1 files changed, 104 insertions, 0 deletions
diff --git a/libmproxy/contrib/jsbeautifier/unpackers/packer.py b/libmproxy/contrib/jsbeautifier/unpackers/packer.py
new file mode 100644
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+++ b/libmproxy/contrib/jsbeautifier/unpackers/packer.py
@@ -0,0 +1,104 @@
+#
+# Unpacker for Dean Edward's p.a.c.k.e.r, a part of javascript beautifier
+# by Einar Lielmanis <einar@jsbeautifier.org>
+#
+#     written by Stefano Sanfilippo <a.little.coder@gmail.com>
+#
+# usage:
+#
+# if detect(some_string):
+#     unpacked = unpack(some_string)
+#
+
+"""Unpacker for Dean Edward's p.a.c.k.e.r"""
+
+import re
+import string
+from jsbeautifier.unpackers import UnpackingError
+
+PRIORITY = 1
+
+def detect(source):
+    """Detects whether `source` is P.A.C.K.E.R. coded."""
+    return source.replace(' ', '').startswith('eval(function(p,a,c,k,e,r')
+
+def unpack(source):
+    """Unpacks P.A.C.K.E.R. packed js code."""
+    payload, symtab, radix, count = _filterargs(source)
+
+    if count != len(symtab):
+        raise UnpackingError('Malformed p.a.c.k.e.r. symtab.')
+
+    try:
+        unbase = Unbaser(radix)
+    except TypeError:
+        raise UnpackingError('Unknown p.a.c.k.e.r. encoding.')
+
+    def lookup(match):
+        """Look up symbols in the synthetic symtab."""
+        word  = match.group(0)
+        return symtab[unbase(word)] or word
+
+    source = re.sub(r'\b\w+\b', lookup, payload)
+    return _replacestrings(source)
+
+def _filterargs(source):
+    """Juice from a source file the four args needed by decoder."""
+    argsregex = (r"}\('(.*)', *(\d+), *(\d+), *'(.*)'\."
+                 r"split\('\|'\), *(\d+), *(.*)\)\)")
+    args = re.search(argsregex, source, re.DOTALL).groups()
+
+    try:
+        return args[0], args[3].split('|'), int(args[1]), int(args[2])
+    except ValueError:
+        raise UnpackingError('Corrupted p.a.c.k.e.r. data.')
+
+def _replacestrings(source):
+    """Strip string lookup table (list) and replace values in source."""
+    match = re.search(r'var *(_\w+)\=\["(.*?)"\];', source, re.DOTALL)
+
+    if match:
+        varname, strings = match.groups()
+        startpoint = len(match.group(0))
+        lookup = strings.split('","')
+        variable = '%s[%%d]' % varname
+        for index, value in enumerate(lookup):
+            source = source.replace(variable % index, '"%s"' % value)
+        return source[startpoint:]
+    return source
+
+
+class Unbaser(object):
+    """Functor for a given base. Will efficiently convert
+    strings to natural numbers."""
+    ALPHABET  = {
+        62 : '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
+        95 : (' !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+              '[\]^_`abcdefghijklmnopqrstuvwxyz{|}~')
+    }
+
+    def __init__(self, base):
+        self.base = base
+
+        # If base can be handled by int() builtin, let it do it for us
+        if 2 <= base <= 36:
+            self.unbase = lambda string: int(string, base)
+        else:
+            # Build conversion dictionary cache
+            try:
+                self.dictionary = dict((cipher, index) for
+                    index, cipher in enumerate(self.ALPHABET[base]))
+            except KeyError:
+                raise TypeError('Unsupported base encoding.')
+
+            self.unbase = self._dictunbaser
+
+    def __call__(self, string):
+        return self.unbase(string)
+
+    def _dictunbaser(self, string):
+        """Decodes a  value to an integer."""
+        ret = 0
+        for index, cipher in enumerate(string[::-1]):
+            ret += (self.base ** index) * self.dictionary[cipher]
+        return ret