private async Task OnRequestAsync(LdapRequestMessage message, LdapClientConnection connection)
{
if (!await connection.TryAddPendingAsync(message).ConfigureAwait(false))
{
return;
}
try
{
if (message is LdapAbandonRequest abandon)
{
connection.ContinueRead();
if (CriticalControlsSupported(abandon.Controls))
{
connection.AbandonRequest(abandon.MessageId);
}
}
else if (message is LdapBindRequest bind)
{
connection.ContinueRead();
try
{
await connection.BeginBindAsync().ConfigureAwait(false);
var response = await BindRequestAsync(bind, connection).ConfigureAwait(false);
await WriteAsync(response, connection).ConfigureAwait(false);
}
catch (Exception ex)
{
await WriteAsync(bind.Response(ResultCode.Other, ex.Message), connection).ConfigureAwait(false);
}
finally
{
connection.FinishBind();
}
}
else if (message is LdapUnbindRequest)
{
connection.ContinueRead();
UnbindRequest(connection);
}
else if (message is LdapSearchRequest search)
{
connection.ContinueRead();
await SearchRequestAsync(search, connection).ConfigureAwait(false);
}
else if (message is LdapExtendedRequest extended)
{
await ExtendedRequestAsync(extended, connection).ConfigureAwait(false);
}
else
{
connection.ContinueRead();
throw new NotImplementedException();
}
}
finally
{
connection.RemovePending(message);
}
}
private async Task SearchRequestAsync(LdapSearchRequest request, LdapClientConnection connection, CancellationToken cancellationToken)
{
try
{
if (request.BaseObject.RDNs.Count == 0 &&
request.Scope == SearchScope.BaseObject &&
request.Filter is LdapPresentFilter filter &&
(filter.Attribute.Oid.Equals("objectClass", StringComparison.OrdinalIgnoreCase) || filter.Attribute.Oid == "2.5.4.0"))
{
ICollection <LdapAttribute> attributes = _rootDse.GetAttributes(request.Attributes, request.TypesOnly).ToList();
if (_sslOptions != null && request.Attributes.Where(x => x.Selector != null).Any(x => x.Selector.Oid == SupportedExtensionAttribute.OidValue || x.Selector.Oid == SupportedExtensionAttribute.ShortName))
{
var attribute = attributes.OfType <SupportedExtensionAttribute>().FirstOrDefault();
if (attribute == null)
{
attribute = new SupportedExtensionAttribute
{
Entries = { LdapExtendedRequest.StartTLS }
};
attributes.Add(attribute);
}
else
{
attribute.Entries.Add(LdapExtendedRequest.StartTLS);
}
}
attributes = await OnGetRootDSEAsync(attributes, connection, cancellationToken).ConfigureAwait(false);
var entry = request.Result(LdapDistinguishedName.Empty, attributes.ToArray(), Array.Empty <LdapControl>());
await WriteAsync(entry, connection).ConfigureAwait(false);
await WriteAsync(request.Done(), connection).ConfigureAwait(false);
}
else
{
var results = await OnSearchAsync(request, connection, cancellationToken).ConfigureAwait(false);
bool done = false;
foreach (var response in results)
{
await WriteAsync(response, connection).ConfigureAwait(false);
if (response is LdapSearchResultDone)
{
done = true;
break;
}
}
if (!done)
{
await WriteAsync(request.Done(), connection).ConfigureAwait(false);
}
}
}
private async Task <LdapBindResponse> OnBindAsync(LdapBindRequest request, LdapClientConnection connection)
{
ResultCode result = ResultCode.AuthMethodNotSupported;
if (request.Simple != null)
{
result = await OnBindAsync(request.Name, request.Simple.Value, connection).ConfigureAwait(false);
}
else if (request.SaslMechanism == SupportedSASLMechanismsAttribute.Anonymous)
{
var credentials = request.SaslCredentials.GetValueOrDefault(ReadOnlyMemory <byte> .Empty);
result = await OnSaslBindAsync(request.Name, String.Empty, credentials, connection).ConfigureAwait(false);
}
else if (request.SaslMechanism == SupportedSASLMechanismsAttribute.Plain)
{
if (request.SaslCredentials == null)
{
result = ResultCode.InappropriateAuthentication;
}
else
{
var credentials = request.SaslCredentials.Value;
var first = credentials.Span.IndexOf((byte)0);
var last = credentials.Span.LastIndexOf((byte)0);
if (first == last)
{
result = ResultCode.InappropriateAuthentication;
}
else
{
first++;
var user = Encoding.UTF8.GetString(credentials.Slice(first, last - first).Span);
var password = credentials.Slice(last + 1);
result = await OnSaslBindAsync(request.Name, user, password, connection).ConfigureAwait(false);
}
}
}
switch (result)
{
case ResultCode.Other:
return(request.Response(result, "Not implemented"));
case ResultCode.Success:
return(request.Response());
default:
return(request.Response(result, String.Empty));
}
}
private async Task SearchRequestAsync(LdapSearchRequest request, LdapClientConnection connection)
{
if (request.TimeLimit != TimeSpan.Zero)
{
using (var cts = new CancellationTokenSource(request.TimeLimit))
using (var combined = CancellationTokenSource.CreateLinkedTokenSource(connection.CancellationToken, cts.Token))
{
await SearchRequestAsync(request, connection, combined.Token).ConfigureAwait(false);
}
}
else
{
await SearchRequestAsync(request, connection, connection.CancellationToken).ConfigureAwait(false);
}
}
private Task <LdapBindResponse> BindRequestAsync(LdapBindRequest request, LdapClientConnection connection)
{
if (request.Version != 3)
{
return(Task.FromResult(request.Response(ResultCode.ProtocolError, "only version 3 is supported")));
}
if (!CriticalControlsSupported(request.Controls))
{
return(Task.FromResult(request.Response(ResultCode.UnavailableCriticalExtension, String.Empty)));
}
if (request.Simple.HasValue && request.Simple.Value.Length == 0 && request.Name.RDNs.Count > 0)
{
//https://tools.ietf.org/html/rfc4513#section-5.1.2
return(Task.FromResult(request.Response(ResultCode.UnwillingToPerform, "Unauthenticated Bind")));
}
if (request.SaslMechanism != null && request.SaslMechanism.Length == 0)
{
return(Task.FromResult(request.Response(ResultCode.AuthMethodNotSupported, "SASL aborted")));
}
return(OnBindAsync(request, connection));
}
private static void UnbindRequest(LdapClientConnection connection)
{
connection.CloseConnection();
}
protected virtual Task <LdapExtendedResponse> OnExtendedAsync(LdapExtendedRequest request, LdapClientConnection connection)
{
return(Task.FromResult(request.NotSupported()));
}
protected virtual Task <ICollection <LdapAttribute> > OnGetRootDSEAsync(ICollection <LdapAttribute> attributes, LdapClientConnection connection, CancellationToken cancellationToken)
{
return(Task.FromResult(attributes));
}
protected virtual Task <IEnumerable <LdapRequestMessage> > OnSearchAsync(LdapSearchRequest request, LdapClientConnection connection, CancellationToken cancellationToken)
{
return(Task.FromResult(Enumerable.Empty <LdapRequestMessage>()));
}
protected virtual Task <ResultCode> OnSaslBindAsync(LdapDistinguishedName bindDN, string username, ReadOnlyMemory <byte> password, LdapClientConnection connection)
{
return(Task.FromResult(ResultCode.Other));
}
protected virtual void OnError(LdapClientConnection connection, LdapException exception)
{
return;
}