public static SecureboxKey GetSecureboxKey(string GUID)
{
SecureboxKey el = new SecureboxKey();
byte[] IV = new byte[16];
byte[] KEY = new byte[16];
SQLiteConnection m_dbConnection = new SQLiteConnection(connstring);
m_dbConnection.Open();
string sql = "select IV, KEY from lookup WHERE GUID=@guid";
SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection);
command.Parameters.AddWithValue("@guid", GUID);
SQLiteDataReader reader = command.ExecuteReader();
while (reader.Read())
{
IV = (byte[])reader["IV"];
KEY = (byte[])reader["KEY"];
}
reader.Close();
m_dbConnection.Close();
el.IV = IV;
el.KEY = KEY;
el.GUID = GUID;
return(el);
}
private static void _DecryptPreprocess(string inputFile)
{
string outputFile = inputFile + ".tmp";
int numberOfBytes = 16;
byte[] bytes = new byte[numberOfBytes];
//get GUID from file
using (var fs = new FileStream(inputFile, FileMode.Open, FileAccess.Read))
{
fs.Read(bytes, 0, bytes.Length);
}
// var buffer2 = File.ReadAllBytes(inputFile);
Guid guid = new Guid(bytes);
string GUID = guid.ToString();
//create new file without GUID
char[] delimiterChars = { '.' };
string[] newFile = outputFile.Split(delimiterChars);
string newFileFullPathName = String.Join(".", newFile.Take(newFile.Length - 2));
using (var fs = new FileStream(inputFile, FileMode.Open, FileAccess.Read))
{
byte[] fullfile = new byte[fs.Length];
int toRead = (int)fs.Length - 1, bytesRead;
fs.Seek(16, SeekOrigin.Begin);
while (toRead > 0 && (bytesRead = fs.Read(fullfile, 0, toRead)) > 0)
{
toRead -= bytesRead;
numberOfBytes += bytesRead;
}
using (var newFS = new FileStream(outputFile, FileMode.Create, FileAccess.Write))
{
newFS.Write(fullfile, 0, fullfile.Length);
}
}
//get IV and key from SQLite DB
SecureboxKey el = DatabaseManagement.GetSecureboxKey(GUID);
if (el != null &&
el.IV != null &&
el.IV.Length > 0)
{
Securebox._DecryptFile(outputFile, newFileFullPathName, el);
}
Securebox.DeleteCurrentFile(outputFile);
}
private static void _DecryptFile(string inputFile, string outputFile, SecureboxKey skey)
{
try
{
using (AesCryptoServiceProvider aes = new AesCryptoServiceProvider())
{
// byte[] key = ASCIIEncoding.UTF8.GetBytes(skey.KEY);
byte[] key = skey.KEY;
/* This is for demostrating purposes only.
* Ideally you will want the IV key to be different from your key and you should always generate a new one for each encryption in other to achieve maximum security*/
byte[] IV = skey.IV;
using (FileStream fsCrypt = new FileStream(inputFile, FileMode.Open))
{
using (FileStream fsOut = new FileStream(outputFile, FileMode.Create))
{
using (ICryptoTransform decryptor = aes.CreateDecryptor(key, IV))
{
using (CryptoStream cs = new CryptoStream(fsCrypt, decryptor, CryptoStreamMode.Read))
{
int data;
while ((data = cs.ReadByte()) != -1)
{
fsOut.WriteByte((byte)data);
}
}
}
}
}
}
}
catch (Exception ex)
{
Trace.TraceError(ex.Message);
}
}
private static void _DecryptFile(string inputFile, string outputFile, SecureboxKey skey)
{
try
{
using (AesCryptoServiceProvider aes = new AesCryptoServiceProvider())
{
// byte[] key = ASCIIEncoding.UTF8.GetBytes(skey.KEY);
byte[] key = skey.KEY;
/* This is for demostrating purposes only.
* Ideally you will want the IV key to be different from your key and you should always generate a new one for each encryption in other to achieve maximum security*/
byte[] IV = skey.IV;
using (FileStream fsCrypt = new FileStream(inputFile, FileMode.Open))
{
using (FileStream fsOut = new FileStream(outputFile, FileMode.Create))
{
using (ICryptoTransform decryptor = aes.CreateDecryptor(key, IV))
{
using (CryptoStream cs = new CryptoStream(fsCrypt, decryptor, CryptoStreamMode.Read))
{
int data;
while ((data = cs.ReadByte()) != -1)
{
fsOut.WriteByte((byte)data);
}
}
}
}
}
}
}
catch (Exception ex)
{
Trace.TraceError(ex.Message);
}
}
public static SecureboxKey GetSecureboxKey(string GUID)
{
SecureboxKey el = new SecureboxKey();
byte[] IV = new byte[16];
byte[] KEY = new byte[16];
SQLiteConnection m_dbConnection = new SQLiteConnection(connstring);
m_dbConnection.Open();
string sql = "select IV, KEY from lookup WHERE GUID=@guid";
SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection);
command.Parameters.AddWithValue("@guid", GUID);
SQLiteDataReader reader = command.ExecuteReader();
while (reader.Read())
{
IV = (byte[])reader["IV"];
KEY = (byte[])reader["KEY"];
}
reader.Close();
m_dbConnection.Close();
el.IV = IV;
el.KEY = KEY;
el.GUID = GUID;
return el;
}
