work on lanman hash

3 files changed, 71 insertions, 2 deletions

diff --git a/passlib/utils/__init__.py b/passlib/utils/__init__.py
index dd17d1d..9b8a472 100644
--- a/passlib/utils/__init__.py
+++ b/passlib/utils/__init__.py
@@ -73,8 +73,29 @@ Undef = object() #singleton used as default kwd value in some functions
 #numeric helpers
 #=================================================================================
 
-#TODO: rename 'bytes' kwd for py30 compat purposes
+##def int_to_bytes(value, count=None):
+##    """encode a integer into a string of bytes"""
+##
+##def bytes_to_int(value, order="big"):
+##    """decode a byte string into an integer representation of it's binary value.
+##
+##    :arg value: the string to decode.
+##    :param order: the byte ordering; "big" (the default), "little", or "native"
+##
+##    :returns: the decoded positive integer.
+##    """
+##    if not value:
+##        return 0
+##    if order == "native":
+##        order = sys.byteorder
+##    if order == "little":
+##        value = reversed(value)
+##    out = 0
+##    for v in value:
+##        out = (out<<8) | ord(v)
+##    return out
 
+#TODO: rename 'bytes' kwd for py30 compat purposes
 def list_to_bytes(value, bytes=None, order="big"):
     """Returns a multi-character string corresponding to a list of byte values.
 
diff --git a/passlib/utils/_slow_des_crypt.py b/passlib/utils/_slow_des_crypt.py
index cc68327..9ebf518 100644
--- a/passlib/utils/_slow_des_crypt.py
+++ b/passlib/utils/_slow_des_crypt.py
@@ -620,8 +620,55 @@ def permute(c, p):
         c >>= 4
     return out
 
+def bytes_to_int(value):
+    out = 0
+    for v in value:
+        out = (out<<8) | ord(v)
+    return out
+
+def int_to_bytes(value, count):
+    return ''.join(
+        chr((value>>s) & 0xff)
+        for s in xrange(8*count-8,-8,-8)
+    )
+
+def des_encrypt_block(key, input):
+    "do traditional encryption of a single DES block"
+    assert len(input) == 8
+    assert len(key) == 8
+    input = bytes_to_int(input)
+    key = bytes_to_int(key)
+    out = des_encrypt_rounds(input, 0, 1, key)
+    return int_to_bytes(out, 8)
+
+def expand_des_key(source):
+    "convert 7 byte des key to 8 byte des key (by adding parity bit every 7 bits)"
+    #NOTE: could probably do this much more cleverly and efficiently,
+    # but no need really given it's use
+    assert len(source) == 7
+
+    def iter_bits(source):
+        for c in source:
+            v = ord(c)
+            for i in xrange(7,-1,-1):
+                yield (v>>i) & 1
+
+    out = 0
+    p = 1
+    for i, b in enumerate(iter_bits(source)):
+        out = (out<<1) + b
+        p ^= b
+        if i % 7 == 6:
+            out = (out<<1) + p
+            p = 1
+
+    return ''.join(
+        chr((out>>s) & 0xFF)
+        for s in xrange(8*7,-8,-8)
+    )
+
 def des_encrypt_rounds(input, salt, rounds, key):
-    """Returns modified DES for single block of input"""
+    """returns modified DES for single block of input, used by des-crypt algorithm"""
     global SPE, PCXROT, IE3264, CF6464
 
     #bounds check
diff --git a/passlib/utils/md4.py b/passlib/utils/md4.py
index fe88f6a..2eb2c95 100644
--- a/passlib/utils/md4.py
+++ b/passlib/utils/md4.py
@@ -27,6 +27,7 @@ class md4(object):
     "md4 hash algorithm"
     #FIXME: make this follow hash object PEP better.
     #FIXME: this isn't threadsafe
+    #XXX: should we monkeypatch ourselves into hashlib for general use? probably wouldn't be nice.
 
     digest_size = digestsize = 16