import org.bouncycastle.crypto.macs.Poly1305; //导入依赖的package包/类
/**
 * Encrypt a plaintext using the given key and nonce.
 *
 * @param nonce a 24-byte nonce (cf. {@link #nonce(ByteString)}, {@link #nonce()})
 * @param plaintext an arbitrary message
 * @return the ciphertext
 */
public ByteString seal(@Nonnull ByteString nonce, @Nonnull ByteString plaintext) {
  // initialize XSalsa20
  final XSalsa20Engine xsalsa20 = new XSalsa20Engine();
  xsalsa20.init(true, new ParametersWithIV(new KeyParameter(key), nonce.toByteArray()));

  // generate Poly1305 subkey
  final byte[] sk = new byte[32];
  xsalsa20.processBytes(sk, 0, 32, sk, 0);

  // encrypt plaintext
  final byte[] out = new byte[plaintext.size() + 16];
  xsalsa20.processBytes(plaintext.toByteArray(), 0, plaintext.size(), out, 16);

  // hash ciphertext and prepend mac to ciphertext
  final Poly1305 poly1305 = new Poly1305();
  poly1305.init(new KeyParameter(sk));
  poly1305.update(out, 16, plaintext.size());
  poly1305.doFinal(out, 0);
  return ByteString.of(out);
}
 

import org.bouncycastle.crypto.macs.Poly1305; //导入依赖的package包/类
/**
 * Decrypt a ciphertext using the given key and nonce.
 *
 * @param nonce a 24-byte nonce
 * @param ciphertext the encrypted message
 * @return an {@link Optional} of the original plaintext, or if either the key, nonce, or
 *     ciphertext was modified, an empty {@link Optional}
 * @see #nonce(ByteString)
 * @see #nonce()
 */
public Optional<ByteString> open(@Nonnull ByteString nonce, @Nonnull ByteString ciphertext) {
  final byte[] in = ciphertext.toByteArray();
  final XSalsa20Engine xsalsa20 = new XSalsa20Engine();
  final Poly1305 poly1305 = new Poly1305();

  // initialize XSalsa20
  xsalsa20.init(false, new ParametersWithIV(new KeyParameter(key), nonce.toByteArray()));

  // generate mac subkey
  final byte[] sk = new byte[32];
  xsalsa20.processBytes(sk, 0, sk.length, sk, 0);

  // hash ciphertext
  poly1305.init(new KeyParameter(sk));
  final int len = Math.max(ciphertext.size() - 16, 0);
  poly1305.update(in, 16, len);
  final byte[] calculatedMAC = new byte[16];
  poly1305.doFinal(calculatedMAC, 0);

  // extract mac
  final byte[] presentedMAC = new byte[16];
  System.arraycopy(in, 0, presentedMAC, 0, Math.min(ciphertext.size(), 16));

  // compare macs
  if (!MessageDigest.isEqual(calculatedMAC, presentedMAC)) {
    return Optional.empty();
  }

  // decrypt ciphertext
  final byte[] plaintext = new byte[len];
  xsalsa20.processBytes(in, 16, plaintext.length, plaintext, 0);
  return Optional.of(ByteString.of(plaintext));
}
 

import org.bouncycastle.crypto.macs.Poly1305; //导入依赖的package包/类
protected byte[] calculateRecordMAC(KeyParameter macKey, byte[] additionalData, byte[] buf, int off, int len)
{
    Mac mac = new Poly1305();
    mac.init(macKey);

    updateRecordMAC(mac, additionalData, 0, additionalData.length);
    updateRecordMAC(mac, buf, off, len);

    byte[] output = new byte[mac.getMacSize()];
    mac.doFinal(output, 0);
    return output;
}
 

import org.bouncycastle.crypto.macs.Poly1305; //导入依赖的package包/类
public static void main(String[] args)
{
    testMac(new HMac(new SHA1Digest()), new KeyParameter(generateNonce(20)), 3);
    testMac(new SkeinMac(SkeinMac.SKEIN_512, 128), new KeyParameter(generateNonce(64)), 2);
    testMac(new SipHash(), new KeyParameter(generateNonce(16)), 1);
    testMac(new CMac(new AESFastEngine()), new KeyParameter(generateNonce(16)), 3);
    testMac(new GMac(new GCMBlockCipher(new AESFastEngine())), new ParametersWithIV(new KeyParameter(
            generateNonce(16)), generateNonce(16)), 5);
    testMac(new Poly1305(new NullEngine(16)), new ParametersWithIV(generatePoly1305Key(), generateNonce(16)), 1);
    testMac(new Poly1305(new AESFastEngine()), new ParametersWithIV(generatePoly1305Key(), generateNonce(16)), 1);
    testMac(new Poly1305Reference(new NullEngine(16)), new ParametersWithIV(generatePoly1305Key(),
            generateNonce(16)), 1);
}
 

import org.bouncycastle.crypto.macs.Poly1305; //导入依赖的package包/类
private void testSequential()
{
    // Sequential test, adapted from test-poly1305aes
    int len;
    byte[] kr = new byte[32];
    byte[] m = new byte[MAXLEN];
    byte[] n = new byte[16];
    byte[] out = new byte[16];

    int c = 0;
    final Mac mac = new Poly1305(new AESFastEngine());
    for (int loop = 0; loop < 13; loop++)
    {
        len = 0;
        for (;;)
        {
            c++;
            mac.init(new ParametersWithIV(new KeyParameter(kr), n));
            mac.update(m, 0, len);
            mac.doFinal(out, 0);

            // if (c == 678)
            // {
            // TestCase tc = CASES[0];
            //
            // if (!Arrays.areEqual(tc.key, kr))
            // {
            // System.err.println("Key bad");
            // System.err.println(new String(Hex.encode(tc.key)));
            // System.err.println(new String(Hex.encode(kr)));
            // System.exit(1);
            // }
            // if (!Arrays.areEqual(tc.nonce, n))
            // {
            // System.err.println("Nonce bad");
            // System.exit(1);
            // }
            // System.out.printf("[%d] m: %s\n", c, new String(Hex.encode(m, 0, len)));
            // System.out.printf("[%d] K: %s\n", c, new String(Hex.encodje(kr)));
            // System.out.printf("[%d] N: %s\n", c, new String(Hex.encode(n)));
            // System.out.printf("[%d] M: ", c);
            // }
            // System.out.printf("%d/%s\n", c, new String(Hex.encode(out)));

            if (len >= MAXLEN)
                break;
            n[0] ^= loop;
            for (int i = 0; i < 16; ++i)
                n[i] ^= out[i];
            if (len % 2 != 0)
                for (int i = 0; i < 16; ++i)
                    kr[i] ^= out[i];
            if (len % 3 != 0)
                for (int i = 0; i < 16; ++i)
                    kr[i + 16] ^= out[i];
            Poly1305KeyGenerator.clamp(kr);
            m[len++] ^= out[0];
        }
    }
    // Output after 13 loops as generated by poly1305 ref
    if (c != 13013 || !Arrays.areEqual(out, Hex.decode("c96f60a23701a5b0fd2016f58cbe4f7e")))
    {
        fail("Sequential Poly1305 " + c, "c96f60a23701a5b0fd2016f58cbe4f7e", new String(Hex.encode(out)));
    }
}
 

import org.bouncycastle.crypto.macs.Poly1305; //导入依赖的package包/类
private void testReset()
{
    CipherKeyGenerator gen = new Poly1305KeyGenerator();
    gen.init(new KeyGenerationParameters(new SecureRandom(), 256));
    byte[] k = gen.generateKey();

    byte[] m = new byte[10000];
    byte[] check = new byte[16];
    byte[] out = new byte[16];

    // Generate baseline
    Mac poly = new Poly1305(new AESFastEngine());
    poly.init(new ParametersWithIV(new KeyParameter(k), new byte[16]));

    poly.update(m, 0, m.length);
    poly.doFinal(check, 0);

    // Check reset after doFinal
    poly.update(m, 0, m.length);
    poly.doFinal(out, 0);

    if (!Arrays.areEqual(check, out))
    {
        fail("Mac not reset after doFinal");
    }

    // Check reset
    poly.update((byte)1);
    poly.update((byte)2);
    poly.reset();
    poly.update(m, 0, m.length);
    poly.doFinal(out, 0);

    if (!Arrays.areEqual(check, out))
    {
        fail("Mac not reset after doFinal");
    }

    // Check init resets
    poly.update((byte)1);
    poly.update((byte)2);
    poly.init(new ParametersWithIV(new KeyParameter(k), new byte[16]));
    poly.update(m, 0, m.length);
    poly.doFinal(out, 0);

    if (!Arrays.areEqual(check, out))
    {
        fail("Mac not reset after doFinal");
    }
}
 

import org.bouncycastle.crypto.macs.Poly1305; //导入依赖的package包/类
/**
 * Constructor
 *
 * @throws NoSuchAlgorithmException thrown if the given algorithm is not supported
 */
public BCPoly1305MacHelper() throws NoSuchAlgorithmException {
    this.mac = new Poly1305();
}