[gentoo-portage-dev] [PATCH 3/4] Manifest2 hash backend provider: mhash

[Robin H. Johnson]

Offer mhash as a provider for Manifest2 hash generation and validation.
This is important as none of pycrypto/hashlib/fchksum offer an
accelerated Whirlpool implementaiton. Additionally, the mhash
implementation is accelerated and ships with a rigorious testsuite.

Signed-off-by: Robin H. Johnson <robbat2@g.o>
---
 pym/portage/checksum.py |   19 +++++++++++++++++--
 1 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/pym/portage/checksum.py b/pym/portage/checksum.py
index b2c9333..c3df36b 100644
--- a/pym/portage/checksum.py
+++ b/pym/portage/checksum.py
@@ -16,7 +16,7 @@ import tempfile
 hashfunc_map = {}
 hashorigin_map = {}
 
-def _generate_hash_function(hashtype, hashobject, origin="unknown"):
+def _generate_hash_function(hashtype, hashobject, origin="unknown", hashobjectargs=None):
 	def pyhash(filename):
 		"""
 		Run a checksum against a file.
@@ -41,7 +41,11 @@ def _generate_hash_function(hashtype, hashobject, origin="unknown"):
 		blocksize = HASHING_BLOCKSIZE
 		data = f.read(blocksize)
 		size = 0
-		checksum = hashobject()
+		if hashobjectargs is None:
+			checksum = hashobject()
+		else:
+			checksum = hashobject(hashobjectargs)
+
 		while data:
 			checksum.update(data)
 			size = size + len(data)
@@ -103,6 +107,17 @@ try:
 except ImportError as e:
 	pass
 	
+# Try to use mhash if available
+try:
+	import mhash
+	md5hash = _generate_hash_function("MD5", mhash.MHASH, origin="mhash", hashobjectargs=mhash.MHASH_MD5)
+	sha1hash = _generate_hash_function("SHA1", mhash.MHASH, origin="mhash", hashobjectargs=mhash.MHASH_SHA1)
+	sha256hash = _generate_hash_function("SHA256", mhash.MHASH, origin="mhash", hashobjectargs=mhash.MHASH_SHA256)
+	sha512hash = _generate_hash_function("SHA512", mhash.MHASH, origin="mhash", hashobjectargs=mhash.MHASH_SHA512)
+	rmd160hash = _generate_hash_function("RMD160", mhash.MHASH, origin="mhash", hashobjectargs=mhash.MHASH_RIPEMD160)
+	whirlpoolhash = _generate_hash_function("WHIRLPOOL", mhash.MHASH, origin="mhash", hashobjectargs=mhash.MHASH_WHIRLPOOL)
+except ImportError as e:
+	pass
 
 # Use python-fchksum if available, prefer it over all other MD5 implementations
 try:
-- 
1.7.6