md5crypt.py
author Rémi Cardona <remi.cardona@logilab.fr>
Wed, 11 Mar 2015 15:17:25 +0100
changeset 10224 996cf2c0ec99
parent 8317 9c59258e7798
child 10609 e2d8e81bfe68
permissions -rw-r--r--
[config] Lowercase the FQDN we get from the OS (closes #5040345) Browsers convert the host name part of URLs to lowercase. This has the unfortunate effect of triggering various CORS error messages in CubicWeb (because the Origin: header will contain lowercase letters). As per RFC 4343, host name comparison should be case-insensitive. So let's put it in lowercase when we grab it from the host system. If admins put uppercase letters in "host" or "base-url" in their all-in-one.conf, then it's their fault.

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

from hashlib import md5 # pylint: disable=E0611

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

def crypt(pw, salt):
    if isinstance(pw, unicode):
        pw = pw.encode('utf-8')
    # 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('$', 1)[0]
    salt = salt[:8]
    ctx = pw + MAGIC + salt
    final = md5(pw + salt + pw).digest()
    for pl in xrange(len(pw), 0, -16):
        if pl > 16:
            ctx = ctx + final[:16]
        else:
            ctx = ctx + final[:pl]
    # Now the 'weird' xform (??)
    i = len(pw)
    while i:
        if i & 1:
            ctx = ctx + chr(0)  #if ($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 xrange(1000):
        ctx1 = ''
        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 = ''
    passwd = passwd + to64((int(ord(final[0])) << 16)
                           |(int(ord(final[6])) << 8)
                           |(int(ord(final[12]))),4)
    passwd = passwd + to64((int(ord(final[1])) << 16)
                           |(int(ord(final[7])) << 8)
                           |(int(ord(final[13]))), 4)
    passwd = passwd + to64((int(ord(final[2])) << 16)
                           |(int(ord(final[8])) << 8)
                           |(int(ord(final[14]))), 4)
    passwd = passwd + to64((int(ord(final[3])) << 16)
                           |(int(ord(final[9])) << 8)
                           |(int(ord(final[15]))), 4)
    passwd = passwd + to64((int(ord(final[4])) << 16)
                           |(int(ord(final[10])) << 8)
                           |(int(ord(final[5]))), 4)
    passwd = passwd + to64((int(ord(final[11]))), 2)
    return passwd