
+        return {}
+
+    def get_username(self):
+        return self.username
+
+
+class BasicProxyAuth(NullProxyAuth):
+
+    def __init__(self, password_manager, realm="mitmproxy"):
+        NullProxyAuth.__init__(self, password_manager)
+        self.realm = "mitmproxy"
+
+    def authenticate(self, auth_value):
+        if (not auth_value) or (not auth_value[0]):
+            return False;
+        try:
+            scheme, username, password = self.parse_authorization_header(auth_value[0])
+        except:
+            return False
+        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 {'Proxy-Authenticate':'Basic realm="%s"'%self.realm}
+
+    def parse_authorization_header(self, auth_value):
+        words = auth_value.split()
+        scheme = words[0]
+        user = binascii.a2b_base64(words[1])
+        username, password = user.split(':')
+        return scheme, username, password
+
+class PasswordManager():
+    def __init__(self):
+        pass
+
+    def test(self, username, password_token):
+        return False
+
+class PermissivePasswordManager(PasswordManager):
+
+    def __init__(self):
+        PasswordManager.__init__(self)
+
+    def test(self, username, password_token):
+        if username:
+            return True
+        return False
+
+class HtpasswdPasswordManager(PasswordManager):
+    """ Read usernames and passwords from a file created by Apache htpasswd"""
+
+    def __init__(self, filehandle):
+        PasswordManager.__init__(self)
+        entries = (line.strip().split(':') for line in filehandle)
+        valid_entries = (entry for entry in entries if len(entry)==2)
+        self.usernames = {username:token for username,token in valid_entries}
+
+
+    def test(self, username, password_token):
+        if username not in self.usernames:
+            return False
+        full_token = self.usernames[username]
+        dummy, magic, salt, hashed_password = full_token.split('$')
+        expected = md5crypt.md5crypt(password_token, salt, '$'+magic+'$')
+        return expected==full_token
+
+class SingleUserPasswordManager(PasswordManager):
+
+    def __init__(self, username, password):
+        PasswordManager.__init__(self)
+        self.username = username
+        self.password = password
+
+    def test(self, username, password_token):
+        return self.username==username and self.password==password_token