# $Id: hashlib.py 52533 2006-10-29 18:01:12Z georg.brandl $
#
#  Copyright (C) 2005   Gregory P. Smith (greg@electricrain.com)
#  Licensed to PSF under a Contributor Agreement.
#

__doc__ = """hashlib module - A common interface to many hash functions.

new(name, string='') - returns a new hash object implementing the
                       given hash function; initializing the hash
                       using the given string data.

Named constructor functions are also available, these are much faster
than using new():

md5(), sha1(), sha224(), sha256(), sha384(), and sha512()

More algorithms may be available on your platform but the above are
guaranteed to exist.

Choose your hash function wisely.  Some have known collision weaknesses.
sha384 and sha512 will be slow on 32 bit platforms.

Hash objects have these methods:
 - update(arg): Update the hash object with the string arg. Repeated calls
                are equivalent to a single call with the concatenation of all
                the arguments.
 - digest():    Return the digest of the strings passed to the update() method
                so far. This may contain non-ASCII characters, including
                NUL bytes.
 - hexdigest(): Like digest() except the digest is returned as a string of
                double length, containing only hexadecimal digits.
 - copy():      Return a copy (clone) of the hash object. This can be used to
                efficiently compute the digests of strings that share a common
                initial substring.

For example, to obtain the digest of the string 'Nobody inspects the
spammish repetition':

    >>> import hashlib
    >>> m = hashlib.md5()
    >>> m.update("Nobody inspects")
    >>> m.update(" the spammish repetition")
    >>> m.digest()
    '\xbbd\x9c\x83\xdd\x1e\xa5\xc9\xd9\xde\xc9\xa1\x8d\xf0\xff\xe9'

More condensed:

    >>> hashlib.sha224("Nobody inspects the spammish repetition").hexdigest()
    'a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2'

"""

try:
	import _sechash
	md5 = _sechash.md5
	sha1 = _sechash.sha1
	sha224 = _sechash.sha224
	sha256 = _sechash.sha256
	sha384 = _sechash.sha384
	sha512 = _sechash.sha512
except ImportError:
	import _hashlib
	md5 = _hashlib.openssl_md5
	sha1 = _hashlib.openssl_sha1
	sha224 = _hashlib.openssl_sha224
	sha256 = _hashlib.openssl_sha256
	sha384 = _hashlib.openssl_sha384
	sha512 = _hashlib.openssl_sha512

algs = dict()
for a in [md5, sha1, sha224, sha256, sha384, sha512]:
	algs[a().name.lower()] = a

def new(name, string=''):
	"""new(name, string='') - Return a new hashing object using the named algorithm;
	optionally initialized with a string.
	"""
	a = algs[name.lower()]
	if a != None:
		return a(string)
	raise ValueError, "unsupported hash type"