| public Decrypt ( byte input, byte key, byte iv ) : byte[] | ||
| input | byte | |
| key | byte | |
| iv | byte | |
| return | byte[] | |
public void TestEncryptDecrypt(Cipher cipher)
{
var inputMsg = "This is a message";
var input = Encoding.ASCII.GetBytes(inputMsg);
var iv = Encoding.ASCII.GetBytes("12345678");
var key = Encoding.ASCII.GetBytes("This is the key");
Console.Write("Using cipher {0}: ", cipher.LongName);
using (var cc = new CipherContext(cipher))
{
Console.Write(" KeyLength: {0}, IVLength: {1}, BlockSize: {2}, Stream: {3} ",
cipher.KeyLength, cipher.IVLength, cipher.BlockSize, cc.IsStream);
var pt = cc.Encrypt(input, key, iv);
if (cipher == Cipher.Null)
Assert.AreEqual(input, pt);
else
Assert.AreNotEqual(input, pt);
var ct = cc.Decrypt(pt, key, iv);
var msg = Encoding.ASCII.GetString(ct);
Console.WriteLine("\"{0}\"", msg);
Assert.AreEqual(inputMsg, msg);
}
}
public void TestEncryptDecryptWithSalt()
{
string inputMsg = "This is a message";
byte[] input = Encoding.ASCII.GetBytes(inputMsg);
byte[] salt = Encoding.ASCII.GetBytes("salt");
byte[] secret = Encoding.ASCII.GetBytes("Password!");
foreach (var cipher in Ciphers(true)) {
Console.Write("Using cipher {0}: ", cipher.LongName);
using (var cc = new CipherContext(cipher)) {
Console.Write(" KeyLength: {0}, IVLength: {1}, BlockSize: {2}, Stream: {3} ",
cipher.KeyLength, cipher.IVLength, cipher.BlockSize, cc.IsStream);
byte[] iv;
byte[] key = cc.BytesToKey(MessageDigest.SHA1, salt, secret, 1, out iv);
var pt = cc.Encrypt(input, key, iv);
Assert.AreNotEqual(input, pt);
var ct = cc.Decrypt(pt, key, iv);
var msg = Encoding.ASCII.GetString(ct);
Console.WriteLine("\"{0}\"", msg);
Assert.AreEqual(inputMsg, msg);
}
}
}
public void TestCase()
{
string magic = "Salted__";
const int PKCS5_SALT_LEN = 8;
string base64 = "U2FsdGVkX1/moDHvAjok9X4prr8TXQtv9LRAIHk1IE8=";
byte[] input = Convert.FromBase64String(base64);
byte[] salt = new byte[PKCS5_SALT_LEN];
byte[] msg = new byte[input.Length - magic.Length - PKCS5_SALT_LEN];
Buffer.BlockCopy(input, magic.Length, salt, 0, salt.Length);
Buffer.BlockCopy(input, magic.Length + PKCS5_SALT_LEN, msg, 0, msg.Length);
using (CipherContext cc = new CipherContext(Cipher.AES_256_CBC)) {
byte[] iv;
byte[] password = Encoding.ASCII.GetBytes("example");
byte[] key = cc.BytesToKey(MessageDigest.MD5, salt, password, 1, out iv);
byte[] output = cc.Decrypt(msg, key, iv);
string text = Encoding.ASCII.GetString(output);
Console.WriteLine(text);
}
}
/// <summary>
/// Decrypt the specified data using salt, saltBytes, and passphraseBytes.
/// </summary>
/// <param name="salt">The salt.</param>
/// <param name="data">The data to decrypt.</param>
/// <param name="passphraseBytes">The passphrase bytes.</param>
/// <returns>The plain text after decryption.</returns>
private string Decrypt(string salt, byte[] data, byte[] passphraseBytes)
{
using (CipherContext cc = new CipherContext(Cipher.AES_256_CBC))
{
byte[] iv;
byte[] encryptionKey = cc.BytesToKey(
MessageDigest.SHA512,
this.encoding.GetBytes(salt),
passphraseBytes,
Iterations,
out iv);
byte[] decryptedBytes = cc.Decrypt(data, encryptionKey, iv);
string decryptedText = this.encoding.GetString(decryptedBytes);
return decryptedText.Replace(salt, string.Empty);
}
}