关于bouncycastle下国密SM2 API的使用

本文不对SM2做过多的介绍，主要介绍java bouncycastle库关于SM2的相关API的使用及注意事项

1. SM2 签名：

注意：

　　1）签名格式ASN1（描述了一种对数据进行表示、编码、传输和解码的数据格式），包括两个大整数。

　　2）注意USER_ID的一致性（规范默认是"1234567812345678"），否则影响验签。

　　

主要代码

SM2Signer localSM2Signer = new SM2Signer();
       Security.addProvider(new BouncyCastleProvider());
       PublicKey publicKey = cert.getPublicKey();
       ECPublicKeyParameters param = null;
       
       if (publicKey instanceof BCECPublicKey)
       {
           BCECPublicKey localECPublicKey = (BCECPublicKey)publicKey;
           ECParameterSpec localECParameterSpec = localECPublicKey.getParameters();
           ECDomainParameters localECDomainParameters = new ECDomainParameters(localECParameterSpec.getCurve(),
           localECParameterSpec.getG(), localECParameterSpec.getN());
           param = new ECPublicKeyParameters(localECPublicKey.getQ(),localECDomainParameters);
       }
       ByteArrayInputStream inStream = new ByteArrayInputStream(signdatebyte);
       ASN1InputStream asnInputStream = new ASN1InputStream(inStream);
       ASN1Primitive derObject = asnInputStream.readObject();
       BigInteger R = null;
       BigInteger S = null;
       if (derObject instanceof ASN1Sequence) {  
           ASN1Sequence signSequence = (ASN1Sequence) derObject;  
           Enumeration<ASN1Integer> enumer = signSequence.getObjects();
               R =  ((ASN1Integer)enumer.nextElement()).getValue();
               S =  ((ASN1Integer)enumer.nextElement()).getValue();
       }
       ParametersWithID parametersWithID = new ParametersWithID(param,SM2_USER_ID);
       localSM2Signer.init(false, parametersWithID);
       boolean res = localSM2Signer.verifySignature(databyte, BigIntegerUtil.toPositiveInteger(R.toByteArray()),
           BigIntegerUtil.toPositiveInteger(S.toByteArray()));
       return res;

2. SM2 验签：

注意：同签名

主要代码

SM2Signer localSM2Signer = new SM2Signer();
       Security.addProvider(new BouncyCastleProvider());
       PublicKey publicKey = cert.getPublicKey();
       ECPublicKeyParameters param = null;
       
       if (publicKey instanceof BCECPublicKey)
       {
           BCECPublicKey localECPublicKey = (BCECPublicKey)publicKey;
           ECParameterSpec localECParameterSpec = localECPublicKey.getParameters();
           ECDomainParameters localECDomainParameters = new ECDomainParameters(localECParameterSpec.getCurve(),
           localECParameterSpec.getG(), localECParameterSpec.getN());
           param = new ECPublicKeyParameters(localECPublicKey.getQ(),localECDomainParameters);
       }
       ByteArrayInputStream inStream = new ByteArrayInputStream(signdatebyte);
       ASN1InputStream asnInputStream = new ASN1InputStream(inStream);
       ASN1Primitive derObject = asnInputStream.readObject();
       BigInteger R = null;
       BigInteger S = null;
       if (derObject instanceof ASN1Sequence) {  
           ASN1Sequence signSequence = (ASN1Sequence) derObject;  
           Enumeration<ASN1Integer> enumer = signSequence.getObjects();
               R =  ((ASN1Integer)enumer.nextElement()).getValue();
               S =  ((ASN1Integer)enumer.nextElement()).getValue();
       }
       ParametersWithID parametersWithID = new ParametersWithID(param,SM2_USER_ID);
       localSM2Signer.init(false, parametersWithID);
       boolean res = localSM2Signer.verifySignature(databyte, BigIntegerUtil.toPositiveInteger(R.toByteArray()),
           BigIntegerUtil.toPositiveInteger(S.toByteArray()));

3. 加解密

public static String encrypt(String data, PublicKey publicKey)
    {

        ECPublicKeyParameters localECPublicKeyParameters = null;

        if (publicKey instanceof BCECPublicKey)
        {
            BCECPublicKey localECPublicKey = (BCECPublicKey)publicKey;
            ECParameterSpec localECParameterSpec = localECPublicKey.getParameters();
            ECDomainParameters localECDomainParameters = new ECDomainParameters(
                localECParameterSpec.getCurve(), localECParameterSpec.getG(),
                localECParameterSpec.getN());
            localECPublicKeyParameters = new ECPublicKeyParameters(localECPublicKey.getQ(),
                localECDomainParameters);
        }
        SM2Engine localSM2Engine = new SM2Engine();
        localSM2Engine.init(true, new ParametersWithRandom(localECPublicKeyParameters,
            new SecureRandom()));
        byte[] arrayOfByte2;
        try
        {
            arrayOfByte2 = localSM2Engine.processBlock(data.getBytes(), 0, data.getBytes().length);
            return new String(Base64.encode(arrayOfByte2));
        }
        catch (InvalidCipherTextException e)
        {

            e.printStackTrace();
            return null;
        }

    }

    public static String decrypt(String encodedata, PrivateKey privateKey)
    {
        byte[] encodedataByte = Base64.decode(encodedata.getBytes());
        SM2Engine localSM2Engine = new SM2Engine();
        BCECPrivateKey sm2PriK = (BCECPrivateKey)privateKey;
        ECParameterSpec localECParameterSpec = sm2PriK.getParameters();
        ECDomainParameters localECDomainParameters = new ECDomainParameters(
            localECParameterSpec.getCurve(), localECParameterSpec.getG(),
            localECParameterSpec.getN());
        ECPrivateKeyParameters localECPrivateKeyParameters = new ECPrivateKeyParameters(
            sm2PriK.getD(), localECDomainParameters);
        localSM2Engine.init(false, localECPrivateKeyParameters);
        try
        {
            byte[] arrayOfByte3 = localSM2Engine.processBlock(encodedataByte, 0,
                encodedataByte.length);
            return new String(arrayOfByte3);
        }
        catch (InvalidCipherTextException e)
        {
            e.printStackTrace();
            return null;
        }

    }

4. pkcs#7(CMS)格式

可以使用bouncycastle的CMS包下的API进行封装，或者自己实现，或使用j4sign库（基于bouncycastle）实现。这里就不贴代码了。

注意：相关OID

国密标准GM/T 0010定义的oid如下：
数据类型data                                                            1.2.156.10197.6.1.4.2.1
签名数据类型signedData                                                   1.2.156.10197.6.1.4.2.2
数字信封数据类型envelopedData                                  　　　　　　 1.2.156.10197.6.1.4.2.3
签名及数字信封数据类型signedAndEnvelopedData  　　　　　　　　　　　　　　　　　1.2.156.10197.6.1.4.2.4
加密数据类型encryptedData                                                1.2.156.10197.6.1.4.2.5
密钥协商类型keyAgreementInfo                                      　　    1.2.156.10197.6.1.4.2.6

参考资料：

1.GM T 0009-2012 SM2密码算法使用规范

2.https://tools.ietf.org/html/rfc2315

3.http://j4sign.sourceforge.net/

4.http://gmssl.org/docs/oid.html

5.https://stackoverflow.com/questions/39925946/generate-cmssigneddata-with-no-private-key-in-java

6.https://github.com/bcgit/bc-java

7.https://www.zhihu.com/question/62639301/answer/214184309

转载请注明原博客地址http://www.cnblogs.com/jeffreyluo/p/sm2forjava.html)