using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace DBTestes
{
    public partial class Form1 : Form
    {

        SqlConnection conn;
        string input, username, password, usersalt, userlogin;
        bool correctuser, passwordcerta;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
     conn = new System.Data.SqlClient.SqlConnection();
                conn.ConnectionString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\DemoDB.mdf;Integrated Security=True;Connect Timeout=30";
                conn.Open();
    }

        public String CreateSalt(int size)
        {
            var rng = new System.Security.Cryptography.RNGCryptoServiceProvider();
            var buff = new byte[size];
            rng.GetBytes(buff);
            return Convert.ToBase64String(buff);
        }
        public String GenerateSHA512Hash(String input, String salt)
        {
            byte[] bytes = System.Text.Encoding.UTF8.GetBytes(input + salt);
            System.Security.Cryptography.SHA256Managed sha256hashstring = new System.Security.Cryptography.SHA256Managed();
            byte[] hash = sha256hashstring.ComputeHash(bytes);

            return Convert.ToBase64String(hash);
        }

        private void button1_Click(object sender, EventArgs e)
        {

                username = textBox2.Text;
                password = textBox1.Text;
                String salt = CreateSalt(10);
                String hashedpassword = GenerateSHA512Hash(textBox1.Text, salt);
                usersalt = salt;
            try
            {
                SqlCommand cmd = new SqlCommand();
                cmd.CommandText = "INSERT INTO password(user,salt,hash) VALUES(@user,@salt,@hash)";
                cmd.CommandType = CommandType.Text;
                cmd.Connection = conn;
                cmd.Parameters.AddWithValue("@user", username);
                cmd.Parameters.AddWithValue("@salt", usersalt);
                cmd.Parameters.AddWithValue("@hash", hashedpassword);
                cmd.ExecuteNonQuery();
            }
            catch (SqlException sqlEx)
            {

                MessageBox.Show(sqlEx.Message);
            }
        }
    }
}