public static List <Decrypted_logline> get_database_logs()
{
try
{
string queryString = "select * from logs";
var command = new Microsoft.Data.SqlClient.SqlCommand(queryString, database_connection);
if (command.Connection.State != System.Data.ConnectionState.Open)
{
command.Connection.Open();
}
command.ExecuteNonQuery();
var reader = command.ExecuteReader();
List <Decrypted_logline> logs = new List <Decrypted_logline>();
while (reader.Read())
{
//DEFINE BYTE LENGTH
//byte[] EncryptedBytes = new byte[1024];
//reader.GetBytes(1, 0, EncryptedBytes, 0, 1024);
byte[] EncryptedBytes = (byte[])reader[2];
//count non-zero end bytes
int nonZeroBytes = 0;
for (int i = EncryptedBytes.Length - 1; i > -1; i--)
{
if (EncryptedBytes[i] == 0x00)
{
nonZeroBytes++;
}
else
{
break;
}
}
var DecryptedBytes = AesInst.CreateDecryptor().TransformFinalBlock(EncryptedBytes, 0, EncryptedBytes.Length - nonZeroBytes);
var DecryptedChars = Encoding.UTF8.GetChars(DecryptedBytes);
var Decrypted_Text = new string(DecryptedChars);
logs.Add(new Decrypted_logline(reader.GetDateTime(3), reader.GetString(1), Decrypted_Text));
}
command.Connection.Close();
return(logs);
}
catch
{
string queryString = "select * from logs";
var command = new Microsoft.Data.SqlClient.SqlCommand(queryString, database_connection);
if (command.Connection.State == System.Data.ConnectionState.Open)
{
command.Connection.Close();
}
return(new List <Decrypted_logline>());
}
}
public static int log_error(DateTime logDateTime, string labnumber, string logtext)
{
try
{
if (logtext.Length >= 256 || labnumber.Length >= 40)
{
throw new Exception("Too long!");
}
var log_in_char = logtext.ToArray();
byte[] log_bytes = Encoding.UTF8.GetBytes(log_in_char);
var encrypted_log = AesInst.CreateEncryptor().TransformFinalBlock(log_bytes, 0, log_bytes.Length);
string encrypted_log_HEX = "0x";
foreach (byte part in encrypted_log)
{
encrypted_log_HEX += part.ToString("X2");
}
string queryString = "insert into logs values(\'" + labnumber + "\', " + encrypted_log_HEX + ", CURRENT_TIMESTAMP)";
Microsoft.Data.SqlClient.SqlCommand command = new Microsoft.Data.SqlClient.SqlCommand(queryString, database_connection);
if (command.Connection.State != System.Data.ConnectionState.Open)
{
command.Connection.Open();
}
command.ExecuteNonQuery();
command.Connection.Close();
return(0);
}
catch
{
return(-1);
}
}
public static void GetPrivateKeyFromDB()
{
//getting key
string queryString = "select * from keys where login_id=" + user_id.ToString();
var command_newkey = new Microsoft.Data.SqlClient.SqlCommand(queryString, database_connection);
if (command_newkey.Connection.State != System.Data.ConnectionState.Open)
{
command_newkey.Connection.Open();
}
command_newkey.ExecuteNonQuery();
var reader = command_newkey.ExecuteReader();
byte[] dbprivkey = new byte[48];
byte[] dbiv = new byte[32];
while (reader.Read())
{
reader.GetBytes(1, 0, dbprivkey, 0, 48);
reader.GetBytes(2, 0, dbiv, 0, 32);
}
AesInst = System.Security.Cryptography.Aes.Create();
var privKeysha256 = MathOperations.sha256_byte(userpassword);
var ivmd5 = MathOperations.md5_byte(userpassword);
//enc private key with sha256(pwd) and md5(pwd)
AesInst.Key = privKeysha256;
AesInst.IV = ivmd5;
var SecretKey = AesInst.CreateDecryptor().TransformFinalBlock(dbprivkey, 0, dbprivkey.Length);
var InitVector = AesInst.CreateDecryptor().TransformFinalBlock(dbiv, 0, dbiv.Length);
//apply decrypted key
AesInst.Key = SecretKey;
AesInst.IV = InitVector;
command_newkey.Connection.Close();
}
