DSA签名算法实现

DSA签名

package com.albedo.security;

/**
 * DSA 加解密实现
 */
public class DSAUtils extends Base {

    //字符编码
    public static final String ALGORITHM = "DSA";
    public static final String SIGN_ALGORITHM = "SHA1withDSA";


    /**
     * DSA 验签
     *
     * @param str       加密字符串
     * @param publicKey 公钥
     * @return 密文
     * @throws Exception 加密过程中的异常信息
     */
    public static boolean verify(String sign, String str, String publicKey) throws Exception {
        return verify(sign, str, publicKey, ALGORITHM, SIGN_ALGORITHM);
    }

    /**
     * DSA 签名
     *
     * @param str        加密字符串
     * @param privateKey 私钥
     * @return 铭文
     * @throws Exception 解密过程中的异常信息
     */
    public static String sign(String str, String privateKey) throws Exception {
        return sign(str, privateKey, ALGORITHM, SIGN_ALGORITHM);
    }


    public static void main(String[] args) throws Exception {
        String publicKey = getPublicKey(ALGORITHM, 1024);
        String privateKey = getPrivateKey(ALGORITHM, 1024);
        String message = "我要测试DSA";
        String sign = sign(message, privateKey);
        System.out.println(verify(sign, message, publicKey));
    }
}

基类实现

package com.albedo.security;

import com.albedo.num.ByteUtils;

import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Objects;

class Base {
    static KeyPair keyPair;

    /**
     * 生成密钥实际方法，可以使用多种方式
     * 一篇文档提供一下多种方式
     * { "DSA", "SHA1withDSA", "1024" }, { "DSA", "SHA256withDSA", "1024" },
     * { "DSA", "SHA256withDSA", "2048" }, { "RSA", "SHA256withRSA", "1024" },
     * { "RSA", "SHA256withRSA", "2048" }, { "RSA", "SHA256withRSA", "3192" },
     * { "RSA", "SHA512withRSA", "1024" }, { "RSA", "SHA512withRSA", "2048" },
     * { "RSA", "SHA512withRSA", "3192" }, { "RSA", "MD5withRSA", "1024" },
     * { "RSA", "MD5withRSA", "2048" },
     * { "RSA", "MD5withRSA", "3192" }, { "EC", "SHA1withECDSA", "128" },
     * { "EC", "SHA1withECDSA", "256" },
     * { "EC", "SHA256withECDSA", "128" }, { "EC", "SHA256withECDSA", "256" },
     * { "EC", "SHA512withECDSA", "128" }, { "EC", "SHA512withECDSA", "256" },
     *
     * @param algorithm
     * @param bit
     * @return
     * @throws Exception
     */
    protected static KeyPair createKey(String algorithm, int bit) throws Exception {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(algorithm);
        keyPairGenerator.initialize(bit);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        return keyPair;
    }




    /**
     * 获取公钥
     *
     * @return
     * @throws Exception
     */
    public static String getPublicKey(String algorithm,int bit) throws Exception {
        if (Objects.isNull(keyPair)) {
            keyPair = createKey(algorithm,bit);
        }
        return ByteUtils.byteArr2HexStr(keyPair.getPublic().getEncoded());

    }

    /**
     * 获取私钥
     *
     * @return
     * @throws Exception
     */
    public static String getPrivateKey(String algorithm,int bit) throws Exception {
        if (Objects.isNull(keyPair)) {
            keyPair = createKey(algorithm,bit);
        }
        return ByteUtils.byteArr2HexStr(keyPair.getPrivate().getEncoded());

    }
    /**
     * 非对称加密签名
     * @param str
     * @param privateKey
     * @param algorithm
     * @param signAlgorithm
     * @return
     * @throws Exception
     */
    public static String sign(String str, String privateKey, String algorithm, String signAlgorithm) throws Exception {
        PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(ByteUtils.hexstr2ByteArr(privateKey));
        KeyFactory keyFactory = KeyFactory.getInstance(algorithm);
        PrivateKey dsaPrivateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
        Signature signature = Signature.getInstance(signAlgorithm);
        signature.initSign(dsaPrivateKey);
        signature.update(str.getBytes());
        return ByteUtils.byteArr2HexStr(signature.sign());
    }

    /**
     * 非对称加密验证
     * @param sign
     * @param str
     * @param publicKey
     * @param algorithm
     * @param signAlgorithm
     * @return
     * @throws Exception
     */
    public static boolean verify(String sign, String str, String publicKey,String algorithm,String signAlgorithm) throws Exception {
        //base64编码的公钥
        X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(ByteUtils.hexstr2ByteArr(publicKey));
        KeyFactory keyFactory = KeyFactory.getInstance(algorithm);
        PublicKey dsaPublicKey = keyFactory.generatePublic(x509EncodedKeySpec);
        Signature signature = Signature.getInstance(signAlgorithm);
        signature.initVerify(dsaPublicKey);
        signature.update(str.getBytes());
        return signature.verify(ByteUtils.hexstr2ByteArr(sign));
    }
}