ciphers.py

# ciphers.py
#
# Copyright (C) 2006-2025 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

from enum import IntEnum

from wolfcrypt._ffi import ffi as _ffi
from wolfcrypt._ffi import lib as _lib
from wolfcrypt.utils import t2b
from wolfcrypt.random import Random
from wolfcrypt.asn import pem_to_der
from wolfcrypt.hashes import hash_type_to_cls

from wolfcrypt.exceptions import WolfCryptError


# key direction flags
_ENCRYPTION = 0
_DECRYPTION = 1


# feedback modes
MODE_ECB = 1  # Electronic Code Book
MODE_CBC = 2  # Cipher Block Chaining
MODE_CFB = 3  # Cipher Feedback
MODE_OFB = 5  # Output Feedback
MODE_CTR = 6  # Counter

_FEEDBACK_MODES = [MODE_ECB, MODE_CBC, MODE_CFB, MODE_OFB, MODE_CTR]

# ECC curve id
ECC_CURVE_INVALID = -1
ECC_CURVE_DEF = 0

# NIST Prime Curves
ECC_SECP192R1 = 1
ECC_PRIME192V2 = 2
ECC_PRIME192V3 = 3
ECC_PRIME239V1 = 4
ECC_PRIME239V2 = 5
ECC_PRIME239V3 = 6
ECC_SECP256R1 = 7

# SECP Curves
ECC_SECP112R1 = 8
ECC_SECP112R2 = 9
ECC_SECP128R1 = 10
ECC_SECP128R2 = 11
ECC_SECP160R1 = 12
ECC_SECP160R2 = 13
ECC_SECP224R1 = 14
ECC_SECP384R1 = 15
ECC_SECP521R1 = 16

# Koblitz
ECC_SECP160K1 = 17
ECC_SECP192K1 = 18
ECC_SECP224K1 = 19
ECC_SECP256K1 = 20

# Brainpool Curves
ECC_BRAINPOOLP160R1 = 21
ECC_BRAINPOOLP192R1 = 22
ECC_BRAINPOOLP224R1 = 23
ECC_BRAINPOOLP256R1 = 24
ECC_BRAINPOOLP320R1 = 25
ECC_BRAINPOOLP384R1 = 26
ECC_BRAINPOOLP512R1 = 27

if _lib.RSA_ENABLED:
    MGF1NONE = _lib.WC_MGF1NONE
    MGF1SHA1 = _lib.WC_MGF1SHA1
    MGF1SHA224 = _lib.WC_MGF1SHA224
    MGF1SHA256 = _lib.WC_MGF1SHA256
    MGF1SHA384 = _lib.WC_MGF1SHA384
    MGF1SHA512 = _lib.WC_MGF1SHA512

    HASH_TYPE_NONE = _lib.WC_HASH_TYPE_NONE
    HASH_TYPE_MD2 = _lib.WC_HASH_TYPE_MD2
    HASH_TYPE_MD4 = _lib.WC_HASH_TYPE_MD4
    HASH_TYPE_MD5 = _lib.WC_HASH_TYPE_MD5
    HASH_TYPE_SHA = _lib.WC_HASH_TYPE_SHA
    HASH_TYPE_SHA224 = _lib.WC_HASH_TYPE_SHA224
    HASH_TYPE_SHA256 = _lib.WC_HASH_TYPE_SHA256
    HASH_TYPE_SHA384 = _lib.WC_HASH_TYPE_SHA384
    HASH_TYPE_SHA512 = _lib.WC_HASH_TYPE_SHA512
    HASH_TYPE_MD5_SHA = _lib.WC_HASH_TYPE_MD5_SHA
    HASH_TYPE_SHA3_224 = _lib.WC_HASH_TYPE_SHA3_224
    HASH_TYPE_SHA3_256 = _lib.WC_HASH_TYPE_SHA3_256
    HASH_TYPE_SHA3_384 = _lib.WC_HASH_TYPE_SHA3_384
    HASH_TYPE_SHA3_512 = _lib.WC_HASH_TYPE_SHA3_512
    HASH_TYPE_BLAKE2B = _lib.WC_HASH_TYPE_BLAKE2B
    HASH_TYPE_BLAKE2S = _lib.WC_HASH_TYPE_BLAKE2S



class _Cipher(object):
    """
    A **PEP 272: Block Encryption Algorithms** compliant
    **Symmetric Key Cipher**.
    """
    def __init__(self, key, mode, IV=None):
        if mode not in _FEEDBACK_MODES:
            raise ValueError("this mode is not supported")

        if mode == MODE_CBC or mode == MODE_CTR:
            if IV is None:
                raise ValueError("this mode requires an 'IV' string")
        else:
            raise ValueError("this mode is not supported by this cipher")

        self.mode = mode

        if self.key_size:
            if self.key_size != len(key):
                raise ValueError("key must be %d in length, not %d" %
                                 (self.key_size, len(key)))
        elif self._key_sizes:
            if len(key) not in self._key_sizes:
                raise ValueError("key must be %s in length, not %d" %
                                 (self._key_sizes, len(key)))
        elif not key:  # pragma: no cover
            raise ValueError("key must not be 0 in length")

        if IV is not None and len(IV) != self.block_size:
            raise ValueError("IV must be %d in length, not %d" %
                             (self.block_size, len(IV)))

        self._native_object = _ffi.new(self._native_type)
        self._enc = None
        self._dec = None
        self._key = t2b(key)

        if IV:
            self._IV = t2b(IV)
        else:  # pragma: no cover
            self._IV = _ffi.new("byte[%d]" % self.block_size)

    @classmethod
    def new(cls, key, mode, IV=None, **kwargs):  # pylint: disable=W0613
        """
        Returns a ciphering object, using the secret key contained in
        the string **key**, and using the feedback mode **mode**, which
        must be one of MODE_* defined in this module.

        If **mode** is MODE_CBC or MODE_CFB, **IV** must be provided and
        must be a string of the same length as the block size. Not
        providing a value of **IV** will result in a ValueError exception
        being raised.
        """
        return cls(key, mode, IV)

    def encrypt(self, string):
        """
        Encrypts a non-empty string, using the key-dependent data in
        the object, and with the appropriate feedback mode.

        The string's length must be an exact multiple of the algorithm's
        block size or, in CFB mode, of the segment size.

        Returns a string containing the ciphertext.
        """
        string = t2b(string)
        if not string:
            raise ValueError(
                    "empty string not allowed")

        if len(string) % self.block_size and not self.mode == MODE_CTR and not "ChaCha" in self._native_type:
            raise ValueError(
                "string must be a multiple of %d in length" % self.block_size)

        if self._enc is None:
            self._enc = _ffi.new(self._native_type)
            ret = self._set_key(_ENCRYPTION)
            if ret < 0:  # pragma: no cover
                raise WolfCryptError("Invalid key error (%d)" % ret)

        result = _ffi.new("byte[%d]" % len(string))
        ret = self._encrypt(result, string)
        if ret < 0:  # pragma: no cover
            raise WolfCryptError("Encryption error (%d)" % ret)

        return _ffi.buffer(result)[:]

    def decrypt(self, string):
        """
        Decrypts **string**, using the key-dependent data in the
        object and with the appropriate feedback mode.

        The string's length must be an exact multiple of the algorithm's
        block size or, in CFB mode, of the segment size.

        Returns a string containing the plaintext.
        """
        string = t2b(string)

        if not string:
            raise ValueError(
                    "empty string not allowed")

        if len(string) % self.block_size and not self.mode == MODE_CTR and not "ChaCha" in self._native_type:
            raise ValueError(
                "string must be a multiple of %d in length" % self.block_size)

        if self._dec is None:
            self._dec = _ffi.new(self._native_type)
            ret = self._set_key(_DECRYPTION)
            if ret < 0:  # pragma: no cover
                raise WolfCryptError("Invalid key error (%d)" % ret)

        result = _ffi.new("byte[%d]" % len(string))
        ret = self._decrypt(result, string)
        if ret < 0:  # pragma: no cover
            raise WolfCryptError("Decryption error (%d)" % ret)

        return _ffi.buffer(result)[:]


if _lib.AES_ENABLED:
    class Aes(_Cipher):
        """
        The **Advanced Encryption Standard** (AES), a.k.a. Rijndael, is
        a symmetric-key cipher standardized by **NIST**.
        """
        block_size = 16
        key_size = None  # 16, 24, 32
        _key_sizes = [16, 24, 32]
        _native_type = "Aes *"

        def _set_key(self, direction):
            if direction == _ENCRYPTION:
                return _lib.wc_AesSetKey(
                    self._enc, self._key, len(self._key), self._IV, _ENCRYPTION)
            if self.mode == MODE_CTR:
                return _lib.wc_AesSetKey(
                    self._dec, self._key, len(self._key), self._IV, _ENCRYPTION)
            return _lib.wc_AesSetKey(
                self._dec, self._key, len(self._key), self._IV, _DECRYPTION)

        def _encrypt(self, destination, source):
            if self.mode == MODE_CBC:
                return _lib.wc_AesCbcEncrypt(self._enc, destination,
                        source, len(source))
            elif self.mode == MODE_CTR:
                return _lib.wc_AesCtrEncrypt(self._enc, destination,
                        source, len(source))
            else:
                raise ValueError("Invalid mode associated to cipher")

        def _decrypt(self, destination, source):
            if self.mode == MODE_CBC:
                return _lib.wc_AesCbcDecrypt(self._dec, destination,
                        source, len(source))
            elif self.mode == MODE_CTR:
                return _lib.wc_AesCtrEncrypt(self._dec, destination,
                        source, len(source))
            else:
                raise ValueError("Invalid mode associated to cipher")

if _lib.AES_SIV_ENABLED:
    class AesSiv(object):
        """
        AES-SIV (Synthetic Initialization Vector) implementation as described in RFC 5297.
        """
        # RFC 5297 defines key sizes of 256-, 384-, or 512 bits.
        _key_sizes = [32, 48, 64]
        block_size = 16

        def __init__(self, key):
            self._key = t2b(key)
            if len(self._key) not in AesSiv._key_sizes:
                raise ValueError("key must be %s in length, not %d" %
                                 (AesSiv._key_sizes, len(self._key)))

        def encrypt(self, associated_data, nonce, plaintext):
            """
            Encrypt plaintext data using the nonce provided. The associated
            data is not encrypted but is included in the authentication tag.

            Associated data may be provided as single str or bytes, or as a
            list of str or bytes in case of multiple blocks.

            Returns a tuple of the IV and ciphertext.
            """
            # Prepare the associated data blocks. Make sure to hold on to the
            # returned references until the C function has been called in order
            # to prevent garbage collection of them until the function is done.
            associated_data, _refs = (
                AesSiv._prepare_associated_data(associated_data))
            nonce = t2b(nonce)
            plaintext = t2b(plaintext)
            siv = _ffi.new("byte[%d]" % AesSiv.block_size)
            ciphertext = _ffi.new("byte[%d]" % len(plaintext))
            ret = _lib.wc_AesSivEncrypt_ex(self._key, len(self._key),
                associated_data, len(associated_data), nonce, len(nonce),
                plaintext, len(plaintext), siv, ciphertext)
            if ret < 0:  # pragma: no cover
                raise WolfCryptError("AES-SIV encryption error (%d)" % ret)
            return _ffi.buffer(siv)[:], _ffi.buffer(ciphertext)[:]

        def decrypt(self, associated_data, nonce, siv, ciphertext):
            """
            Decrypt the ciphertext using the nonce and SIV provided.
            The integrity of the associated data is checked.

            Associated data may be provided as single str or bytes, or as a
            list of str or bytes in case of multiple blocks.

            Returns the decrypted plaintext.
            """
            # Prepare the associated data blocks. Make sure to hold on to the
            # returned references until the C function has been called in order
            # to prevent garbage collection of them until the function is done.
            associated_data, _refs = (
                AesSiv._prepare_associated_data(associated_data))
            nonce = t2b(nonce)
            siv = t2b(siv)
            if len(siv) != AesSiv.block_size:
                raise ValueError("SIV must be %s in length, not %d" %
                                 (AesSiv.block_size, len(siv)))
            ciphertext = t2b(ciphertext)
            plaintext = _ffi.new("byte[%d]" % len(ciphertext))
            ref = _lib.wc_AesSivDecrypt_ex(self._key, len(self._key),
                associated_data, len(associated_data), nonce, len(nonce),
                ciphertext, len(ciphertext), siv, plaintext)
            if ref < 0:
                raise WolfCryptError("AES-SIV decryption error (%d)" % ref)
            return _ffi.buffer(plaintext)[:]

        @staticmethod
        def _prepare_associated_data(associated_data):
            """
            Prepare associated data for sending to C library.

            Associated data may be provided as single str or bytes, or as a
            list of str or bytes in case of multiple blocks.

            The result is a tuple of the list of cffi cdata pointers to
            AesSivAssoc structures, as well as the converted associated
            data blocks. The caller **must** hold on to these until the
            C function has been called, in order to make sure that the memory
            is not freed by the FFI garbage collector before the data is read.
            """
            if (isinstance(associated_data, str) or isinstance(associated_data, bytes)):
                # A single block is provided.
                # Make sure we have bytes.
                associated_data = t2b(associated_data)
                result = _ffi.new("AesSivAssoc[1]")
                result[0].assoc = _ffi.from_buffer(associated_data)
                result[0].assocSz = len(associated_data)
            else:
                # It is assumed that a list is provided.
                num_blocks = len(associated_data)
                if (num_blocks > 126):
                    raise WolfCryptError("AES-SIV does not support more than 126 blocks "
                                         "of associated data, got: %d" % num_blocks)
                # Make sure we have bytes.
                associated_data = [t2b(block) for block in associated_data]
                result = _ffi.new("AesSivAssoc[]", num_blocks)
                for index, block in enumerate(associated_data):
                    result[index].assoc = _ffi.from_buffer(block)
                    result[index].assocSz = len(block)
            # Return the converted associated data blocks so the caller can
            # hold on to them until the function has been called.
            return result, associated_data


if _lib.AESGCM_STREAM_ENABLED:
    class AesGcmStream(object):
        """
        AES GCM Stream
        """
        block_size = 16
        _key_sizes = [16, 24, 32]
        _native_type = "Aes *"
        _aad = bytes()
        _tag_bytes = 16
        _mode = None

        def __init__(self, key, IV, tag_bytes=16):
            """
            tag_bytes is the number of bytes to use for the authentication tag during encryption
            """
            key = t2b(key)
            IV = t2b(IV)
            self._tag_bytes = tag_bytes
            if len(key) not in self._key_sizes:
                raise ValueError("key must be %s in length, not %d" %
                                 (self._key_sizes, len(key)))
            self._native_object = _ffi.new(self._native_type)
            _lib.wc_AesInit(self._native_object, _ffi.NULL, -2)
            ret = _lib.wc_AesGcmInit(self._native_object, key, len(key), IV, len(IV))
            if ret < 0:
                raise WolfCryptError("Init error (%d)" % ret)

        def set_aad(self, data):
            """
            Set the additional authentication data for the stream
            """
            if self._mode is not None:
                raise WolfCryptError("AAD can only be set before encrypt() or decrypt() is called")
            self._aad = t2b(data)

        def get_aad(self):
            return self._aad

        def encrypt(self, data):
            """
            Add more data to the encryption stream
            """
            data = t2b(data)
            aad = bytes()
            if self._mode is None:
                self._mode = _ENCRYPTION
                aad = self._aad
            elif self._mode == _DECRYPTION:
                raise WolfCryptError("Class instance already in use for decryption")
            self._buf = _ffi.new("byte[%d]" % (len(data)))
            ret = _lib.wc_AesGcmEncryptUpdate(self._native_object, self._buf, data, len(data), aad, len(aad))
            if ret < 0:
                raise WolfCryptError("Decryption error (%d)" % ret)
            return bytes(self._buf)

        def decrypt(self, data):
            """
            Add more data to the decryption stream
            """
            aad = bytes()
            data = t2b(data)
            if self._mode is None:
                self._mode = _DECRYPTION
                aad = self._aad
            elif self._mode == _ENCRYPTION:
                raise WolfCryptError("Class instance already in use for decryption")
            self._buf = _ffi.new("byte[%d]" % (len(data)))
            ret = _lib.wc_AesGcmDecryptUpdate(self._native_object, self._buf, data, len(data), aad, len(aad))
            if ret < 0:
                raise WolfCryptError("Decryption error (%d)" % ret)
            return bytes(self._buf)

        def final(self, authTag=None):
            """
            When encrypting, finalize the stream and return an authentication tag for the stream.
            When decrypting, verify the authentication tag for the stream.
            The authTag parameter is only used for decrypting.
            """
            if self._mode is None:
                raise WolfCryptError("Final called with no encryption or decryption")
            elif self._mode == _ENCRYPTION:
                authTag = _ffi.new("byte[%d]" % self._tag_bytes)
                ret = _lib.wc_AesGcmEncryptFinal(self._native_object, authTag, self._tag_bytes)
                if ret < 0:
                    raise WolfCryptError("Encryption error (%d)" % ret)
                return _ffi.buffer(authTag)[:]
            else:
                if authTag is None:
                    raise WolfCryptError("authTag parameter required")
                authTag = t2b(authTag)
                ret = _lib.wc_AesGcmDecryptFinal(self._native_object, authTag, len(authTag))
                if ret < 0:
                    raise WolfCryptError("Decryption error (%d)" % ret)



if _lib.CHACHA_ENABLED:
    class ChaCha(_Cipher):
        """
        ChaCha20
        """
        block_size = 16
        key_size = None  # 16, 24, 32
        _key_sizes = [16, 32]
        _native_type = "ChaCha *"
        _IV_nonce = []
        _IV_counter = 0

        def __init__(self, key="", size=32):
            self._native_object = _ffi.new(self._native_type)
            self._enc = None
            self._dec = None
            self._key = None
            if len(key) > 0:
                if not size in self._key_sizes:
                    raise ValueError("Invalid key size %d" % size)
                self._key = t2b(key)
                self.key_size = size
            self._IV_nonce = []
            self._IV_counter = 0

        def _set_key(self, direction):
            if self._key == None:
                return -1
            if self._enc:
                ret = _lib.wc_Chacha_SetKey(self._enc, self._key, len(self._key))
                if ret == 0:
                    _lib.wc_Chacha_SetIV(self._enc, self._IV_nonce, self._IV_counter)
                if ret != 0:
                    return ret
            if self._dec:
                ret = _lib.wc_Chacha_SetKey(self._dec, self._key, len(self._key))
                if ret == 0:
                    _lib.wc_Chacha_SetIV(self._dec, self._IV_nonce, self._IV_counter)
                if ret != 0:
                    return ret
            return 0

        def _encrypt(self, destination, source):
            return _lib.wc_Chacha_Process(self._enc, destination,
                                         source, len(source))

        def _decrypt(self, destination, source):
            return _lib.wc_Chacha_Process(self._dec,
                                          destination, source, len(source))

        _NONCE_SIZE = 12

        def set_iv(self, nonce, counter = 0):
            self._IV_nonce = t2b(nonce)
            if len(self._IV_nonce) != self._NONCE_SIZE:
                raise ValueError("nonce must be %d bytes, got %d" %
                                 (self._NONCE_SIZE, len(self._IV_nonce)))
            self._IV_counter = counter
            self._set_key(0)

if _lib.CHACHA20_POLY1305_ENABLED:
    class ChaCha20Poly1305(object):
        """
        ChaCha20-Poly1305 AEAD cipher.

        One-shot encrypt/decrypt interface (non-streaming).
        """
        _key_sizes = [32]
        _tag_bytes = 16

        def __init__(self, key):
            self._key = t2b(key)
            if len(self._key) not in self._key_sizes:
                raise ValueError("key must be %s in length, not %d" %
                                 (self._key_sizes, len(self._key)))

        def encrypt(self, aad, iv, plaintext):
            """
            Encrypt plaintext data using the IV/nonce provided. The
            associated data (aad) is not encrypted but is included in the
            authentication tag.

            Returns a tuple of (ciphertext, authTag).
            """
            aad = t2b(aad)
            iv = t2b(iv)
            if len(iv) != 12:
                raise ValueError("iv must be 12 bytes, got %d" % len(iv))
            plaintext = t2b(plaintext)
            ciphertext = _ffi.new("byte[%d]" % len(plaintext))
            authTag = _ffi.new("byte[%d]" % self._tag_bytes)
            ret = _lib.wc_ChaCha20Poly1305_Encrypt(
                _ffi.from_buffer(self._key),
                _ffi.from_buffer(iv),
                _ffi.from_buffer(aad),
                len(aad),
                _ffi.from_buffer(plaintext),
                len(plaintext),
                ciphertext,
                authTag
            )
            if ret < 0:
                raise WolfCryptError("Encryption error (%d)" % ret)
            return bytes(ciphertext), bytes(authTag)

        def decrypt(self, aad, iv, authTag, ciphertext):
            """
            Decrypt the ciphertext using the IV/nonce and authentication tag
            provided. The integrity of the associated data (aad) is checked.

            Returns the decrypted plaintext.
            """
            aad = t2b(aad)
            iv = t2b(iv)
            if len(iv) != 12:
                raise ValueError("iv must be 12 bytes, got %d" % len(iv))
            authTag = t2b(authTag)
            if len(authTag) != self._tag_bytes:
                raise ValueError("authTag must be %d bytes, got %d" %
                                 (self._tag_bytes, len(authTag)))
            ciphertext = t2b(ciphertext)
            plaintext = _ffi.new("byte[%d]" % len(ciphertext))
            ret = _lib.wc_ChaCha20Poly1305_Decrypt(
                _ffi.from_buffer(self._key),
                _ffi.from_buffer(iv),
                _ffi.from_buffer(aad),
                len(aad),
                _ffi.from_buffer(ciphertext),
                len(ciphertext),
                _ffi.from_buffer(authTag),
                plaintext
            )
            if ret < 0:
                raise WolfCryptError("Decryption error (%d)" % ret)
            return bytes(plaintext)

if _lib.DES3_ENABLED:
    class Des3(_Cipher):
        """
        **Triple DES** (3DES) is the common name for the **Triple Data
        Encryption Algorithm** (TDEA or Triple DEA) symmetric-key block
        cipher, which applies the **Data Encryption Standard** (DES)
        cipher algorithm three times to each data block.
        """
        block_size = 8
        key_size = 24
        _native_type = "Des3 *"

        def _set_key(self, direction):
            if direction == _ENCRYPTION:
                return _lib.wc_Des3_SetKey(self._enc, self._key,
                                           self._IV, _ENCRYPTION)

            return _lib.wc_Des3_SetKey(self._dec, self._key,
                                       self._IV, _DECRYPTION)

        def _encrypt(self, destination, source):
            return _lib.wc_Des3_CbcEncrypt(self._enc, destination,
                                           source, len(source))

        def _decrypt(self, destination, source):
            return _lib.wc_Des3_CbcDecrypt(self._dec, destination,
                                           source, len(source))


if _lib.RSA_ENABLED:
    class _Rsa(object):  # pylint: disable=too-few-public-methods
        RSA_MIN_PAD_SIZE = 11
        _mgf = None
        _hash_type = None

        def __init__(self):
            self.native_object = _ffi.new("RsaKey *")
            ret = _lib.wc_InitRsaKey(self.native_object, _ffi.NULL)
            if ret < 0:  # pragma: no cover
                raise WolfCryptError("Invalid key error (%d)" % ret)

            self._random = Random()
            if _lib.RSA_BLINDING_ENABLED:
                ret = _lib.wc_RsaSetRNG(self.native_object,
                        self._random.native_object)
                if ret < 0:  # pragma: no cover
                    raise WolfCryptError("Key initialization error (%d)" % ret)

        # making sure _lib.wc_FreeRsaKey outlives RsaKey instances
        _delete = _lib.wc_FreeRsaKey

        def __del__(self):
            if self.native_object:
                self._delete(self.native_object)

        def set_mgf(self, mgf):
            self._mgf = mgf

        def _get_mgf(self):
            if self._hash_type == _lib.WC_HASH_TYPE_SHA:
                self._mgf = _lib.WC_MGF1SHA1
            elif self._hash_type == _lib.WC_HASH_TYPE_SHA224:
                self._mgf = _lib.WC_MGF1SHA224
            elif self._hash_type == _lib.WC_HASH_TYPE_SHA256:
                self._mgf = _lib.WC_MGF1SHA256
            elif self._hash_type == _lib.WC_HASH_TYPE_SHA384:
                self._mgf = _lib.WC_MGF1SHA384
            elif self._hash_type == _lib.WC_HASH_TYPE_SHA512:
                self._mgf = _lib.WC_MGF1SHA512
            else:
                self._mgf = _lib.WC_MGF1NONE



    class RsaPublic(_Rsa):
        def __init__(self, key=None, hash_type=None):
            if key != None:
                key = t2b(key)
            self._hash_type = hash_type

            _Rsa.__init__(self)

            idx = _ffi.new("word32*")
            idx[0] = 0

            ret = _lib.wc_RsaPublicKeyDecode(key, idx,
                    self.native_object, len(key))
            if ret < 0:
                raise WolfCryptError("Invalid key error (%d)" % ret)

            self.output_size = _lib.wc_RsaEncryptSize(self.native_object)
            self.size = len(key)
            if self.output_size <= 0:  # pragma: no cover
                raise WolfCryptError("Invalid key error (%d)" %
                        self.output_size)

        if _lib.ASN_ENABLED:
            @classmethod
            def from_pem(cls, file, hash_type=None):
                der = pem_to_der(file, _lib.PUBLICKEY_TYPE)
                return cls(key=der, hash_type=hash_type)

        def encrypt(self, plaintext):
            """
            Encrypts **plaintext**, using the public key data in the
            object. The plaintext's length must not be greater than:

                **self.output_size - self.RSA_MIN_PAD_SIZE**

            Returns a string containing the ciphertext.
            """

            plaintext = t2b(plaintext)
            ciphertext = _ffi.new("byte[%d]" % self.output_size)

            ret = _lib.wc_RsaPublicEncrypt(plaintext, len(plaintext),
                                           ciphertext, self.output_size,
                                           self.native_object,
                                           self._random.native_object)

            if ret != self.output_size:  # pragma: no cover
                raise WolfCryptError("Encryption error (%d)" % ret)

            return _ffi.buffer(ciphertext)[:]

        def encrypt_oaep(self, plaintext, label=""):
            plaintext = t2b(plaintext)
            label = t2b(label)
            ciphertext = _ffi.new("byte[%d]" % self.output_size)
            if self._mgf is None:
                self._get_mgf()
            ret = _lib.wc_RsaPublicEncrypt_ex(plaintext, len(plaintext),
                                              ciphertext, self.output_size,
                                              self.native_object,
                                              self._random.native_object,
                                              _lib.WC_RSA_OAEP_PAD, self._hash_type,
                                              self._mgf, label, len(label))

            if ret != self.output_size:  # pragma: no cover
                raise WolfCryptError("Encryption error (%d)" % ret)

            return _ffi.buffer(ciphertext)[:]

        def verify(self, signature):
            """
            Verifies **signature**, using the public key data in the
            object. The signature's length must be equal to:

                **self.output_size**

            Returns a string containing the plaintext.
            """
            signature = t2b(signature)
            plaintext = _ffi.new("byte[%d]" % self.output_size)

            ret = _lib.wc_RsaSSL_Verify(signature, len(signature),
                                        plaintext, self.output_size,
                                        self.native_object)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("Verify error (%d)" % ret)

            return _ffi.buffer(plaintext, ret)[:]

        if _lib.RSA_PSS_ENABLED:
            def verify_pss(self, plaintext, signature):
                """
                Verifies **signature**, using the public key data in the
                object. The signature's length must be equal to:

                    **self.output_size**

                Returns a string containing the plaintext.
                """
                if not self._hash_type:
                    raise WolfCryptError(("Hash type not set. Cannot verify a "
                        "PSS signature without a hash type."))

                hash_cls = hash_type_to_cls(self._hash_type)
                if not hash_cls:
                    raise WolfCryptError("Unsupported PSS hash type.")

                plaintext = t2b(plaintext)
                signature = t2b(signature)
                if self._mgf is None:
                    self._get_mgf()
                verify = _ffi.new("byte[%d]" % self.output_size)

                ret = _lib.wc_RsaPSS_Verify(signature, len(signature),
                                            verify, self.output_size,
                                            self._hash_type, self._mgf,
                                            self.native_object)

                if ret < 0:  # pragma: no cover
                    raise WolfCryptError("Verify error (%d)" % ret)

                digest = hash_cls.new(plaintext).digest()
                ret = _lib.wc_RsaPSS_CheckPadding(digest, len(digest),
                                                  verify, ret, self._hash_type)

                if ret < 0:  # pragma: no cover
                    raise WolfCryptError("PSS padding check error (%d)" % ret)

                return ret == 0


    class RsaPrivate(RsaPublic):
        if _lib.KEYGEN_ENABLED:
            @classmethod
            def make_key(cls, size, rng=Random(), hash_type=None):
                """
                Generates a new key pair of desired length **size**.
                """
                rsa = cls(hash_type=hash_type)
                if rsa == None:  # pragma: no cover
                    raise WolfCryptError("Invalid key error (%d)" % ret)

                ret = _lib.wc_MakeRsaKey(rsa.native_object, size, 65537,
                        rng.native_object)
                if ret < 0:
                    raise WolfCryptError("Key generation error (%d)" % ret)

                rsa.output_size = _lib.wc_RsaEncryptSize(rsa.native_object)
                rsa.size = size
                if rsa.output_size <= 0:  # pragma: no cover
                    raise WolfCryptError("Invalid key size error (%d)" % ret)

                return rsa

        def __init__(self, key=None, hash_type=None):  # pylint: disable=super-init-not-called

            _Rsa.__init__(self)  # pylint: disable=non-parent-init-called
            self._hash_type = hash_type
            idx = _ffi.new("word32*")
            idx[0] = 0

            if key != None:
                key = t2b(key)
                ret = _lib.wc_RsaPrivateKeyDecode(key, idx,
                                              self.native_object, len(key))
                if ret < 0:
                    idx[0] = 0
                    ret = _lib.wc_GetPkcs8TraditionalOffset(key, idx, len(key))
                    if ret < 0:
                        raise WolfCryptError("Invalid key error (%d)" % ret)

                    ret = _lib.wc_RsaPrivateKeyDecode(key, idx,
                                              self.native_object, len(key))
                    if ret < 0:
                        raise WolfCryptError("Invalid key error (%d)" % ret)

                self.size = len(key)
                self.output_size = _lib.wc_RsaEncryptSize(self.native_object)
                if self.output_size <= 0:  # pragma: no cover
                    raise WolfCryptError("Invalid key size error (%d)" %
                            self.output_size)

        if _lib.ASN_ENABLED:
            @classmethod
            def from_pem(cls, file, hash_type=None):
                der = pem_to_der(file, _lib.PRIVATEKEY_TYPE)
                return cls(key=der, hash_type=hash_type)

        if _lib.KEYGEN_ENABLED:
            def encode_key(self):
                """
                Encodes the RSA private and public keys in an ASN sequence.

                Returns the encoded key.
                """
                priv = _ffi.new("byte[%d]" % (self.size * 4))
                pub = _ffi.new("byte[%d]" % (self.size * 4))


                ret = _lib.wc_RsaKeyToDer(self.native_object, priv, self.size)
                if ret <= 0:  # pragma: no cover
                    raise WolfCryptError("Private RSA key error (%d)" % ret)
                privlen = ret
                ret = _lib.wc_RsaKeyToPublicDer(self.native_object, pub,
                        self.size)
                if ret <= 0:  # pragma: no cover
                    raise WolfCryptError("Public RSA key encode error (%d)" %
                            ret)
                publen = ret
                return _ffi.buffer(priv, privlen)[:], _ffi.buffer(pub,
                        publen)[:]

        def decrypt(self, ciphertext):
            """
            Decrypts **ciphertext**, using the private key data in the
            object. The ciphertext's length must be equal to:

                **self.output_size**

            Returns a string containing the plaintext.
            """
            ciphertext = t2b(ciphertext)
            plaintext = _ffi.new("byte[%d]" % self.output_size)

            ret = _lib.wc_RsaPrivateDecrypt(ciphertext, len(ciphertext),
                                            plaintext, self.output_size,
                                            self.native_object)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("Decryption error (%d)" % ret)

            return _ffi.buffer(plaintext, ret)[:]

        def decrypt_oaep(self, ciphertext, label=""):
            """
            Decrypts **ciphertext**, using the private key data in the
            object. The ciphertext's length must be equal to:

                **self.output_size**

            Returns a string containing the plaintext.
            """
            ciphertext = t2b(ciphertext)
            label = t2b(label)
            plaintext = _ffi.new("byte[%d]" % self.output_size)
            if self._mgf is None:
                self._get_mgf()
            ret = _lib.wc_RsaPrivateDecrypt_ex(ciphertext, len(ciphertext),
                                               plaintext, self.output_size,
                                               self.native_object,
                                               _lib.WC_RSA_OAEP_PAD, self._hash_type,
                                               self._mgf, label, len(label))

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("Decryption error (%d)" % ret)

            return _ffi.buffer(plaintext, ret)[:]

        def sign(self, plaintext):
            """
            Signs **plaintext**, using the private key data in the object.
            The plaintext's length must not be greater than:

                **self.output_size - self.RSA_MIN_PAD_SIZE**

            Returns a string containing the signature.
            """
            plaintext = t2b(plaintext)
            signature = _ffi.new("byte[%d]" % self.output_size)

            ret = _lib.wc_RsaSSL_Sign(plaintext, len(plaintext),
                                      signature, self.output_size,
                                      self.native_object,
                                      self._random.native_object)

            if ret != self.output_size:  # pragma: no cover
                raise WolfCryptError("Signature error (%d)" % ret)

            return _ffi.buffer(signature, self.output_size)[:]

        if _lib.RSA_PSS_ENABLED:
            def sign_pss(self, plaintext):
                """
                Signs **plaintext**, using the private key data in the object.
                The plaintext's length must not be greater than:

                    **self.output_size - self.RSA_MIN_PAD_SIZE**

                Returns a string containing the signature.
                """
                if not self._hash_type:
                    raise WolfCryptError(("Hash type not set. Cannot verify a "
                        "PSS signature without a hash type."))

                hash_cls = hash_type_to_cls(self._hash_type)
                if not hash_cls:
                    raise WolfCryptError("Unsupported PSS hash type.")

                plaintext = t2b(plaintext)
                digest = hash_cls.new(plaintext).digest()

                signature = _ffi.new("byte[%d]" % self.output_size)
                if self._mgf is None:
                    self._get_mgf()

                ret = _lib.wc_RsaPSS_Sign(digest, len(digest),
                                          signature, self.output_size,
                                          self._hash_type, self._mgf,
                                          self.native_object,
                                          self._random.native_object)

                if ret != self.output_size:  # pragma: no cover
                    raise WolfCryptError("Signature error (%d)" % ret)

                return _ffi.buffer(signature, self.output_size)[:]


if _lib.ECC_ENABLED:
    class _Ecc(object):  # pylint: disable=too-few-public-methods
        def __init__(self):
            self.native_object = _ffi.new("ecc_key *")
            ret = _lib.wc_ecc_init(self.native_object)
            if ret < 0:  # pragma: no cover
                raise WolfCryptError("Invalid key error (%d)" % ret)

        # making sure _lib.wc_ecc_free outlives ecc_key instances
        _delete = _lib.wc_ecc_free

        def __del__(self):
            if self.native_object:
                self._delete(self.native_object)

        @property
        def size(self):
            return _lib.wc_ecc_size(self.native_object)

        @property
        def max_signature_size(self):
            return _lib.wc_ecc_sig_size(self.native_object)


    class EccPublic(_Ecc):
        def __init__(self, key=None):
            _Ecc.__init__(self)

            if key:
                self.decode_key(key)

        def decode_key(self, key):
            """
            Decodes an ECC public key from an ASN sequence.
            """
            key = t2b(key)

            idx = _ffi.new("word32*")
            idx[0] = 0

            ret = _lib.wc_EccPublicKeyDecode(key, idx,
                                             self.native_object, len(key))
            if ret < 0:
                raise WolfCryptError("Key decode error (%d)" % ret)
            if self.size <= 0:  # pragma: no cover
                raise WolfCryptError("Key decode error (%d)" % self.size)
            if self.max_signature_size <= 0:  # pragma: no cover
                raise WolfCryptError(
                    "Key decode error (%d)" % self.max_signature_size)

        def decode_key_raw(self, qx, qy, curve_id=ECC_SECP256R1):
            """
            Decodes an ECC public key from its raw elements: (Qx,Qy)
            """
            ret = _lib.wc_ecc_import_unsigned(self.native_object, qx, qy,
                    _ffi.NULL, curve_id)
            if ret != 0:
                raise WolfCryptError("Key decode error (%d)" % ret)

        def encode_key(self, with_curve=True):
            """
            Encodes the ECC public key in an ASN sequence.

            Returns the encoded key.
            """
            key = _ffi.new("byte[%d]" % (self.size * 4))

            ret = _lib.wc_EccPublicKeyToDer(self.native_object, key, len(key),
                                            with_curve)
            if ret <= 0:  # pragma: no cover
                raise WolfCryptError("Key encode error (%d)" % ret)

            return _ffi.buffer(key, ret)[:]

        def encode_key_raw(self):
            """
            Encodes the ECC public key in its two raw elements

            Returns (Qx, Qy)
            """
            Qx = _ffi.new("byte[%d]" % (self.size))
            Qy = _ffi.new("byte[%d]" % (self.size))
            qx_size = _ffi.new("word32[1]")
            qy_size = _ffi.new("word32[1]")
            qx_size[0] = self.size
            qy_size[0] = self.size

            ret = _lib.wc_ecc_export_public_raw(self.native_object, Qx,
                    qx_size, Qy, qy_size);
            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Key encode error (%d)" % ret)

            return _ffi.buffer(Qx, qx_size[0])[:], _ffi.buffer(Qy,
                    qy_size[0])[:]

        def import_x963(self, x963):
            """
            Imports an ECC public key in ANSI X9.63 format.
            """
            ret = _lib.wc_ecc_import_x963(x963, len(x963), self.native_object)
            if ret != 0:
                raise WolfCryptError("x963 import error (%d)" % ret)

        def export_x963(self):
            """
            Exports the public key data of the object in ANSI X9.63 format.

            Returns the exported key.
            """
            x963 = _ffi.new("byte[%d]" % (self.size * 4))
            x963_size = _ffi.new("word32[1]")
            x963_size[0] = self.size * 4

            ret = _lib.wc_ecc_export_x963(self.native_object, x963, x963_size)
            if ret != 0:  # pragma: no cover
                raise WolfCryptError("x963 export error (%d)" % ret)

            return _ffi.buffer(x963, x963_size[0])[:]

        def verify(self, signature, data):
            """
            Verifies **signature**, using the public key data in the object.

            Returns **True** in case of a valid signature, otherwise **False**.
            """
            data = t2b(data)
            status = _ffi.new("int[1]")

            ret = _lib.wc_ecc_verify_hash(signature, len(signature),
                                          data, len(data),
                                          status, self.native_object)

            if ret < 0:
                raise WolfCryptError("Verify error (%d)" % ret)

            return status[0] == 1

        if _lib.MPAPI_ENABLED:
            def verify_raw(self, R, S, data):
                """
                Verifies signature from its raw elements **R** and **S**, using
                the public key data in the object.

                Returns **True** in case of a valid signature, otherwise
                **False**.
                """
                data = t2b(data)
                status = _ffi.new("int[1]")
                mpR = _ffi.new("mp_int[1]")
                mpS = _ffi.new("mp_int[1]")
                ret = _lib.mp_init(mpR)
                if ret != 0:  # pragma: no cover
                    raise WolfCryptError("wolfCrypt error (%d)" % ret)
                ret = _lib.mp_init(mpS)
                if ret != 0:  # pragma: no cover
                    raise WolfCryptError("wolfCrypt error (%d)" % ret)

                ret = _lib.mp_read_unsigned_bin(mpR, R, len(R))
                if ret != 0:  # pragma: no cover
                    raise WolfCryptError("wolfCrypt error (%d)" % ret)

                ret = _lib.mp_read_unsigned_bin(mpS, S, len(S))
                if ret != 0:  # pragma: no cover
                    raise WolfCryptError("wolfCrypt error (%d)" % ret)


                ret = _lib.wc_ecc_verify_hash_ex(mpR, mpS,
                                              data, len(data),
                                              status, self.native_object)

                if ret < 0:
                    raise WolfCryptError("Verify error (%d)" % ret)

                return status[0] == 1


    class EccPrivate(EccPublic):
        @classmethod
        def make_key(cls, size, rng=Random()):
            """
            Generates a new key pair of desired length **size**.
            """
            ecc = cls()

            ret = _lib.wc_ecc_make_key(rng.native_object, size,
                    ecc.native_object)
            if ret < 0:
                raise WolfCryptError("Key generation error (%d)" % ret)

            if _lib.ECC_TIMING_RESISTANCE_ENABLED and (not _lib.FIPS_ENABLED or
               _lib.FIPS_VERSION > 2):
                ret = _lib.wc_ecc_set_rng(ecc.native_object, rng.native_object)
                if ret < 0:
                    raise WolfCryptError("Error setting ECC RNG (%d)" % ret)

            return ecc

        def decode_key(self, key):
            """
            Decodes an ECC private key from an ASN sequence.
            """
            key = t2b(key)

            idx = _ffi.new("word32*")
            idx[0] = 0

            ret = _lib.wc_EccPrivateKeyDecode(key, idx,
                                              self.native_object, len(key))
            if ret < 0:
                raise WolfCryptError("Key decode error (%d)" % ret)
            if self.size <= 0:  # pragma: no cover
                raise WolfCryptError("Key decode error (%d)" % self.size)
            if self.max_signature_size <= 0:  # pragma: no cover
                raise WolfCryptError(
                    "Key decode error (%d)" % self.max_signature_size)

        def decode_key_raw(self, qx, qy, d, curve_id=ECC_SECP256R1):
            """
            Decodes an ECC private key from its raw elements: public (Qx,Qy)
            and private(d)
            """
            ret = _lib.wc_ecc_import_unsigned(self.native_object, qx, qy, d,
                    curve_id)
            if ret != 0:
                raise WolfCryptError("Key decode error (%d)" % ret)

        def encode_key(self):
            """
            Encodes the ECC private key in an ASN sequence.

            Returns the encoded key.
            """
            key = _ffi.new("byte[%d]" % (self.size * 4))

            ret = _lib.wc_EccKeyToDer(self.native_object, key, len(key))
            if ret <= 0:  # pragma: no cover
                raise WolfCryptError("Key encode error (%d)" % ret)

            return _ffi.buffer(key, ret)[:]

        def encode_key_raw(self):
            """
            Encodes the ECC private key in its three raw elements

            Returns (Qx, Qy, d)
            """
            Qx = _ffi.new("byte[%d]" % (self.size))
            Qy = _ffi.new("byte[%d]" % (self.size))
            d = _ffi.new("byte[%d]" % (self.size))
            qx_size = _ffi.new("word32[1]")
            qy_size = _ffi.new("word32[1]")
            d_size = _ffi.new("word32[1]")
            qx_size[0] = self.size
            qy_size[0] = self.size
            d_size[0] = self.size

            ret = _lib.wc_ecc_export_private_raw(self.native_object, Qx,
                    qx_size, Qy, qy_size, d, d_size);
            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Key encode error (%d)" % ret)

            return _ffi.buffer(Qx, qx_size[0])[:], _ffi.buffer(Qy,
                    qy_size[0])[:], _ffi.buffer(d, d_size[0])[:]

        def shared_secret(self, peer):
            """
            Generates a new secret key using the private key data in the object
            and the peer's public key.

            Returns the shared secret.
            """
            shared_secret = _ffi.new("byte[%d]" % self.max_signature_size)
            secret_size = _ffi.new("word32[1]")
            secret_size[0] = self.max_signature_size

            ret = _lib.wc_ecc_shared_secret(self.native_object,
                                            peer.native_object,
                                            shared_secret, secret_size)

            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Shared secret error (%d)" % ret)

            return _ffi.buffer(shared_secret, secret_size[0])[:]

        def sign(self, plaintext, rng=Random()):
            """
            Signs **plaintext**, using the private key data in the object.

            Returns the signature.
            """
            plaintext = t2b(plaintext)
            signature = _ffi.new("byte[%d]" % self.max_signature_size)

            signature_size = _ffi.new("word32[1]")
            signature_size[0] = self.max_signature_size

            ret = _lib.wc_ecc_sign_hash(plaintext, len(plaintext),
                                        signature, signature_size,
                                        rng.native_object,
                                        self.native_object)

            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Signature error (%d)" % ret)

            return _ffi.buffer(signature, signature_size[0])[:]

        if _lib.MPAPI_ENABLED:
            def sign_raw(self, plaintext, rng=Random()):
                """
                Signs **plaintext**, using the private key data in the object.

                Returns the signature in its two raw components r, s
                """
                plaintext = t2b(plaintext)
                R = _ffi.new("mp_int[1]");
                S = _ffi.new("mp_int[1]");

                R_bin = _ffi.new("unsigned char[%d]" % self.size )
                S_bin = _ffi.new("unsigned char[%d]" % self.size )

                ret = _lib.mp_init(R)
                if ret != 0:  # pragma: no cover
                    raise WolfCryptError("wolfCrypt error (%d)" % ret)
                ret = _lib.mp_init(S)
                if ret != 0:  # pragma: no cover
                    raise WolfCryptError("wolfCrypt error (%d)" % ret)

                ret = _lib.wc_ecc_sign_hash_ex(plaintext, len(plaintext),
                                            rng.native_object,
                                            self.native_object,
                                            R, S)
                if ret != 0:  # pragma: no cover
                    raise WolfCryptError("Signature error (%d)" % ret)

                ret = _lib.mp_to_unsigned_bin_len(R, R_bin, self.size)
                if ret != 0:  # pragma: no cover
                    raise WolfCryptError("wolfCrypt error (%d)" % ret)

                ret = _lib.mp_to_unsigned_bin_len(S, S_bin, self.size)
                if ret != 0:  # pragma: no cover
                    raise WolfCryptError("wolfCrypt error (%d)" % ret)

                return _ffi.buffer(R_bin, self.size)[:], _ffi.buffer(S_bin,
                        self.size)[:]


if _lib.ED25519_ENABLED:
    class _Ed25519(object):  # pylint: disable=too-few-public-methods
        def __init__(self):
            self.native_object = _ffi.new("ed25519_key *")
            ret = _lib.wc_ed25519_init(self.native_object)
            if ret < 0:  # pragma: no cover
                raise WolfCryptError("Invalid key error (%d)" % ret)

        # making sure _lib.wc_ed25519_free outlives ed25519_key instances
        _delete = _lib.wc_ed25519_free

        def __del__(self):
            if self.native_object:
                self._delete(self.native_object)

        @property
        def size(self):
            return _lib.wc_ed25519_size(self.native_object)

        @property
        def max_signature_size(self):
            return _lib.wc_ed25519_sig_size(self.native_object)


    class Ed25519Public(_Ed25519):
        def __init__(self, key=None):
            _Ed25519.__init__(self)

            if key:
                self.decode_key(key)

        def decode_key(self, key):
            """
            Decodes an ED25519 public key
            """
            key = t2b(key)
            if (len(key) < _lib.wc_ed25519_pub_size(self.native_object)):
                raise WolfCryptError("Key decode error: key too short")

            idx = _ffi.new("word32*")
            idx[0] = 0
            ret = _lib.wc_ed25519_import_public(key, len(key),
                    self.native_object)
            if ret < 0:
                raise WolfCryptError("Key decode error (%d)" % ret)
            if self.size <= 0:  # pragma: no cover
                raise WolfCryptError("Key decode error (%d)" % self.size)
            if self.max_signature_size <= 0:  # pragma: no cover
                raise WolfCryptError(
                    "Key decode error (%d)" % self.max_signature_size)

        def encode_key(self):
            """
            Encodes the ED25519 public key

            Returns the encoded key.
            """
            key = _ffi.new("byte[%d]" % (self.size * 4))
            size = _ffi.new("word32[1]")

            size[0] = _lib.wc_ed25519_pub_size(self.native_object)

            ret = _lib.wc_ed25519_export_public(self.native_object, key, size)
            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Key encode error (%d)" % ret)

            return _ffi.buffer(key, size[0])[:]

        def verify(self, signature, data):
            """
            Verifies **signature**, using the public key data in the object.

            Returns **True** in case of a valid signature, otherwise **False**.
            """
            data = t2b(data)
            status = _ffi.new("int[1]")

            ret = _lib.wc_ed25519_verify_msg(signature, len(signature),
                                          data, len(data),
                                          status, self.native_object)

            if ret < 0:
                raise WolfCryptError("Verify error (%d)" % ret)

            return status[0] == 1



    class Ed25519Private(Ed25519Public):
        def __init__(self, key=None, pub=None):
            _Ed25519.__init__(self)

            if key and not pub:
                self.decode_key(key)
            if key and pub:
                self.decode_key(key,pub)

        @classmethod
        def make_key(cls, size, rng=Random()):
            """
            Generates a new key pair of desired length **size**.
            """
            ed25519 = cls()

            ret = _lib.wc_ed25519_make_key(rng.native_object, size,
                    ed25519.native_object)
            if ret < 0:
                raise WolfCryptError("Key generation error (%d)" % ret)

            return ed25519

        def decode_key(self, key, pub = None):
            """
            Decodes an ED25519 private + pub key
            """
            key = t2b(key)

            if (len(key) < _lib.wc_ed25519_priv_size(self.native_object)/2):
                raise WolfCryptError("Key decode error: key too short")

            idx = _ffi.new("word32*")
            idx[0] = 0
            if pub:
                ret = _lib.wc_ed25519_import_private_key(key, len(key), pub,
                        len(pub), self.native_object);
                if ret < 0:
                    raise WolfCryptError("Key decode error (%d)" % ret)
            else:
                ret = _lib.wc_ed25519_import_private_only(key, len(key),
                        self.native_object);
                if ret < 0:
                    raise WolfCryptError("Key decode error (%d)" % ret)
                pubkey = _ffi.new("byte[%d]" % (self.size * 4))
                ret = _lib.wc_ed25519_make_public(self.native_object, pubkey,
                        self.size)
                if ret < 0:
                    raise WolfCryptError("Public key generate error (%d)" % ret)
                ret = _lib.wc_ed25519_import_public(pubkey, self.size,
                        self.native_object);

            if self.size <= 0:  # pragma: no cover
                raise WolfCryptError("Key decode error (%d)" % self.size)
            if self.max_signature_size <= 0:  # pragma: no cover
                raise WolfCryptError(
                    "Key decode error (%d)" % self.max_signature_size)

        def encode_key(self):
            """
            Encodes the ED25519 private key.

            Returns the encoded key.
            """
            key = _ffi.new("byte[%d]" % (self.size * 4))
            pubkey = _ffi.new("byte[%d]" % (self.size * 4))
            size = _ffi.new("word32[1]")

            size[0] = _lib.wc_ed25519_priv_size(self.native_object)

            ret = _lib.wc_ed25519_export_private_only(self.native_object,
                    key, size)
            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Private key encode error (%d)" % ret)
            ret = _lib.wc_ed25519_export_public(self.native_object, pubkey,
                    size)
            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Public key encode error (%d)" % ret)

            return _ffi.buffer(key, size[0])[:], _ffi.buffer(pubkey, size[0])[:]

        def sign(self, plaintext):
            """
            Signs **plaintext**, using the private key data in the object.

            Returns the signature.
            """
            plaintext = t2b(plaintext)
            signature = _ffi.new("byte[%d]" % self.max_signature_size)

            signature_size = _ffi.new("word32[1]")
            signature_size[0] = self.max_signature_size

            ret = _lib.wc_ed25519_sign_msg(plaintext, len(plaintext),
                                        signature, signature_size,
                                        self.native_object)

            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Signature error (%d)" % ret)

            return _ffi.buffer(signature, signature_size[0])[:]

if _lib.ED448_ENABLED:
    class _Ed448(object):  # pylint: disable=too-few-public-methods
        def __init__(self):
            self.native_object = _ffi.new("ed448_key *")
            ret = _lib.wc_ed448_init(self.native_object)
            if ret < 0:  # pragma: no cover
                raise WolfCryptError("Invalid key error (%d)" % ret)

        # making sure _lib.wc_ed448_free outlives ed448_key instances
        _delete = _lib.wc_ed448_free

        def __del__(self):
            if self.native_object:
                self._delete(self.native_object)

        @property
        def size(self):
            return _lib.wc_ed448_size(self.native_object)

        @property
        def max_signature_size(self):
            return _lib.wc_ed448_sig_size(self.native_object)


    class Ed448Public(_Ed448):
        def __init__(self, key=None):
            _Ed448.__init__(self)

            if key:
                self.decode_key(key)

        def decode_key(self, key):
            """
            Decodes an ED448 public key
            """
            key = t2b(key)
            if (len(key) < _lib.wc_ed448_pub_size(self.native_object)):
                raise WolfCryptError("Key decode error: key too short")

            idx = _ffi.new("word32*")
            idx[0] = 0
            ret = _lib.wc_ed448_import_public(key, len(key),
                    self.native_object)
            if ret < 0:
                raise WolfCryptError("Key decode error (%d)" % ret)
            if self.size <= 0:  # pragma: no cover
                raise WolfCryptError("Key decode error (%d)" % self.size)
            if self.max_signature_size <= 0:  # pragma: no cover
                raise WolfCryptError(
                    "Key decode error (%d)" % self.max_signature_size)

        def encode_key(self):
            """
            Encodes the ED448 public key

            Returns the encoded key.
            """
            key = _ffi.new("byte[%d]" % (self.size * 4))
            size = _ffi.new("word32[1]")

            size[0] = _lib.wc_ed448_pub_size(self.native_object)

            ret = _lib.wc_ed448_export_public(self.native_object, key, size)
            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Key encode error (%d)" % ret)

            return _ffi.buffer(key, size[0])[:]

        def verify(self, signature, data, ctx=None):
            """
            Verifies **signature**, using the public key data in the object.

            Returns **True** in case of a valid signature, otherwise **False**.
            """
            data = t2b(data)
            status = _ffi.new("int[1]")
            ctx_buf = _ffi.NULL
            ctx_buf_len = 0
            if ctx != None:
                ctx_buf = t2b(ctx)
                ctx_buf_len = len(ctx_buf)

            ret = _lib.wc_ed448_verify_msg(signature, len(signature),
                                          data, len(data), status,
                                          self.native_object, ctx_buf,
                                          ctx_buf_len)

            if ret < 0:
                raise WolfCryptError("Verify error (%d)" % ret)

            return status[0] == 1



    class Ed448Private(Ed448Public):
        def __init__(self, key=None, pub=None):
            _Ed448.__init__(self)

            if key and not pub:
                self.decode_key(key)
            if key and pub:
                self.decode_key(key,pub)

        @classmethod
        def make_key(cls, size, rng=Random()):
            """
            Generates a new key pair of desired length **size**.
            """
            ed448 = cls()

            ret = _lib.wc_ed448_make_key(rng.native_object, size,
                    ed448.native_object)
            if ret < 0:
                raise WolfCryptError("Key generation error (%d)" % ret)

            return ed448

        def decode_key(self, key, pub = None):
            """
            Decodes an ED448 private + pub key
            """
            key = t2b(key)

            if (len(key) < _lib.wc_ed448_priv_size(self.native_object)/2):
                raise WolfCryptError("Key decode error: key too short")

            idx = _ffi.new("word32*")
            idx[0] = 0
            if pub:
                ret = _lib.wc_ed448_import_private_key(key, len(key), pub,
                        len(pub), self.native_object);
                if ret < 0:
                    raise WolfCryptError("Key decode error (%d)" % ret)
            else:
                ret = _lib.wc_ed448_import_private_only(key, len(key),
                        self.native_object);
                if ret < 0:
                    raise WolfCryptError("Key decode error (%d)" % ret)
                pubkey = _ffi.new("byte[%d]" % (self.size * 4))
                ret = _lib.wc_ed448_make_public(self.native_object, pubkey,
                        self.size)
                if ret < 0:
                    raise WolfCryptError("Public key generate error (%d)" % ret)
                ret = _lib.wc_ed448_import_public(pubkey, self.size,
                        self.native_object);

            if self.size <= 0:  # pragma: no cover
                raise WolfCryptError("Key decode error (%d)" % self.size)
            if self.max_signature_size <= 0:  # pragma: no cover
                raise WolfCryptError(
                    "Key decode error (%d)" % self.max_signature_size)

        def encode_key(self):
            """
            Encodes the ED448 private key.

            Returns the encoded key.
            """
            key = _ffi.new("byte[%d]" % (self.size * 4))
            pubkey = _ffi.new("byte[%d]" % (self.size * 4))
            size = _ffi.new("word32[1]")

            size[0] = _lib.wc_ed448_priv_size(self.native_object)

            ret = _lib.wc_ed448_export_private_only(self.native_object,
                    key, size)
            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Private key encode error (%d)" % ret)
            ret = _lib.wc_ed448_export_public(self.native_object, pubkey,
                    size)
            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Public key encode error (%d)" % ret)

            return _ffi.buffer(key, size[0])[:], _ffi.buffer(pubkey, size[0])[:]

        def sign(self, plaintext, ctx=None):
            """
            Signs **plaintext**, using the private key data in the object.

            Returns the signature.
            """
            plaintext = t2b(plaintext)
            signature = _ffi.new("byte[%d]" % self.max_signature_size)

            signature_size = _ffi.new("word32[1]")
            signature_size[0] = self.max_signature_size
            ctx_buf = _ffi.NULL
            ctx_buf_len = 0
            if (ctx != None):
                ctx_buf = t2b(ctx)
                ctx_buf_len = len(ctx_buf)

            ret = _lib.wc_ed448_sign_msg(plaintext, len(plaintext),
                                        signature, signature_size,
                                        self.native_object, ctx_buf,
                                        ctx_buf_len)

            if ret != 0:  # pragma: no cover
                raise WolfCryptError("Signature error (%d)" % ret)

            return _ffi.buffer(signature, signature_size[0])[:]


if _lib.ML_KEM_ENABLED:
    class MlKemType(IntEnum):
        """
        `MlKemType` specifies supported ML-KEM types.

        `MlKemType` is arguments for constructors and some initialization functions for `MlKemPublic` and `MlKemPrivate`.

        Followings are all possible values:

        - `ML_KEM_512`
        - `ML_KEM_768`
        - `ML_KEM_1024`
        """

        ML_KEM_512 = _lib.WC_ML_KEM_512
        ML_KEM_768 = _lib.WC_ML_KEM_768
        ML_KEM_1024 = _lib.WC_ML_KEM_1024

    class _MlKemBase(object):
        INVALID_DEVID = _lib.INVALID_DEVID

        def __init__(self, mlkem_type):
            self.init_done = False
            self.native_object = _ffi.new("KyberKey *")
            ret = _lib.wc_KyberKey_Init(
                mlkem_type, self.native_object, _ffi.NULL, self.INVALID_DEVID
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_Init() error (%d)" % ret)

            self.init_done = True

        def __del__(self):
            if self.init_done:
                _lib.wc_KyberKey_Free(self.native_object)

        @property
        def ct_size(self):
            """
            :return: cipher text size in bytes
            :rtype: int
            """
            len = _ffi.new("word32 *")
            ret = _lib.wc_KyberKey_CipherTextSize(self.native_object, len)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_CipherTextSize() error (%d)" % ret)

            return len[0]

        @property
        def ss_size(self):
            """
            :return: shared secret size in bytes
            :rtype: int
            """
            len = _ffi.new("word32 *")
            ret = _lib.wc_KyberKey_SharedSecretSize(self.native_object, len)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_SharedSecretSize() error (%d)" % ret)

            return len[0]

        @property
        def _pub_key_size(self):
            len = _ffi.new("word32 *")
            ret = _lib.wc_KyberKey_PublicKeySize(self.native_object, len)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_PublicKeySize() error (%d)" % ret)

            return len[0]

        def _encode_pub_key(self):
            pub_key_size = self._pub_key_size
            pub_key = _ffi.new(f"unsigned char[{pub_key_size}]")
            ret = _lib.wc_KyberKey_EncodePublicKey(
                self.native_object, pub_key, pub_key_size
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_EncodePublicKey() error (%d)" % ret)

            return _ffi.buffer(pub_key, pub_key_size)[:]

    class MlKemPublic(_MlKemBase):
        @property
        def key_size(self):
            """
            :return: public key size in bytes
            :rtype: int
            """
            return self._pub_key_size

        def encode_key(self):
            """
            :return: exported public key
            :rtype: bytes
            """
            return self._encode_pub_key()

        def decode_key(self, pub_key):
            """
            :param pub_key: public key to be imported
            :type pub_key: bytes or str
            """
            pub_key_bytestype = t2b(pub_key)
            ret = _lib.wc_KyberKey_DecodePublicKey(
                self.native_object,
                _ffi.from_buffer(pub_key_bytestype),
                len(pub_key_bytestype),
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_DecodePublicKey() error (%d)" % ret)

        def encapsulate(self, rng=Random()):
            """
            :param rng: random number generator for an encupsulation
            :type rng: Random
            :return: tuple of a shared secret (first element) and the cipher text (second element)
            :rtype: tuple[bytes, bytes]
            """
            ct_size = self.ct_size
            ss_size = self.ss_size
            ct = _ffi.new(f"unsigned char[{ct_size}]")
            ss = _ffi.new(f"unsigned char[{ss_size}]")
            ret = _lib.wc_KyberKey_Encapsulate(
                self.native_object, ct, ss, rng.native_object
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_Encapsulate() error (%d)" % ret)

            return _ffi.buffer(ss, ss_size)[:], _ffi.buffer(ct, ct_size)[:]

        def encapsulate_with_random(self, rand):
            """
            :param rand: random number for an encapsulation
            :type rand: bytes
            :return: tuple of a shared secret (first element) and the cipher text (second element)
            :rtype: tuple[bytes, bytes]
            """
            ct_size = self.ct_size
            ss_size = self.ss_size
            ct = _ffi.new(f"unsigned char[{ct_size}]")
            ss = _ffi.new(f"unsigned char[{ss_size}]")
            ret = _lib.wc_KyberKey_EncapsulateWithRandom(
                self.native_object, ct, ss, _ffi.from_buffer(rand), len(rand)
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError(
                    "wc_KyberKey_EncapsulateWithRandom() error (%d)" % ret
                )

            return _ffi.buffer(ss, ss_size)[:], _ffi.buffer(ct, ct_size)[:]

    class MlKemPrivate(_MlKemBase):
        @classmethod
        def make_key(cls, mlkem_type, rng=Random()):
            """
            :param mlkem_type: ML-KEM type
            :type mlkem_type: MlKemType
            :param rng: random number generator for a key generation
            :type rng: Random
            :return: `MlKemPrivate` object
            :rtype: MlKemPrivate
            """
            mlkem_priv = cls(mlkem_type)
            ret = _lib.wc_KyberKey_MakeKey(mlkem_priv.native_object, rng.native_object)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_MakeKey() error (%d)" % ret)

            return mlkem_priv

        @classmethod
        def make_key_with_random(cls, mlkem_type, rand):
            """
            :param mlkem_type: ML-KEM type
            :type mlkem_type: MlKemType
            :param rand: random number for a key generation
            :type rand: bytes
            :return: `MlKemPrivate` object
            :rtype: MlKemPrivate
            """
            mlkem_priv = cls(mlkem_type)
            ret = _lib.wc_KyberKey_MakeKeyWithRandom(
                mlkem_priv.native_object, _ffi.from_buffer(rand), len(rand)
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_MakeKeyWithRandom() error (%d)" % ret)

            return mlkem_priv

        @property
        def pub_key_size(self):
            """
            :return: public key size in bytes
            :rtype: int
            """
            return self._pub_key_size

        @property
        def priv_key_size(self):
            """
            :return: private key size in bytes
            :rtype: int
            """
            len = _ffi.new("word32 *")
            ret = _lib.wc_KyberKey_PrivateKeySize(self.native_object, len)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_PrivateKeySize() error (%d)" % ret)

            return len[0]

        def encode_pub_key(self):
            """
            :return: exported public key
            :rtype: bytes
            """
            return self._encode_pub_key()

        def encode_priv_key(self):
            """
            :return: exported private key
            :rtype: bytes
            """
            priv_key_size = self.priv_key_size
            priv_key = _ffi.new(f"unsigned char[{priv_key_size}]")
            ret = _lib.wc_KyberKey_EncodePrivateKey(
                self.native_object, priv_key, priv_key_size
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_EncodePrivateKey() error (%d)" % ret)

            return _ffi.buffer(priv_key, priv_key_size)[:]

        def decode_key(self, priv_key: tuple[bytes, str]):
            """
            :param priv_key: private key to be imported
            :type priv_key: bytes or str
            """
            priv_key_bytestype = t2b(priv_key)
            ret = _lib.wc_KyberKey_DecodePrivateKey(
                self.native_object,
                _ffi.from_buffer(priv_key_bytestype),
                len(priv_key_bytestype),
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_KyberKey_DecodePrivateKey() error (%d)" % ret)

        def decapsulate(self, ct):
            """
            :param ct: cipher text
            :type ct: bytes or str
            :return: shared secret
            :rtype: bytes
            """
            ss_size = self.ss_size
            ss = _ffi.new(f"unsigned char[{ss_size}]")
            ct_bytestype = t2b(ct)
            ret = _lib.wc_KyberKey_Decapsulate(
                self.native_object,
                ss,
                _ffi.from_buffer(ct_bytestype),
                len(ct_bytestype),
            )

            if ret < 0:  # pragma: no cover
                self.native_object = None
                raise WolfCryptError("wc_KyberKey_Decapsulate() error (%d)" % ret)

            return _ffi.buffer(ss, ss_size)[:]


if _lib.ML_DSA_ENABLED:
    class MlDsaType(IntEnum):
        """
        `MlDsaType` specifies supported ML-DSA types.

        `MlDsaType` is arguments for constructors and some initialization functions for `MlDsaPublic` and `MlDsaPrivate`.

        Followings are all possible values:

        - `ML_DSA_44`
        - `ML_DSA_65`
        - `ML_DSA_87`
        """

        ML_DSA_44 = _lib.WC_ML_DSA_44
        ML_DSA_65 = _lib.WC_ML_DSA_65
        ML_DSA_87 = _lib.WC_ML_DSA_87

    class _MlDsaBase(object):
        INVALID_DEVID = _lib.INVALID_DEVID

        def __init__(self, mldsa_type):
            self._init_done = False
            self.native_object = _ffi.new("dilithium_key *")
            ret = _lib.wc_dilithium_init_ex(
                self.native_object, _ffi.NULL, self.INVALID_DEVID
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_dilithium_init_ex() error (%d)" % ret)

            self._init_done = True

            ret = _lib.wc_dilithium_set_level(self.native_object, mldsa_type)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_dilithium_set_level() error (%d)" % ret)

        def __del__(self):
            if self._init_done:
                _lib.wc_dilithium_free(self.native_object)

        @property
        def _pub_key_size(self):
            size = _ffi.new("int *")
            ret = _lib.wc_MlDsaKey_GetPubLen(self.native_object, size)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_MlDsaKey_GetPubLen() error (%d)" % ret)

            return size[0]

        @property
        def sig_size(self):
            """
            :return: signature size in bytes
            :rtype: int
            """
            size = _ffi.new("int *")
            ret = _lib.wc_MlDsaKey_GetSigLen(self.native_object, size)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_MlDsaKey_GetSigLen() error (%d)" % ret)

            return size[0]

        def _decode_pub_key(self, pub_key):
            pub_key_bytestype = t2b(pub_key)
            ret = _lib.wc_dilithium_import_public(
                _ffi.from_buffer(pub_key_bytestype),
                len(pub_key_bytestype),
                self.native_object,
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_dilithium_import_public() error (%d)" % ret)

        def _encode_pub_key(self):
            in_size = self._pub_key_size
            pub_key = _ffi.new(f"byte[{in_size}]")
            out_size = _ffi.new("word32 *")
            out_size[0] = in_size
            ret = _lib.wc_dilithium_export_public(self.native_object, pub_key, out_size)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_dilithium_export_public() error (%d)" % ret)

            if in_size != out_size[0]:
                raise WolfCryptError(
                    "in_size=%d and out_size=%d don't match" % (in_size, out_size[0])
                )

            return _ffi.buffer(pub_key, out_size[0])[:]

        def verify(self, signature, message):
            """
            :param signature: signature to be verified
            :type signature: bytes or str
            :param message: message to be verified
            :type message: bytes or str
            :return: True if the verification is successful, False otherwise
            :rtype: bool
            """
            sig_bytestype = t2b(signature)
            msg_bytestype = t2b(message)
            res = _ffi.new("int *")

            ret = _lib.wc_dilithium_verify_msg(
                _ffi.from_buffer(sig_bytestype),
                len(sig_bytestype),
                _ffi.from_buffer(msg_bytestype),
                len(msg_bytestype),
                res,
                self.native_object,
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_dilithium_verify_msg() error (%d)" % ret)

            return res[0] == 1

    class MlDsaPrivate(_MlDsaBase):
        _SIGNATURE_SEED_LENGTH = 32
        """The length of a signature generation seed."""

        @classmethod
        def make_key(cls, mldsa_type, rng=Random()):
            """
            :param mldsa_type: ML-DSA type
            :type mldsa_type: MlDsaType
            :param rng: random number generator for a key generation
            :type rng: Random
            :return: `MlDsaPrivate` object
            :rtype: MlDsaPrivate
            """
            mldsa_priv = cls(mldsa_type)
            ret = _lib.wc_dilithium_make_key(
                mldsa_priv.native_object, rng.native_object
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_dilithium_make_key() error (%d)" % ret)

            return mldsa_priv

        @property
        def pub_key_size(self):
            """
            :return: public key size in bytes
            :rtype: int
            """
            return self._pub_key_size

        @property
        def priv_key_size(self):
            """
            :return: private key size in bytes
            :rtype: int
            """
            size = _ffi.new("int *")
            ret = _lib.wc_MlDsaKey_GetPrivLen(self.native_object, size)

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_MlDsaKey_GetPrivLen() error (%d)" % ret)

            key_pair_size = size[0]

            return key_pair_size - self.pub_key_size

        def encode_pub_key(self):
            """
            :return: exported public key
            :rtype: bytes
            """
            return self._encode_pub_key()

        def encode_priv_key(self):
            """
            :return: exported private key
            :rtype: bytes
            """
            in_size = self.priv_key_size
            priv_key = _ffi.new(f"byte[{in_size}]")
            out_size = _ffi.new("word32 *")
            out_size[0] = in_size
            ret = _lib.wc_dilithium_export_private(
                self.native_object, priv_key, out_size
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_dilithium_export_private() error (%d)" % ret)

            if in_size != out_size[0]:
                raise WolfCryptError(
                    "in_size=%d and out_size=%d don't match" % (in_size, out_size[0])
                )

            return _ffi.buffer(priv_key, out_size[0])[:]

        def decode_key(self, priv_key, pub_key=None):
            """
            :param priv_key: private key to be imported
            :type priv_key: bytes or str
            :param pub_key: public key to be imported
            :type pub_key: bytes or str or None
            """
            priv_key_bytestype = t2b(priv_key)
            ret = _lib.wc_dilithium_import_private(
                _ffi.from_buffer(priv_key_bytestype),
                len(priv_key_bytestype),
                self.native_object,
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_dilithium_import_private() error (%d)" % ret)

            if pub_key is not None:
                self._decode_pub_key(pub_key)

        def sign(self, message, rng=Random()):
            """
            :param message: message to be signed
            :type message: bytes or str
            :param rng: random number generator for sign
            :type rng: Random
            :return: signature
            :rtype: bytes
            """
            msg_bytestype = t2b(message)
            in_size = self.sig_size
            signature = _ffi.new(f"byte[{in_size}]")
            out_size = _ffi.new("word32 *")
            out_size[0] = in_size

            ret = _lib.wc_dilithium_sign_msg(
                _ffi.from_buffer(msg_bytestype),
                len(msg_bytestype),
                signature,
                out_size,
                self.native_object,
                rng.native_object,
            )

            if ret < 0:  # pragma: no cover
                raise WolfCryptError("wc_dilithium_sign_msg() error (%d)" % ret)

            if in_size != out_size[0]:
                raise WolfCryptError(
                    "in_size=%d and out_size=%d don't match" % (in_size, out_size[0])
                )

            return _ffi.buffer(signature, out_size[0])[:]

        def sign_with_seed(self, message, seed, ctx=None):
            """
            :param message: message to be signed
            :type message: bytes or str
            :param seed: 32-byte seed for deterministic signature generation.
            :type seed: bytes
            :param ctx: context (optional)
            :type ctx: None for no context, str or bytes otherwise
            :return: signature
            :rtype: bytes
            """
            msg_bytestype = t2b(message)
            in_size = self.sig_size
            signature = _ffi.new(f"byte[{in_size}]")
            out_size = _ffi.new("word32 *")
            out_size[0] = in_size

            assert isinstance(seed, bytes) and len(seed) == MlDsaPrivate._SIGNATURE_SEED_LENGTH, \
                f"Seed for generating a signature must be {MlDsaPrivate._SIGNATURE_SEED_LENGTH} bytes."

            if ctx is not None:
                ctx_bytestype = t2b(ctx)
                ret = _lib.wc_dilithium_sign_ctx_msg_with_seed(
                    _ffi.from_buffer(ctx_bytestype),
                    len(ctx_bytestype),
                    _ffi.from_buffer(msg_bytestype),
                    len(msg_bytestype),
                    signature,
                    out_size,
                    self.native_object,
                    _ffi.from_buffer(seed),
                )
                if ret < 0:  # pragma: no cover
                    raise WolfCryptError("wc_dilithium_sign_ctx_msg_with_seed() error (%d)" % ret)
            else:
                ret = _lib.wc_dilithium_sign_msg_with_seed(
                    _ffi.from_buffer(msg_bytestype),
                    len(msg_bytestype),
                    signature,
                    out_size,
                    self.native_object,
                    _ffi.from_buffer(seed),
                )
                if ret < 0:  # pragma: no cover
                    raise WolfCryptError("wc_dilithium_sign_msg_with_seed() error (%d)" % ret)


            if in_size != out_size[0]:
                raise WolfCryptError(
                    "in_size=%d and out_size=%d don't match" % (in_size, out_size[0])
                )

            return _ffi.buffer(signature, out_size[0])[:]

    class MlDsaPublic(_MlDsaBase):
        @property
        def key_size(self):
            """
            :return: public key size in bytes
            :rtype: int
            """
            return self._pub_key_size

        def decode_key(self, pub_key):
            """
            :param pub_key: public key to be imported
            :type pub_key: bytes or str
            """
            return self._decode_pub_key(pub_key)

        def encode_key(self):
            """
            :return: exported public key
            :rtype: bytes
            """
            return self._encode_pub_key()