open-JSD-9967/src/main/java/com/eco/plugin/xx/kksso/utils/RSAUtil.java

package com.eco.plugin.xx.kksso.utils;

import javax.crypto.Cipher;
import java.security.KeyFactory;
import java.security.interfaces.RSAPrivateKey;
import java.security.spec.PKCS8EncodedKeySpec;

public class RSAUtil {
    
    /**
     * RSA私钥解密
     *
     * @param str 加密字符串
     * @param privateKeyString 私钥
     * @return 明文
     * @throws Exception 解密过程中的异常信息
     */
    public static String decrypt(String str, String privateKeyString) throws Exception{
        //64位解码加密后的字符串
        byte[] inputByte = EncryptUtils.base64DecodeB(str);
        //base64编码的私钥
        byte[] decoded = EncryptUtils.base64DecodeB(privateKeyString);
        RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));
        //RSA解密
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, priKey);
        String outStr = new String(cipher.doFinal(inputByte));
        return outStr;
    }

}