Python hashlib 模块，new() 实例源码

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def jumpahead(self, n):
        """Change the internal state to one that is likely far away
        from the current state.  This method will not be in Py3.x,
        so it is better to simply reseed.
        """
        # The super.jumpahead() method uses shuffling to change state,
        # so it needs a large and "interesting" n to work with.  Here,
        # we use hashing to create a large n for the shuffle.
        s = repr(n) + repr(self.getstate())
        n = int(_hashlib.new('sha512', s).hexdigest(), 16)
        super(Random, self).jumpahead(n)

## ---- Methods below this point do not need to be overridden when
## ---- subclassing for the purpose of using a different core generator.

## -------------------- pickle support  -------------------

def __process(l, inFile, stateDir):
    if l.startswith("="):
        return bytes.fromhex(l[1:])
    elif l.startswith("<"):
        with open(l[1:], "rb") as f:
            return f.read()
    elif l.startswith("{"):
        import hashlib
        return __processBlock(hashlib.new(l[1:]), inFile, stateDir)
    elif l.startswith("#"):
        import os.path
        if stateDir:
            stateFile = os.path.join(stateDir, l[1:].replace(os.sep, "_"))
        else:
            stateFile = None
        return hashPath(l[1:], stateFile)
    elif l.startswith("g"):
        from .scm.git import GitScm
        return bytes.fromhex(GitScm.processLiveBuildIdSpec(l[1:]))
    else:
        print("Malformed spec:", l, file=sys.stderr)
        sys.exit(1)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def hashex(method,    # type: HashMethod
           key,       # type: KeyType
           **options  # type: typing.Any
           ):
    # type: (...) -> int
    if isinstance(key, six.text_type):
        key = key.encode('utf-8')
    if method.name.lower() in hashlib.algorithms_guaranteed:
        return int(hashlib.new(method.name.lower(), key).hexdigest(), 16)
    elif method == HashMethod.MMH3_32:
        return hash_murmur3(key, size=32, **options)
    elif method == HashMethod.MMH3_64:
        return hash_murmur3(key, size=64, **options)
    elif method == HashMethod.MMH3_128:
        return hash_murmur3(key, size=128, **options)
    elif method == HashMethod.SIPHASH:
        return hash_siphash(key, **options)

def encrypt(self, passwd=None, length=32):
        """
        encrypt gen password
        ???????????
        """
        if not passwd:
            passwd = self.gen_rand_pass()

        cryptor = AES.new(self.key, self.mode, b'8122ca7d906ad5e1')
        try:
            count = len(passwd)
        except TypeError:
            raise ServerError('Encrypt password error, TYpe error.')

        add = (length - (count % length))
        passwd += ('\0' * add)
        cipher_text = cryptor.encrypt(passwd)
        return b2a_hex(cipher_text)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def file_digest(self, file_path, digest_type=None):
        '''Creates a digest based on the digest_type argument.
        digest_type defaults to SHA256.'''
        valid_digests = ['md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512']
        block_size = 65536

        if not digest_type:
            digest_type = 'sha256'

        if digest_type in valid_digests:
            h = hashlib.new(digest_type)
            with open(file_path, 'rb') as f:
                for block in iter(lambda: f.read(block_size), b''):
                    h.update(block)
                return h.hexdigest()
        else:
            raise Exception('%s not a valid digest - choose from %s' %
                            (digest_type, valid_digests))

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def jumpahead(self, n):
        """Change the internal state to one that is likely far away
        from the current state.  This method will not be in Py3.x,
        so it is better to simply reseed.
        """
        # The super.jumpahead() method uses shuffling to change state,
        # so it needs a large and "interesting" n to work with.  Here,
        # we use hashing to create a large n for the shuffle.
        s = repr(n) + repr(self.getstate())
        n = int(_hashlib.new('sha512', s).hexdigest(), 16)
        super(Random, self).jumpahead(n)

## ---- Methods below this point do not need to be overridden when
## ---- subclassing for the purpose of using a different core generator.

## -------------------- pickle support  -------------------

def setUp(self):
        super(MD4_Builtin_Test, self).setUp()

        if has_native_md4():

            # Temporarily make lookup_hash() use builtin pure-python implementation,
            # by monkeypatching hashlib.new() to ensure we fall back to passlib's md4 class.
            orig = hashlib.new
            def wrapper(name, *args):
                if name == "md4":
                    raise ValueError("md4 disabled for testing")
                return orig(name, *args)
            self.patchAttr(hashlib, "new", wrapper)

            # flush cache before & after test, since we're mucking with it.
            lookup_hash.clear_cache()
            self.addCleanup(lookup_hash.clear_cache)

        # make sure we're using right constructor.
        self.assertEqual(self.get_md4_const().__module__, "passlib.crypto._md4")


#=============================================================================
# eof
#=============================================================================

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def SignECDSA(self,m):
        #Sign a message. The private key is self.d .
        h=hashlib.new("SHA256")
        h.update(m)
        z=int(h.hexdigest(),16)

        r=0
        s=0
        while not r or not s:
            #k=random.randint(1,self.n-1)
            k=random.SystemRandom().randint(1,self.n-1) # Better random fix
            R=self*k
            R.Normalize()
            r=R.x[0]%self.n
            s=(InvMod(k,self.n)*(z+r*self.d))%self.n

        return (r,s)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def leaves(self, value):

        if value is None:
            raise ValueError('Leaves should be a list.')
        elif not isinstance(value, list) and \
                not isinstance(value, types.GeneratorType):
            raise ValueError('Leaves should be a list or a generator (%s).' % type(value))

        if self.prehashed:
            # it will create a copy of list or
            # it will create a new list based on the generator
            self._leaves = list(value)
        else:
            self._leaves = [ShardManager.hash(leaf) for leaf in value]

        if not len(self._leaves) > 0:
            raise ValueError('Leaves must contain at least one entry.')

        for leaf in self._leaves:
            if not isinstance(leaf, six.string_types):
                raise ValueError('Leaves should only contain strings.')

def ComputeSessionKeyStrongKey(sharedSecret, clientChallenge, serverChallenge, sharedSecretHash = None):
    # added the ability to receive hashes already

    if sharedSecretHash is None:
        M4SS = ntlm.NTOWFv1(sharedSecret)
    else:
        M4SS = sharedSecretHash

    md5 = hashlib.new('md5')
    md5.update('\x00'*4)
    md5.update(clientChallenge)
    md5.update(serverChallenge)
    finalMD5 = md5.digest()
    hm = hmac.new(M4SS) 
    hm.update(finalMD5)
    return hm.digest()

def DecryptAttributeValue(dce, attribute):
    sessionKey = dce.get_session_key()
    # Is it a Kerberos Session Key?
    if isinstance(sessionKey, crypto.Key):
        # Extract its contents and move on
        sessionKey = sessionKey.contents

    encryptedPayload = ENCRYPTED_PAYLOAD(attribute)

    md5 = hashlib.new('md5')
    md5.update(sessionKey)
    md5.update(encryptedPayload['Salt'])
    finalMD5 = md5.digest()

    cipher = ARC4.new(finalMD5)
    plainText = cipher.decrypt(attribute[16:])

    #chkSum = (binascii.crc32(plainText[4:])) & 0xffffffff
    #if unpack('<L',plainText[:4])[0] != chkSum:
    #    print "RECEIVED 0x%x" % unpack('<L',plainText[:4])[0]
    #    print "CALCULATED 0x%x" % chkSum

    return plainText[4:]

# 5.16.4 ATTRTYP-to-OID Conversion

def __decryptSecret(self, key, value):
        # [MS-LSAD] Section 5.1.2
        plainText = ''

        encryptedSecretSize = unpack('<I', value[:4])[0]
        value = value[len(value)-encryptedSecretSize:]

        key0 = key
        for i in range(0, len(value), 8):
            cipherText = value[:8]
            tmpStrKey = key0[:7]
            tmpKey = self.__cryptoCommon.transformKey(tmpStrKey)
            Crypt1 = DES.new(tmpKey, DES.MODE_ECB)
            plainText += Crypt1.decrypt(cipherText)
            key0 = key0[7:]
            value = value[8:]
            # AdvanceKey
            if len(key0) < 7:
                key0 = key[len(key0):]

        secret = LSA_SECRET_XP(plainText)
        return secret['Secret']

def __decryptLSA(self, value):
        if self.__vistaStyle is True:
            # ToDo: There could be more than one LSA Keys
            record = LSA_SECRET(value)
            tmpKey = self.__sha256(self.__bootKey, record['EncryptedData'][:32])
            plainText = self.__cryptoCommon.decryptAES(tmpKey, record['EncryptedData'][32:])
            record = LSA_SECRET_BLOB(plainText)
            self.__LSAKey = record['Secret'][52:][:32]

        else:
            md5 = hashlib.new('md5')
            md5.update(self.__bootKey)
            for i in range(1000):
                md5.update(value[60:76])
            tmpKey = md5.digest()
            rc4 = ARC4.new(tmpKey)
            plainText = rc4.decrypt(value[12:60])
            self.__LSAKey = plainText[0x10:0x20]

def computeResponseNTLMv1(flags, serverChallenge, clientChallenge, serverName, domain, user, password, lmhash='',
                          nthash='', use_ntlmv2=USE_NTLMv2):
    if user == '' and password == '':
        # Special case for anonymous authentication
        lmResponse = ''
        ntResponse = ''
    else:
        lmhash = LMOWFv1(password, lmhash, nthash)
        nthash = NTOWFv1(password, lmhash, nthash)
        if flags & NTLMSSP_NEGOTIATE_LM_KEY:
           ntResponse = ''
           lmResponse = get_ntlmv1_response(lmhash, serverChallenge)
        elif flags & NTLMSSP_NEGOTIATE_EXTENDED_SESSIONSECURITY:
           md5 = hashlib.new('md5')
           chall = (serverChallenge + clientChallenge)
           md5.update(chall)
           ntResponse = ntlmssp_DES_encrypt(nthash, md5.digest()[:8])
           lmResponse = clientChallenge + '\x00'*16
        else:
           ntResponse = get_ntlmv1_response(nthash,serverChallenge)
           lmResponse = get_ntlmv1_response(lmhash, serverChallenge)

    sessionBaseKey = generateSessionKeyV1(password, lmhash, nthash)
    return ntResponse, lmResponse, sessionBaseKey

def SEALKEY(flags, randomSessionKey, mode = 'Client'):
   if flags & NTLMSSP_NEGOTIATE_EXTENDED_SESSIONSECURITY:
       if flags & NTLMSSP_NEGOTIATE_128:
           sealKey = randomSessionKey
       elif flags & NTLMSSP_NEGOTIATE_56:
           sealKey = randomSessionKey[:7]
       else:
           sealKey = randomSessionKey[:5]

       if mode == 'Client':
               md5 = hashlib.new('md5')
               md5.update(sealKey + 'session key to client-to-server sealing key magic constant\x00')
               sealKey = md5.digest()
       else:
               md5 = hashlib.new('md5')
               md5.update(sealKey + 'session key to server-to-client sealing key magic constant\x00')
               sealKey = md5.digest()

   elif flags & NTLMSSP_NEGOTIATE_56:
       sealKey = randomSessionKey[:7] + '\xa0'
   else:
       sealKey = randomSessionKey[:5] + '\xe5\x38\xb0'

   return sealKey

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def uuid_from_file(fn, block_size=1 << 20):
    """
    Returns an arbitrary sized unique ASCII string based on the file contents.
    (exact hashing method may change).
    """
    with open(fn, 'rb') as f:
        # first get the size
        import os
        f.seek(0, os.SEEK_END)
        size = f.tell()
        f.seek(0, os.SEEK_SET)
        del os
        # done!

        import hashlib
        sha1 = hashlib.new('sha512')
        while True:
            data = f.read(block_size)
            if not data:
                break
            sha1.update(data)
        # skip the '0x'
        return hex(size)[2:] + sha1.hexdigest()

def _uuid_from_file(fn, block_size=1 << 20):
    with open(fn, 'rb') as f:
        # first get the size
        f.seek(0, os.SEEK_END)
        size = f.tell()
        f.seek(0, os.SEEK_SET)
        # done!

        import hashlib
        sha1 = hashlib.new('sha512')
        while True:
            data = f.read(block_size)
            if not data:
                break
            sha1.update(data)
        return (hex(size)[2:] + sha1.hexdigest()).encode()

def uuid_from_file(fn, block_size=1 << 20):
    """
    Returns an arbitrary sized unique ASCII string based on the file contents.
    (exact hashing method may change).
    """
    with open(fn, 'rb') as f:
        # first get the size
        import os
        f.seek(0, os.SEEK_END)
        size = f.tell()
        f.seek(0, os.SEEK_SET)
        del os
        # done!

        import hashlib
        sha1 = hashlib.new('sha512')
        while True:
            data = f.read(block_size)
            if not data:
                break
            sha1.update(data)
        # skip the '0x'
        return hex(size)[2:] + sha1.hexdigest()

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def make_hash(self):
        ''' hash the metadata in a sane way '''
        h = hashlib.new('ripemd160')
        pre_h = str()
        post_h = None
        # nodhcp -> dhcp withname makes different hashes
        # {u'tenant': u'FLOORPLATE', u'mac': u'ac:87:a3:2b:7f:12', u'segment': u'prod', u'name': None, u'ip-address': u'10.179.0.100'}}^
        # {u'tenant': u'FLOORPLATE', u'mac': u'ac:87:a3:2b:7f:12', u'segment': u'prod', u'name': u'demo-laptop', u'ip-address': u'10.179.0.100'}}
        # ^^^ make different hashes if name is included
        # for word in ['tenant', 'mac', 'segment', 'name', 'ip-address']:

        for word in ['tenant', 'mac', 'segment', 'ip-address']:
            pre_h = pre_h + str(self.endpoint_data.get(str(word), 'missing'))
        h.update(pre_h.encode('utf-8'))
        post_h = h.hexdigest()
        return post_h

def check_against_chunks(self, chunks):
        """Check good hashes against ones built from iterable of chunks of
        data.

        Raise HashMismatch if none match.

        """
        gots = {}
        for hash_name in iterkeys(self._allowed):
            try:
                gots[hash_name] = hashlib.new(hash_name)
            except (ValueError, TypeError):
                raise InstallationError('Unknown hash name: %s' % hash_name)

        for chunk in chunks:
            for hash in itervalues(gots):
                hash.update(chunk)

        for hash_name, got in iteritems(gots):
            if got.hexdigest() in self._allowed[hash_name]:
                return
        self._raise(gots)

def rehash(path, algo='sha256', blocksize=1 << 20):
    """Return (hash, length) for path using hashlib.new(algo)"""
    h = hashlib.new(algo)
    length = 0
    with open(path, 'rb') as f:
        for block in read_chunks(f, size=blocksize):
            length += len(block)
            h.update(block)
    digest = 'sha256=' + urlsafe_b64encode(
        h.digest()
    ).decode('latin1').rstrip('=')
    return (digest, length)

def _hash_of_file(path, algorithm):
    """Return the hash digest of a file."""
    with open(path, 'rb') as archive:
        hash = hashlib.new(algorithm)
        for chunk in read_chunks(archive):
            hash.update(chunk)
    return hash.hexdigest()

def __init__(self, fd, hashtype='sha256'):
        self.fd = fd
        self.hashtype = hashtype
        self.hash = hashlib.new(hashtype)
        self.length = 0

def __init__(self, hash_name, expected):
        self.hash_name = hash_name
        self.hash = hashlib.new(hash_name)
        self.expected = expected

def new(key, msg = None, digestmod = None):
    """Create a new hashing object and return it.

    key: The starting key for the hash.
    msg: if available, will immediately be hashed into the object's starting
    state.

    You can now feed arbitrary strings into the object using its update()
    method, and can ask for the hash value at any time by calling its digest()
    method.
    """
    return HMAC(key, msg, digestmod)

def __init__(self, url, chunksize, hash_algo=None, verify=True,
                 certs=None):
        if hash_algo is not None:
            self.hasher = hashlib.new(hash_algo)
        else:
            self.hasher = None
        self.chunksize = chunksize
        resp = requests.get(url, stream=True, verify=verify, certs=certs)
        if resp.status_code != 200:
            raise Exception('Invalid response code: %s' % resp.status_code)

        self._request = resp

def rehash(path, algo='sha256', blocksize=1 << 20):
    """Return (hash, length) for path using hashlib.new(algo)"""
    h = hashlib.new(algo)
    length = 0
    with open(path, 'rb') as f:
        for block in read_chunks(f, size=blocksize):
            length += len(block)
            h.update(block)
    digest = 'sha256=' + urlsafe_b64encode(
        h.digest()
    ).decode('latin1').rstrip('=')
    return (digest, length)

def _hash_of_file(path, algorithm):
    """Return the hash digest of a file."""
    with open(path, 'rb') as archive:
        hash = hashlib.new(algorithm)
        for chunk in read_chunks(archive):
            hash.update(chunk)
    return hash.hexdigest()

def __init__(self, path, mode, hashtype='sha256'):
        self.fd = open(path, mode)
        self.hashtype = hashtype
        self.hash = hashlib.new(hashtype)
        self.length = 0

def __init__(self, hash_name, expected):
        self.hash_name = hash_name
        self.hash = hashlib.new(hash_name)
        self.expected = expected

def _randbelow(self, n, _log=_log, int=int, _maxwidth=1L<<BPF,
                   _Method=_MethodType, _BuiltinMethod=_BuiltinMethodType):
        """Return a random int in the range [0,n)

        Handles the case where n has more bits than returned
        by a single call to the underlying generator.
        """

        try:
            getrandbits = self.getrandbits
        except AttributeError:
            pass
        else:
            # Only call self.getrandbits if the original random() builtin method
            # has not been overridden or if a new getrandbits() was supplied.
            # This assures that the two methods correspond.
            if type(self.random) is _BuiltinMethod or type(getrandbits) is _Method:
                k = int(1.00001 + _log(n-1, 2.0))   # 2**k > n-1 > 2**(k-2)
                r = getrandbits(k)
                while r >= n:
                    r = getrandbits(k)
                return r
        if n >= _maxwidth:
            _warn("Underlying random() generator does not supply \n"
                "enough bits to choose from a population range this large")
        return int(self.random() * n)

## -------------------- sequence methods  -------------------

def evpKDF(passwd, salt, key_size=8, iv_size=4, iterations=1, hash_algorithm="md5"):
    target_key_size = key_size + iv_size
    derived_bytes = ""
    number_of_derived_words = 0
    block = None
    hasher = hashlib.new(hash_algorithm)
    while number_of_derived_words < target_key_size:
        if block is not None:
            hasher.update(block)

        hasher.update(passwd)
        hasher.update(salt)
        block = hasher.digest()
        hasher = hashlib.new(hash_algorithm)

        for _i in range(1, iterations):
            hasher.update(block)
            block = hasher.digest()
            hasher = hashlib.new(hash_algorithm)

        derived_bytes += block[0: min(len(block), (target_key_size - number_of_derived_words) * 4)]

        number_of_derived_words += len(block) / 4

    return {
        "key": derived_bytes[0: key_size * 4],
        "iv": derived_bytes[key_size * 4:]
    }

def _initial_hasher(self, stream, num_chunks, buffer):
        """Fill initial hash values"""
        for chunkid in range(num_chunks):
            data = stream.read(self._chunk_len)
            hasher = hashlib.new(self._hash_func)
            hasher.update(data)
            buffer[chunkid] = hasher.digest()

def create_address(pubkey):
    if is_hex(pubkey):
        pubkey = from_hex(pubkey)

    h = hashlib.new('ripemd160')
    h.update(pubkey)
    return h.digest()