Example usage for java.security KeyFactory generatePublic

Introduction

In this page you can find the example usage for java.security KeyFactory generatePublic.

Prototype

public final PublicKey generatePublic(KeySpec keySpec) throws InvalidKeySpecException

Source Link

Document

Generates a public key object from the provided key specification (key material).

Usage

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA", "BC");

    generator.initialize(128, new SecureRandom());
    KeyPair pair = generator.generateKeyPair();
    ASN1InputStream aIn = new ASN1InputStream(pair.getPublic().getEncoded());
    SubjectPublicKeyInfo info = SubjectPublicKeyInfo.getInstance(aIn.readObject());

    System.out.println(ASN1Dump.dumpAsString(info));
    System.out.println(ASN1Dump.dumpAsString(info.getPublicKey()));

    X509EncodedKeySpec x509Spec = new X509EncodedKeySpec(pair.getPublic().getEncoded());
    KeyFactory keyFact = KeyFactory.getInstance("RSA", "BC");
    PublicKey pubKey = keyFact.generatePublic(x509Spec);

    System.out.println(pubKey.equals(pair.getPublic()));
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
    keyGen.initialize(1024);//w ww .  j  a v  a 2s .c o m
    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);/*from   w w w. ja v a  2 s . c  om*/
    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);
    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);

}

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);/*from  w ww . j  av  a  2 s  .c o m*/
    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 {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    byte[] input = new byte[] { (byte) 0xbe, (byte) 0xef };
    Cipher cipher = Cipher.getInstance("RSA/None/NoPadding", "BC");

    KeyFactory keyFactory = KeyFactory.getInstance("RSA", "BC");
    RSAPublicKeySpec pubKeySpec = new RSAPublicKeySpec(new BigInteger("12345678", 16),
            new BigInteger("11", 16));
    RSAPrivateKeySpec privKeySpec = new RSAPrivateKeySpec(new BigInteger("12345678", 16),
            new BigInteger("12345678", 16));

    RSAPublicKey pubKey = (RSAPublicKey) keyFactory.generatePublic(pubKeySpec);
    RSAPrivateKey privKey = (RSAPrivateKey) keyFactory.generatePrivate(privKeySpec);

    cipher.init(Cipher.ENCRYPT_MODE, pubKey);

    byte[] cipherText = cipher.doFinal(input);
    System.out.println("cipher: " + new String(cipherText));

    cipher.init(Cipher.DECRYPT_MODE, privKey);
    byte[] plainText = cipher.doFinal(cipherText);
    System.out.println("plain : " + new String(plainText));
}

From source file:MainClass.java

public static void main(String args[]) throws Exception {
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
    SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN");
    random.setSeed(101L);/*  www  .j ava  2  s  . c  o  m*/
    keyGen.initialize(1024, random);
    KeyPair keypair = keyGen.generateKeyPair();

    KeyFactory kfactory = KeyFactory.getInstance("DSA");

    DSAPublicKeySpec kspec = (DSAPublicKeySpec) kfactory.getKeySpec(keypair.getPublic(),
            DSAPublicKeySpec.class);

    System.out.println(keypair.getPublic());
    FileOutputStream fos = new FileOutputStream("publicKeys");
    ObjectOutputStream oos = new ObjectOutputStream(fos);

    oos.writeObject(kspec.getY());
    oos.writeObject(kspec.getP());
    oos.writeObject(kspec.getQ());
    oos.writeObject(kspec.getG());

    FileInputStream fin = new FileInputStream("publicKeys");
    ObjectInputStream ois = new ObjectInputStream(fin);

    BigInteger Y = (BigInteger) ois.readObject();
    BigInteger P = (BigInteger) ois.readObject();
    BigInteger Q = (BigInteger) ois.readObject();
    BigInteger G = (BigInteger) ois.readObject();

    DSAPublicKeySpec keyspec = new DSAPublicKeySpec(Y, P, Q, G);
    PublicKey pkey = kfactory.generatePublic(keyspec);
    System.out.println(pkey);
}

From source file:Main.java

static PublicKey loadDERPublicKey(byte[] der) throws Exception {
    X509EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(der);
    KeyFactory factory = KeyFactory.getInstance("RSA");
    return factory.generatePublic(publicKeySpec);
}

From source file:Main.java

public static RSAPublicKey getRSAPubKeyfromEncoded(byte[] encKey)
        throws NoSuchAlgorithmException, InvalidKeySpecException {
    X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(encKey);
    KeyFactory kf = KeyFactory.getInstance("RSA");
    return (RSAPublicKey) kf.generatePublic(pubKeySpec);
}

From source file:Main.java

public static DSAPublicKey getDSAPubKeyfromEncoded(byte[] encKey)
        throws NoSuchAlgorithmException, InvalidKeySpecException {
    X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(encKey);
    KeyFactory kf = KeyFactory.getInstance("DSA");
    return (DSAPublicKey) kf.generatePublic(pubKeySpec);
}

From source file:Main.java

public static PublicKey decodePublic(byte[] encoded, String keyType)
        throws NoSuchAlgorithmException, InvalidKeySpecException {
    X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(encoded);
    KeyFactory kf = KeyFactory.getInstance(keyType);
    return kf.generatePublic(pubKeySpec);
}