/// <summary>
/// Try to get a cached entry.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="entry">The entry.</param>
/// <returns>True if the cache contained an entry for the key.</returns>
public bool TryGet(ScramCacheKey key, out ScramCacheEntry entry)
{
if (key.Equals(_cacheKey))
{
entry = _cachedEntry;
return(true);
}
else
{
entry = null;
return(false);
}
}
public ISaslStep Transition(SaslConversation conversation, byte[] bytesReceivedFromServer)
{
var encoding = Utf8Encodings.Strict;
var serverFirstMessage = encoding.GetString(bytesReceivedFromServer);
var map = SaslMapParser.Parse(serverFirstMessage);
var r = map['r'];
if (!r.StartsWith(_rPrefix, StringComparison.Ordinal))
{
throw new MongoAuthenticationException(conversation.ConnectionId, message: "Server sent an invalid nonce.");
}
var s = map['s'];
var i = map['i'];
const string gs2Header = "n,,";
var channelBinding = "c=" + Convert.ToBase64String(encoding.GetBytes(gs2Header));
var nonce = "r=" + r;
var clientFinalMessageWithoutProof = channelBinding + "," + nonce;
var salt = Convert.FromBase64String(map['s']);
var iterations = int.Parse(map['i']);
byte[] clientKey;
byte[] serverKey;
var cacheKey = new ScramCacheKey(_credential.SaslPreppedPassword, salt, iterations);
if (_cache.TryGet(cacheKey, out var cacheEntry))
{
clientKey = cacheEntry.ClientKey;
serverKey = cacheEntry.ServerKey;
}
else
{
var saltedPassword = _hi(_credential, salt, iterations);
clientKey = _hmac(encoding, saltedPassword, "Client Key");
serverKey = _hmac(encoding, saltedPassword, "Server Key");
_cache.Add(cacheKey, new ScramCacheEntry(clientKey, serverKey));
}
var storedKey = _h(clientKey);
var authMessage = _clientFirstMessageBare + "," + serverFirstMessage + "," + clientFinalMessageWithoutProof;
var clientSignature = _hmac(encoding, storedKey, authMessage);
var clientProof = XOR(clientKey, clientSignature);
var serverSignature = _hmac(encoding, serverKey, authMessage);
var proof = "p=" + Convert.ToBase64String(clientProof);
var clientFinalMessage = clientFinalMessageWithoutProof + "," + proof;
return(new ClientLast(encoding.GetBytes(clientFinalMessage), serverSignature));
}
public override bool Equals(object obj)
{
if (this == obj)
{
return(true);
}
if (obj == null || obj.GetType() != obj.GetType())
{
return(false);
}
ScramCacheKey other = (ScramCacheKey)obj;
return
(Equals(_password, other._password) &&
_iterationCount == other._iterationCount &&
_salt.SequenceEqual(other._salt));
}
/// <summary>
/// Add a cached entry.
/// </summary>
/// <param name="key">The key.</param>
/// <param name="entry">The entry.</param>
public void Add(ScramCacheKey key, ScramCacheEntry entry)
{
_cacheKey = key;
_cachedEntry = entry;
}