wolfcrypt-py/wolfcrypt/hashes.py

220 lines
4.9 KiB
Python

# hashes.py
#
# Copyright (C) 2006-2016 wolfSSL Inc.
#
# This file is part of wolfSSL. (formerly known as CyaSSL)
#
# wolfSSL is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# wolfSSL is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
from wolfcrypt._ffi import ffi as _ffi
from wolfcrypt._ffi import lib as _lib
from wolfcrypt.utils import t2b, b2h
from wolfcrypt.exceptions import *
class _Hash(object):
def __init__(self, string=None):
self._native_object = _ffi.new(self._native_type)
ret = self._init()
if ret < 0:
raise WolfCryptError("Hash init error (%d)" % ret)
@classmethod
def new(cls, string=None):
# PEP 247 -- API for Cryptographic Hash Functions
self = cls(string)
if (string):
self.update(string)
return self
def copy(self):
copy = self.new("")
_ffi.memmove(copy._native_object,
self._native_object,
self._native_size)
return copy
def update(self, string):
string = t2b(string)
ret = self._update(string)
if ret < 0:
raise WolfCryptError("Hash update error (%d)" % ret)
def digest(self):
result = t2b("\0" * self.digest_size)
if self._native_object:
obj = _ffi.new(self._native_type)
_ffi.memmove(obj, self._native_object, self._native_size)
ret = self._final(obj, result)
if ret < 0:
raise WolfCryptError("Hash finalize error (%d)" % ret)
return result
def hexdigest(self):
return b2h(self.digest())
class Sha(_Hash):
digest_size = 20
_native_type = "Sha *"
_native_size = _ffi.sizeof("Sha")
def _init(self):
return _lib.wc_InitSha(self._native_object)
def _update(self, data):
return _lib.wc_ShaUpdate(self._native_object, data, len(data))
def _final(self, obj, ret):
return _lib.wc_ShaFinal(obj, ret)
class Sha256(_Hash):
digest_size = 32
_native_type = "Sha256 *"
_native_size = _ffi.sizeof("Sha256")
def _init(self):
return _lib.wc_InitSha256(self._native_object)
def _update(self, data):
return _lib.wc_Sha256Update(self._native_object, data, len(data))
def _final(self, obj, ret):
return _lib.wc_Sha256Final(obj, ret)
class Sha384(_Hash):
digest_size = 48
_native_type = "Sha384 *"
_native_size = _ffi.sizeof("Sha384")
def _init(self):
return _lib.wc_InitSha384(self._native_object)
def _update(self, data):
return _lib.wc_Sha384Update(self._native_object, data, len(data))
def _final(self, obj, ret):
return _lib.wc_Sha384Final(obj, ret)
class Sha512(_Hash):
digest_size = 64
_native_type = "Sha512 *"
_native_size = _ffi.sizeof("Sha512")
def _init(self):
return _lib.wc_InitSha512(self._native_object)
def _update(self, data):
return _lib.wc_Sha512Update(self._native_object, data, len(data))
def _final(self, obj, ret):
return _lib.wc_Sha512Final(obj, ret)
# Hmac types
_TYPE_SHA = 1
_TYPE_SHA256 = 2
_TYPE_SHA384 = 5
_TYPE_SHA512 = 4
_HMAC_TYPES = [_TYPE_SHA, _TYPE_SHA256, _TYPE_SHA384, _TYPE_SHA512]
class _Hmac(_Hash):
digest_size = None
_native_type = "Hmac *"
_native_size = _ffi.sizeof("Hmac")
def __init__(self, key):
key = t2b(key)
self._native_object = _ffi.new(self._native_type)
ret = self._init(self._type, key)
if ret < 0:
raise WolfCryptError("Hmac init error (%d)" % ret)
@classmethod
def new(cls, key, string=None):
# PEP 247 -- API for Cryptographic Hash Functions
self = cls(key)
if (string):
self.update(string)
return self
def _init(self, type, key):
return _lib.wc_HmacSetKey(self._native_object, type, key, len(key))
def _update(self, data):
return _lib.wc_HmacUpdate(self._native_object, data, len(data))
def _final(self, obj, ret):
return _lib.wc_HmacFinal(obj, ret)
class HmacSha(_Hmac):
_type = _TYPE_SHA
digest_size = Sha.digest_size
class HmacSha256(_Hmac):
_type = _TYPE_SHA256
digest_size = Sha256.digest_size
class HmacSha384(_Hmac):
_type = _TYPE_SHA384
digest_size = Sha384.digest_size
class HmacSha512(_Hmac):
_type = _TYPE_SHA512
digest_size = Sha512.digest_size