private static void DispatchEncryptEcb(ReadOnlySpan <byte> plaintext,
Span <byte> ciphertext,
AesKey key,
PaddingMode paddingMode)
{
switch (key)
{
case Aes128Key aes128Key:
EncryptEcb(plaintext, ciphertext, aes128Key, paddingMode);
return;
case Aes192Key aes192Key:
EncryptEcb(plaintext, ciphertext, aes192Key, paddingMode);
return;
case Aes256Key aes256Key:
EncryptEcb(plaintext, ciphertext, aes256Key, paddingMode);
return;
}
}
private static void DispatchDecryptEcb(
ReadOnlySpan <byte> ciphertext,
Span <byte> plaintext,
AesKey key,
PaddingMode paddingMode)
{
switch (key)
{
case Aes128Key aes128Key:
DecryptEcb(ciphertext, plaintext, aes128Key);
break;
case Aes192Key aes192Key:
DecryptEcb(ciphertext, plaintext, aes192Key);
break;
case Aes256Key aes256Key:
DecryptEcb(ciphertext, plaintext, aes256Key);
break;
}
}
// TODO: harmonize default parameter values (e.g. paddingMode)
public static void Encrypt(ReadOnlySpan <byte> plaintext,
Span <byte> ciphertext,
ReadOnlySpan <byte> iv,
AesKey key,
CipherMode cipherMode = CipherMode.CBC,
PaddingMode paddingMode = PaddingMode.PKCS7)
{
if (cipherMode != CipherMode.ECB && cipherMode != CipherMode.CBC)
{
ThrowHelper.ThrowNotImplementedException();
}
if (paddingMode == PaddingMode.None && plaintext.Length % BlockSize != 0)
{
ThrowHelper.ThrowInputNotMultipleOfBlockSizeException(nameof(plaintext));
}
if (cipherMode == CipherMode.CBC && iv == null)
{
ThrowHelper.ThrowArgumentNullException(nameof(iv));
}
// TODO: correctly validate ciphertext length
if (ciphertext.Length < plaintext.Length)
{
ThrowHelper.ThrowDestinationBufferTooSmallException(nameof(ciphertext));
}
// TODO: moar validation
switch (cipherMode)
{
case CipherMode.ECB:
DispatchEncryptEcb(plaintext, ciphertext, key, paddingMode);
return;
case CipherMode.CBC:
DispatchEncryptCbc(plaintext, ciphertext, iv, key, paddingMode);
return;
}
ThrowHelper.ThrowNotImplementedException();
}
