md5crypt.py
author Alexandre Fayolle <alexandre.fayolle@logilab.fr>
Fri, 15 Apr 2011 15:42:17 +0200
changeset 7237 9f619715665b
parent 5771 c077df1d0333
child 7879 9aae456abab5
permissions -rw-r--r--
[server] improve the speed of setting relations between entities (closes #1625257) The main idea is to add methods equivalent to session.add_relation and repository.glob_add_relation which handle several relations in one call. Speed gain results from: * using cursor.executemany to run SQL statements * factorizing some code which otherwise has to be performed for each relation, such as context manager creation before calling hooks or to enable security, creation of the EditedEntity instance (when several inlined relations are set on a single entity, and consequently when refreshing the cached entity) benchmark runs 1.1x faster for non inlined entities and 125x faster for inlined entities :-)

# 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"

import hashlib as md5

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, magic=None):
    if isinstance(pw, unicode):
        pw = pw.encode('utf-8')
    if magic is None:
        magic = MAGIC
    # Take care of the magic string if present
    if salt[:len(magic)] == magic:
        salt = salt[len(magic):]
    # salt can have up to 8 characters:
    salt = salt.split('$', 1)[0]
    salt = salt[:8]
    ctx = pw + magic + salt
    final = md5.md5(pw + salt + pw).digest()
    for pl in xrange(len(pw), 0, -16):
        if pl > 16:
            ctx = ctx + final[:16]
        else:
            ctx = ctx + final[:pl]
    # Now the 'weird' xform (??)
    i = len(pw)
    while i:
        if i & 1:
            ctx = ctx + chr(0)  #if ($i & 1) { $ctx->add(pack("C", 0)); }
        else:
            ctx = ctx + pw[0]
        i = i >> 1
    final = md5.md5(ctx).digest()
    # The following is supposed to make
    # things run slower.
    # my question: WTF???
    for i in xrange(1000):
        ctx1 = ''
        if i & 1:
            ctx1 = ctx1 + pw
        else:
            ctx1 = ctx1 + final[:16]
        if i % 3:
            ctx1 = ctx1 + salt
        if i % 7:
            ctx1 = ctx1 + pw
        if i & 1:
            ctx1 = ctx1 + final[:16]
        else:
            ctx1 = ctx1 + pw
        final = md5.md5(ctx1).digest()
    # Final xform
    passwd = ''
    passwd = passwd + to64((int(ord(final[0])) << 16)
                           |(int(ord(final[6])) << 8)
                           |(int(ord(final[12]))),4)
    passwd = passwd + to64((int(ord(final[1])) << 16)
                           |(int(ord(final[7])) << 8)
                           |(int(ord(final[13]))), 4)
    passwd = passwd + to64((int(ord(final[2])) << 16)
                           |(int(ord(final[8])) << 8)
                           |(int(ord(final[14]))), 4)
    passwd = passwd + to64((int(ord(final[3])) << 16)
                           |(int(ord(final[9])) << 8)
                           |(int(ord(final[15]))), 4)
    passwd = passwd + to64((int(ord(final[4])) << 16)
                           |(int(ord(final[10])) << 8)
                           |(int(ord(final[5]))), 4)
    passwd = passwd + to64((int(ord(final[11]))), 2)
    return salt + '$' + passwd