how to enable SQL Application Role via Entity Framework - sql

Question

I'm now developing big government application with entity framework. at first i have one problem about enable SQL application role. with ado.net I'm using below code:
SqlCommand cmd = new SqlCommand("sys.sp_setapprole");
cmd.CommandType = CommandType.StoredProcedure;
cmd.Connection = _sqlConn;
SqlParameter paramAppRoleName = new SqlParameter();
paramAppRoleName.Direction = ParameterDirection.Input;
paramAppRoleName.ParameterName = "#rolename";
paramAppRoleName.Value = "AppRole";
cmd.Parameters.Add(paramAppRoleName);
SqlParameter paramAppRolePwd = new SqlParameter();
paramAppRolePwd.Direction = ParameterDirection.Input;
paramAppRolePwd.ParameterName = "#password";
paramAppRolePwd.Value = "123456";
cmd.Parameters.Add(paramAppRolePwd);
SqlParameter paramCreateCookie = new SqlParameter();
paramCreateCookie.Direction = ParameterDirection.Input;
paramCreateCookie.ParameterName = "#fCreateCookie";
paramCreateCookie.DbType = DbType.Boolean;
paramCreateCookie.Value = 1;
cmd.Parameters.Add(paramCreateCookie);
SqlParameter paramEncrypt = new SqlParameter();
paramEncrypt.Direction = ParameterDirection.Input;
paramEncrypt.ParameterName = "#encrypt";
paramEncrypt.Value = "none";
cmd.Parameters.Add(paramEncrypt);
SqlParameter paramEnableCookie = new SqlParameter();
paramEnableCookie.ParameterName = "#cookie";
paramEnableCookie.DbType = DbType.Binary;
paramEnableCookie.Direction = ParameterDirection.Output;
paramEnableCookie.Size = 1000;
cmd.Parameters.Add(paramEnableCookie);
try
{
cmd.ExecuteNonQuery();
SqlParameter outVal = cmd.Parameters["#cookie"];
// Store the enabled cookie so that approle can be disabled with the cookie.
_appRoleEnableCookie = (byte[]) outVal.Value;
}
catch (Exception ex)
{
result = false;
msg = "Could not execute enable approle proc." + Environment.NewLine + ex.Message;
}
But no matter how much I searched I could not find a way to implement on EF.
Another question is: how to Add Application Role to Entity data model designer?
I'm using the below code for execute parameter with EF:
AEntities ar = new AEntities();
DbConnection con = ar.Connection;
con.Open();
msg = "";
bool result = true;
DbCommand cmd = con.CreateCommand();
cmd.CommandType = CommandType.StoredProcedure;
cmd.Connection = con;
var d = new DbParameter[]{
new SqlParameter{ ParameterName="#r", Value ="AppRole",Direction = ParameterDirection.Input}
, new SqlParameter{ ParameterName="#p", Value ="123456",Direction = ParameterDirection.Input}
};
string sql = "EXEC " + procName + " #rolename=#r,#password=#p";
var s = ar.ExecuteStoreCommand(sql, d);
When run ExecuteStoreCommand this line return error:
Application roles can only be activated at the ad hoc level.

Answer 1

I do it the following way (assuming Database First):
I create the DbContext from the db and call it MyEntitiesBase
I inherit from MyEntitiesBase to create MyEntities with the following code:
public partial class MyEntities : MyEntitiesBase
{
private byte[] appRoleCookie;
private void SetAppRole()
{
try
{
appRoleCookie = Database.SqlQuery<byte[]>(
#"
DECLARE #cookie VARBINARY(8000)
DECLARE #r INT
EXEC sp_setapprole 'user', 'pass', #fCreateCookie = true, #cookie = #cookie OUTPUT
SELECT #cookie").First();
}
catch
{
throw new AuthenticationException();
}
}
private void UnSetAppRole()
{
bool failed = Database.SqlQuery<bool>("DECLARE #result BIT; EXEC #result = sp_unsetapprole #cookie = " + appRoleCookie.ToHexadecimalString() + "; SELECT #result").First();
if (failed)
throw new SecurityException();
}
public MyEntities() : base()
{
Database.Connection.Open();
SetAppRole();
}
private bool disposed = false;
protected override void Dispose(bool disposing)
{
if (disposed)
return;
UnSetAppRole();
Database.Connection.Close();
disposed = true;
base.Dispose(disposing);
}
}
Where ToHexadecimalString is an extension method for IEnumerable<byte>, as follows:
public static class BytesExtensions
{
public static string ToHexadecimalString(this IEnumerable<byte> bytes)
{
return "0x" + string.Concat(bytes.Select(b => b.ToString("X2")));
}
}
And that's it. Works with connection pooling on and everything. You just use this inherited version instead of the one generated by EF.

Answer 2

Basically what you are doing is calling a stored procedure.
Entity Framework has functionality to excute stored procedures. Here is an explaination with a video: http://msdn.microsoft.com/en-us/data/gg699321.aspx
If your scrol down to the section "Using Import Functions to Map Stored Procedures" you will find the part that is relevant for you.