package cn.com.capcloud.core.util.sm;

import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECFieldElement;
import org.bouncycastle.math.ec.ECFieldElement.Fp;
import org.bouncycastle.math.ec.ECPoint;

import java.math.BigInteger;
import java.security.SecureRandom;

public class SM2 {
    //测试参数
  /*public static final String[] ecc_param = {
      "8542D69E4C044F18E8B92435BF6FF7DE457283915C45517D722EDB8B08F1DFC3",
      "787968B4FA32C3FD2417842E73BBFEFF2F3C848B6831D7E0EC65228B3937E498",
      "63E4C6D3B23B0C849CF84241484BFE48F61D59A5B16BA06E6E12D1DA27C5249A",
      "8542D69E4C044F18E8B92435BF6FF7DD297720630485628D5AE74EE7C32E79B7",
      "421DEBD61B62EAB6746434EBC3CC315E32220B3BADD50BDC4C4E6C147FEDD43D",
      "0680512BCBB42C07D47349D2153B70C4E5D7FDFCBFA36EA1A85841B9E46E09A2"
  };*/

    //正式参数
    public static String[] ecc_param = {
            "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF",
            "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC",
            "28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93",
            "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123",
            "32C4AE2C1F1981195F9904466A39C9948FE30BBFF2660BE1715A4589334C74C7",
            "BC3736A2F4F6779C59BDCEE36B692153D0A9877CC62A474002DF32E52139F0A0"
    };

    public static SM2 Instance()
    {
        return new SM2();
    }

    public final BigInteger ecc_p;
    public final BigInteger ecc_a;
    public final BigInteger ecc_b;
    public final BigInteger ecc_n;
    public final BigInteger ecc_gx;
    public final BigInteger ecc_gy;
    public final ECCurve ecc_curve;
    public final ECPoint ecc_point_g;
    public final ECDomainParameters ecc_bc_spec;
    public final ECKeyPairGenerator ecc_key_pair_generator;
    public final ECFieldElement ecc_gx_fieldelement;
    public final ECFieldElement ecc_gy_fieldelement;

    public SM2()
    {
        this.ecc_p = new BigInteger(ecc_param[0], 16);
        this.ecc_a = new BigInteger(ecc_param[1], 16);
        this.ecc_b = new BigInteger(ecc_param[2], 16);
        this.ecc_n = new BigInteger(ecc_param[3], 16);
        this.ecc_gx = new BigInteger(ecc_param[4], 16);
        this.ecc_gy = new BigInteger(ecc_param[5], 16);

        this.ecc_gx_fieldelement = new Fp(this.ecc_p, this.ecc_gx);
        this.ecc_gy_fieldelement = new Fp(this.ecc_p, this.ecc_gy);

        this.ecc_curve = new ECCurve.Fp(this.ecc_p, this.ecc_a, this.ecc_b);
        this.ecc_point_g = new ECPoint.Fp(this.ecc_curve, this.ecc_gx_fieldelement, this.ecc_gy_fieldelement);

        this.ecc_bc_spec = new ECDomainParameters(this.ecc_curve, this.ecc_point_g, this.ecc_n);

        ECKeyGenerationParameters ecc_ecgenparam;
        ecc_ecgenparam = new ECKeyGenerationParameters(this.ecc_bc_spec, new SecureRandom());

        this.ecc_key_pair_generator = new ECKeyPairGenerator();
        this.ecc_key_pair_generator.init(ecc_ecgenparam);
    }
}
