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

Introduction

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

Prototype

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

Source Link

Usage

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

License:Open Source License

/**
 * encrypt data with asymmetric key. create asymmetricla encrypted data:<br>
 * <ul>//from   w w  w.ja v a2 s.com
 * <li>OAEP padding [42 bytes] (RSA-encrypted)
 * <li>Symmetric key [16 bytes]                   FIXME: we assume that we ALWAYS need this 
 * <li>First part of data [70 bytes]
 * <li>Second part of data [x-70 bytes] (Symmetrically encrypted)
 * <ul>
 * encrypt and store in result
 * 
 * @param pub
 * @param symmetricKey    AES key  
 * @param data
 *            to be encrypted, needs currently to be at least 70 bytes long
 * @return the first half of the key exchange, ready to be send to the other
 *         partner
 */
public static byte[] asymEncrypt(RSAPublicKey pub, byte[] symmetricKey, 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;

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

        // initialize 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 + part2.length];
        System.arraycopy(part1, 0, result, 0, part1.length);
        System.arraycopy(part2, 0, result, part1.length, part2.length);

        return result;
    } catch (InvalidCipherTextException e) {
        log.severe("Node.asymEncrypt(): can't encrypt cipher text:" + e.getMessage());
        throw new TorException("InvalidCipherTextException:" + e.getMessage());
    }
}

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From source file:TorJava.Node.java

License:Open Source License

/**
 * encrypt data with asymmetric key. create asymmetricla encrypted data:<br>
 * <ul>/*from w  w  w  .j  a va  2s.c  om*/
 * <li>OAEP padding [42 bytes] (RSA-encrypted)
 * <li>Symmetric key [16 bytes]                   FIXME: we assume that we ALWAYS need this 
 * <li>First part of data [70 bytes]
 * <li>Second part of data [x-70 bytes] (Symmetrically encrypted)
 * <ul>
 * encrypt and store in result
 * 
 * @param data
 *            to be encrypted, needs currently to be at least 70 bytes long
 * @return the first half of the key exchange, ready to be send to the other
 *         partner
 */
byte[] asym_encrypt(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(true,
                new RSAKeyParameters(false, server.onionKey.getModulus(), server.onionKey.getPublicExponent()));
        // 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.encodeBlock(oaep_input, 0, encrypted_bytes);

        // init AES
        AESCounterMode aes = new AESCounterMode(true, symmetric_key_for_create);
        // 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 + part2.length];
        System.arraycopy(part1, 0, result, 0, part1.length);
        System.arraycopy(part2, 0, result, part1.length, part2.length);

        return result;
    } catch (InvalidCipherTextException e) {
        Logger.logCell(Logger.ERROR, "Node.asym_encrypt(): can't encrypt cipher text:" + e.getMessage());
        throw new TorException("InvalidCipherTextException:" + e.getMessage());
    }
}

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