Error in CLR: InvalidOperationException - The current type is an interface and cannot be constructed. Are you missing a type mapping?

Question

Hi, I'm trying to execute a .NET assembly's method from SQL Server 2012 Express, but I'm stuck with this error calling the sp:
Microsoft.Practices.ServiceLocation.ActivationException: Activation error occured while trying to get instance of type ISymmetricCryptoProvider, key "TripleDESCryptoServiceProvider" ---> Microsoft.Practices.Unity.ResolutionFailedException:
Resolution of the dependency failed, type = "Microsoft.Practices.EnterpriseLibrary.Security.Cryptography.ISymmetricCryptoProvider", name = "TripleDESCryptoServiceProvider".
Exception occurred while: while resolving.
Exception is: InvalidOperationException - The current type, Microsoft.Practices.EnterpriseLibrary.Security.Cryptography.ISymmetricCryptoProvider, is an interface and cannot be constructed. Are you missing a type mapping?
At the time of the exception, the container was:
  Resolving Microsoft.Practices.EnterpriseLibrary.Security.Cryptography.ISymmetricCryptoProvider,TripleDESCryptoServiceProvider
 ---> System.InvalidOperationException: The current type, Microsoft.Practices.EnterpriseLibrary.Security.Cryptography.ISymmetricCryptoProvider, is an interface and cannot be constructed. Are you missing a type mapping?
System.InvalidOperationException:
   en Microsoft.Practices.ObjectBuilder2.DynamicMethodConstructorStrategy.ThrowForAttemptingToConstructInterface(IBuilderContext context)
   en BuildUp_Microsoft.Practices.EnterpriseLibrary.Security
Microsoft.Practices.ServiceLocation.ActivationException:
   en Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance(Type serviceType, String key)
   en Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance[TService](String key)
   en Microsoft.Practices.EnterpriseLibrary.Security.Cryptography.Cryptographer.GetSymmetricCryptoProvider(String symmetricInstance)
   en Microsoft.Practices.EnterpriseLibrary.Security.Cryptography.Cryptographer.DecryptSymmetric(String symmetricInstance, String ciphertextBase64)
   en ...
Is there any limitation by design for Interface instantiation from CLR database?
Any help I will appreciate, thanks a million!!

Answer 1

Bob, thanks for your response.. Yes, the code works fine outside of SQLCLR. This is the class I'm trying to instantiate, I'm using it to envolve Cryptographer, an Enterprise Library 5.0 class actually, so I have no control to test it without referring the
interface.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Practices.EnterpriseLibrary.Security.Cryptography;
using System.Security.Cryptography;
using Microsoft.SqlServer.Server;
using System.Data.SqlTypes;
namespace Cars.UtileriasGlobales.Helpers
    /// <summary>
    /// Clase que permite encriptar y desencriptar cadenas de textos utilizando
    /// TripleDESCryptoServiceProvider de Enterprise Library 5.0
    /// </summary>
    public static class Cryptography
        #region Metodos
        [SqlProcedure]
        public static void DesencriptarSQLServer(SqlString cadena, out SqlString cadenaDesencriptada)
            cadenaDesencriptada = !String.IsNullOrEmpty(cadena.ToString()) ? Cryptographer.DecryptSymmetric("TripleDESCryptoServiceProvider", cadena.ToString().Replace(" ", "+"))
: String.Empty;
        #endregion
I have collected all the dependent assemblies in one directory 'C:\migrate', so the create assembly finish ok. This is the script to create the assembly I'm using:
sp_configure 'clr enable', 1
GO
RECONFIGURE
GO
ALTER DATABASE cars SET TRUSTWORTHY ON
GO
CREATE ASSEMBLY CryptographyEntLib5
AUTHORIZATION dbo
FROM 'C:\migrate\Cars.UtileriasGlobales.dll'
WITH PERMISSION_SET = UNSAFE
GO
CREATE PROCEDURE usp_Desencriptar
@cadena nvarchar(200),
@cadenaDesencriptada nvarchar(MAX) OUTPUT
AS EXTERNAL NAME CryptographyEntLib5.[Cars.UtileriasGlobales.Helpers.Cryptography].DesencriptarSQLServer
GO
DECLARE @msg nvarchar(MAX)
EXEC usp_Desencriptar 'Kittu And Tannu',@msg output
PRINT @msg