使用RSA加密解密

最新推荐文章于 2024-03-28 14:06:36 发布

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最新推荐文章于 2024-03-28 14:06:36 发布

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分类专栏： java 文章标签： java jsp rsa

本文链接：https://blog.youkuaiyun.com/kawayiyy123/article/details/98079476

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使用RSA加密解密

1.项目登录密码暴露出来，对网站安全有隐患

在这里插入图片描述

解决思路：使用密码以字符串的方式传输

2.使用rsa加密方式

思路：1.生成密钥对（公钥和私钥）

2.把公钥传给前端

3.前端加密后公钥传给后端

4.后端用私钥解开公钥取得数据

3.rsa以及相关工具类

RSAUtils：

public class RSAUtils {

    /**
     * 加密算法RSA
     */
    public static final String KEY_ALGORITHM = "RSA";

    /**
     * 签名算法
     */
    public static final String SIGNATURE_ALGORITHM = "SHA1withRSA";

    /**
     * 获取公钥的key
     */
    private static final String PUBLIC_KEY = "RSAPublicKey";

    /**
     * 获取私钥的key
     */
    private static final String PRIVATE_KEY = "RSAPrivateKey";

    /**
     * RSA最大加密明文大小
     */
    private static final int MAX_ENCRYPT_BLOCK = 117;

    /**
     * RSA最大解密密文大小
     */
    private static final int MAX_DECRYPT_BLOCK = 128;
    
    public static Map<String, Object> map = RSAUtils.genKeyPair();

    /**
     * <p>
     * 生成密钥对(公钥和私钥)
     * </p>
     *
     * @return
     * @throws Exception
     */
    public static Map<String, Object> genKeyPair() {
        Map<String, Object> keyMap = new HashMap<String, Object>(2);
        try {
            KeyPair keyPair = getKeyPair();
            RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
            RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
            keyMap.put(PUBLIC_KEY, publicKey);
            keyMap.put(PRIVATE_KEY, privateKey);
            return keyMap;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return keyMap;
    }

    /**
     * 获取密钥对
     *
     * @return 密钥对
     */
    public static KeyPair getKeyPair() throws Exception {
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
        keyPairGen.initialize(1024);
        KeyPair keyPair = keyPairGen.generateKeyPair();
        return keyPair;
    }

    /**
     * <p>
     * 用私钥对信息生成数字签名
     * </p>
     *
     * @param data       已加密数据
     * @param privateKey 私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static String sign(byte[] data, String privateKey) throws Exception {
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PrivateKey privateK = null;

        //判断是pkcs1私钥还是pkcs8私钥
        if (privateKey.indexOf("BEGIN RSA PRIVATE KEY") > 0) {//如果是pkcs1私钥
            privateKey = privateKey.replace("-----BEGIN RSA PRIVATE KEY-----", "")
                    .replace("-----END RSA PRIVATE KEY-----", "").replace("\n", "");
            byte[] keyBytes = Base64Utils.decode(privateKey);
            RSAPrivateKeyStructure asn1PrivKey = new RSAPrivateKeyStructure((ASN1Sequence) ASN1Sequence.fromByteArray(keyBytes));
            RSAPrivateKeySpec rsaPrivKeySpec = new RSAPrivateKeySpec(asn1PrivKey.getModulus(), asn1PrivKey.getPrivateExponent());
            privateK = keyFactory.generatePrivate(rsaPrivKeySpec);

        } else {//如果是pkcs8私钥
            privateKey = privateKey.replace("-----BEGIN PRIVATE KEY-----", "")
                    .replace("-----END PRIVATE KEY-----", "").replace("\n", "");
            byte[] keyBytes = Base64Utils.decode(privateKey);
            PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
            privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        }

        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initSign(privateK);
        signature.update(data);
        return Base64Utils.encode(signature.sign());
    }

    /**
     * <p>
     * 校验数字签名
     * </p>
     *
     * @param data      已加密数据
     * @param publicKey 公钥(BASE64编码)
     * @param sign      数字签名
     * @return
     * @throws Exception
     */
    public static boolean verify(byte[] data, String publicKey, String sign)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(publicKey);
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PublicKey publicK = keyFactory.generatePublic(keySpec);
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initVerify(publicK);
        signature.update(data);
        return signature.verify(Base64Utils.decode(sign));
    }

    /**
     * <P>
     * 私钥解密
     * </p>
     *
     * @param encryptedData 已加密数据
     * @param privateKey    私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, privateK);
        int inputLen = encryptedData.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] decryptedData = out.toByteArray();
        out.close();
        return decryptedData;
    }

    /**
     * <p>
     * 公钥解密
     * </p>
     *
     * @param encryptedData 已加密数据
     * @param publicKey     公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(publicKey);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicK = keyFactory.generatePublic(x509KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, publicK);
        int inputLen = encryptedData.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] decryptedData = out.toByteArray();
        out.close();
        return decryptedData;
    }

    /**
     * <p>
     * 公钥加密
     * </p>
     *
     * @param data      源数据
     * @param publicKey 公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPublicKey(byte[] data, String publicKey)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(publicKey);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicK = keyFactory.generatePublic(x509KeySpec);
        // 对数据加密
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, publicK);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;
    }

    /**
     * <p>
     * 私钥加密
     * </p>
     *
     * @param data       源数据
     * @param privateKey 私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPrivateKey(byte[] data, String privateKey)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, privateK);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;
    }

    /**
     * <p>
     * 获取私钥
     * </p>
     *
     * @param keyMap 密钥对
     * @return
     * @throws Exception
     */
    public static String getPrivateKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PRIVATE_KEY);
        return Base64Utils.encode(key.getEncoded());
    }

    /**
     * <p>
     * 获取公钥
     * </p>
     *
     * @param keyMap 密钥对
     * @return
     * @throws Exception
     */
    public static String getPublicKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PUBLIC_KEY);
        return Base64Utils.encode(key.getEncoded());
    }

    /**
     * java端公钥加密
     */
    public static String encryptedDataOnJava(String data, String PUBLICKEY) {
        try {
            data = Base64Utils.encode(encryptByPublicKey(data.getBytes(), PUBLICKEY));
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return data;
    }

    /**
     * java端私钥解密
     */
    public static String decryptDataOnJava(String data, String PRIVATEKEY) {
        String temp = "";
        try {
            byte[] rs = Base64Utils.decode(data);
            temp = new String(RSAUtils.decryptByPrivateKey(rs, PRIVATEKEY), "UTF-8");

        } catch (Exception e) {
            e.printStackTrace();
        }
        return temp;
    }
    public static void main(String[] args) {
        //jsp传后台思路
        //1.把密钥对传给前台     2.获取到前台加密后得内容和RSA签名  3.用私钥解密前台传得公钥 5.RSA验签是否为true
        try {
            Map<String, Object> map = genKeyPair();
            // RSA加密
            String data = "待加密的文字内容";
            String publicKey = getPublicKey(map);
            String privateKey = getPrivateKey(map);
            System.out.println("私钥:" + privateKey);
            System.out.println("公钥:" + publicKey);
            //Base64.decodeBase64(data.getBytes());Base64.decodeBase64(data.getBytes())
            byte[] bytes = encryptByPublicKey(data.getBytes(), publicKey);
            System.out.println("加密后内容:" + new String(Base64.encodeBase64(bytes)));
            // System.out.println("加密后内容:" +  new String(bytes, "GB2312"));
            // RSA解
            byte[] bytes1 = decryptByPrivateKey(bytes, privateKey);
            System.out.println("解密后内容:" + new String(bytes1));
            // System.out.println("解密后内容:" + new String(Base64.encodeBase64(bytes1)));
            // System.out.println("解密后内容:" + new String(bytes1));

            // RSA签名
            String sign = sign(data.getBytes(), privateKey);
            System.out.println("签名："+sign);
            // RSA验签
            boolean result = verify(data.getBytes(), publicKey, sign);
            System.out.println("验签结果:" + result);
        } catch (Exception e) {
            e.printStackTrace();
            System.out.print("加解密异常");
        }
    }
}

Base64Utils：用到的包org.bouncycastle:bcprov-jdk15on:1.59

/**
 * <p>
 * BASE64编码解码工具包
 * </p>
 * 
 */
public class Base64Utils {
 
    /**
     * 文件读取缓冲区大小
     */
    private static final int CACHE_SIZE = 1024;
     
    /**
     * <p>
     * BASE64字符串解码为二进制数据
     * </p>
     * 
     * @param base64
     * @return
     * @throws Exception
     */
    public static byte[] decode(String base64) throws Exception {
        return Base64.decodeBase64(base64.getBytes());
    }
     
    /**
     * <p>
     * 二进制数据编码为BASE64字符串
     * </p>
     * 
     * @param bytes
     * @return
     * @throws Exception
     */
    public static String encode(byte[] bytes) throws Exception {
        return new String(Base64.encodeBase64(bytes));
    }
     
    /**
     * <p>
     * 将文件编码为BASE64字符串
     * </p>
     * <p>
     * 大文件慎用，可能会导致内存溢出
     * </p>
     * 
     * @param filePath 文件绝对路径
     * @return
     * @throws Exception
     */
    public static String encodeFile(String filePath) throws Exception {
        byte[] bytes = fileToByte(filePath);
        return encode(bytes);
    }
     
    /**
     * <p>
     * BASE64字符串转回文件
     * </p>
     * 
     * @param filePath 文件绝对路径
     * @param base64 编码字符串
     * @throws Exception
     */
    public static void decodeToFile(String filePath, String base64) throws Exception {
        byte[] bytes = decode(base64);
        byteArrayToFile(bytes, filePath);
    }
     
    /**
     * <p>
     * 文件转换为二进制数组
     * </p>
     * 
     * @param filePath 文件路径
     * @return
     * @throws Exception
     */
    public static byte[] fileToByte(String filePath) throws Exception {
        byte[] data = new byte[0];
        File file = new File(filePath);
        if (file.exists()) {
            FileInputStream in = new FileInputStream(file);
            ByteArrayOutputStream out = new ByteArrayOutputStream(2048);
            byte[] cache = new byte[CACHE_SIZE];
            int nRead = 0;
            while ((nRead = in.read(cache)) != -1) {
                out.write(cache, 0, nRead);
                out.flush();
            }
            out.close();
            in.close();
            data = out.toByteArray();
         }
        return data;
    }
     
    /**
     * <p>
     * 二进制数据写文件
     * </p>
     * 
     * @param bytes 二进制数据
     * @param filePath 文件生成目录
     */
    public static void byteArrayToFile(byte[] bytes, String filePath) throws Exception {
        InputStream in = new ByteArrayInputStream(bytes);   
        File destFile = new File(filePath);
        if (!destFile.getParentFile().exists()) {
            destFile.getParentFile().mkdirs();
        }
        destFile.createNewFile();
        OutputStream out = new FileOutputStream(destFile);
        byte[] cache = new byte[CACHE_SIZE];
        int nRead = 0;
        while ((nRead = in.read(cache)) != -1) {   
            out.write(cache, 0, nRead);
            out.flush();
        }
        out.close();
        in.close();
    }
}

前端代码：需要引入jsencrypt.min.js


      <p>
			<input type="text" id="password"  size="20" class="login_input" placeholder="密码" autocomplete="off"/>
             <input type="hidden" id="subPassword" name="subPassword"/>
	  </p>


<script type="text/javascript" src="/static/js/jqery.jsencrypt.min.js"></script>
<script type="text/javascript">
    function rsaKeys() {
        var password = jQuery('#password').val();
        if (password == null || password == "") {
            alert("密码不能为空！");
            return;
        }
        $.ajax({
            type: 'POST',
            url: 'url路径',
            success: function (data) {
                //获得公钥
                var publicKey = data;
               
                var encryptor = new JSEncrypt();  // JSEncrypt对象
                encryptor.setPublicKey('-----BEGIN PUBLIC KEY-----' + publicKey + '-----END PUBLIC KEY-----');  // 公钥
                var rsaPassWord = encryptor.encrypt(password);  // 密码进行加密

                jQuery('#subPassword').val(rsaPassWord);
                var subPasswords = jQuery('#subPassword').val();
                console.log("subPassword = "+subPasswords);

            }
        });
    }
    </script>

关于js的解释：第一个password是让用户输入密码并不传入后端，第二个虽然是隐藏的，但是传入后台的是它（被公钥加密过后的代码，是相当长的一段字符串）

后台解释：接收到加密后的公钥用私钥解密，得到原本的密码，subPassword为公钥加密后的密码，encrypted是解密后的密码

	 String privateKey = RSAUtils.getPrivateKey(RSAUtils.map);
		String decryption = RSAUtils.decryptDataOnJava(subPassword, privateKey);

至此：感慨良多，周末会把之前的杂七杂八的总结一些，交流qq:1401769508

如有不当之处，请多多指教！！！