Springboot整合SM2加密的笔记

首先要明白公钥是加密，私钥用来解密。

国密公钥格式：公钥为64位，前后各32位，对应椭圆算法中BigInteger X  和 BigInteger X ，私钥为32位，对应算法中的BigInteger d。

工具类：

可以参考https://www.cnblogs.com/jing99/p/14920120.html，我猜测这个也是看https://gitee.com/lucky_ldx/sm_national_secret_algorithm.git这个项目做的

引入的依赖：

        <dependency>
            <groupId>org.bouncycastle</groupId>
            <artifactId>bcprov-jdk15on</artifactId>
            <version>1.54</version>
        </dependency>

Cipher密码类：

import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.digests.SM3Digest;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.math.ec.ECPoint;

import java.math.BigInteger;

public class Cipher {
    private int ct;
    private ECPoint p2;
    private SM3Digest sm3keybase;
    private SM3Digest sm3c3;
    private byte key[];
    private byte keyOff;

    public Cipher()
    {
        this.ct = 1;
        this.key = new byte[32];
        this.keyOff = 0;
    }

    private void Reset()
    {
        this.sm3keybase = new SM3Digest();
        this.sm3c3 = new SM3Digest();

        byte p[] = Util.byteConvert32Bytes(p2.getX().toBigInteger());
        this.sm3keybase.update(p, 0, p.length);
        this.sm3c3.update(p, 0, p.length);

        p = Util.byteConvert32Bytes(p2.getY().toBigInteger());
        this.sm3keybase.update(p, 0, p.length);
        this.ct = 1;
        NextKey();
    }

    private void NextKey()
    {
        SM3Digest sm3keycur = new SM3Digest(this.sm3keybase);
        sm3keycur.update((byte) (ct >> 24 & 0xff));
        sm3keycur.update((byte) (ct >> 16 & 0xff));
        sm3keycur.update((byte) (ct >> 8 & 0xff));
        sm3keycur.update((byte) (ct & 0xff));
        sm3keycur.doFinal(key, 0);
        this.keyOff = 0;
        this.ct++;
    }

    public ECPoint Init_enc(SM2 sm2, ECPoint userKey)
    {
        AsymmetricCipherKeyPair key = sm2.ecc_key_pair_generator.generateKeyPair();
        ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate();
        ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic();
        BigInteger k = ecpriv.getD();
        ECPoint c1 = ecpub.getQ();
        this.p2 = userKey.multiply(k);
        Reset();
        return c1;
    }

    public void Encrypt(byte data[])
    {
        this.sm3c3.update(data, 0, data.length);
        for (int i = 0; i < data.length; i++)
        {
            if (keyOff == key.length)
            {
                NextKey();
            }
            data[i] ^= key[keyOff++];
        }
    }

    public void Init_dec(BigInteger userD, ECPoint c1)
    {
        this.p2 = c1.multiply(userD);
        Reset();
    }

    public void Decrypt(byte data[])
    {
        for (int i = 0; i < data.length; i++)
        {
            if (keyOff == key.length)
            {
                NextKey();
            }
            data[i] ^= key[keyOff++];
        }

        this.sm3c3.update(data, 0, data.length);
    }

    public void Dofinal(byte c3[])
    {
        byte p[] = Util.byteConvert32Bytes(p2.getY().toBigInteger());
        this.sm3c3.update(p, 0, p.length);
        this.sm3c3.doFinal(c3, 0);
        Reset();
    }
}

 参数类SM2

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 {

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

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

	/** 素数p */
	public final BigInteger ecc_p;
	/** 系数a */
	public final BigInteger ecc_a;
	/** 系数b */
	public final BigInteger ecc_b;
	/** 基点G, G=(xg,yg),其介记为n */
	public final BigInteger ecc_n;
	/** 坐标x */
	public final BigInteger ecc_gx;
	/** 坐标y */
	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);
	}
}