md5crypt.py
author Julien Cristau <julien.cristau@logilab.fr>
Thu, 10 Dec 2015 16:58:45 +0100
changeset 10997 da712d3f0601
parent 10775 4b3c1069bd4e
permissions -rw-r--r--
Bring back the separate web-side entity cache Prior to changeset 635cfac73d28 "[repoapi] fold ClientConnection into Connection", we had two entity caches: one on the client/dbapi/web side, and one on the server/repo side. This is a waste, but it is actually needed as long as we have the magic _cw attribute on entities which must sometimes be a request and sometimes a cnx. Removing the duplication caused weird problems with entity._cw alternating between both types of objects, which is unexpected by both the repo and the web sides. We add an entity cache on ConnectionCubicWebRequestBase, separate from the Connection's, and bring back the _cw_update_attr_cache/dont-cache-attrs mechanism, to let the server/edition code let caches know which attributes have been modified Entity.as_rset can be cached again, as ResultSet no longer modifies the entity when fetching it from a cache. Contrary to the pre-3.21 code, _cw_update_attr_cache now handles web requests and connections in the same way (otherwise the cache ends up with wrong values if a hook modifies attributes), but dont-cache-attrs is never set for (inlined) relations. Closes #6863543

# 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