hashlib

# Copyright (c) 2006 Seo Sanghyeon# 2006-01-26 sanxiyn Created as md5.py# 2006-03-25 sanxiyn Copied md5.py as sha.py# 2006-10-11 sanxiyn Reorganized to follow hashlib API#                    Added digest_size# 2006-11-11 sanxiyn Accept array as well as string# 2008-04-28 sandra  Fixed to work with Silverlight 2.0b1from System.Security import Cryptographyfrom System import Array, Bytedef to_bytes(string):    return Array[Byte](map(ord, string))def to_string(bytes):     return ''.join(map(chr, bytes))empty = Array[Byte]([])import arrayclass PythonHash:    def __init__(self, context):        self.context = context        self.digest_size = context.HashSize / 8                self.is_digested = False # Silverlight 2.0b1    def update(self, string):        if not self.is_digested:                        if isinstance(string, array.array):                string = string.array            if isinstance(string, str):                bytes = to_bytes(string)            elif isinstance(string, Array[Byte]):                bytes = string            elif isinstance(string, Array):                bytes = Array[Byte](list(string))            else:                raise TypeError("argument must be string or array")            self.context.TransformBlock(bytes, 0, len(bytes), bytes, 0)        else:            raise NotImplementedError(                'Cannot call update() after digest() in this version of the .NET framework')    def digest(self):        try:            context = self.context.MemberwiseClone()        except:            context = self.context                    if not self.is_digested:            context.TransformFinalBlock(empty, 0, 0)            self.is_digested = context is self.context        return to_string(context.Hash)    def hexdigest(self):            return ''.join(['%02x' % ord(c) for c in self.digest()])    def copy(self):        try:            context = self.context.MemberwiseClone()        except:            raise NotImplementedError(                'copy() is not implemented for this version of the .NET framework')                return PythonHash(context)# As of Mono 1.1.17.1, HashAlgorithm.Create doesn't accept lowercased# algorithm names unlike .NET. Mono bug #79641.def new(name, string=''):    hash = None    if hasattr(HashAlgorithm, 'Create'):        name = name.upper()        context = Cryptography.HashAlgorithm.Create(name)        if context:            hash = PythonHash(context)    else: # Silverlight 2.0b1        name = name.lower()        try:            hash = globals()[name.lower()]        except KeyError:            pass       if hash is None:        raise ValueError('unsupported hash type')        if string and isinstance(hash, PythonHash):        hash.update(string)    return hashdef make_new(name):    algorithm = getattr(Cryptography, name)    if hasattr(algorithm, 'Create'):        factory = algorithm.Create    else: # Silverlight 2.0b1        factory = getattr(Cryptography, name + 'Managed')            def new(string=''):        hash = PythonHash(factory())        if string:            hash.update(string)        return hash    return newfor algo in ('MD5', 'SHA1', 'SHA224', 'SHA256', 'SHA384', 'SHA512'):    if hasattr(Cryptography, algo):        hash = make_new(algo)    else:        def not_available(string=''):            raise NotImplementedError(               ".NET Framework doesn't provide %s hash algorithm" % algo)                 hash = not_available            globals()[algo.lower()] = hashtry:    import clr    clr.AddReference('Mono.Security')except:    passelse:    # Use Mono's SHA224 implementation when available    from Mono.Security.Cryptography import SHA224    sha224 = make_new(SHA224)