Example usage for javax.crypto Cipher init

Introduction

In this page you can find the example usage for javax.crypto Cipher init.

Prototype

public final void init(int opmode, Certificate certificate, SecureRandom random) throws InvalidKeyException 

Source Link

Document

Initializes this cipher with the public key from the given certificate and a source of randomness.

Usage

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    byte[] input = "www.java2s.com".getBytes();
    byte[] keyBytes = new byte[] { 0x01, 0x23, 0x45, 0x67, (byte) 0x89, (byte) 0xab, (byte) 0xcd, (byte) 0xef };
    byte[] msgNumber = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

    IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]);
    SecretKeySpec key = new SecretKeySpec(keyBytes, "DES");
    Cipher cipher = Cipher.getInstance("DES/CBC/PKCS7Padding", "BC");
    System.out.println("input : " + new String(input));

    // encryption pass
    cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
    IvParameterSpec encryptionIv = new IvParameterSpec(cipher.doFinal(msgNumber), 0, 8);

    // encrypt message
    cipher.init(Cipher.ENCRYPT_MODE, key, encryptionIv);
    byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
    ctLength += cipher.doFinal(cipherText, ctLength);
    System.out.println("cipher: " + new String(cipherText) + " bytes: " + ctLength);
    cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
    IvParameterSpec decryptionIv = new IvParameterSpec(cipher.doFinal(msgNumber), 0, 8);

    // decrypt message

    cipher.init(Cipher.DECRYPT_MODE, key, decryptionIv);
    byte[] plainText = new byte[cipher.getOutputSize(ctLength)];
    int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
    ptLength += cipher.doFinal(plainText, ptLength);
    System.out.println("plain : " + new String(plainText) + " bytes: " + ptLength);
}

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From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    byte[] input = "www.java2s.com".getBytes();
    byte[] keyBytes = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c,
            0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 };
    byte[] ivBytes = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x02, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x00, 0x00, 0x01 };/*w  w w  .  j a  v  a2  s .  c  om*/

    SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
    IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
    Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
    System.out.println("input : " + new String(input));

    // encryption pass
    cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
    ByteArrayInputStream bIn = new ByteArrayInputStream(input);
    CipherInputStream cIn = new CipherInputStream(bIn, cipher);
    ByteArrayOutputStream bOut = new ByteArrayOutputStream();

    int ch;
    while ((ch = cIn.read()) >= 0) {
        bOut.write(ch);
    }

    byte[] cipherText = bOut.toByteArray();

    System.out.println("cipher: " + new String(cipherText));

    // decryption pass
    cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
    bOut = new ByteArrayOutputStream();
    CipherOutputStream cOut = new CipherOutputStream(bOut, cipher);
    cOut.write(cipherText);
    cOut.close();
    System.out.println("plain : " + new String(bOut.toByteArray()));
}

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From source file:MainClass.java

public static void main(String args[]) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    SecretKey key = KeyGenerator.getInstance("DES").generateKey();

    // for CBC; must be 8 bytes
    byte[] initVector = new byte[] { 0x10, 0x10, 0x01, 0x04, 0x01, 0x01, 0x01, 0x02 };

    AlgorithmParameterSpec algParamSpec = new IvParameterSpec(initVector);
    Cipher m_encrypter = Cipher.getInstance("DES/CBC/PKCS5Padding");
    Cipher m_decrypter = Cipher.getInstance("DES/CBC/PKCS5Padding");

    m_encrypter.init(Cipher.ENCRYPT_MODE, key, algParamSpec);
    m_decrypter.init(Cipher.DECRYPT_MODE, key, algParamSpec);

    FileInputStream fis = new FileInputStream("cipherTest.in");
    FileOutputStream fos = new FileOutputStream("cipherTest.out");
    int dataInputSize = fis.available();

    byte[] inputBytes = new byte[dataInputSize];
    fis.read(inputBytes);/*from w w w.ja v  a 2  s .com*/
    write(inputBytes, fos);
    fos.flush();
    fis.close();
    fos.close();

    String inputFileAsString = new String(inputBytes);
    System.out.println("INPUT FILE CONTENTS\n" + inputFileAsString + "\n");

    System.out.println("File encrypted and saved to disk\n");

    fis = new FileInputStream("cipherTest.out");

    byte[] decrypted = new byte[dataInputSize];
    read(decrypted, fis);

    fis.close();
    String decryptedAsString = new String(decrypted);

    System.out.println("DECRYPTED FILE:\n" + decryptedAsString + "\n");

}

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From source file:Main.java

public static void main(String[] args) throws Exception {
    // Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    byte[] input = "input".getBytes();
    byte[] ivBytes = "1234567812345678".getBytes();

    Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
    KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
    generator.init(128);// w w w.  j  a v  a  2  s  . co  m
    Key encryptionKey = generator.generateKey();
    System.out.println("key : " + new String(encryptionKey.getEncoded()));

    cipher.init(Cipher.ENCRYPT_MODE, encryptionKey, new IvParameterSpec(ivBytes));
    byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
    ctLength += cipher.doFinal(cipherText, ctLength);
    Key decryptionKey = new SecretKeySpec(encryptionKey.getEncoded(), encryptionKey.getAlgorithm());

    cipher.init(Cipher.DECRYPT_MODE, decryptionKey, new IvParameterSpec(ivBytes));
    byte[] plainText = new byte[cipher.getOutputSize(ctLength)];
    int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
    ptLength += cipher.doFinal(plainText, ptLength);
    System.out.println("plain : " + new String(plainText));
}

---

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    SecureRandom random = new SecureRandom();
    IvParameterSpec ivSpec = createCtrIvForAES();
    Key key = createKeyForAES(256, random);
    Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
    String input = "12345678";
    Mac mac = Mac.getInstance("DES", "BC");
    byte[] macKeyBytes = new byte[] { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 };
    Key macKey = new SecretKeySpec(macKeyBytes, "DES");

    cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);

    byte[] cipherText = new byte[cipher.getOutputSize(input.length() + mac.getMacLength())];

    int ctLength = cipher.update(input.getBytes(), 0, input.length(), cipherText, 0);

    mac.init(macKey);/*from  ww w.  j  a  v  a 2 s  .  com*/
    mac.update(input.getBytes());

    ctLength += cipher.doFinal(mac.doFinal(), 0, mac.getMacLength(), cipherText, ctLength);

    cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);

    byte[] plainText = cipher.doFinal(cipherText, 0, ctLength);
    int messageLength = plainText.length - mac.getMacLength();

    mac.init(macKey);
    mac.update(plainText, 0, messageLength);

    byte[] messageHash = new byte[mac.getMacLength()];
    System.arraycopy(plainText, messageLength, messageHash, 0, messageHash.length);

    System.out.println("plain : " + new String(plainText) + " verified: "
            + MessageDigest.isEqual(mac.doFinal(), messageHash));

}

---

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    byte[] input = "abc".getBytes();
    Cipher cipher = Cipher.getInstance("RSA/None/PKCS1Padding", "BC");
    SecureRandom random = new SecureRandom();
    KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA", "BC");

    generator.initialize(256, random);//  w  w w. ja v  a  2  s  .  c om

    KeyPair pair = generator.generateKeyPair();
    Key pubKey = pair.getPublic();
    Key privKey = pair.getPrivate();

    cipher.init(Cipher.ENCRYPT_MODE, pubKey, random);
    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:Main.java

public static void main(String[] args) throws Exception {
    //Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    byte[] input = "ab".getBytes();
    Cipher cipher = Cipher.getInstance("ElGamal/None/NoPadding", "BC");
    KeyPairGenerator generator = KeyPairGenerator.getInstance("ElGamal", "BC");
    SecureRandom random = new SecureRandom();

    generator.initialize(128, random);/*from  ww w. j av  a2s.co m*/

    KeyPair pair = generator.generateKeyPair();
    Key pubKey = pair.getPublic();
    Key privKey = pair.getPrivate();
    cipher.init(Cipher.ENCRYPT_MODE, pubKey, random);
    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 {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    byte[] input = "ab".getBytes();
    Cipher cipher = Cipher.getInstance("ElGamal/None/NoPadding", "BC");
    KeyPairGenerator generator = KeyPairGenerator.getInstance("ElGamal", "BC");
    SecureRandom random = new SecureRandom();

    generator.initialize(128, random);//from  w w  w .  j a  v  a2  s .  c  o  m

    KeyPair pair = generator.generateKeyPair();
    Key pubKey = pair.getPublic();
    Key privKey = pair.getPrivate();
    cipher.init(Cipher.ENCRYPT_MODE, pubKey, random);
    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 {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    byte[] input = "abc".getBytes();
    Cipher cipher = Cipher.getInstance("RSA/None/OAEPWithSHA1AndMGF1Padding", "BC");
    SecureRandom random = new SecureRandom();
    KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA", "BC");

    generator.initialize(386, random);//from ww w.j a  va2  s.c om

    KeyPair pair = generator.generateKeyPair();
    Key pubKey = pair.getPublic();

    Key privKey = pair.getPrivate();

    cipher.init(Cipher.ENCRYPT_MODE, pubKey, random);
    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 {
    Security.addProvider(new BouncyCastleProvider());
    SecureRandom random = new SecureRandom();
    IvParameterSpec ivSpec = createCtrIvForAES(1, random);
    Key key = createKeyForAES(256, random);
    Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
    String input = "www.java2s.com";
    Mac mac = Mac.getInstance("DES", "BC");
    byte[] macKeyBytes = "12345678".getBytes();
    Key macKey = new SecretKeySpec(macKeyBytes, "DES");
    System.out.println("input : " + input);

    // encryption step
    cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
    byte[] cipherText = new byte[cipher.getOutputSize(input.length() + mac.getMacLength())];
    int ctLength = cipher.update(input.getBytes(), 0, input.length(), cipherText, 0);
    mac.init(macKey);//from  ww  w . j  a  v a  2s.c o m
    mac.update(input.getBytes());
    ctLength += cipher.doFinal(mac.doFinal(), 0, mac.getMacLength(), cipherText, ctLength);
    System.out.println("cipherText : " + new String(cipherText));

    // decryption step
    cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
    byte[] plainText = cipher.doFinal(cipherText, 0, ctLength);
    int messageLength = plainText.length - mac.getMacLength();

    mac.init(macKey);
    mac.update(plainText, 0, messageLength);

    byte[] messageHash = new byte[mac.getMacLength()];
    System.arraycopy(plainText, messageLength, messageHash, 0, messageHash.length);

    System.out.println("plain : " + new String(plainText) + " verified: "
            + MessageDigest.isEqual(mac.doFinal(), messageHash));
}

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