wolfcrypt-py/wolfcrypt/hashes.py

394 lines
13 KiB
Python

# hashes.py
#
# Copyright (C) 2006-2022 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
# pylint: disable=no-member,no-name-in-module, no-self-use
from wolfcrypt._ffi import ffi as _ffi
from wolfcrypt._ffi import lib as _lib
from wolfcrypt.utils import t2b, b2h
from wolfcrypt.exceptions import WolfCryptError
class _Hash(object):
"""
A **PEP 247: Cryptographic Hash Functions** compliant
**Hash Function Interface**.
"""
def __init__(self, string=None):
self._native_object = _ffi.new(self._native_type)
ret = self._init()
if ret < 0: # pragma: no cover
raise WolfCryptError("Hash init error (%d)" % ret)
if string:
self.update(string)
@classmethod
def new(cls, string=None):
"""
Creates a new hashing object and returns it. The optional
**string** parameter, if supplied, will be immediately
hashed into the object's starting state, as if
obj.update(string) was called.
"""
return cls(string)
def copy(self):
"""
Returns a separate copy of this hashing object. An update
to this copy won't affect the original object.
"""
copy = self.new("")
_ffi.memmove(copy._native_object, # pylint: disable=protected-access
self._native_object,
self._native_size)
return copy
def update(self, string):
"""
Hashes **string** into the current state of the hashing
object. update() can be called any number of times during
a hashing object's lifetime.
"""
string = t2b(string)
ret = self._update(string)
if ret < 0: # pragma: no cover
raise WolfCryptError("Hash update error (%d)" % ret)
def digest(self):
"""
Returns the hash value of this hashing object as a string
containing 8-bit data. The object is not altered in any
way by this function; you can continue updating the object
after calling this function.
"""
result = _ffi.new("byte[%d]" % 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: # pragma: no cover
raise WolfCryptError("Hash finalize error (%d)" % ret)
return _ffi.buffer(result, self.digest_size)[:]
def hexdigest(self):
"""
Returns the hash value of this hashing object as a string
containing hexadecimal digits. Lowercase letters are used
for the digits 'a' through 'f'. Like the .digest() method,
this method doesn't alter the object.
"""
return b2h(self.digest())
if _lib.SHA_ENABLED:
class Sha(_Hash):
"""
**SHA-1** is a cryptographic hash function standardized by **NIST**.
It produces an [ **160-bit | 20 bytes** ] message digest.
"""
digest_size = 20
_native_type = "wc_Sha *"
_native_size = _ffi.sizeof("wc_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)
if _lib.SHA256_ENABLED:
class Sha256(_Hash):
"""
**SHA-256** is a cryptographic hash function from the
**SHA-2 family** and is standardized by **NIST**.
It produces a [ **256-bit | 32 bytes** ] message digest.
"""
digest_size = 32
_native_type = "wc_Sha256 *"
_native_size = _ffi.sizeof("wc_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)
if _lib.SHA384_ENABLED:
class Sha384(_Hash):
"""
**SHA-384** is a cryptographic hash function from the
**SHA-2 family** and is standardized by **NIST**.
It produces a [ **384-bit | 48 bytes** ] message digest.
"""
digest_size = 48
_native_type = "wc_Sha384 *"
_native_size = _ffi.sizeof("wc_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)
if _lib.SHA512_ENABLED:
class Sha512(_Hash):
"""
**SHA-512** is a cryptographic hash function from the
**SHA-2 family** and is standardized by **NIST**.
It produces a [ **512-bit | 64 bytes** ] message digest.
"""
digest_size = 64
_native_type = "wc_Sha512 *"
_native_size = _ffi.sizeof("wc_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)
if _lib.SHA3_ENABLED:
class Sha3(_Hash):
"""
**SHA3 ** is a cryptographic hash function family
standardized by **NIST**.
It produces from [ **224-bit | 28 bytes** ] up to [ **512-bit | 64 bytes] message digests.
Using SHA3-384 by default, unless a different digest size is passed through __init__.
"""
_native_type = "wc_Sha3 *"
_native_size = _ffi.sizeof("wc_Sha3")
SHA3_224_DIGEST_SIZE = 28
SHA3_256_DIGEST_SIZE = 32
SHA3_384_DIGEST_SIZE = 48
SHA3_512_DIGEST_SIZE = 64
def __init__(self): # pylint: disable=W0231
self._native_object = _ffi.new(self._native_type)
self.digest_size = SHA3_384_DIGEST_SIZE
ret = self._init()
if ret < 0: # pragma: no cover
raise WolfCryptError("Sha3 init error (%d)" % ret)
def __init__(self, string, size=SHA3_384_DIGEST_SIZE): # pylint: disable=W0231
self._native_object = _ffi.new(self._native_type)
self.digest_size = size
ret = self._init()
if ret < 0: # pragma: no cover
raise WolfCryptError("Sha3 init error (%d)" % ret)
if string:
self.update(string)
def _init(self):
if (self.digest_size != Sha3.SHA3_224_DIGEST_SIZE and
self.digest_size != Sha3.SHA3_256_DIGEST_SIZE and
self.digest_size != Sha3.SHA3_384_DIGEST_SIZE and
self.digest_size != Sha3.SHA3_512_DIGEST_SIZE):
return -1
if self.digest_size == Sha3.SHA3_224_DIGEST_SIZE:
return _lib.wc_InitSha3_224(self._native_object, _ffi.NULL, 0)
if self.digest_size == Sha3.SHA3_256_DIGEST_SIZE:
return _lib.wc_InitSha3_256(self._native_object, _ffi.NULL, 0)
if self.digest_size == Sha3.SHA3_384_DIGEST_SIZE:
return _lib.wc_InitSha3_384(self._native_object, _ffi.NULL, 0)
if self.digest_size == Sha3.SHA3_512_DIGEST_SIZE:
return _lib.wc_InitSha3_512(self._native_object, _ffi.NULL, 0)
def _update(self, data):
if self.digest_size == Sha3.SHA3_224_DIGEST_SIZE:
return _lib.wc_Sha3_224_Update(self._native_object, data, len(data))
if self.digest_size == Sha3.SHA3_256_DIGEST_SIZE:
return _lib.wc_Sha3_256_Update(self._native_object, data, len(data))
if self.digest_size == Sha3.SHA3_384_DIGEST_SIZE:
return _lib.wc_Sha3_384_Update(self._native_object, data, len(data))
if self.digest_size == Sha3.SHA3_512_DIGEST_SIZE:
return _lib.wc_Sha3_512_Update(self._native_object, data, len(data))
def _final(self, obj, ret):
if self.digest_size == Sha3.SHA3_224_DIGEST_SIZE:
return _lib.wc_Sha3_224_Final(obj, ret)
if self.digest_size == Sha3.SHA3_256_DIGEST_SIZE:
return _lib.wc_Sha3_256_Final(obj, ret)
if self.digest_size == Sha3.SHA3_384_DIGEST_SIZE:
return _lib.wc_Sha3_384_Final(obj, ret)
if self.digest_size == Sha3.SHA3_512_DIGEST_SIZE:
return _lib.wc_Sha3_512_Final(obj, ret)
# Hmac types
if _lib.FIPS_ENABLED and _lib.FIPS_VERSION <= 2:
_TYPE_SHA = 1
_TYPE_SHA256 = 2
_TYPE_SHA384 = 5
_TYPE_SHA512 = 4
else:
_TYPE_SHA = 4
_TYPE_SHA256 = 6
_TYPE_SHA384 = 7
_TYPE_SHA512 = 8
_HMAC_TYPES = [_TYPE_SHA, _TYPE_SHA256, _TYPE_SHA384, _TYPE_SHA512]
if _lib.HMAC_ENABLED:
class _Hmac(_Hash):
"""
A **PEP 247: Cryptographic Hash Functions** compliant
**Keyed Hash Function Interface**.
"""
digest_size = None
_native_type = "Hmac *"
_native_size = _ffi.sizeof("Hmac")
def __init__(self, key, string=None): # pylint: disable=W0231
key = t2b(key)
self._native_object = _ffi.new(self._native_type)
ret = self._init(self._type, key)
if ret < 0: # pragma: no cover
raise WolfCryptError("Hmac init error (%d)" % ret)
if string:
self.update(string)
@classmethod
def new(cls, key, string=None): # pylint: disable=W0221
"""
Creates a new hashing object and returns it. **key** is
a required parameter containing a string giving the key
to use. The optional **string** parameter, if supplied,
will be immediately hashed into the object's starting
state, as if obj.update(string) was called.
"""
return cls(key, string)
def _init(self, hmac, key):
if _lib.wc_HmacInit(self._native_object, _ffi.NULL, -2) != 0:
raise WolfCryptError("wc_HmacInit error")
# If the key isn't set, don't call wc_HmacSetKey. This can happen,
# for example, when the HMAC object is being copied. See the copy
# function of _Hash.
ret = 0
if len(key) > 0:
ret = _lib.wc_HmacSetKey(self._native_object, hmac, key, len(key))
if ret < 0:
err_str = "no error description found"
try:
err_str = _ffi.string(_lib.wc_GetErrorString(ret)).decode()
except:
pass
raise WolfCryptError("wc_HmacSetKey returned {}: {}".format(ret, err_str))
return ret
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)
if _lib.SHA_ENABLED:
class HmacSha(_Hmac):
"""
A HMAC function using **SHA-1** as it's cryptographic
hash function.
It produces a [ **512-bit | 64 bytes** ] message digest.
"""
_type = _TYPE_SHA
digest_size = Sha.digest_size
if _lib.SHA256_ENABLED:
class HmacSha256(_Hmac):
"""
A HMAC function using **SHA-256** as it's cryptographic
hash function.
It produces a [ **512-bit | 64 bytes** ] message digest.
"""
_type = _TYPE_SHA256
digest_size = Sha256.digest_size
if _lib.SHA384_ENABLED:
class HmacSha384(_Hmac):
"""
A HMAC function using **SHA-384** as it's cryptographic
hash function.
It produces a [ **512-bit | 64 bytes** ] message digest.
"""
_type = _TYPE_SHA384
digest_size = Sha384.digest_size
if _lib.SHA512_ENABLED:
class HmacSha512(_Hmac):
"""
A HMAC function using **SHA-512** as it's cryptographic
hash function.
It produces a [ **512-bit | 64 bytes** ] message digest.
"""
_type = _TYPE_SHA512
digest_size = Sha512.digest_size
def hash_type_to_cls(hash_type):
if _lib.SHA_ENABLED and hash_type == _lib.WC_HASH_TYPE_SHA:
hash_cls = Sha
elif _lib.SHA256_ENABLED and hash_type == _lib.WC_HASH_TYPE_SHA256:
hash_cls = Sha256
elif _lib.SHA384_ENABLED and hash_type == _lib.WC_HASH_TYPE_SHA384:
hash_cls = Sha384
elif _lib.SHA512_ENABLED and hash_type == _lib.WC_HASH_TYPE_SHA512:
hash_cls = Sha512
else:
hash_cls = None
return hash_cls