md5crypt.py
changeset 0 b97547f5f1fa
child 1132 96752791c2b6
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/md5crypt.py	Wed Nov 05 15:52:50 2008 +0100
@@ -0,0 +1,116 @@
+#########################################################
+# 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
+#########################################################
+"""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 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 magic==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('$', 1)[0]
+    salt = salt[:8]
+    ctx = pw + magic + salt
+    final = md5.md5(pw + salt + pw).digest()
+    for pl in range(len(pw),0,-16):
+        if pl > 16:
+            ctx = ctx + final[:16]
+        else:
+            ctx = ctx + final[:pl]
+    # Now the 'weird' xform (??)
+    i = len(pw)
+    while i:
+        if i & 1:
+            ctx = ctx + chr(0)  #if ($i & 1) { $ctx->add(pack("C", 0)); }
+        else:
+            ctx = ctx + pw[0]
+        i = i >> 1
+    final = md5.md5(ctx).digest()
+    # The following is supposed to make
+    # things run slower. 
+    # my question: WTF???
+    for i in range(1000):
+        ctx1 = ''
+        if i & 1:
+            ctx1 = ctx1 + pw
+        else:
+            ctx1 = ctx1 + final[:16]
+        if i % 3:
+            ctx1 = ctx1 + salt
+        if i % 7:
+            ctx1 = ctx1 + pw
+        if i & 1:
+            ctx1 = ctx1 + final[:16]
+        else:
+            ctx1 = ctx1 + pw
+        final = md5.md5(ctx1).digest()
+    # Final xform
+    passwd = ''
+    passwd = passwd + to64((int(ord(final[0])) << 16)
+                           |(int(ord(final[6])) << 8)
+                           |(int(ord(final[12]))),4)
+    passwd = passwd + to64((int(ord(final[1])) << 16)
+                           |(int(ord(final[7])) << 8)
+                           |(int(ord(final[13]))), 4)
+    passwd = passwd + to64((int(ord(final[2])) << 16)
+                           |(int(ord(final[8])) << 8)
+                           |(int(ord(final[14]))), 4)
+    passwd = passwd + to64((int(ord(final[3])) << 16)
+                           |(int(ord(final[9])) << 8)
+                           |(int(ord(final[15]))), 4)
+    passwd = passwd + to64((int(ord(final[4])) << 16)
+                           |(int(ord(final[10])) << 8)
+                           |(int(ord(final[5]))), 4)
+    passwd = passwd + to64((int(ord(final[11]))), 2)
+    return salt + '$' + passwd