/*
* Generate random salt
*/
private byte[] getSalt() {
// Generate a random salt.
byte[] salt = new byte[SALT_LEN];
if (random == null) {
random = new SecureRandom();
}
salt = random.generateSeed(SALT_LEN);
return salt;
}
/**
* Encrypts the given input data.
*
* @param in input data to encrypt
* @param k key
* @param a encryption algorithm
* @param ivl initialization vector length
* @return encrypted input data
* @throws InvalidKeyException ex
* @throws InvalidAlgorithmParameterException ex
* @throws NoSuchAlgorithmException ex
* @throws NoSuchPaddingException ex
* @throws IllegalBlockSizeException ex
* @throws BadPaddingException ex
*/
private static byte[] encrypt(final byte[] in, final byte[] k, final byte[] a, final int ivl)
throws InvalidKeyException, InvalidAlgorithmParameterException, NoSuchAlgorithmException,
NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException {
final Cipher cipher = Cipher.getInstance(string(ALGN.get(lc(a))));
final SecretKeySpec kspec = new SecretKeySpec(k, string(a));
// generate random iv. random iv is necessary to make the encryption of a
// string look different every time it is encrypted.
final byte[] iv = new byte[ivl];
// create new random iv if encrypting
final SecureRandom rand = SecureRandom.getInstance("SHA1PRNG");
rand.nextBytes(iv);
final IvParameterSpec ivspec = new IvParameterSpec(iv);
// encrypt/decrypt
cipher.init(Cipher.ENCRYPT_MODE, kspec, ivspec);
final byte[] t = cipher.doFinal(in);
// initialization vector is appended to the message for later decryption
return concat(iv, t);
}
public void generate_new_aes_key() {
try {
KeyGenerator localKeyGenerator = KeyGenerator.getInstance("AES");
localKeyGenerator.init(128, SecureRandom.getInstance("SHA1PRNG"));
// aes_key = Base64.encodeBase64String(localKeyGenerator.generateKey().getEncoded());
aes_key =
new String(Base64.encode(localKeyGenerator.generateKey().getEncoded(), Base64.DEFAULT));
} catch (NoSuchAlgorithmException localNoSuchAlgorithmException) {
System.out.println(localNoSuchAlgorithmException);
}
return;
}
// actual init() implementation
private void implInit(int opmode, Key key, byte[] iv, SecureRandom random)
throws InvalidKeyException, InvalidAlgorithmParameterException {
cancelOperation();
switch (opmode) {
case Cipher.ENCRYPT_MODE:
encrypt = true;
break;
case Cipher.DECRYPT_MODE:
encrypt = false;
break;
default:
throw new InvalidAlgorithmParameterException("Unsupported mode: " + opmode);
}
if (blockMode == MODE_ECB) { // ECB or stream cipher
if (iv != null) {
if (blockSize == 0) {
throw new InvalidAlgorithmParameterException("IV not used with stream ciphers");
} else {
throw new InvalidAlgorithmParameterException("IV not used in ECB mode");
}
}
} else { // MODE_CBC or MODE_CTR
if (iv == null) {
if (encrypt == false) {
String exMsg =
(blockMode == MODE_CBC
? "IV must be specified for decryption in CBC mode"
: "IV must be specified for decryption in CTR mode");
throw new InvalidAlgorithmParameterException(exMsg);
}
// generate random IV
if (random == null) {
random = new SecureRandom();
}
iv = new byte[blockSize];
random.nextBytes(iv);
} else {
if (iv.length != blockSize) {
throw new InvalidAlgorithmParameterException("IV length must match block size");
}
}
}
this.iv = iv;
p11Key = P11SecretKeyFactory.convertKey(token, key, keyAlgorithm);
try {
initialize();
} catch (PKCS11Exception e) {
throw new InvalidKeyException("Could not initialize cipher", e);
}
}
public static void main(String[] args) throws Exception {
// prompt user to enter a port number
System.out.print("Enter the port number: ");
Scanner scan = new Scanner(System.in);
int port = scan.nextInt();
scan.nextLine();
System.out.print("Enter the host name: ");
String hostName = scan.nextLine();
// Initialize a key pair generator with the SKIP parameters we sepcified, and genrating a pair
// This will take a while: 5...15 seconrds
System.out.println("Generating a Diffie-Hellman keypair: ");
KeyPairGenerator kpg = KeyPairGenerator.getInstance("DH");
kpg.initialize(PARAMETER_SPEC);
KeyPair keyPair = kpg.genKeyPair();
System.out.println("key pair has been made...");
// one the key pair has been generated, we want to listen on
// a given port for a connection to come in
// once we get a connection, we will get two streams, One for input
// and one for output
// open a port and wait for a connection
ServerSocket ss = new ServerSocket(port);
System.out.println("Listeining on port " + port + " ...");
Socket socket = ss.accept();
// use to output and input primitive data type
DataOutputStream out = new DataOutputStream(socket.getOutputStream());
// next thing to do is send our public key and receive client's
// this corresponds to server step 3 and step 4 in the diagram
System.out.println("Sending my public key...");
byte[] keyBytes = keyPair.getPublic().getEncoded();
out.writeInt(keyBytes.length);
out.write(keyBytes);
System.out.println("Server public key bytes: " + CryptoUtils.toHex(keyBytes));
// receive the client's public key
System.out.println("Receiving client's public key...");
DataInputStream in = new DataInputStream(socket.getInputStream());
keyBytes = new byte[in.readInt()];
in.readFully(keyBytes);
// create client's public key
KeyFactory kf = KeyFactory.getInstance("DH");
X509EncodedKeySpec x509Spec = new X509EncodedKeySpec(keyBytes);
PublicKey clientPublicKey = kf.generatePublic(x509Spec);
// print out client's public key bytes
System.out.println(
"Client public key bytes: " + CryptoUtils.toHex(clientPublicKey.getEncoded()));
// we can now use the client's public key and
// our own private key to perform the key agreement
System.out.println("Performing the key agreement ... ");
KeyAgreement ka = KeyAgreement.getInstance("DH");
ka.init(keyPair.getPrivate());
ka.doPhase(clientPublicKey, true);
// in a chat application, each character is sendt over the wire, separetly encrypted,
// Instead of using ECB, we are goin to use CFB, with a block size of 8 bits(1byte)
// to send each character. We will encrypt the same character in a different way
// each time. But in order to use CFB8, we need an IVof 8 bytes. We will create
// that IV randomly and and send it to the client. It doesn't matter if somoene
// eavesdrops on the IV when it is sent over the wire. it's not sensitive info
// creating the IV and sending it corresponds to step 6 and 7
byte[] iv = new byte[8];
SecureRandom sr = new SecureRandom();
sr.nextBytes(iv);
out.write(iv);
// we generate the secret byte array we share with the client and use it
// to create the session key (Step 8)
byte[] sessionKeyBytes = ka.generateSecret();
// create the session key
SecretKeyFactory skf = SecretKeyFactory.getInstance("DESede");
DESedeKeySpec DESedeSpec = new DESedeKeySpec(sessionKeyBytes);
SecretKey sessionKey = skf.generateSecret(DESedeSpec);
// printout session key bytes
System.out.println("Session key bytes: " + CryptoUtils.toHex(sessionKey.getEncoded()));
// now use tha that session key and IV to create a CipherInputStream. We will use them to read
// all character
// that are sent to us by the client
System.out.println("Creating the cipher stream ...");
Cipher decrypter = Cipher.getInstance("DESede/CFB8/NoPadding");
IvParameterSpec spec = new IvParameterSpec(iv);
decrypter.init(Cipher.DECRYPT_MODE, sessionKey, spec);
CipherInputStream cipherIn = new CipherInputStream(socket.getInputStream(), decrypter);
// we just keep reading the input and print int to the screen, until -1 sent over
int theCharacter = 0;
theCharacter = cipherIn.read();
while (theCharacter != -1) {
System.out.print((char) theCharacter);
theCharacter = cipherIn.read();
}
// once -1 is received we want to close up our stream and exit
cipherIn.close();
in.close();
out.close();
socket.close();
}
void implInit(
int opmode, Key key, AlgorithmParameterSpec params, SecureRandom random, CipherSpi cipherImpl)
throws InvalidKeyException, InvalidAlgorithmParameterException {
char[] passwdChars = null;
salt = null;
iCount = 0;
if (key instanceof javax.crypto.interfaces.PBEKey) {
javax.crypto.interfaces.PBEKey pbeKey = (javax.crypto.interfaces.PBEKey) key;
passwdChars = pbeKey.getPassword();
salt = pbeKey.getSalt(); // maybe null if unspecified
iCount = pbeKey.getIterationCount(); // maybe 0 if unspecified
} else if (key instanceof SecretKey) {
byte[] passwdBytes = key.getEncoded();
if ((passwdBytes == null) || !(key.getAlgorithm().regionMatches(true, 0, "PBE", 0, 3))) {
throw new InvalidKeyException("Missing password");
}
passwdChars = new char[passwdBytes.length];
for (int i = 0; i < passwdChars.length; i++) {
passwdChars[i] = (char) (passwdBytes[i] & 0x7f);
}
} else {
throw new InvalidKeyException("SecretKey of PBE type required");
}
if (((opmode == Cipher.DECRYPT_MODE) || (opmode == Cipher.UNWRAP_MODE))
&& ((params == null) && ((salt == null) || (iCount == 0)))) {
throw new InvalidAlgorithmParameterException("Parameters missing");
}
if (params == null) {
// generate default for salt and iteration count if necessary
if (salt == null) {
salt = new byte[DEFAULT_SALT_LENGTH];
if (random != null) {
random.nextBytes(salt);
} else {
SunJCE.getRandom().nextBytes(salt);
}
}
if (iCount == 0) iCount = DEFAULT_COUNT;
} else if (!(params instanceof PBEParameterSpec)) {
throw new InvalidAlgorithmParameterException("PBEParameterSpec type required");
} else {
PBEParameterSpec pbeParams = (PBEParameterSpec) params;
// make sure the parameter values are consistent
if (salt != null) {
if (!Arrays.equals(salt, pbeParams.getSalt())) {
throw new InvalidAlgorithmParameterException(
"Inconsistent value of salt between key and params");
}
} else {
salt = pbeParams.getSalt();
}
if (iCount != 0) {
if (iCount != pbeParams.getIterationCount()) {
throw new InvalidAlgorithmParameterException(
"Different iteration count between key and params");
}
} else {
iCount = pbeParams.getIterationCount();
}
}
// salt is recommended to be ideally as long as the output
// of the hash function. However, it may be too strict to
// force this; so instead, we'll just require the minimum
// salt length to be 8-byte which is what PKCS#5 recommends
// and openssl does.
if (salt.length < 8) {
throw new InvalidAlgorithmParameterException("Salt must be at least 8 bytes long");
}
if (iCount <= 0) {
throw new InvalidAlgorithmParameterException("IterationCount must be a positive number");
}
byte[] derivedKey = derive(passwdChars, salt, iCount, keySize, CIPHER_KEY);
SecretKey cipherKey = new SecretKeySpec(derivedKey, algo);
if (cipherImpl != null && cipherImpl instanceof ARCFOURCipher) {
((ARCFOURCipher) cipherImpl).engineInit(opmode, cipherKey, random);
} else {
byte[] derivedIv = derive(passwdChars, salt, iCount, 8, CIPHER_IV);
IvParameterSpec ivSpec = new IvParameterSpec(derivedIv, 0, 8);
// initialize the underlying cipher
cipher.init(opmode, cipherKey, ivSpec, random);
}
}