[gentoo-portage-dev] [PATCH 07/14] portage.checksum: Remove fallbacks for algorithms guaranteed since py2.7

[Michał Górny]

The MD5, SHA1 and SHA2 algorithms are guaranteed to be available in
hashlib for Python 2.7 and newer, making the fallbacks to other
implementations meaningless. Remove them to simplify the code.
---
 pym/portage/checksum.py | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/pym/portage/checksum.py b/pym/portage/checksum.py
index 82e8bec00..7812791ad 100644
--- a/pym/portage/checksum.py
+++ b/pym/portage/checksum.py
@@ -19,10 +19,10 @@ import tempfile
 # most preferred first. Please keep this in sync with logic below.
 # ================================================================
 #
-# MD5: hashlib, mhash
-# SHA1: hashlib, mhash
-# SHA256: hashlib, pycrypto, mhash
-# SHA512: hashlib, mhash
+# MD5: hashlib
+# SHA1: hashlib
+# SHA256: hashlib
+# SHA512: hashlib
 # RMD160: hashlib, pycrypto, mhash
 # WHIRLPOOL: hashlib, mhash, bundled
 # BLAKE2B (512): hashlib (3.6+), pycrypto
@@ -100,10 +100,6 @@ class _generate_hash_function(object):
 # WHIRLPOOL available.
 try:
 	import mhash, functools
-	md5hash = _generate_hash_function("MD5", functools.partial(mhash.MHASH, mhash.MHASH_MD5), origin="mhash")
-	sha1hash = _generate_hash_function("SHA1", functools.partial(mhash.MHASH, mhash.MHASH_SHA1), origin="mhash")
-	sha256hash = _generate_hash_function("SHA256", functools.partial(mhash.MHASH, mhash.MHASH_SHA256), origin="mhash")
-	sha512hash = _generate_hash_function("SHA512", functools.partial(mhash.MHASH, mhash.MHASH_SHA512), origin="mhash")
 	for local_name, hash_name in (("rmd160", "ripemd160"), ("whirlpool", "whirlpool")):
 		if hasattr(mhash, 'MHASH_%s' % local_name.upper()):
 			globals()['%shash' % local_name] = \
@@ -117,11 +113,7 @@ except ImportError:
 # Check for 'new' attributes, since they can be missing if the module
 # is broken somehow.
 try:
-	from Crypto.Hash import SHA256, RIPEMD
-	sha256hash_ = getattr(SHA256, 'new', None)
-	if sha256hash_ is not None:
-		sha256hash = _generate_hash_function("SHA256",
-			sha256hash_, origin="pycrypto")
+	from Crypto.Hash import RIPEMD
 	rmd160hash_ = getattr(RIPEMD, 'new', None)
 	if rmd160hash_ is not None:
 		rmd160hash = _generate_hash_function("RMD160",
-- 
2.12.0