md5crypt.py
author Denis Laxalde <denis.laxalde@logilab.fr>
Wed, 25 Mar 2015 14:20:56 +0100
changeset 10837 b71511460a4f
parent 10775 4b3c1069bd4e
permissions -rw-r--r--
[devtools/testlib] Remove assertions about direct usage of CubicWebTC/AutomaticWebTest The point is to be able to use a test runner other than pytest (e.g. nose2, nosetests or py.test) to run CubicWeb test suite. The issue is that most other test loaders inspects members of all base classes of test case classes to determine test methods and it hits this `config` property (actually executing it), which breaks the assertion. So just return None instead of failing. Closes #7817147.

# md5crypt.py
#
# 0423.2000 by michal wallace http://www.sabren.com/
# based on perl's Crypt::PasswdMD5 by Luis Munoz (lem@cantv.net)
# based on /usr/src/libcrypt/crypt.c from FreeBSD 2.2.5-RELEASE
#
# MANY THANKS TO
#
#  Carey Evans - http://home.clear.net.nz/pages/c.evans/
#  Dennis Marti - http://users.starpower.net/marti1/
#
#  For the patches that got this thing working!
#
# modification by logilab:
# * remove usage of the string module
# * don't include the magic string in the output string
#   for true crypt.crypt compatibility
# * use hashlib module instead of md5
#########################################################
"""md5crypt.py - Provides interoperable MD5-based crypt() function

SYNOPSIS

        import md5crypt.py

        cryptedpassword = md5crypt.md5crypt(password, salt);

DESCRIPTION

unix_md5_crypt() provides a crypt()-compatible interface to the
rather new MD5-based crypt() function found in modern operating systems.
It's based on the implementation found on FreeBSD 2.2.[56]-RELEASE and
contains the following license in it:

 "THE BEER-WARE LICENSE" (Revision 42):
 <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
 can do whatever you want with this stuff. If we meet some day, and you think
 this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
"""

MAGIC = b'$1$'                        # Magic string
ITOA64 = b"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"

from hashlib import md5 # pylint: disable=E0611

from six import text_type, indexbytes
from six.moves import range


def to64 (v, n):
    ret = bytearray()
    while (n - 1 >= 0):
        n = n - 1
        ret.append(ITOA64[v & 0x3f])
        v = v >> 6
    return ret

def crypt(pw, salt):
    if isinstance(pw, text_type):
        pw = pw.encode('utf-8')
    if isinstance(salt, text_type):
        salt = salt.encode('ascii')
    # Take care of the magic string if present
    if salt.startswith(MAGIC):
        salt = salt[len(MAGIC):]
    # salt can have up to 8 characters:
    salt = salt.split(b'$', 1)[0]
    salt = salt[:8]
    ctx = pw + MAGIC + salt
    final = md5(pw + salt + pw).digest()
    for pl in range(len(pw), 0, -16):
        if pl > 16:
            ctx = ctx + final[:16]
        else:
            ctx = ctx + final[:pl]
    # Now the 'weird' xform (??)
    i = len(pw)
    while i:
        if i & 1:
            ctx = ctx + b'\0'  #if ($i & 1) { $ctx->add(pack("C", 0)); }
        else:
            ctx = ctx + pw[0]
        i = i >> 1
    final = md5(ctx).digest()
    # The following is supposed to make
    # things run slower.
    # my question: WTF???
    for i in range(1000):
        ctx1 = b''
        if i & 1:
            ctx1 = ctx1 + pw
        else:
            ctx1 = ctx1 + final[:16]
        if i % 3:
            ctx1 = ctx1 + salt
        if i % 7:
            ctx1 = ctx1 + pw
        if i & 1:
            ctx1 = ctx1 + final[:16]
        else:
            ctx1 = ctx1 + pw
        final = md5(ctx1).digest()
    # Final xform
    passwd = b''
    passwd += to64((indexbytes(final, 0) << 16)
                   |(indexbytes(final, 6) << 8)
                   |(indexbytes(final, 12)),4)
    passwd += to64((indexbytes(final, 1) << 16)
                   |(indexbytes(final, 7) << 8)
                   |(indexbytes(final, 13)), 4)
    passwd += to64((indexbytes(final, 2) << 16)
                   |(indexbytes(final, 8) << 8)
                   |(indexbytes(final, 14)), 4)
    passwd += to64((indexbytes(final, 3) << 16)
                   |(indexbytes(final, 9) << 8)
                   |(indexbytes(final, 15)), 4)
    passwd += to64((indexbytes(final, 4) << 16)
                   |(indexbytes(final, 10) << 8)
                   |(indexbytes(final, 5)), 4)
    passwd += to64((indexbytes(final, 11)), 2)
    return passwd