How can I validate an account with a stored procedure that uses hash encryption, C#, ASP.NET MVC, Entity Framework

Question

So basically I have a stored procedure which is able to decrypt the password and return 1 if user exists. Here is the code:

CREATE PROCEDURE [dbo].[ValidateAccount]    
     @Username VARCHAR(50),
     @AccountPwd VARCHAR(100)   
AS 
BEGIN      
    SET NOCOUNT ON;

    DECLARE @Salt CHAR(25);   
    DECLARE @PwdWithSalt VARCHAR(125);  
    DECLARE @PwdHash VARBINARY(20);  

    SELECT @Salt = Salt, @PwdHash = [Pass]   
    FROM dbo.Users 
    WHERE Username = @Username;

    SET @PwdWithSalt = @Salt + @AccountPwd;

    IF (HASHBYTES('SHA1', @PwdWithSalt) = @PwdHash)
        RETURN 1;   
    ELSE
        RETURN 0;
END;

And also have a login:

@using (Html.BeginForm("Index", "Home", FormMethod.Post))
{
    <div class="form-group">
    <i class="fa fa-user"></i>
    <!-- I'm using htmlAtributes to add CSS class styles and HTML atributes on Editor controls-->
    @Html.EditorFor(model => model.Username , new { htmlAttributes = new { @class = "form-control", @required = "true", @placeholder = "Username" } })
    </div>
    <div class="form-group">
        <i class="fa fa-lock"></i>                   
        @Html.TextBoxFor(model => model.Pass , new { data_bind = "value: Password", @class = "form-control", @required = "true", @placeholder = "Password", @type = "password" })
    </div>
    <div class="form-group">
        <input type="submit" class="btn btn-primary btn-block btn-lg" value="Login">
    </div>
    }

I have a model:

public partial class Users
{
        public string Username { get; set; }
        public byte[] Pass { get; set; }

        public string Name { get; set; }
        public string Salt { get; set; }
        public int ID { get; set; }
}

As you can see, the 'Pass' column in the database is Byte[] , so I'm having issues executing the procedure and validate if the user exists or not and take actions like go to the dashboard.

Any idea?, I was not able to find a practical solution on this

Here is the Home controller where I should do the validation:

[HttpPost]
public ActionResult Index(Warehouse_APP.Models.Users userMod)
{
    return View();
}

Answer 1

Actually what you got is a stored procedure that does hashes the entered password for the user with same salt as it did when the original password was entered. If those 2 matches, then you get an 1 otherwise a 0 as a return value.

So in the HTTP_POST method of your MVC controller you just need to call that stored procedure with the user name and password from the bound model and based on the result you need to redirect to the appropriate success/error page.

You will probably use entity framework, so here's how to execute that SQL: https://www.learnentityframeworkcore.com/raw-sql