Deserialization permissions error in CLR stored procedure

Question

Environment: SQL Server 2008 R2 standard edition and VS2010, .Net Framework 3.5
I've got a table with a varbinary column that contains a serialized Hashtable. I'm writing a CLR stored procedure that, given the contents of such a field from a row in the table, does a lookup on a key in the Hashtable. and returns the element's value.
To get the Hashtable, I need to deserialize it, and it appears that the BinaryFormatter's Deserialize function requires certain permissions that I don't know how to grant.
This SQL Server instance runs on my own development machine, and was installed pretty much with all defaults. I'm the owner.
Any help on solving this? I should point out while I write a fair amount of SQL and a LOT of VB, I'm far from a SQL Server expert, so if you have suggestions I'd appreciate it if you'd spell things out clearly for me.
Thanks in advance for any help,
Tom
Here's a fragment from the VB source:
    ' the bytes variable is defined as Byte()
    Dim ms As MemoryStream = New MemoryStream()
    ms.Write(bytes, 0, bytes.Length)
    ms.Seek(0, 0)
    Dim formatter As New System.Runtime.Serialization.Formatters.Binary.BinaryFormatter()
    Dim oHT As Object = formatter.Deserialize(ms)    'hurls here
The CREATE ASSEMBLY statement had WITH PERMISSION_SET = SAFE. I tried it with UNSAFE, and got this error:
CREATE ASSEMBLY for assembly 'ddmi.deep.data.sqlserver' failed because assembly 'ddmi.deep.data.sqlserver' is not authorized for PERMISSION_SET = UNSAFE.  The assembly is authorized when either of the following is true: the database owner (DBO) has
UNSAFE ASSEMBLY permission and the database has the TRUSTWORTHY database property on; or the assembly is signed with a certificate or an asymmetric key that has a corresponding login with UNSAFE ASSEMBLY permission.
Here's an SQL script that runs it:
declare
    @id int
  , @raw_req_bin varbinary(1500)
  , @value nvarchar(max)
set @id = 327
set @raw_req_bin = (select raw_req_bin from dp_payment where transaction_id = @id)
set @value = dbo.dp_fx_hash_table_lookup(@raw_req_bin, 'first_name')
and here's what I get when I run the script:
SecurityExceptionSystem.Security.SecurityException: Request for the permission of type 'System.Security.Permissions.SecurityPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.
   at System.Security.CodeAccessSecurityEngine.SpecialDemand(PermissionType whatPermission, StackCrawlMark& stackMark)
   at System.Security.CodeAccessPermission.DemandInternal(PermissionType permissionType)
   at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(HeaderHandler handler, __BinaryParser serParser, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
   at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream, HeaderHandler handler, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
   at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream)
   at ddmi.deep.data.sqlserver.UserDefinedFunctions.AsHashTable(Byte[] bytes, String& phase)
The action that failed was:
Demand
The type of the first permission that failed was:
System.Security.Permissions.SecurityPermission
The Zone of the assembly that failed was:
MyComputer

Answer 1

Set the database (in a test system) to trustworthy (ALTER DATABSE foo SET TRUSTWORTHY ON) for testing. If this works, look into code signing (sign an assembly and catalog the cert/asymmetric key to master) for production. If you have problems with
"native" serialization, you might get better results using XML serializers.
Re: XML serializers. SQLCLR will not load dynamically generated serializers. So you need to pregenerate XML serializers with sgen.exe.
Your specific error message (the permission error) might be fixed by cataloging the SQLCLR assembly as UNSAFE. If that doesn't work, you might attempt to change the .NET permission configuration on your machine using either of the tools described here:
http://msdn.microsoft.com/en-us/library/7c9c2y1w(v=vs.90).aspx
Hope this helps, Cheers, Bob