Example usage for java.security KeyPairGenerator initialize

List of usage examples for java.security KeyPairGenerator initialize

  1. HOME
  2. Java
  3. java
  4. java.security.*
  5. KeyPairGenerator
  6. initialize

Introduction

In this page you can find the example usage for java.security KeyPairGenerator initialize.

Prototype

public void initialize(AlgorithmParameterSpec params) throws InvalidAlgorithmParameterException

Source Link

Document

Initializes the key pair generator using the specified parameter set and the SecureRandom implementation of the highest-priority installed provider as the source of randomness.

Usage

From source file:Main.java

public static void main(String[] argv) throws Exception {
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
    keyGen.initialize(1024);
    KeyPair keypair = keyGen.genKeyPair();
    DSAPrivateKey privateKey = (DSAPrivateKey) keypair.getPrivate();
    DSAPublicKey publicKey = (DSAPublicKey) keypair.getPublic();

    DSAParams dsaParams = privateKey.getParams();
    BigInteger p = dsaParams.getP();
    BigInteger q = dsaParams.getQ();
    BigInteger g = dsaParams.getG();
    BigInteger x = privateKey.getX();
    BigInteger y = publicKey.getY();

    KeyFactory keyFactory = KeyFactory.getInstance("DSA");
    KeySpec publicKeySpec = new DSAPublicKeySpec(y, p, q, g);
    PublicKey publicKey1 = keyFactory.generatePublic(publicKeySpec);
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
    keyGen.initialize(1024);
    KeyPair keypair = keyGen.genKeyPair();
    DSAPrivateKey privateKey = (DSAPrivateKey) keypair.getPrivate();
    DSAPublicKey publicKey = (DSAPublicKey) keypair.getPublic();

    DSAParams dsaParams = privateKey.getParams();
    BigInteger p = dsaParams.getP();
    BigInteger q = dsaParams.getQ();
    BigInteger g = dsaParams.getG();
    BigInteger x = privateKey.getX();
    BigInteger y = publicKey.getY();

    KeyFactory keyFactory = KeyFactory.getInstance("DSA");
    KeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
    PrivateKey privateKey1 = keyFactory.generatePrivate(privateKeySpec);
}

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    int eValue = 79;
    int bitLength = 1024; // KeySize

    BigInteger e = e = new BigInteger(Integer.toString(eValue));

    KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
    kpg.initialize(bitLength);
    KeyPair kp = kpg.generateKeyPair();

    KeyFactory kfactory = KeyFactory.getInstance("RSA");
    RSAPublicKeySpec kspec = (RSAPublicKeySpec) kfactory.getKeySpec(kp.getPublic(), RSAPublicKeySpec.class);

    kpg = KeyPairGenerator.getInstance("RSA", "SunRsaSign");

    e = new BigInteger(Integer.toString(eValue));
    System.out.println("e =" + e);
    RSAKeyGenParameterSpec param = new RSAKeyGenParameterSpec(bitLength, e);
    kpg.initialize(param);//from  w w w.j  a  va2  s  .com
    kp = kpg.generateKeyPair();

    kfactory = KeyFactory.getInstance("RSA", "SunRsaSign");

    kspec = (RSAPublicKeySpec) kfactory.getKeySpec(kp.getPublic(), RSAPublicKeySpec.class);
}

From source file:MainClass.java

public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException {
    KeyPairGenerator kpg = KeyPairGenerator.getInstance("DSA");
    kpg.initialize(512);
    KeyPair keys = kpg.genKeyPair();
    PrivateKey priKey = keys.getPrivate();
    PublicKey pubKey = keys.getPublic();
    KeyFactory kf = KeyFactory.getInstance("DSA");
    DSAPrivateKeySpec dsaPriKeySpec = (DSAPrivateKeySpec) kf.getKeySpec(priKey, DSAPrivateKeySpec.class);
    DSAPublicKeySpec dsaPubKeySpec = (DSAPublicKeySpec) kf.getKeySpec(pubKey, DSAPublicKeySpec.class);
    System.out.println("\nDSA Private Key");
    System.out.println("\nx = " + dsaPriKeySpec.getX());
    System.out.println("\nDSA Public Key");
    System.out.println("\ng = " + dsaPubKeySpec.getG());
    System.out.println("\np = " + dsaPubKeySpec.getP());
    System.out.println("\nq = " + dsaPubKeySpec.getQ());
    System.out.println("\ny = " + dsaPubKeySpec.getY());
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    String algorithm = "DSA"; // or RSA, DH, etc.

    // Generate a 1024-bit Digital Signature Algorithm (DSA) key pair
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance(algorithm);
    keyGen.initialize(1024);
    KeyPair keypair = keyGen.genKeyPair();
    PrivateKey privateKey = keypair.getPrivate();
    PublicKey publicKey = keypair.getPublic();

    byte[] privateKeyBytes = privateKey.getEncoded();
    byte[] publicKeyBytes = publicKey.getEncoded();

    KeyFactory keyFactory = KeyFactory.getInstance(algorithm);
    EncodedKeySpec privateKeySpec = new PKCS8EncodedKeySpec(privateKeyBytes);
    PrivateKey privateKey2 = keyFactory.generatePrivate(privateKeySpec);

    EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(publicKeyBytes);
    PublicKey publicKey2 = keyFactory.generatePublic(publicKeySpec);

    // The orginal and new keys are the same
    boolean same = privateKey.equals(privateKey2);
    same = publicKey.equals(publicKey2);
}

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    KeyGenerator keyGenerator = KeyGenerator.getInstance("Blowfish");
    keyGenerator.init(128);//from   ww  w.j  a va 2  s .  c o m
    Key blowfishKey = keyGenerator.generateKey();

    KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
    keyPairGenerator.initialize(1024);
    KeyPair keyPair = keyPairGenerator.genKeyPair();

    Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
    cipher.init(Cipher.ENCRYPT_MODE, keyPair.getPublic());

    byte[] blowfishKeyBytes = blowfishKey.getEncoded();
    System.out.println(new String(blowfishKeyBytes));
    byte[] cipherText = cipher.doFinal(blowfishKeyBytes);
    System.out.println(new String(cipherText));
    cipher.init(Cipher.DECRYPT_MODE, keyPair.getPrivate());

    byte[] decryptedKeyBytes = cipher.doFinal(cipherText);
    System.out.println(new String(decryptedKeyBytes));
    SecretKey newBlowfishKey = new SecretKeySpec(decryptedKeyBytes, "Blowfish");
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
    keyGen.initialize(1024);
    KeyPair keypair = keyGen.genKeyPair();
    DSAPrivateKey privateKey = (DSAPrivateKey) keypair.getPrivate();
    DSAPublicKey publicKey = (DSAPublicKey) keypair.getPublic();

    DSAParams dsaParams = privateKey.getParams();
    BigInteger p = dsaParams.getP();
    BigInteger q = dsaParams.getQ();
    BigInteger g = dsaParams.getG();
    BigInteger x = privateKey.getX();
    BigInteger y = publicKey.getY();

    // Create the DSA key factory
    KeyFactory keyFactory = KeyFactory.getInstance("DSA");
    // Create the DSA private key
    KeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
    PrivateKey privateKey1 = keyFactory.generatePrivate(privateKeySpec);

    byte[] buffer = new byte[1024];

    Signature sig = Signature.getInstance(privateKey1.getAlgorithm());
    sig.initSign(privateKey1);/*from   www . java 2  s .co  m*/
    sig.update(buffer, 0, buffer.length);
}

From source file:MainClass.java

public static void main(String[] args) {
    if (args.length != 2) {
        String err = "Usage: KeyGeneratorApp algorithmName keySize";
        System.out.println(err);//from www. j a v a2  s  . co m
        System.exit(0);
    }
    int keySize = (new Integer(args[1])).intValue();
    SecretKey skey = null;
    KeyPair keys = null;
    String algorithm = args[0];

    try {
        KeyPairGenerator kpg = KeyPairGenerator.getInstance(algorithm);
        kpg.initialize(keySize);
        keys = kpg.genKeyPair();
    } catch (NoSuchAlgorithmException ex1) {
        try {
            KeyGenerator kg = KeyGenerator.getInstance(algorithm);
            kg.init(keySize);
            skey = kg.generateKey();
        } catch (NoSuchAlgorithmException ex2) {
            System.out.println("Algorithm not supported: " + algorithm);
            System.exit(0);

        }
    }
}

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    String s = "F488FD584E49DBCD20B49DE49107366B336C380D451D0F7C88"
            + "11111111111111111111111111111111111111111111111111"
            + "11111111111111111111111111111111111111111111111111"
            + "11111111111111111111111111111111111111111111111111"
            + "11111111111111111111111111111111111111111111111111" + "2F78C7";
    BigInteger base = BigInteger.valueOf(2);
    BigInteger modulus = new BigInteger(s, 16);
    DHParameterSpec skipParameterSpec = new DHParameterSpec(modulus, base);

    KeyPairGenerator kpg1 = KeyPairGenerator.getInstance("DH");
    kpg1.initialize(skipParameterSpec);
    KeyPair kp1 = kpg1.generateKeyPair();

    KeyAgreement ka1 = KeyAgreement.getInstance("DH");
    DHPrivateKey privateKey1 = (DHPrivateKey) kp1.getPrivate();
    DHPublicKey publicKey1 = (DHPublicKey) kp1.getPublic();
    ka1.init(privateKey1);/*from  www  .  ja  va 2s  .c  o  m*/
    System.out.println("1 is using " + publicKey1.getY() + " for its public key");
    KeyPairGenerator kpg2 = KeyPairGenerator.getInstance("DH");
    kpg2.initialize(skipParameterSpec);
    KeyPair kp2 = kpg2.generateKeyPair();

    KeyAgreement ka2 = KeyAgreement.getInstance("DH");
    DHPrivateKey privateKey2 = (DHPrivateKey) kp2.getPrivate();
    DHPublicKey publicKey2 = (DHPublicKey) kp2.getPublic();
    ka2.init(privateKey2);
    System.out.println("2 is using " + publicKey2.getY() + " for its public key");
    ka1.doPhase(publicKey2, true);
    byte[] sharedKey1 = ka1.generateSecret();
    System.out.println("1 is using " + new BigInteger(1, sharedKey1) + " for its shared key");

    ka2.doPhase(publicKey1, true);
    byte[] sharedKey2 = ka2.generateSecret();
    System.out.println("2 is using " + new BigInteger(1, sharedKey2) + " for its shared key");
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
    keyGen.initialize(1024);
    KeyPair keypair = keyGen.genKeyPair();
    DSAPrivateKey privateKey = (DSAPrivateKey) keypair.getPrivate();
    DSAPublicKey publicKey = (DSAPublicKey) keypair.getPublic();

    DSAParams dsaParams = privateKey.getParams();
    BigInteger p = dsaParams.getP();
    BigInteger q = dsaParams.getQ();
    BigInteger g = dsaParams.getG();
    BigInteger x = privateKey.getX();
    BigInteger y = publicKey.getY();

    KeyFactory keyFactory = KeyFactory.getInstance("DSA");
    KeySpec publicKeySpec = new DSAPublicKeySpec(y, p, q, g);
    PublicKey publicKey1 = keyFactory.generatePublic(publicKeySpec);
    KeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
    PrivateKey privateKey1 = keyFactory.generatePrivate(privateKeySpec);

    byte[] buffer = new byte[1024];

    Signature sig = Signature.getInstance(privateKey1.getAlgorithm());
    sig.initSign(privateKey1);// ww  w  .j  a v a  2  s . c o  m
    sig.update(buffer, 0, buffer.length);

    byte[] signature = sig.sign();

    sig = Signature.getInstance(publicKey1.getAlgorithm());
    sig.initVerify(publicKey1);
    sig.update(buffer, 0, buffer.length);
    sig.verify(signature);

}