安全系列之——RSA 的公钥私钥有多少人能分的清楚？RSA 的签名验签与加密解密如何使用公私钥？

/**
 * Description:
 *
 * @author 诸葛小猿
 * @date 2020-08-21
 */
@Slf4j
public class SignAndEncryptTest {
    public static final String  SIGN_ALGORITHMS = "SHA1WithRSA";
    public static final String CHATSET = "utf-8";
    public static String publicKey_A = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAsnen01CdQc2zh/HihCNNYI6u7AFXf/NrZ/9auPvFsJcK1cWj5EFBU3lrts2OTvrmYVurhABg2g/Ya7glzUt6DwUojHOWtpwFxSH1v7FUJMvxDsbd4GXKRdWqMkqkcCMQYDpGpshbL3IAWYIw6pgnBcKksbzkDrZCZMAyHa1bB3zh5uEm9mcrRlBUGirbPNVt++3ztIfdc4Vp5hbw++daNMFr/VGDohMVg3Dlk4ZktDgHc5nakXkE8hSr6UDTw45JpfZZ0dP9XTi/CSVQdoYD+dsJIZ8uletlbrErRfZEJNx/k0w88P4kfGteNBGhlzzVo45tMkHT33O8QB6JxI4xVQIDAQAB";
    public static String privateKey_A = "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";
    public static String publicKey_B = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAv8GjRufWGPI7Xe6caZ5h5PbnRIQVzD4P1gDjKZaibcxcApGEaqFkT3Am2U6iKv6paELuwxy+dUL1Jvbs09QljuHgDB9SV0VxSM5LscpCmWJ5P1V6Y/QiholCQHCFR6ok6oE2HWGRw/bPQWr/gHfa2zNPu+CB64cbOxLHIQYIRji47tyywAL5ABhF1msZY2vW8xaFKHGq74sxNpf8s0NUnRnVRANjHtuDa/zvrHim45gqBWg+3gPVSQyPU3ydMoj0AiORJQmqprHaZDB7BufpTEZA6I2WElsKJcsGMdwfSd1s0B1iCzrkMmT30n/XXxyw8qQGsvJvQ2V90QiAV9bV+wIDAQAB";
    public static String privateKey_B = "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";
    // 封装发送的消息
    public static Map<String,String> communicationParams = null;
    public static void main(String[] args) {
        // A给B发消息
        ASendMsgToB();
        // B接收来自A的消息
        BReceiveFromA();
    }
    /**
     * A给B发消息，首先A-B交换公钥，A拥有 privateKey_A 和 publicKey_B
     *
     * A使用publicKey_B加密消息，再使用privateKey_A对密文签名，然后将密文和签名发给B
     */
    public static void ASendMsgToB(){
        // 消息明文
        String msg = "你好";
        // 加密
        String encryptMsg = encryptByPublicKey(msg,publicKey_B);
        // 签名
        String sign = signByPrivateKey(encryptMsg,privateKey_A);
        // 发送消息
        communicationParams = new HashMap<String,String>();
        communicationParams.put("encryptMsg",encryptMsg);
        communicationParams.put("sign",sign);
        log.info("A发送给B的消息:{}", JSON.toJSONString(communicationParams));
        log.info("-------------------------------------------------");
    }
    /**
     * B接收A的消息，首先A-B交换公钥，B拥有 privateKey_B 和 publicKey_A
     *
     * B收到消息后，先使用publicKey_A验签，再使用privateKey_B解密
     */
    public static void BReceiveFromA(){
        // 接收消息
        Map<String,String> receiveMsg = communicationParams;
        log.info("B接收到A的消息:{}", JSON.toJSONString(receiveMsg));
        String sign = receiveMsg.get("sign");
        String encryptMsg = receiveMsg.get("encryptMsg");
        // 验签
        Boolean tf = verifySignPublicKey(encryptMsg,publicKey_A,sign);
        if(tf){
            log.info("验签通过，说明这个信息是B认可的用户发来的");
        }
        // 解密
        String msg = decryptByPrivateKey(encryptMsg,privateKey_B);
        log.info("解密成功，说明这个信息就是发给B的");
        log.info("B收到的消息:{}", msg);
    }
    /**
     * RSA签名
     * @param content 待签名数据
     * @param privateKey 商户私钥
     * @return 签名值
     */
    public static String signByPrivateKey(String content, String privateKey)
    {
        try{
            PKCS8EncodedKeySpec priPKCS8    = new PKCS8EncodedKeySpec( Base64.decode(privateKey) );
            KeyFactory keyf                 = KeyFactory.getInstance("RSA");
            PrivateKey priKey               = keyf.generatePrivate(priPKCS8);
            Signature signature = Signature.getInstance(SIGN_ALGORITHMS);
            signature.initSign(priKey);
            signature.update( content.getBytes(CHATSET) );
            byte[] signed = signature.sign();
            return Base64.encode(signed);
        }catch (Exception e){
            log.error(e.getMessage(), e);
        }
        return null;
    }
    /**
     * RSA验签名检查
     * @param content 待签名数据
     * @param sign 签名值
     * @param publicKey 公钥
     * @return 布尔值
     */
    public static boolean verifySignPublicKey(String content, String publicKey, String sign)
    {
        try{
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            byte[] encodedKey = Base64.decode(publicKey);
            PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));
            Signature signature = Signature.getInstance(SIGN_ALGORITHMS);
            signature.initVerify(pubKey);
            signature.update( content.getBytes(CHATSET) );
            boolean bverify = signature.verify( Base64.decode(sign) );
            return bverify;
        }catch (Exception e){
            log.error(e.getMessage(), e);
        }
        return false;
    }
    /**
     * RSA公钥加密
     * @param str 加密字符串
     * @param publicKey 公钥
     * @return 密文
     */
    public static String encryptByPublicKey( String str, String publicKey ) {
        try{
            //base64编码的公钥
            byte[] decoded = org.apache.commons.codec.binary.Base64.decodeBase64(publicKey);
            RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
            //RSA加密
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, pubKey);
            String outStr = org.apache.commons.codec.binary.Base64.encodeBase64String(cipher.doFinal(str.getBytes(CHATSET)));
            return outStr;
        }catch (Exception e) {
            log.error(e.getMessage(), e);
        }
        return null;
    }
    /**
     * RSA私钥解密
     * @param str 加密字符串
     * @param privateKey 私钥
     * @return 明文
     */
    public static String decryptByPrivateKey(String str, String privateKey){
        try{
            //64位解码加密后的字符串
            byte[] inputByte = org.apache.commons.codec.binary.Base64.decodeBase64(str.getBytes(CHATSET));
            //base64编码的私钥
            byte[] decoded = org.apache.commons.codec.binary.Base64.decodeBase64(privateKey);
            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;
        }catch (Exception e) {
            log.error(e.getMessage(), e);
        }
        return null;
    }
}

00:09:01.375 [main] INFO com.wuxiaolong.EncrypteDecrypt.SignAndEncryptTest - A发送给B的消息:{"sign":"X13XFI2khSarCOTDjENC/ZTtKfUKAPXuO3b7vossIvC6Aj9WMnKd9w/w64/EqTg+42SGvJXjVpvdglRMmWVrbFSWfmrEfjejaNcq35+aor6j4tMMq0ZVxRO4BxTe+qKDx/e0037dHACvAY2ecojVcbAQaECEc3TrZJguQnte/Nv0DZYPSv/9evPnuKL3DuTl/wy+JaTEhVrvsu/4jXpQ6HRbrhrC4dnzs6AZEqtBXvgfRSkq62jbAvUguDhhZ6yexA2/5S+oOqO8mgRVnooQxkAI5QZd9z0voDIrCDp4emKuznj7vMUjmOXgdD0C3l7LuBqQ469JmAD0U2fRLWMIiQ==","encryptMsg":"lFrlwDA4RjXaxrFPkd8DrbiWQ15o7nNzvLwdWUmTgkDyV5DGMXXsbcEP8aBWqmCje49ymAdzQl3MdO+U2t51QtTvzJOS55EBOZgonN8XJHKNiW7XikWbgf54vUx/mNdHH7fqpBM8AM1qcyH2N3OISFK4NP6eCKgMXRRb3hxw4oko3cGTa98Hnl8jlR9yR2Goy1euT7lpL04VqWcJtP0aEW5gurPkTEDRmOn1UC6x8qZX+K3dxrQfOQhJVRoIOb2hbu/HhzBsknJw1QZTS5IN/n0GlRiJQUwJllQUT4XRF6zmc2y4ewnLwlMY99WqwCaB4XFaBNQO9/5fa7A/XZTr7g=="}
00:09:01.378 [main] INFO com.wuxiaolong.EncrypteDecrypt.SignAndEncryptTest - -------------------------------------------------
00:09:01.378 [main] INFO com.wuxiaolong.EncrypteDecrypt.SignAndEncryptTest - B接收到A的消息:{"sign":"X13XFI2khSarCOTDjENC/ZTtKfUKAPXuO3b7vossIvC6Aj9WMnKd9w/w64/EqTg+42SGvJXjVpvdglRMmWVrbFSWfmrEfjejaNcq35+aor6j4tMMq0ZVxRO4BxTe+qKDx/e0037dHACvAY2ecojVcbAQaECEc3TrZJguQnte/Nv0DZYPSv/9evPnuKL3DuTl/wy+JaTEhVrvsu/4jXpQ6HRbrhrC4dnzs6AZEqtBXvgfRSkq62jbAvUguDhhZ6yexA2/5S+oOqO8mgRVnooQxkAI5QZd9z0voDIrCDp4emKuznj7vMUjmOXgdD0C3l7LuBqQ469JmAD0U2fRLWMIiQ==","encryptMsg":"lFrlwDA4RjXaxrFPkd8DrbiWQ15o7nNzvLwdWUmTgkDyV5DGMXXsbcEP8aBWqmCje49ymAdzQl3MdO+U2t51QtTvzJOS55EBOZgonN8XJHKNiW7XikWbgf54vUx/mNdHH7fqpBM8AM1qcyH2N3OISFK4NP6eCKgMXRRb3hxw4oko3cGTa98Hnl8jlR9yR2Goy1euT7lpL04VqWcJtP0aEW5gurPkTEDRmOn1UC6x8qZX+K3dxrQfOQhJVRoIOb2hbu/HhzBsknJw1QZTS5IN/n0GlRiJQUwJllQUT4XRF6zmc2y4ewnLwlMY99WqwCaB4XFaBNQO9/5fa7A/XZTr7g=="}
00:09:01.379 [main] INFO com.wuxiaolong.EncrypteDecrypt.SignAndEncryptTest - 验签通过，说明这个信息是B认可的用户发来的
00:09:01.386 [main] INFO com.wuxiaolong.EncrypteDecrypt.SignAndEncryptTest - 解密成功，说明这个信息就是发给B的
00:09:01.386 [main] INFO com.wuxiaolong.EncrypteDecrypt.SignAndEncryptTest - B收到的消息:你好