LINQ Varbinary to C# Byte Array

Question

I am new to the whole LINQ system, i have my passwords hashed and stored in a varbinary field in my database, now i want to get that value from my database and store it in a byte array to do a comparison using LINQ. I did it like this before:

System.Data.SqlTypes.SqlBytes sqlPassBinary = dr.GetSqlBytes(dr.GetOrdinal("Password"));

Now i want to try and apply this same concept but using LINQ this time. I tried this but it didn't work:

public bool Authenticate(string user, string pass)
{
    ***LINQDataContext d = new ***LINQDataContext();

    var login = from us in d.Users
                join ur in d.UserRoles on us.UserRoleID equals ur.UserRoleID
                where us.Username == user 
                select us;

    if ((login as IEnumerable<object>).Any())
    {
        System.Web.HttpContext.Current.Session["UserID"] = login.FirstOrDefault().UserID.ToString();
        System.Web.HttpContext.Current.Session["UserRole"] = login.FirstOrDefault().UserRole.ToString();
        byte[] sqlbinary = (byte[]) login.FirstOrDefault().Password;;

        return true;
    }

    return false;
}

And i get this error:

Answer 1

This error indicates that the collection returned by LINQ is a System.Data.Linq.Binary object and you cannot use it to initialize the byte[], nor to convert it explicitly.

First, you need to convert it to the array, use the LINQ's built-in ToArray() function.

Use

byte[] sqlbinary = login.FirstOrDefault().Password.ToArray();

It should be just fine.