CSHARP-5360: Fix resource leaks in LibMongoCryptControllerBase::SendKmsRequest (#1519)

Author: adelinowona

src/MongoDB.Driver.Encryption/KmsRequest.cs

@@ -81,14 +81,11 @@ public string KmsProvider
         /// Gets the message to send to KMS.
         /// </summary>
         /// <returns>The message</returns>
-        public Binary Message
+        public Binary GetMessage()
         {
-            get {
             Binary binary = new Binary();
-
             Check(Library.mongocrypt_kms_ctx_message(_id, binary.Handle));
             return binary;
-            }
         }
 
         /// <summary>

src/MongoDB.Driver.Encryption/LibMongoCryptControllerBase.cs

@@ -283,8 +283,9 @@ private void SendKmsRequest(KmsRequest request, CancellationToken cancellation)
             var tlsStreamSettings = GetTlsStreamSettings(request.KmsProvider);
             var sslStreamFactory = new SslStreamFactory(tlsStreamSettings, _networkStreamFactory);
             using (var sslStream = sslStreamFactory.CreateStream(endpoint, cancellation))
+            using (var binary = request.GetMessage())
             {
-                var requestBytes = request.Message.ToArray();
+                var requestBytes = binary.ToArray();
                 sslStream.Write(requestBytes, 0, requestBytes.Length);
 
                 while (request.BytesNeeded > 0)
@@ -305,8 +306,9 @@ private async Task SendKmsRequestAsync(KmsRequest request, CancellationToken can
             var tlsStreamSettings = GetTlsStreamSettings(request.KmsProvider);
             var sslStreamFactory = new SslStreamFactory(tlsStreamSettings, _networkStreamFactory);
             using (var sslStream = await sslStreamFactory.CreateStreamAsync(endpoint, cancellation).ConfigureAwait(false))
+            using (var binary = request.GetMessage())
             {
-                var requestBytes = request.Message.ToArray();
+                var requestBytes = binary.ToArray();
                 await sslStream.WriteAsync(requestBytes, 0, requestBytes.Length).ConfigureAwait(false);
 
                 while (request.BytesNeeded > 0)

tests/MongoDB.Driver.Encryption.Tests/BasicTests.cs

@@ -244,7 +244,7 @@ public void EncryptExplicitStepwise()
                 }
             }
         }
-        
+
         [Fact]
         public void TestAwsKeyCreationWithEndPoint()
         {
@@ -637,7 +637,7 @@ private CryptOptions CreateOptions()
                         var requests = context.GetKmsMessageRequests();
                         foreach (var req in requests)
                         {
-                            var binary = req.Message;
+                            using var binary = req.GetMessage();
                             _output.WriteLine("Key Document: " + binary);
                             var postRequest = binary.ToString();
                             // TODO: add different hosts handling