public override void AppendPublicKey(ref SequenceWriter writer)
{
RSAParameters parameters = _rsa.ExportParameters(includePrivateParameters: false);
using var innerData = writer.SequencePool.RentSequence();
var innerWriter = new SequenceWriter(innerData);
innerWriter.WriteString(AlgorithmNames.SshRsa);
innerWriter.WriteMPInt(parameters.Exponent);
innerWriter.WriteMPInt(parameters.Modulus);
writer.WriteString(innerData.AsReadOnlySequence());
}
private byte[] CalculateExchangeHash(SequencePool sequencePool, SshConnectionInfo connectionInfo, Packet clientKexInitMsg, Packet serverKexInitMsg, ReadOnlySequence <byte> public_host_key, ECPoint q_c, ECPoint q_s, BigInteger sharedSecret)
{
/*
* string V_C, client's identification string (CR and LF excluded)
* string V_S, server's identification string (CR and LF excluded)
* string I_C, payload of the client's SSH_MSG_KEXINIT
* string I_S, payload of the server's SSH_MSG_KEXINIT
* string K_S, server's public host key
* string Q_C, client's ephemeral public key octet string
* string Q_S, server's ephemeral public key octet string
* mpint K, shared secret
*/
using Sequence sequence = sequencePool.RentSequence();
var writer = new SequenceWriter(sequence);
writer.WriteString(connectionInfo.ClientIdentificationString !);
writer.WriteString(connectionInfo.ServerIdentificationString !);
writer.WriteString(clientKexInitMsg.Payload);
writer.WriteString(serverKexInitMsg.Payload);
writer.WriteString(public_host_key);
writer.WriteString(q_c);
writer.WriteString(q_s);
writer.WriteMPInt(sharedSecret);
using IncrementalHash hash = IncrementalHash.CreateHash(_hashAlgorithmName);
foreach (var segment in sequence.AsReadOnlySequence())
{
hash.AppendData(segment.Span);
}
return(hash.GetHashAndReset());
}
private byte[] Hash(SequencePool sequencePool, BigInteger sharedSecret, byte[] exchangeHash, byte c, byte[] sessionId, int hashLength)
{
// https://tools.ietf.org/html/rfc4253#section-7.2
byte[] hashRv = new byte[hashLength];
int hashOffset = 0;
// TODO: handle 'If the key length needed is longer than the output of the HASH'
// HASH(K || H || c || session_id)
using Sequence sequence = sequencePool.RentSequence();
var writer = new SequenceWriter(sequence);
writer.WriteMPInt(sharedSecret);
writer.Write(exchangeHash);
writer.WriteByte(c);
writer.Write(sessionId);
using IncrementalHash hash = IncrementalHash.CreateHash(_hashAlgorithmName);
foreach (var segment in sequence.AsReadOnlySequence())
{
hash.AppendData(segment.Span);
}
byte[] K1 = hash.GetHashAndReset();
Append(hashRv, K1, ref hashOffset);
while (hashOffset != hashRv.Length)
{
// TODO: handle 'If the key length needed is longer than the output of the HASH'
// K3 = HASH(K || H || K1 || K2)
throw new NotSupportedException();
}
return(hashRv);
