Method encrypt

security/src/main/java/pro/tools/security/sm/SM2.java:203–262

公钥加密 @param input 加密原文 @param publicKey 公钥 @return

(String input, ECPoint publicKey)

     * @return
     */
    public byte[] encrypt(String input, ECPoint publicKey) {

        byte[] inputBuffer = input.getBytes();

        byte[] C1Buffer;
        ECPoint kpb;
        byte[] t;
        do {
            /* 1 产生随机数k，k属于[1, n-1] */
            BigInteger k = random(n);

            /* 2 计算椭圆曲线点C1 = [k]G = (x1, y1) */
            ECPoint C1 = G.multiply(k);
            C1Buffer = C1.getEncoded(false);

            /*
             * 3 计算椭圆曲线点 S = [h]Pb
             */
            BigInteger h = ecc_bc_spec.getH();
            if (h != null) {
                ECPoint S = publicKey.multiply(h);
                if (S.isInfinity()) {
                    throw new IllegalStateException();
                }
            }

            /* 4 计算 [k]PB = (x2, y2) */
            kpb = publicKey.multiply(k).normalize();

            /* 5 计算 t = KDF(x2||y2, klen) */
            byte[] kpbBytes = kpb.getEncoded(false);
            t = KDF(kpbBytes, inputBuffer.length);
            // DerivationFunction kdf = new KDF1BytesGenerator(new
            // ShortenedDigest(new SHA256Digest(), DIGEST_LENGTH));
            //
            // t = new byte[inputBuffer.length];
            // kdf.init(new ISO18033KDFParameters(kpbBytes));
            // kdf.generateBytes(t, 0, t.length);
        } while (allZero(t));

        /* 6 计算C2=M^t */
        byte[] C2 = new byte[inputBuffer.length];
        for (int i = 0; i < inputBuffer.length; i++) {
            C2[i] = (byte) (inputBuffer[i] ^ t[i]);
        }

        /* 7 计算C3 = Hash(x2 || M || y2) */
        byte[] C3 = sm3hash(kpb.getXCoord().toBigInteger().toByteArray(), inputBuffer,
                kpb.getYCoord().toBigInteger().toByteArray());

        /* 8 输出密文 C=C1 || C2 || C3 */

        byte[] encryptResult = new byte[C1Buffer.length + C2.length + C3.length];

        System.arraycopy(C1Buffer, 0, encryptResult, 0, C1Buffer.length);
        System.arraycopy(C2, 0, encryptResult, C1Buffer.length, C2.length);
        System.arraycopy(C3, 0, encryptResult, C1Buffer.length + C2.length, C3.length);