utils.des now py3 compat; fixed some other utils as well

2 files changed, 37 insertions, 17 deletions

diff --git a/passlib/utils/__init__.py b/passlib/utils/__init__.py
index fa37035..bebf7a8 100644
--- a/passlib/utils/__init__.py
+++ b/passlib/utils/__init__.py
@@ -372,13 +372,20 @@ bord = ord
 # end Py2k #
 
 def bchrs(*values):
-    "takes series of ints, returns bytes"
+    "takes series of ints, returns bytes; like chr() but for bytes, and w/ multi args"
     # Py2k #
     return bjoin(chr(v) for v in values)
     # Py3k #
     #return bytes(values)
     # end Py3k #
 
+# Py2k #
+def bjoin_ints(values):
+    return bjoin(chr(v) for v in values)
+# Py3k #
+#bjoin_ints = bytes
+# end Py3k #
+
 #=================================================================================
 #numeric helpers
 #=================================================================================
@@ -422,21 +429,25 @@ def bytes_to_int(value):
     "decode string of bytes as single big-endian integer"
     out = 0
     for v in value:
-        out = (out<<8) | ord(v)
+        out = (out<<8) | bord(v)
     return out
 
 def int_to_bytes(value, count):
     "encodes integer into single big-endian byte string"
     assert value < (1<<(8*count)), "value too large for %d bytes: %d" % (count, value)
-    return ''.join(
-        chr((value>>s) & 0xff)
+    return bjoin_ints(
+        ((value>>s) & 0xff)
         for s in xrange(8*count-8,-8,-8)
     )
 
-_join = "".join
 def xor_bytes(left, right):
     "perform bitwise-xor of two byte-strings"
-    return _join(chr(ord(l) ^ ord(r)) for l, r in zip(left, right))
+    #NOTE: this could use bjoin_ints(), but speed is *really* important here (c.f. PBKDF2)
+    # Py2k #
+    return bjoin(chr(ord(l) ^ ord(r)) for l, r in zip(left, right))
+    # Py3k #
+    #return bytes(l ^ r for l, r in zip(left, right))
+    # end Py3k #
 
 #=================================================================================
 #alt base64 encoding
diff --git a/passlib/utils/des.py b/passlib/utils/des.py
index 279c638..88b591d 100644
--- a/passlib/utils/des.py
+++ b/passlib/utils/des.py
@@ -43,7 +43,7 @@ which has some nice notes on how this all works -
 #imports
 #=========================================================
 #pkg
-from passlib.utils import bytes_to_int, int_to_bytes
+from passlib.utils import bytes_to_int, int_to_bytes, bytes, bord, bjoin_ints
 #local
 __all__ = [
     "expand_des_key",
@@ -571,45 +571,54 @@ def permute(c, p):
 #=========================================================
 #des frontend
 #=========================================================
-def expand_des_key(source):
+def expand_des_key(key):
     "convert 7 byte des key to 8 byte des key (by adding parity bit every 7 bits)"
+    if not isinstance(key, bytes):
+        raise TypeError("key must be bytes, not %s" % (type(key),))
+    
     #NOTE: could probably do this much more cleverly and efficiently,
     # but no need really given it's use.
 
     #NOTE: the parity bits are generally ignored, including by des_encrypt_block below
-    assert len(source) == 7
+    assert len(key) == 7
 
     def iter_bits(source):
         for c in source:
-            v = ord(c)
+            v = bord(c)
             for i in xrange(7,-1,-1):
                 yield (v>>i) & 1
 
     out = 0
     p = 1
-    for i, b in enumerate(iter_bits(source)):
+    for i, b in enumerate(iter_bits(key)):
         out = (out<<1) + b
         p ^= b
         if i % 7 == 6:
             out = (out<<1) + p
             p = 1
 
-    return ''.join(
-        chr((out>>s) & 0xFF)
+    return bjoin_ints(
+        ((out>>s) & 0xFF)
         for s in xrange(8*7,-8,-8)
     )
 
 def des_encrypt_block(key, input):
     """do traditional encryption of a single DES block
 
-    :arg key: 8 byte des key string
-    :arg input: 8 byte plaintext string
-    :returns: 8 byte ciphertext string
+    :arg key: 8 byte des key 
+    :arg input: 8 byte plaintext
+    :returns: 8 byte ciphertext
+    
+    all values must be :class:`bytes`
     """
-    assert len(input) == 8
+    if not isinstance(key, bytes):
+        raise TypeError("key must be bytes, not %s" % (type(key),))
     if len(key) == 7:
         key = expand_des_key(key)
     assert len(key) == 8
+    if not isinstance(input, bytes):
+        raise TypeError("input must be bytes, not %s" % (type(input),))
+    assert len(input) == 8
     input = bytes_to_int(input)
     key = bytes_to_int(key)
     out = mdes_encrypt_int_block(key, input, 0, 1)