99 lines
3.6 KiB
Python
99 lines
3.6 KiB
Python
# asn.py
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#
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# Copyright (C) 2006-2022 wolfSSL Inc.
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#
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# This file is part of wolfSSL. (formerly known as CyaSSL)
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#
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# wolfSSL is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# wolfSSL is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
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# pylint: disable=no-member,no-name-in-module
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from wolfcrypt._ffi import ffi as _ffi
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from wolfcrypt._ffi import lib as _lib
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from wolfcrypt.exceptions import WolfCryptError
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if _lib.SHA_ENABLED:
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from wolfcrypt.hashes import Sha
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if _lib.SHA256_ENABLED:
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from wolfcrypt.hashes import Sha256
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if _lib.SHA384_ENABLED:
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from wolfcrypt.hashes import Sha384
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if _lib.SHA512_ENABLED:
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from wolfcrypt.hashes import Sha512
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if _lib.ASN_ENABLED:
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def pem_to_der(pem, pem_type):
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der = _ffi.new("DerBuffer**")
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ret = _lib.wc_PemToDer(pem, len(pem), pem_type, der, _ffi.NULL,
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_ffi.NULL, _ffi.NULL)
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if ret != 0:
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err = "Error converting from PEM to DER. ({})".format(ret)
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raise WolfCryptError(err)
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return _ffi.buffer(der[0][0].buffer, der[0][0].length)[:]
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def der_to_pem(der, pem_type):
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pem_length = _lib.wc_DerToPemEx(der, len(der), _ffi.NULL, 0, _ffi.NULL,
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pem_type)
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if pem_length <= 0:
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err = "Error getting required PEM buffer length. ({})".format(pem_length)
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raise WolfCryptError(err)
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pem = _ffi.new("byte[%d]" % pem_length)
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pem_length = _lib.wc_DerToPemEx(der, len(der), pem, pem_length,
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_ffi.NULL, pem_type)
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if pem_length <= 0:
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err = "Error converting from DER to PEM. ({})".format(pem_length)
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raise WolfCryptError(err)
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return _ffi.buffer(pem, pem_length)[:]
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def hash_oid_from_class(hash_cls):
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if hash_cls == Sha:
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return _lib.SHAh
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elif hash_cls == Sha256:
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return _lib.SHA256h
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elif hash_cls == Sha384:
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return _lib.SHA384h
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elif hash_cls == Sha512:
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return _lib.SHA512h
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else:
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err = "Unknown hash class {}.".format(hash_cls.__name__)
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raise WolfCryptError(err)
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def make_signature(data, hash_cls, key=None):
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hash_obj = hash_cls()
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hash_obj.update(data)
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digest = hash_obj.digest()
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plaintext_sig = _ffi.new("byte[%d]" % _lib.MAX_DER_DIGEST_SZ)
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hash_oid = hash_oid_from_class(hash_cls)
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plaintext_len = _lib.wc_EncodeSignature(plaintext_sig, digest,
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len(digest), hash_oid)
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if plaintext_len == 0:
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err = "Error calling wc_EncodeSignature. ({})".format(plaintext_len)
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raise WolfCryptError(err)
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plaintext_sig = _ffi.buffer(plaintext_sig, plaintext_len)[:]
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if key:
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return key.sign(plaintext_sig)
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else:
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return plaintext_sig
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def check_signature(signature, data, hash_cls, pub_key):
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computed_signature = make_signature(data, hash_cls)
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decrypted_signature = pub_key.verify(signature)
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return computed_signature == decrypted_signature
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