{

public partial class Form7 : Form

{

private OleDbConnection connection = new OleDbConnection();

Form1 formLink;

public Form RefToForm1 { get; set; }

public Form7(Form1 formLink)

{

this.formLink = formLink;

InitializeComponent();

connection.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=DataBase2.accdb;

Persist Security Info=False;";

}

DataTable dt;

private void DF()

{

connection.Open();

OleDbCommand command = new OleDbCommand();

command.Connection = connection;

string query = "select * from Пользователи";

command.CommandText = query;

OleDbDataAdapter da = new OleDbDataAdapter(command);

dt = new DataTable();

da.Fill(dt);

connection.Close();

}

public string sha1(string input)

{

byte[] hash;

using (var sha1 = new System.Security.Cryptography.SHA1CryptoServiceProvider())

hash = sha1.ComputeHash(Encoding.Unicode.GetBytes(input));

var sb = new StringBuilder();

foreach (byte b in hash) sb.AppendFormat("{0:x2}", b);

return sb.ToString();

}

private void button1_Click(object sender, EventArgs e)

{

string pwNow;

string pwSalt;

string hNow;

DF();

string check = dt.Rows[0][2].ToString();

pwNow = textBox1.Text;

pwSalt = dt.Rows[0][3].ToString();

hNow = sha1(pwNow + pwSalt);

if (hNow == check)

{

this.Close();

Form4 form4 = new Form4(this);

form4.RefToForm1 = RefToForm1;

form4.Show();

}

else

{

MessageBox.Show("Неправильный пароль");

}

}

private void button2_Click(object sender, EventArgs e)

{

Form1 obj1 = new Form1();

obj1.RefToForm7 = this;

this.Close();

this.RefToForm1.Show();

}

private void Form7_Load(object sender, EventArgs e)

{

this.ControlBox = false;

}

}