Perform Certificate Validation when Force Encryption enabled on Server (NetFx) (#482)

Author: cheenamalhotra

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

@@ -1134,10 +1134,8 @@ private PreLoginHandshakeStatus ConsumePreLoginHandshake(SqlAuthenticationMethod
 
                             UInt32 error = 0;
 
-                            // If we're using legacy server certificate validation behavior (Authentication keyword not provided and not using access token), then validate if
-                            //     Encrypt=true and Trust Sever Certificate = false.
-                            // If using Authentication keyword or access token, validate if Trust Server Certificate=false.
-                            bool shouldValidateServerCert = (encrypt && !trustServerCert) || ((authType != SqlAuthenticationMethod.NotSpecified || _connHandler._accessTokenInBytes != null) && !trustServerCert);
+                            // Validate Certificate if Trust Server Certificate=false and Encryption forced (EncryptionOptions.ON) from Server.
+                            bool shouldValidateServerCert = (_encryptionOption == EncryptionOptions.ON && !trustServerCert) || ((authType != SqlAuthenticationMethod.NotSpecified || _connHandler._accessTokenInBytes != null) && !trustServerCert);
 
                             UInt32 info = (shouldValidateServerCert ? TdsEnums.SNI_SSL_VALIDATE_CERTIFICATE : 0)
                                 | (isYukonOrLater && (_encryptionOption & EncryptionOptions.CLIENT_CERT) == 0 ? TdsEnums.SNI_SSL_USE_SCHANNEL_CACHE : 0);