Example usage for org.bouncycastle.crypto.encodings OAEPEncoding decodeBlock

Introduction

In this page you can find the example usage for org.bouncycastle.crypto.encodings OAEPEncoding decodeBlock.

Prototype

public byte[] decodeBlock(byte[] in, int inOff, int inLen) throws InvalidCipherTextException 

Source Link

Usage

From source file:cf.monteux.silvertunnel.netlib.layer.tor.util.Encryption.java

License:Open Source License

/**
 * decrypt data with asymmetric key. create asymmetrically encrypted data:<br>
 * <ul>// w  w w.ja v a  2s.co  m
 * <li>OAEP padding [42 bytes] (RSA-encrypted)</li>
 * <li>Symmetric key [16 bytes]</li>
 * <li>First part of data [70 bytes]</li>
 * <li>Second part of data [x-70 bytes] (Symmetrically encrypted)</li>
 * </ul>
 * encrypt and store in result
 *
 * @param priv key to use for decryption
 * @param data to be decrypted, needs currently to be at least 70 bytes long
 * @return raw data
 */
public static byte[] asymDecrypt(final RSAPrivateKey priv, final byte[] data) throws TorException {

    if (data == null) {
        throw new NullPointerException("can't encrypt NULL data");
    }
    if (data.length < 70) {
        throw new TorException("input array too short");
    }

    try {
        int encryptedBytes = 0;

        // init OAEP
        final OAEPEncoding oaep = new OAEPEncoding(new RSAEngine());
        oaep.init(false, new RSAKeyParameters(true, priv.getModulus(), priv.getPrivateExponent()));
        // apply RSA+OAEP
        encryptedBytes = oaep.getInputBlockSize();
        final byte[] oaepInput = new byte[encryptedBytes];
        System.arraycopy(data, 0, oaepInput, 0, encryptedBytes);
        final byte[] part1 = oaep.decodeBlock(oaepInput, 0, encryptedBytes);

        // extract symmetric key
        final byte[] symmetricKey = new byte[16];
        System.arraycopy(part1, 0, symmetricKey, 0, 16);
        // init AES
        final AESCounterMode aes = new AESCounterMode(symmetricKey);
        // apply AES
        final byte[] aesInput = new byte[data.length - encryptedBytes];
        System.arraycopy(data, encryptedBytes, aesInput, 0, aesInput.length);
        final byte[] part2 = aes.processStream(aesInput);

        // replace unencrypted data
        final byte[] result = new byte[part1.length - 16 + part2.length];
        System.arraycopy(part1, 16, result, 0, part1.length - 16);
        System.arraycopy(part2, 0, result, part1.length - 16, part2.length);

        return result;

    } catch (final InvalidCipherTextException e) {
        logger.error("Encryption.asymDecrypt(): can't decrypt cipher text:" + e.getMessage());
        throw new TorException("Encryption.asymDecrypt(): InvalidCipherTextException:" + e.getMessage());
    }
}

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From source file:com.rovemonteux.silvertunnel.netlib.layer.tor.util.Encryption.java

License:Open Source License

/**
 * decrypt data with asymmetric key. create asymmetrically encrypted data:<br>
 * <ul>// w w  w.  ja  va 2s .  c o  m
 * <li>OAEP padding [42 bytes] (RSA-encrypted)</li>
 * <li>Symmetric key [16 bytes]</li>
 * <li>First part of data [70 bytes]</li>
 * <li>Second part of data [x-70 bytes] (Symmetrically encrypted)</li>
 * </ul>
 * encrypt and store in result
 *
 * @param priv key to use for decryption
 * @param data to be decrypted, needs currently to be at least 70 bytes long
 * @return raw data
 */
public static byte[] asymDecrypt(final RSAPrivateKey priv, final byte[] data) throws TorException {

    if (data == null) {
        throw new NullPointerException("can't encrypt NULL data");
    }
    if (data.length < 70) {
        throw new TorException("input array too short");
    }

    try {
        int encryptedBytes = 0;

        // init OAEP
        final OAEPEncoding oaep = new OAEPEncoding(new RSAEngine());
        oaep.init(false, new RSAKeyParameters(true, priv.getModulus(), priv.getPrivateExponent()));
        // apply RSA+OAEP
        encryptedBytes = oaep.getInputBlockSize();
        final byte[] oaepInput = new byte[encryptedBytes];
        System.arraycopy(data, 0, oaepInput, 0, encryptedBytes);
        final byte[] part1 = oaep.decodeBlock(oaepInput, 0, encryptedBytes);

        // extract symmetric key
        final byte[] symmetricKey = new byte[16];
        System.arraycopy(part1, 0, symmetricKey, 0, 16);
        // init AES
        final AESCounterMode aes = new AESCounterMode(symmetricKey);
        // apply AES
        final byte[] aesInput = new byte[data.length - encryptedBytes];
        System.arraycopy(data, encryptedBytes, aesInput, 0, aesInput.length);
        final byte[] part2 = aes.processStream(aesInput);

        // replace unencrypted data
        final byte[] result = new byte[part1.length - 16 + part2.length];
        System.arraycopy(part1, 16, result, 0, part1.length - 16);
        System.arraycopy(part2, 0, result, part1.length - 16, part2.length);

        return result;

    } catch (final InvalidCipherTextException e) {
        LOG.error("Encryption.asymDecrypt(): can't decrypt cipher text:" + e.getMessage());
        throw new TorException("Encryption.asymDecrypt(): InvalidCipherTextException:" + e.getMessage());
    }
}

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From source file:org.silvertunnel.netlib.layer.tor.util.Encryption.java

License:Open Source License

/**
 * decrypt data with asymmetric key. create asymmetrically encrypted data:<br>
 * <ul>/*from   w  w w .j a  v  a  2s . co m*/
 * <li>OAEP padding [42 bytes] (RSA-encrypted)
 * <li>Symmetric key [16 bytes]
 * <li>First part of data [70 bytes]
 * <li>Second part of data [x-70 bytes] (Symmetrically encrypted)
 * <ul>
 * encrypt and store in result
 * 
 * @param priv
 *            key to use for decryption
 * @param data
 *            to be decrypted, needs currently to be at least 70 bytes long
 * @return raw data
 */
public static byte[] asymDecrypt(RSAPrivateKey priv, byte[] data) throws TorException {

    if (data == null) {
        throw new NullPointerException("can't encrypt NULL data");
    }
    if (data.length < 70) {
        throw new TorException("input array too short");
    }

    try {
        int encryptedBytes = 0;

        // init OAEP
        OAEPEncoding oaep = new OAEPEncoding(new RSAEngine());
        oaep.init(false, new RSAKeyParameters(true, priv.getModulus(), priv.getPrivateExponent()));
        // apply RSA+OAEP
        encryptedBytes = oaep.getInputBlockSize();
        byte[] oaepInput = new byte[encryptedBytes];
        System.arraycopy(data, 0, oaepInput, 0, encryptedBytes);
        byte[] part1 = oaep.decodeBlock(oaepInput, 0, encryptedBytes);

        // extract symmetric key
        byte[] symmetricKey = new byte[16];
        System.arraycopy(part1, 0, symmetricKey, 0, 16);
        // init AES
        AESCounterMode aes = new AESCounterMode(true, symmetricKey);
        // apply AES
        byte[] aesInput = new byte[data.length - encryptedBytes];
        System.arraycopy(data, encryptedBytes, aesInput, 0, aesInput.length);
        byte part2[] = aes.processStream(aesInput);

        // replace unencrypted data
        byte[] result = new byte[part1.length - 16 + part2.length];
        System.arraycopy(part1, 16, result, 0, part1.length - 16);
        System.arraycopy(part2, 0, result, part1.length - 16, part2.length);

        return result;

    } catch (InvalidCipherTextException e) {
        log.severe("CommonEncryption.asymDecrypt(): can't decrypt cipher text:" + e.getMessage());
        throw new TorException("CommonEncryption.asymDecrypt(): InvalidCipherTextException:" + e.getMessage());
    }
}

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From source file:TorJava.Common.Encryption.java

License:Open Source License

/**
 * encrypt data with asymmetric key. create asymmetrically encrypted data:<br>
 * <ul>//from  w  ww.  j a  v  a2 s . c  om
 * <li>OAEP padding [42 bytes] (RSA-encrypted)
 * <li>Symmetric key [16 bytes]
 * <li>First part of data [70 bytes]
 * <li>Second part of data [x-70 bytes] (Symmetrically encrypted)
 * <ul>
 * encrypt and store in result
 * 
 * @param priv
 *            key to use for decryption
 * @param data
 *            to be decrypted, needs currently to be at least 70 bytes long
 * @return raw data
 */
public static byte[] asym_decrypt(RSAKeyParameters priv, byte[] data) throws TorException {

    if (data == null)
        throw new NullPointerException("can't encrypt NULL data");
    if (data.length < 70)
        throw new TorException("input array too short");

    try {
        int encrypted_bytes = 0;

        // init OAEP
        OAEPEncoding oaep = new OAEPEncoding(new RSAEngine());
        oaep.init(false, priv);
        // apply RSA+OAEP
        encrypted_bytes = oaep.getInputBlockSize();
        byte[] oaep_input = new byte[encrypted_bytes];
        System.arraycopy(data, 0, oaep_input, 0, encrypted_bytes);
        byte[] part1 = oaep.decodeBlock(oaep_input, 0, encrypted_bytes);

        // extract symmetric key
        byte[] symmetric_key = new byte[16];
        System.arraycopy(part1, 0, symmetric_key, 0, 16);
        // init AES
        AESCounterMode aes = new AESCounterMode(true, symmetric_key);
        // apply AES
        byte[] aes_input = new byte[data.length - encrypted_bytes];
        System.arraycopy(data, encrypted_bytes, aes_input, 0, aes_input.length);
        byte part2[] = aes.processStream(aes_input);

        // replace unencrypted data
        byte[] result = new byte[part1.length - 16 + part2.length];
        System.arraycopy(part1, 16, result, 0, part1.length - 16);
        System.arraycopy(part2, 0, result, part1.length - 16, part2.length);

        return result;

    } catch (InvalidCipherTextException e) {
        Logger.logCell(Logger.ERROR,
                "CommonEncryption.asym_decrypt(): can't decrypt cipher text:" + e.getMessage());
        throw new TorException("CommonEncryption.asym_decrypt(): InvalidCipherTextException:" + e.getMessage());
    }

}

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