make sure to raise error if sspi not created

Author: twsouthwick

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/SSPI/NegotiateSspiContextProvider.cs

@@ -11,7 +11,7 @@ namespace Microsoft.Data.SqlClient
 {
     internal sealed class NegotiateSspiContextProvider : SspiContextProvider
     {
-        private NegotiateAuthentication? _negotiateAuth = null;
+        private NegotiateAuthentication? _negotiateAuth;
 
         protected override bool GenerateSspiClientContext(ReadOnlySpan<byte> incomingBlob, IBufferWriter<byte> outgoingBlobWriter, SspiAuthenticationParameters authParams)
         {

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/SSPI/SspiContextProvider.cs

@@ -15,7 +15,7 @@ internal abstract class SspiContextProvider
         // This is used to store either a single or multiple SspiAuthenticationParameters. Since we initially have potential
         // multiple SPNs, we'll start with that. However, once we've succeeded creating an SSPI context, we'll consider that
         // to be the correct SPN going forward
-        private object? _authParams;
+        private object? _authParamValue;
 
         private protected TdsParserStateObject _physicalStateObj = null!;
 
@@ -35,9 +35,9 @@ string[] serverSpns
             _serverInfo = serverInfo;
 
 #if NETFRAMEWORK
-            _authParams = CreateAuthParams(serverSpn);
+            _authParamValue = CreateAuthParams(serverSpn);
 #else
-            _authParams = serverSpns.Select(CreateAuthParams).ToArray();
+            _authParamValue = serverSpns.Select(CreateAuthParams).ToArray();
 #endif
             Initialize();
         }
@@ -48,23 +48,22 @@ private protected virtual void Initialize()
 
         protected abstract bool GenerateSspiClientContext(ReadOnlySpan<byte> incomingBlob, IBufferWriter<byte> outgoingBlobWriter, SspiAuthenticationParameters authParams);
 
-        internal void SSPIData(ReadOnlySpan<byte> receivedBuff, IBufferWriter<byte> outgoingBlobWriter)
+        internal void WriteSSPIContext(ReadOnlySpan<byte> receivedBuff, IBufferWriter<byte> outgoingBlobWriter)
         {
             using var _ = TrySNIEventScope.Create(nameof(SspiContextProvider));
 
-            if (_authParams is SspiAuthenticationParameters authParam)
+            if (_authParamValue is SspiAuthenticationParameters authParam && RunGenerateSspiClientContext(receivedBuff, outgoingBlobWriter, authParam))
             {
-                RunGenerateSspiClientContext(receivedBuff, outgoingBlobWriter, authParam);
                 return;
             }
-            else if (_authParams is SspiAuthenticationParameters[] authParams)
+            else if (_authParamValue is SspiAuthenticationParameters[] authParams)
             {
                 foreach (var p in authParams)
                 {
                     if (RunGenerateSspiClientContext(receivedBuff, outgoingBlobWriter, p))
                     {
                         // Reset the _authParams to only have a single one going forward to always call the context with that one
-                        _authParams = p;
+                        _authParamValue = p;
                         return;
                     }
                 }

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParser.cs

@@ -35,7 +35,7 @@ internal void ProcessSSPI(int receivedLength)
                 try
                 {
                     // make call for SSPI data
-                    _authenticationProvider!.SSPIData(receivedBuff.AsSpan(0, receivedLength), writer);
+                    _authenticationProvider!.WriteSSPIContext(receivedBuff.AsSpan(0, receivedLength), writer);
 
                     // DO NOT SEND LENGTH - TDS DOC INCORRECT!  JUST SEND SSPI DATA!
                     _physicalStateObj.WriteByteSpan(writer.WrittenSpan);
@@ -175,7 +175,7 @@ internal void TdsLogin(
                         // byte[] buffer and 0 for the int length.
                         Debug.Assert(SniContext.Snix_Login == _physicalStateObj.SniContext, $"Unexpected SniContext. Expecting Snix_Login, actual value is '{_physicalStateObj.SniContext}'");
                         _physicalStateObj.SniContext = SniContext.Snix_LoginSspi;
-                        _authenticationProvider.SSPIData(ReadOnlySpan<byte>.Empty, sspiWriter);
+                        _authenticationProvider.WriteSSPIContext(ReadOnlySpan<byte>.Empty, sspiWriter);
 
                         _physicalStateObj.SniContext = SniContext.Snix_Login;