public bool DecryptAfterReceive(
ReadOnlySpan <byte> associatedData,
ReadOnlySpan <byte> ciphertext,
Span <byte> plaintext)
{
// decrypt the ciphertext with the receive nonce
if (!_algorithm.Decrypt(
_receiveKey,
_receiveNonce,
associatedData,
ciphertext,
plaintext))
{
// abort the connection if decryption fails
_sendKey.Dispose();
_receiveKey.Dispose();
return(false);
}
// increment the counter field of the receive nonce
if (!Nonce.TryIncrement(ref _receiveNonce))
{
// abort the connection when the counter field of the
// receive nonce reaches the maximum value
_sendKey.Dispose();
_receiveKey.Dispose();
}
return(true);
}
private static void EncryptBeforeSend(ReadOnlySpan <byte> associatedData, Nonce sendNonce, ReadOnlySpan <byte> plaintext, Span <byte> ciphertext)
{
_algorithm.Encrypt(_sendKey, sendNonce, associatedData, plaintext, ciphertext);
if (!Nonce.TryIncrement(ref _sendSequenceNumber))
{
_sendKey.Dispose();
}
}
private static bool DecryptAfterReceive(Nonce receiveNonce, ReadOnlySpan <byte> ciphertext, Span <byte> plaintext)
{
if (!_algorithm.Decrypt(_sendKey, receiveNonce, _associatedData, ciphertext, plaintext))
{
_sendKey.Dispose();
return(false);
}
if (!Nonce.TryIncrement(ref _receiveSequenceNumber))
{
_sendKey.Dispose();
return(false);
}
return(true);
}
public void EncryptBeforeSend(
ReadOnlySpan <byte> associatedData,
ReadOnlySpan <byte> plaintext,
Span <byte> ciphertext)
{
// encrypt the plaintext with the send nonce
_algorithm.Encrypt(
_sendKey,
_sendNonce,
associatedData,
plaintext,
ciphertext);
// increment the counter field of the send nonce
if (!Nonce.TryIncrement(ref _sendNonce))
{
// abort the connection when the counter field of the
// send nonce reaches the maximum value
_sendKey.Dispose();
_receiveKey.Dispose();
}
}
public void EncryptBeforeSend(
ReadOnlySpan <byte> associatedData,
ReadOnlySpan <byte> plaintext,
Span <byte> ciphertext)
{
// encrypt the plaintext with the send sequence number XORed
// with the send IV as the nonce
_algorithm.Encrypt(
_sendKey,
_sendSequenceNumber ^ _sendIV,
associatedData,
plaintext,
ciphertext);
// increment the send sequence number
if (!Nonce.TryIncrement(ref _sendSequenceNumber))
{
// abort the connection when the send sequence number
// reaches the maximum value
_sendKey.Dispose();
_receiveKey.Dispose();
}
}