/// <summary>
/// Initializes a new instance of the <see cref="AesCbcHmacDecryptor"/> class.
/// </summary>
/// <param name="keyBytes"></param>
/// <param name="encryptionAlgorithm"></param>
/// <param name="decryptor"></param>
public AesCbcHmacDecryptor(ReadOnlySpan <byte> keyBytes, EncryptionAlgorithm encryptionAlgorithm, AesDecryptor decryptor)
{
if (encryptionAlgorithm is null)
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.encryptionAlgorithm);
}
if (encryptionAlgorithm.Category != EncryptionType.AesHmac)
{
ThrowHelper.ThrowNotSupportedException_EncryptionAlgorithm(encryptionAlgorithm);
}
int keyLength = encryptionAlgorithm.RequiredKeySizeInBits >> 4;
if (keyBytes.Length < keyLength)
{
ThrowHelper.ThrowArgumentOutOfRangeException_EncryptionKeyTooSmall(encryptionAlgorithm, encryptionAlgorithm.RequiredKeySizeInBits, keyBytes.Length >> 3);
}
_decryptor = decryptor;
if (encryptionAlgorithm.SignatureAlgorithm is null)
{
ThrowHelper.ThrowNotSupportedException_SignatureAlgorithm(encryptionAlgorithm.SignatureAlgorithm);
}
_signer = new SymmetricSigner(keyBytes.Slice(0, keyLength), encryptionAlgorithm.SignatureAlgorithm);
}
/// <summary>
/// Initializes a new instance of the <see cref="AesCbcHmacDecryptor"/> class.
/// </summary>
/// <param name="key"></param>
/// <param name="encryptionAlgorithm"></param>
public AesCbcHmacDecryptor(SymmetricJwk key, EncryptionAlgorithm encryptionAlgorithm)
{
if (key is null)
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.key);
}
if (encryptionAlgorithm is null)
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.encryptionAlgorithm);
}
if (encryptionAlgorithm.Category != EncryptionType.AesHmac)
{
ThrowHelper.ThrowNotSupportedException_EncryptionAlgorithm(encryptionAlgorithm);
}
if (key.KeySizeInBits < encryptionAlgorithm.RequiredKeySizeInBits)
{
ThrowHelper.ThrowArgumentOutOfRangeException_EncryptionKeyTooSmall(key, encryptionAlgorithm, encryptionAlgorithm.RequiredKeySizeInBits, key.KeySizeInBits);
}
int keyLength = encryptionAlgorithm.RequiredKeySizeInBits >> 4;
var keyBytes = key.K;
var aesKey = keyBytes.Slice(keyLength);
_decryptor = new AesCbcDecryptor(aesKey, encryptionAlgorithm);
if (encryptionAlgorithm.SignatureAlgorithm is null)
{
ThrowHelper.ThrowNotSupportedException_SignatureAlgorithm(encryptionAlgorithm.SignatureAlgorithm);
}
_signer = new SymmetricSigner(keyBytes.Slice(0, keyLength), encryptionAlgorithm.SignatureAlgorithm);
}