Example usage for javax.crypto Cipher DECRYPT_MODE

Introduction

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

Prototype

int DECRYPT_MODE

To view the source code for javax.crypto Cipher DECRYPT_MODE.

Click Source Link

Document

Constant used to initialize cipher to decryption mode.

Usage

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));
}

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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[] { 0x01, 0x23, 0x45, 0x67, (byte) 0x89, (byte) 0xab, (byte) 0xcd, (byte) 0xef };
    byte[] ivBytes = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x00, 0x00, 0x00, 0x01 };

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

    // encryption pass
    cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
    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);

    // decryption pass
    cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
    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 = "input".getBytes();
    byte[] keyBytes = "input123".getBytes();
    byte[] msgNumber = "input".getBytes();

    IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]);

    SecretKeySpec key = new SecretKeySpec(keyBytes, "DES");

    Cipher cipher = Cipher.getInstance("DES/CBC/PKCS7Padding", "BC");

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

    IvParameterSpec encryptionIv = new IvParameterSpec(cipher.doFinal(msgNumber), 0, 8);

    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);

    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, ptLength));
}

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From source file:MainClass.java

public static void main(String[] args) throws Exception {
    KeyGenerator kg = KeyGenerator.getInstance("DESede");
    Key sharedKey = kg.generateKey();

    String password = "password";
    byte[] salt = "salt1234".getBytes();
    PBEParameterSpec paramSpec = new PBEParameterSpec(salt, 20);
    PBEKeySpec keySpec = new PBEKeySpec(password.toCharArray());
    SecretKeyFactory kf = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
    SecretKey passwordKey = kf.generateSecret(keySpec);
    Cipher c = Cipher.getInstance("PBEWithMD5AndDES");
    c.init(Cipher.WRAP_MODE, passwordKey, paramSpec);
    byte[] wrappedKey = c.wrap(sharedKey);

    c = Cipher.getInstance("DESede");
    c.init(Cipher.ENCRYPT_MODE, sharedKey);
    byte[] input = "input".getBytes();
    byte[] encrypted = c.doFinal(input);

    c = Cipher.getInstance("PBEWithMD5AndDES");

    c.init(Cipher.UNWRAP_MODE, passwordKey, paramSpec);
    Key unwrappedKey = c.unwrap(wrappedKey, "DESede", Cipher.SECRET_KEY);

    c = Cipher.getInstance("DESede");
    c.init(Cipher.DECRYPT_MODE, unwrappedKey);
    System.out.println(new String(c.doFinal(encrypted)));
}

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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());

    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 ava2 s  .  co m*/
    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));

}

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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[] ivBytes = new byte[] { 0x00, 0x00, 0x00, 0x01, 0x04, 0x05, 0x06, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x00, 0x00, 0x01 };//from   w  w  w  .  j a va2 s  .  com

    Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
    KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");

    generator.init(192);

    Key encryptionKey = generator.generateKey();

    System.out.println("key   : " + Utils.toHex(encryptionKey.getEncoded()));
    System.out.println("input : " + new String(input));

    // encryption pass
    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);

    // decryption pass
    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) + " 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[] { 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 };/*from   w w  w  .  ja  va 2s .  co m*/

    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 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  w  w w  .  ja va2s . com
    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));
}

---

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[] { 0x73, 0x2f, 0x2d, 0x33, (byte) 0xc8, 0x01, 0x73, 0x2b, 0x72, 0x06, 0x75,
            0x6c, (byte) 0xbd, 0x44, (byte) 0xf9, (byte) 0xc1, (byte) 0xc1, 0x03, (byte) 0xdd, (byte) 0xd9,
            0x7c, 0x7c, (byte) 0xbe, (byte) 0x8e };
    byte[] ivBytes = new byte[] { (byte) 0xb0, 0x7b, (byte) 0xf5, 0x22, (byte) 0xc8, (byte) 0xd6, 0x08,
            (byte) 0xb8 };

    // encrypt the data using precalculated keys

    Cipher cEnc = Cipher.getInstance("DESede/CBC/PKCS7Padding", "BC");
    cEnc.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(keyBytes, "DESede"), new IvParameterSpec(ivBytes));

    byte[] out = cEnc.doFinal(input);
    // decrypt the data using PBE

    char[] password = "password".toCharArray();
    byte[] salt = new byte[] { 0x7d, 0x60, 0x43, 0x5f, 0x02, (byte) 0xe9, (byte) 0xe0, (byte) 0xae };
    int iterationCount = 2048;
    PBEKeySpec pbeSpec = new PBEKeySpec(password, salt, iterationCount);
    SecretKeyFactory keyFact = SecretKeyFactory.getInstance("PBEWithSHAAnd3KeyTripleDES");

    Cipher cDec = Cipher.getInstance("PBEWithSHAAnd3KeyTripleDES");
    Key sKey = keyFact.generateSecret(pbeSpec);

    cDec.init(Cipher.DECRYPT_MODE, sKey);

    System.out.println("cipher : " + new String(out));
    System.out.println("gen key: " + new String(sKey.getEncoded()));
    System.out.println("gen iv : " + new String(cDec.getIV()));
    System.out.println("plain  : " + new String(cDec.doFinal(out)));
}

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