[ sf.net patch # 1121611 ]

A new hashlib module to replace the md5 and sha modules.  It adds
support for additional secure hashes such as SHA-256 and SHA-512.  The
hashlib module uses OpenSSL for fast platform optimized
implementations of algorithms when available.  The old md5 and sha
modules still exist as wrappers around hashlib to preserve backwards
compatibility.

1 files changed, 15 insertions, 9 deletions

diff --git a/Lib/hmac.py b/Lib/hmac.py
index 11b0fb3..41d6c6c 100644
--- a/Lib/hmac.py
+++ b/Lib/hmac.py
@@ -28,27 +28,33 @@ class HMAC:
 
         key:       key for the keyed hash object.
         msg:       Initial input for the hash, if provided.
-        digestmod: A module supporting PEP 247. Defaults to the md5 module.
+        digestmod: A module supporting PEP 247.  *OR*
+                   A hashlib constructor returning a new hash object.
+                   Defaults to hashlib.md5.
         """
 
         if key is _secret_backdoor_key: # cheap
             return
 
         if digestmod is None:
-            import md5
-            digestmod = md5
+            import hashlib
+            digestmod = hashlib.md5
 
-        self.digestmod = digestmod
-        self.outer = digestmod.new()
-        self.inner = digestmod.new()
-        self.digest_size = digestmod.digest_size
+        if callable(digestmod):
+            self.digest_cons = digestmod
+        else:
+            self.digest_cons = lambda d='': digestmod.new(d)
+
+        self.outer = self.digest_cons()
+        self.inner = self.digest_cons()
+        self.digest_size = self.inner.digest_size
 
         blocksize = 64
         ipad = "\x36" * blocksize
         opad = "\x5C" * blocksize
 
         if len(key) > blocksize:
-            key = digestmod.new(key).digest()
+            key = self.digest_cons(key).digest()
 
         key = key + chr(0) * (blocksize - len(key))
         self.outer.update(_strxor(key, opad))
@@ -70,7 +76,7 @@ class HMAC:
         An update to this copy won't affect the original object.
         """
         other = HMAC(_secret_backdoor_key)
-        other.digestmod = self.digestmod
+        other.digest_cons = self.digest_cons
         other.digest_size = self.digest_size
         other.inner = self.inner.copy()
         other.outer = self.outer.copy()