java提取sm2公钥

问题：java提供的sm2公钥无法在python中使用

解决：因为java和python使用的加密方法有差

方法：

package com.bocsoft.security;
import com.bocsoft.decrypt.Util;
import org.bouncycastle.asn1.*;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import static com.bocsoft.decrypt.Util.getHexString;

public class translate {

    public static void main(String[] args) throws Exception {
        String private_key = "308193020100301306072a8648ce3d020106082a811ccf5501822d0479307702010104205931b7fa3a8ec4e974d48e84b8a64d931c9e7bad295dafe57940573d46481c44a00a06082a811ccf5501822da14403420004798718d3c2152a61ef18ff58adfb83e6694f84ea6c58ce4cfa83f79bb7ff4893d5e6050242cca375a6585f265bd862b448c90af4c61d67620900526f3ebffcaf";
        String public_key = "04251ed256cf8ac425443cc444cda5aafbe8aa22a5c5af1f11b2eecff6217bb3299e554c202f5253eee538ff1576bdba729e9a4d338508ba421b6c6330dca2711c";
        byte[] sm2_private = privateKey(Util.hexStringToBytes(private_key));
        System.out.println("私钥为："+ Util.encodeHexString(sm2_private));

        byte[] publicKey = publicKey(Util.hexStringToBytes(public_key));
        System.out.println("公钥为： " + Util.encodeHexString(publicKey));
    }

    // java读取公钥
    public static byte[] publicKey(byte[] pubkey) throws Exception {
        SubjectPublicKeyInfo subjectPublicKeyInfo = SubjectPublicKeyInfo
                .getInstance(pubkey);    
        DERBitString publicKeyData = subjectPublicKeyInfo.getPublicKeyData();
        byte[] publicKey = publicKeyData.getEncoded();
        byte[] encodedPublicKey = publicKey;
        byte[] ecP = new byte[64];
        System.arraycopy(encodedPublicKey, 4, ecP, 0, ecP.length);    
        byte[] certPKX = new byte[32];
        byte[] certPKY = new byte[32];
        System.arraycopy(ecP, 0, certPKX, 0, 32);
        System.arraycopy(ecP, 32, certPKY, 0, 32);
        return ecP;
    }
    
    // java读取私钥
    public static byte[] privateKey(byte[] privatekey) throws Exception {
        ASN1Sequence seq = ASN1Sequence.getInstance(privatekey);

        ASN1Encodable asn1Encodable = seq.getObjectAt(2);
        DEROctetString eEROctetString = (DEROctetString)asn1Encodable;
        System.out.println("publicKey Hex :" + getHexString(eEROctetString.getOctets(),true));

        DLSequence dLSequence = (DLSequence ) ASN1Sequence
                .fromByteArray(eEROctetString.getOctets());
        asn1Encodable = dLSequence.getObjectAt(1);
        eEROctetString = (DEROctetString)asn1Encodable;
        return eEROctetString.getOctets();    
    }
}

参考：

https://blog.csdn.net/shenshiheng2006/article/details/103959453