diff options
Diffstat (limited to 'Lib/hashlib.py')
| -rw-r--r-- | Lib/hashlib.py | 81 |
1 files changed, 43 insertions, 38 deletions
diff --git a/Lib/hashlib.py b/Lib/hashlib.py index 34ed195cd06..0d7e3250d5b 100644 --- a/Lib/hashlib.py +++ b/Lib/hashlib.py @@ -1,6 +1,4 @@ -# $Id$ -# -# Copyright (C) 2005-2007 Gregory P. Smith (greg@krypto.org) +# Copyright (C) 2005-2010 Gregory P. Smith (greg@krypto.org) # Licensed to PSF under a Contributor Agreement. # @@ -15,8 +13,9 @@ than using new(name): md5(), sha1(), sha224(), sha256(), sha384(), and sha512() -More algorithms may be available on your platform but the above are -guaranteed to exist. +More algorithms may be available on your platform but the above are guaranteed +to exist. See the algorithms_guaranteed and algorithms_available attributes +to find out what algorithm names can be passed to new(). NOTE: If you want the adler32 or crc32 hash functions they are available in the zlib module. @@ -53,6 +52,16 @@ More condensed: """ +# This tuple and __get_builtin_constructor() must be modified if a new +# always available algorithm is added. +__always_supported = ('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512') + +algorithms_guaranteed = set(__always_supported) +algorithms_available = set(__always_supported) + +__all__ = __always_supported + ('new', 'algorithms_guaranteed', + 'algorithms_available') + def __get_builtin_constructor(name): if name in ('SHA1', 'sha1'): @@ -76,7 +85,19 @@ def __get_builtin_constructor(name): elif bs == '384': return _sha512.sha384 - raise ValueError("unsupported hash type") + raise ValueError('unsupported hash type %s' % name) + + +def __get_openssl_constructor(name): + try: + f = getattr(_hashlib, 'openssl_' + name) + # Allow the C module to raise ValueError. The function will be + # defined but the hash not actually available thanks to OpenSSL. + f() + # Use the C function directly (very fast) + return f + except (AttributeError, ValueError): + return __get_builtin_constructor(name) def __py_new(name, data=b''): @@ -102,39 +123,23 @@ def __hash_new(name, data=b''): try: import _hashlib - # use the wrapper of the C implementation new = __hash_new - - for opensslFuncName in filter(lambda n: n.startswith('openssl_'), dir(_hashlib)): - funcName = opensslFuncName[len('openssl_'):] - try: - # try them all, some may not work due to the OpenSSL - # version not supporting that algorithm. - f = getattr(_hashlib, opensslFuncName) - f() - # Use the C function directly (very fast) - exec(funcName + ' = f') - except ValueError: - try: - # Use the builtin implementation directly (fast) - exec(funcName + ' = __get_builtin_constructor(funcName)') - except ValueError: - # this one has no builtin implementation, don't define it - pass - # clean up our locals - del f - del opensslFuncName - del funcName - + __get_hash = __get_openssl_constructor + algorithms_available = algorithms_available.union( + _hashlib.openssl_md_meth_names) except ImportError: - # We don't have the _hashlib OpenSSL module? - # use the built in legacy interfaces via a wrapper function new = __py_new + __get_hash = __get_builtin_constructor + +for __func_name in __always_supported: + # try them all, some may not work due to the OpenSSL + # version not supporting that algorithm. + try: + globals()[__func_name] = __get_hash(__func_name) + except ValueError: + import logging + logging.exception('code for hash %s was not found.', __func_name) - # lookup the C function to use directly for the named constructors - md5 = __get_builtin_constructor('md5') - sha1 = __get_builtin_constructor('sha1') - sha224 = __get_builtin_constructor('sha224') - sha256 = __get_builtin_constructor('sha256') - sha384 = __get_builtin_constructor('sha384') - sha512 = __get_builtin_constructor('sha512') +# Cleanup locals() +del __always_supported, __func_name, __get_hash +del __py_new, __hash_new, __get_openssl_constructor |