/// <summary>
/// Computes the client response containing the client's public key and
/// evidence.
/// </summary>
/// <param name="challenge">The challenge containing the protocol elements
/// received from the server in response to the initial client
/// response.</param>
/// <returns>An array of bytes containing the client's challenge
/// response.</returns>
/// <exception cref="SaslException">Thrown if the server specified any
/// mandatory options which are not supported.</exception>
private byte[] ComputeFinalResponse(byte[] challenge)
{
ServerMessage1 m = ServerMessage1.Deserialize(challenge);
// We don't support integrity protection or confidentiality.
if (!String.IsNullOrEmpty(m.Options["mandatory"]))
{
throw new SaslException("Mandatory options are not supported.");
}
// Set up the message digest algorithm.
var mda = SelectHashAlgorithm(m.Options["mda"]);
HashAlgorithm = Activator.CreateInstance(mda.Item2) as HashAlgorithm;
// Compute public and private key.
PublicKey = Helper.ComputeClientPublicKey(m.Generator,
m.SafePrimeModulus, PrivateKey);
// Compute the shared key and client evidence.
SharedKey = Helper.ComputeSharedKey(m.Salt, Username, Password,
PublicKey, m.PublicKey, PrivateKey, m.Generator, m.SafePrimeModulus,
HashAlgorithm);
ClientProof = Helper.ComputeClientProof(m.SafePrimeModulus,
m.Generator, Username, m.Salt, PublicKey, m.PublicKey, SharedKey,
AuthId, m.RawOptions, HashAlgorithm);
ClientMessage2 response = new ClientMessage2(PublicKey, ClientProof);
// Let the server know which hash algorithm we are using.
response.Options["mda"] = mda.Item1;
// Remember the raw options string because we'll need it again
// when verifying the server signature.
Options = response.BuildOptionsString();
return(response.Serialize());
}
public void DeserializeServerFirstMessage()
{
ServerMessage1 m = ServerMessage1.Deserialize(serverMessage1);
BigInteger expectedGenerator = new BigInteger(2),
expectedModulus = BigInteger.Parse(expectedSafePrimeModulus,
NumberStyles.HexNumber),
_expectedPublicKey = BigInteger.Parse(expectedPublicKey,
NumberStyles.HexNumber);
Assert.AreEqual <BigInteger>(expectedGenerator, m.Generator.Value);
Assert.AreEqual <BigInteger>(expectedModulus, m.SafePrimeModulus.Value);
Assert.AreEqual <BigInteger>(_expectedPublicKey, m.PublicKey.Value);
Assert.IsTrue(m.Salt.SequenceEqual(expectedSalt));
Assert.AreEqual <string>(expectedOptions, m.RawOptions);
Assert.AreEqual <int>(expectedParsedOptions.Count, m.Options.Count);
foreach (KeyValuePair <string, string> pair in expectedParsedOptions)
{
Assert.AreEqual <string>(pair.Value, m.Options[pair.Key]);
}
}
