--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cubicweb/md5crypt.py	Sat Jan 16 13:48:51 2016 +0100
@@ -0,0 +1,121 @@
+# 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