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 MySql.Data.MySqlClient;

namespace Passwords
{
    public partial class Form1 : Form
    {
        MySqlConnection cm;
        string input,username,password,usersalt,userlogin;
        bool correctuser, passwordcerta;
        public Form1()
        {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            input = textBox8.Text;
            try
            {
                cm = new MySqlConnection();
                cm.ConnectionString = "server=127.0.0.1;uid=neuro;pwd=123;database=neuro;Convert Zero Datetime=True;";
                cm.Open();
                MessageBox.Show("Connected to the DataBase");
            }
            catch (MySql.Data.MySqlClient.MySqlException ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        private void button1_Click(object sender, EventArgs e)
        {
            string salt1,hash;
            userlogin = textBox8.Text;
            MySqlCommand cmd = new MySqlCommand();
            cmd.CommandText = "SELECT salt,hash FROM passwords WHERE user='@user';";
            cmd.CommandType = CommandType.Text;
            cmd.Connection = cm;
            cmd.Parameters.AddWithValue("@user", userlogin);
            MySqlDataReader reader = cmd.ExecuteReader();
            while (reader.Read())
            {
                    salt1 = reader[0].ToString();
                    hash = reader[1].ToString();

                string hashedpassword = GenerateSHA512Hash(input, salt1);
                    if (hash == hashedpassword)
                    {
                    passwordcerta = true;
                    MessageBox.Show("Acertou Miseravel");
                    }
            }
            reader.Close();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            try
            {
                username = textBox7.Text;
                password = textBox5.Text;
                String salt = CreateSalt(10);
                String hashedpassword = GenerateSHA512Hash(textBox1.Text, salt);
                usersalt = salt;

                MySqlCommand cmd = new MySqlCommand();
                cmd.CommandText = "INSERT INTO passwords(user,salt,hash) VALUES(@user,@salt,@hash);";
                cmd.CommandType = CommandType.Text;
                cmd.Connection = cm;
                cmd.Parameters.AddWithValue("@user", username);
                cmd.Parameters.AddWithValue("@salt", usersalt);
                cmd.Parameters.AddWithValue("@hash", hashedpassword);
                cmd.ExecuteNonQuery();
            }
            catch (MySql.Data.MySqlClient.MySqlException ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        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);
        }
    }
}