Question

I am trying to create a simple msmq messaging application using clr stored procedure integrated in sql server 2008.

Followed the below steps

1. By defualt System.Messaging reference wont be available in sql server,so created this assembly

   ALTER DATABASE [AdventureWorksLT2008] SET TRUSTWORTHY on
   create ASSEMBLY Messaging
   AUTHORIZATION dbo
   FROM ‘C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Messaging.dll’
   WITH PERMISSION_SET = EXTERNAL_ACCESS
   GO

2.created sql server application with a stored procedure

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Data.SqlTypes;
using System.Data.SqlClient;
using Microsoft.SqlServer.Server;
using System.Messaging;
using System.Security;

    [assembly: AllowPartiallyTrustedCallers]
    namespace CLRProcedure
    {

        public class StoredProcedure
        {
            /// <summary>
            /// Sends message to queue
            /// </summary>
            /// <param name="queue">Queue path</param>
            /// <param name="msg">Message</param>
            [SqlProcedure]

            public static void Proc_Send_Queue(SqlString queue, SqlString msg)
            {
                using (MessageQueue msgQueue = new MessageQueue(queue.ToString(), QueueAccessMode.Send))
                {
                    msgQueue.Formatter = new XmlMessageFormatter(new Type[] { typeof(string) });
                    msgQueue.Send(msg.Value);
                }
            }
         }     
     }

1. registered that assembly in sql server
   create assembly MSMQApp from ‘E:\CCA Parctise\SqlMSMQ.dll’

SqlMSMQ.dll is the sql server applicaiton dll.

1. create stored procedure
   create PROCEDURE [dbo].[Proc_Send_Queue]
   (@queue nvarchar,
   @msg nvarchar)
   WITH EXECUTE AS CALLER
   AS
   EXTERNAL NAME [MSMQApp].[CLRProcedure.StoredProcedure].[Proc_Send_Queue]

2. while executing stored procedure
   USE [AdventureWorksLT2008]
   GO
   DECLARE @return_value int
   EXEC @return_value = [dbo].[Proc_Send_Queue]
   @queue = N’SampleQ’, –msmq name
   @msg = N’Simpel queue message’ — message
   SELECT ‘Return Value’ = @return_value
   GO

   throwing below error

   Msg 6522, Level 16, State 1, Procedure Proc_Send_Queue, Line 0
   A .NET Framework error occurred during execution of user-defined routine or aggregate “Proc_Send_Queue”:
   System.Security.SecurityException: That assembly does not allow partially trusted callers.
   System.Security.SecurityException:
   at CLRProcedure.StoredProcedure.Proc_Send_Queue(SqlString queue, SqlString msg)

Appreciating your help to solve this.

Thanks in advance

Answer 1

Allowing Partially Trusted Callers states:

We recommend that all assemblies registered in SQL Server, except
those assemblies added to the global assembly cache, be marked with
the AllowPartiallyTrustedCallers attribute so that assemblies loaded
by SQL Server can access each other.

You did exactly what the recommendation says, and you get the error. So what’s going on? See Strong named assemblies and AllowPartiallyTrustedCallers:

When assembly B calls strong-named assembly A,

Either A must have AllowPartiallyTrustedCallers attribute Or B must
have unsafe (FullTrust) permission set.

In your case ‘B’ is SqlMSMQ.dll and the strong-named ‘A’ is System.Messaging.dll. Since you cannot modify ‘A’ to have the APTC attribute, the only solution is to modify ‘B’ to be full trusted (ie. UNSAFE):

 create assembly MSMQApp from 'E:\CCA Parctise\SqlMSMQ.dll'
   with permission_set = unsafe;

What is the recipient of your messages? If is another application backed by SQL Server then you have a much better alternative in Service Broker.