public static IDStorage decryptKeyStoreStorage(byte[] c_baKey, byte[] c_baIV, string c_sBase64JsonStorage)
{
const int MacBitSize = 128;
byte [] baPayload = new byte[0];
var decryptCipher = new GcmBlockCipher(new AesFastEngine());
var parameters = new AeadParameters(new KeyParameter(c_baKey), MacBitSize, c_baIV, baPayload);
decryptCipher.Init (false, parameters);
byte[] baEncryptedStorage = Convert.FromBase64String (c_sBase64JsonStorage);
var decryptedText = new byte[decryptCipher.GetOutputSize(baEncryptedStorage.Length)];
try
{
var len = decryptCipher.ProcessBytes(baEncryptedStorage, 0, baEncryptedStorage.Length, decryptedText, 0);
decryptCipher.DoFinal(decryptedText, len);
}
catch (InvalidCipherTextException)
{
//Return null if it doesn't authenticate
return null;
}
string sJsonStorage = Encoding.GetEncoding (1252).GetString (decryptedText);
IDStorage _KeyStoreStorage = JsonConvert.DeserializeObject <IDStorage> (sJsonStorage);
return _KeyStoreStorage;
}
public byte[] Encrypt(byte[] plain, byte[] key, byte[] iv, byte[] aad = null, byte[] associated = null)
{
if (key.Length * 8 != this.KeySize)
{
throw new InvalidOperationException($"the given key has invalid size {key.Length * 8}, expect {this.KeySize}");
}
var cipher = new Modes.GcmBlockCipher(new Engines.AesEngine());
cipher.Init(true, new Parameters.AeadParameters(new Parameters.KeyParameter(key), this.MacSize, iv, associated));
if (aad != null)
{
cipher.ProcessAadBytes(aad, 0, aad.Length);
}
var ret = new byte[cipher.GetOutputSize(plain.Length)];
var len = cipher.ProcessBytes(plain, 0, plain.Length, ret, 0);
cipher.DoFinal(ret, len);
return(ret);
}
private void randomTest(
SecureRandom srng,
IGcmMultiplier m)
{
int kLength = 16 + 8 * srng.Next(3);
byte[] K = new byte[kLength];
srng.NextBytes(K);
int pLength = srng.Next(1024);
byte[] P = new byte[pLength];
srng.NextBytes(P);
int aLength = srng.Next(1024);
byte[] A = new byte[aLength];
srng.NextBytes(A);
int ivLength = 1 + srng.Next(1024);
byte[] IV = new byte[ivLength];
srng.NextBytes(IV);
GcmBlockCipher cipher = new GcmBlockCipher(new AesFastEngine(), m);
AeadParameters parameters = new AeadParameters(new KeyParameter(K), 16 * 8, IV, A);
cipher.Init(true, parameters);
byte[] C = new byte[cipher.GetOutputSize(P.Length)];
int len = cipher.ProcessBytes(P, 0, P.Length, C, 0);
len += cipher.DoFinal(C, len);
if (C.Length != len)
{
// Console.WriteLine("" + C.Length + "/" + len);
Fail("encryption reported incorrect length in randomised test");
}
byte[] encT = cipher.GetMac();
byte[] tail = new byte[C.Length - P.Length];
Array.Copy(C, P.Length, tail, 0, tail.Length);
if (!AreEqual(encT, tail))
{
Fail("stream contained wrong mac in randomised test");
}
cipher.Init(false, parameters);
byte[] decP = new byte[cipher.GetOutputSize(C.Length)];
len = cipher.ProcessBytes(C, 0, C.Length, decP, 0);
len += cipher.DoFinal(decP, len);
if (!AreEqual(P, decP))
{
Fail("incorrect decrypt in randomised test");
}
byte[] decT = cipher.GetMac();
if (!AreEqual(encT, decT))
{
Fail("decryption produced different mac from encryption");
}
}
private void checkTestCase(
GcmBlockCipher encCipher,
GcmBlockCipher decCipher,
string testName,
byte[] P,
byte[] C,
byte[] T)
{
byte[] enc = new byte[encCipher.GetOutputSize(P.Length)];
int len = encCipher.ProcessBytes(P, 0, P.Length, enc, 0);
len += encCipher.DoFinal(enc, len);
if (enc.Length != len)
{
// Console.WriteLine("" + enc.Length + "/" + len);
Fail("encryption reported incorrect length: " + testName);
}
byte[] mac = encCipher.GetMac();
byte[] data = new byte[P.Length];
Array.Copy(enc, data, data.Length);
byte[] tail = new byte[enc.Length - P.Length];
Array.Copy(enc, P.Length, tail, 0, tail.Length);
if (!AreEqual(C, data))
{
Fail("incorrect encrypt in: " + testName);
}
if (!AreEqual(T, mac))
{
Fail("GetMac() returned wrong mac in: " + testName);
}
if (!AreEqual(T, tail))
{
Fail("stream contained wrong mac in: " + testName);
}
byte[] dec = new byte[decCipher.GetOutputSize(enc.Length)];
len = decCipher.ProcessBytes(enc, 0, enc.Length, dec, 0);
len += decCipher.DoFinal(dec, len);
mac = decCipher.GetMac();
data = new byte[C.Length];
Array.Copy(dec, data, data.Length);
if (!AreEqual(P, data))
{
Fail("incorrect decrypt in: " + testName);
}
}
/// <summary>
/// Simple Decryption & Authentication (AES-GCM) of a UTF8 Message
/// </summary>
/// <param name="encryptedMessage">The encrypted message.</param>
/// <param name="key">The key.</param>
/// <param name="nonSecretPayloadLength">Length of the optional non-secret payload.</param>
/// <returns>Decrypted Message</returns>
public static byte[] SimpleDecrypt(byte[] encryptedMessage, byte[] key, int nonSecretPayloadLength = 0)
{
//User Error Checks
if (key == null || key.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "key");
if (encryptedMessage == null || encryptedMessage.Length == 0)
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
using (var cipherStream = new MemoryStream(encryptedMessage))
using (var cipherReader = new BinaryReader(cipherStream))
{
//Grab Payload
var nonSecretPayload = cipherReader.ReadBytes(nonSecretPayloadLength);
//Grab Nonce
var nonce = cipherReader.ReadBytes(NonceBitSize / 8);
var cipher = new GcmBlockCipher(new AesFastEngine());
var parameters = new AeadParameters(new KeyParameter(key), MacBitSize, nonce, nonSecretPayload);
cipher.Init(false, parameters);
//Decrypt Cipher Text
var cipherText = cipherReader.ReadBytes(encryptedMessage.Length - nonSecretPayloadLength - nonce.Length);
var plainText = new byte[cipher.GetOutputSize(cipherText.Length)];
try
{
var len = cipher.ProcessBytes(cipherText, 0, cipherText.Length, plainText, 0);
cipher.DoFinal(plainText, len);
}
catch (InvalidCipherTextException)
{
//Return null if it doesn't authenticate
return null;
}
return plainText;
}
}
/// <summary>
/// Simple Encryption And Authentication (AES-GCM) of a UTF8 string.
/// </summary>
/// <param name="secretMessage">The secret message.</param>
/// <param name="key">The key.</param>
/// <param name="nonSecretPayload">Optional non-secret payload.</param>
/// <returns>Encrypted Message</returns>
/// <remarks>
/// Adds overhead of (Optional-Payload + BlockSize(16) + Message + HMac-Tag(16)) * 1.33 Base64
/// </remarks>
public static byte[] SimpleEncrypt(byte[] secretMessage, byte[] key, byte[] nonSecretPayload = null)
{
//User Error Checks
if (key == null || key.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "key");
if (secretMessage == null || secretMessage.Length == 0)
throw new ArgumentException("Secret Message Required!", "secretMessage");
//Non-secret Payload Optional
nonSecretPayload = nonSecretPayload ?? new byte[] { };
//Using random nonce large enough not to repeat
var nonce = new byte[NonceBitSize / 8];
Random.NextBytes(nonce, 0, nonce.Length);
var cipher = new GcmBlockCipher(new AesFastEngine());
var parameters = new AeadParameters(new KeyParameter(key), MacBitSize, nonce, nonSecretPayload);
cipher.Init(true, parameters);
//Generate Cipher Text With Auth Tag
var cipherText = new byte[cipher.GetOutputSize(secretMessage.Length)];
var len = cipher.ProcessBytes(secretMessage, 0, secretMessage.Length, cipherText, 0);
cipher.DoFinal(cipherText, len);
//Assemble Message
using (var combinedStream = new MemoryStream())
{
using (var binaryWriter = new BinaryWriter(combinedStream))
{
//Prepend Authenticated Payload
binaryWriter.Write(nonSecretPayload);
//Prepend Nonce
binaryWriter.Write(nonce);
//Write Cipher Text
binaryWriter.Write(cipherText);
}
return combinedStream.ToArray();
}
}
// AES
private String decrypt(byte[] data, byte[] key, byte[] iv)
{
var cipher = new GcmBlockCipher(new AesFastEngine());
var parameters = new ParametersWithIV(new KeyParameter(key, 0, 32), iv);
cipher.Init(false, parameters);
var pText = new byte[cipher.GetOutputSize(data.Length)];
var len2 = cipher.ProcessBytes(data, 0, data.Length, pText, 0);
cipher.DoFinal(pText, len2);
return System.Text.Encoding.Default.GetString(pText);
}
public static string encryptIdStorage(byte[] c_baKey, byte[] c_baIV, IDStorage c_KeyStoreStorage)
{
const int MacBitSize = 128;
byte [] baPayload = new byte[0];
var encryptCipher = new GcmBlockCipher(new AesFastEngine());
var parameters = new AeadParameters(new KeyParameter(c_baKey), MacBitSize, c_baIV, baPayload);
encryptCipher.Init (true, parameters);
string sJsonStorage = JsonConvert.SerializeObject (c_KeyStoreStorage);//ConvertToJSON and
byte[] baJsonStorage = Encoding.GetEncoding(1252).GetBytes(sJsonStorage);// get Bytes from ASCII-String
var cipherText = new byte[encryptCipher.GetOutputSize(baJsonStorage.Length)];
var len = encryptCipher.ProcessBytes(baJsonStorage, 0, baJsonStorage.Length, cipherText, 0);
encryptCipher.DoFinal(cipherText, len);
string sCipherString = Convert.ToBase64String (cipherText);
return sCipherString;
}