Examples with NativeBigInteger net.i2p.util.NativeBigInteger used on opensource projects

Example 11 with NativeBigInteger

use of net.i2p.util.NativeBigInteger in project i2p.i2p by i2p.

the class SigUtil method toJavaDSAKey.

public static DSAPublicKey toJavaDSAKey(SigningPublicKey pk) throws GeneralSecurityException {
    KeyFactory kf = KeyFactory.getInstance("DSA");
    // y p q g
    KeySpec ks = new DSAPublicKeySpec(new NativeBigInteger(1, pk.getData()), CryptoConstants.dsap, CryptoConstants.dsaq, CryptoConstants.dsag);
    return (DSAPublicKey) kf.generatePublic(ks);
}

Example 12 with NativeBigInteger

use of net.i2p.util.NativeBigInteger in project i2p.i2p by i2p.

the class SigUtil method split.

/**
 *  Split a byte array into two BigIntegers
 *  @param b length must be even
 *  @return array of two BigIntegers
 *  @since 0.9.9
 */
private static NativeBigInteger[] split(byte[] b) {
    if ((b.length & 0x01) != 0)
        throw new IllegalArgumentException("length must be even");
    int sublen = b.length / 2;
    byte[] bx = new byte[sublen];
    byte[] by = new byte[sublen];
    System.arraycopy(b, 0, bx, 0, sublen);
    System.arraycopy(b, sublen, by, 0, sublen);
    NativeBigInteger x = new NativeBigInteger(1, bx);
    NativeBigInteger y = new NativeBigInteger(1, by);
    return new NativeBigInteger[] { x, y };
}

Example 13 with NativeBigInteger

use of net.i2p.util.NativeBigInteger in project i2p.i2p by i2p.

the class KeyPairGenerator method generateKeyPair.

public KeyPair generateKeyPair() {
    if (!initialized)
        initialize(DEFAULT_STRENGTH, RandomSource.getInstance());
    KeyGenerator kg = KeyGenerator.getInstance();
    SimpleDataStructure[] keys = kg.generatePKIKeys();
    PublicKey pubKey = (PublicKey) keys[0];
    PrivateKey privKey = (PrivateKey) keys[1];
    ElGamalPublicKey epubKey = new ElGamalPublicKeyImpl(new NativeBigInteger(1, pubKey.getData()), elgParams);
    ElGamalPrivateKey eprivKey = new ElGamalPrivateKeyImpl(new NativeBigInteger(1, privKey.getData()), elgParams);
    return new KeyPair(epubKey, eprivKey);
}

Example 14 with NativeBigInteger

use of net.i2p.util.NativeBigInteger in project i2p.i2p by i2p.

the class ElGamalEngine method encrypt.

/**
 * encrypt the data to the public key
 * @return encrypted data, will be exactly 514 bytes long
 *         Contains the two-part encrypted data starting at bytes 0 and 257.
 *         If the encrypted parts are smaller than 257 bytes, they will be
 *         padded with leading zeros.
 *         The parts appear to always be 256 bytes or less, in other words,
 *         bytes 0 and 257 are always zero.
 * @param publicKey public key encrypt to
 * @param data data to encrypt, must be 222 bytes or less
 *         As the encrypted data may contain a substantial number of zeros if the
 *         cleartext is smaller than 222 bytes, it is recommended that the caller pad
 *         the cleartext to 222 bytes with random data.
 */
public byte[] encrypt(byte[] data, PublicKey publicKey) {
    if ((data == null) || (data.length >= 223))
        throw new IllegalArgumentException("Data to encrypt must be < 223 bytes at the moment");
    if (publicKey == null)
        throw new IllegalArgumentException("Null public key specified");
    long start = _context.clock().now();
    byte[] d2 = new byte[1 + Hash.HASH_LENGTH + data.length];
    // random nonzero byte
    do {
        _context.random().nextBytes(d2, 0, 1);
    } while (d2[0] == 0);
    _context.sha().calculateHash(data, 0, data.length, d2, 1);
    System.arraycopy(data, 0, d2, 1 + Hash.HASH_LENGTH, data.length);
    // long t0 = _context.clock().now();
    BigInteger m = new NativeBigInteger(1, d2);
    // long t1 = _context.clock().now();
    if (m.compareTo(CryptoConstants.elgp) >= 0)
        throw new IllegalArgumentException("ARGH.  Data cannot be larger than the ElGamal prime.  FIXME");
    // long t2 = _context.clock().now();
    BigInteger aalpha = new NativeBigInteger(1, publicKey.getData());
    // long t3 = _context.clock().now();
    BigInteger[] yk = getNextYK();
    BigInteger k = yk[1];
    BigInteger y = yk[0];
    // long t7 = _context.clock().now();
    BigInteger d = aalpha.modPow(k, CryptoConstants.elgp);
    // long t8 = _context.clock().now();
    d = d.multiply(m);
    // long t9 = _context.clock().now();
    d = d.mod(CryptoConstants.elgp);
    // long t10 = _context.clock().now();
    byte[] ybytes = y.toByteArray();
    byte[] dbytes = d.toByteArray();
    byte[] out = new byte[514];
    System.arraycopy(ybytes, 0, out, (ybytes.length < 257 ? 257 - ybytes.length : 0), (ybytes.length > 257 ? 257 : ybytes.length));
    System.arraycopy(dbytes, 0, out, (dbytes.length < 257 ? 514 - dbytes.length : 257), (dbytes.length > 257 ? 257 : dbytes.length));
    /*
        StringBuilder buf = new StringBuilder(1024);
        buf.append("Timing\n");
        buf.append("0-1: ").append(t1 - t0).append('\n');
        buf.append("1-2: ").append(t2 - t1).append('\n');
        buf.append("2-3: ").append(t3 - t2).append('\n');
        //buf.append("3-4: ").append(t4-t3).append('\n');
        //buf.append("4-5: ").append(t5-t4).append('\n');
        //buf.append("5-6: ").append(t6-t5).append('\n');
        //buf.append("6-7: ").append(t7-t6).append('\n');
        buf.append("7-8: ").append(t8 - t7).append('\n');
        buf.append("8-9: ").append(t9 - t8).append('\n');
        buf.append("9-10: ").append(t10 - t9).append('\n');
        //_log.debug(buf.toString());
         */
    long end = _context.clock().now();
    long diff = end - start;
    if (diff > 1000) {
        if (_log.shouldLog(Log.WARN))
            _log.warn("Took too long to encrypt ElGamal block (" + diff + "ms)");
    }
    _context.statManager().addRateData("crypto.elGamal.encrypt", diff);
    return out;
}

Example 15 with NativeBigInteger

use of net.i2p.util.NativeBigInteger in project i2p.i2p by i2p.

the class ElGamalEngine method decrypt.

/**
 * Decrypt the data
 * @param encrypted encrypted data, must be exactly 514 bytes
 *         Contains the two-part encrypted data starting at bytes 0 and 257.
 *         If the encrypted parts are smaller than 257 bytes, they must be
 *         padded with leading zeros.
 * @param privateKey private key to decrypt with
 * @return unencrypted data or null on failure
 */
public byte[] decrypt(byte[] encrypted, PrivateKey privateKey) {
    if ((encrypted == null) || (encrypted.length != 514))
        throw new IllegalArgumentException("Data to decrypt must be exactly 514 bytes");
    long start = _context.clock().now();
    BigInteger a = new NativeBigInteger(1, privateKey.getData());
    BigInteger y1p = ELGPM1.subtract(a);
    // we use this buf first for Y, then for D, then for the hash
    byte[] buf = SimpleByteCache.acquire(257);
    System.arraycopy(encrypted, 0, buf, 0, 257);
    NativeBigInteger y = new NativeBigInteger(1, buf);
    BigInteger ya = y.modPowCT(y1p, CryptoConstants.elgp);
    System.arraycopy(encrypted, 257, buf, 0, 257);
    BigInteger d = new NativeBigInteger(1, buf);
    BigInteger m = ya.multiply(d);
    m = m.mod(CryptoConstants.elgp);
    byte[] val = m.toByteArray();
    int i;
    for (i = 0; i < val.length; i++) {
        if (val[i] != (byte) 0x00)
            break;
    }
    int payloadLen = val.length - i - 1 - Hash.HASH_LENGTH;
    if (payloadLen < 0) {
        if (_log.shouldLog(Log.ERROR))
            _log.error("Decrypted data is too small (" + (val.length - i) + ")");
        return null;
    }
    // ByteArrayInputStream bais = new ByteArrayInputStream(val, i, val.length - i);
    // byte hashData[] = new byte[Hash.HASH_LENGTH];
    // System.arraycopy(val, i + 1, hashData, 0, Hash.HASH_LENGTH);
    // Hash hash = new Hash(hashData);
    // Hash hash = Hash.create(val, i + 1);
    byte[] rv = new byte[payloadLen];
    System.arraycopy(val, i + 1 + Hash.HASH_LENGTH, rv, 0, rv.length);
    // we reuse buf here for the calculated hash
    _context.sha().calculateHash(rv, 0, payloadLen, buf, 0);
    boolean ok = DataHelper.eq(buf, 0, val, i + 1, Hash.HASH_LENGTH);
    SimpleByteCache.release(buf);
    long end = _context.clock().now();
    long diff = end - start;
    if (diff > 1000) {
        if (_log.shouldLog(Log.WARN))
            _log.warn("Took too long to decrypt and verify ElGamal block (" + diff + "ms)");
    }
    _context.statManager().addRateData("crypto.elGamal.decrypt", diff);
    if (ok) {
        // _log.debug("Hash matches: " + DataHelper.toString(hash.getData(), hash.getData().length));
        return rv;
    }
    if (_log.shouldLog(Log.DEBUG))
        _log.debug("Doesn't match hash data = " + Base64.encode(rv), new Exception("Doesn't match"));
    return null;
}