RSAUtil 工具类

素颜马尾好姑娘i 2021-11-05 16:36 234阅读 0赞

package com.hollysys.smartfactory.equipmentdiagnosis.util;
    
    import org.apache.commons.codec.binary.Base64;
    
    import javax.crypto.Cipher;
    import java.io.ByteArrayOutputStream;
    import java.security.*;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    /**
     * Description: RSA 工具
     *
     * @author cy
     * @date 2019年08月05日 11:22
     * Version 1.0
     */
    public class RsaUtil {
        /**
         * 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;
        /**
         * 编码
         */
        private static String charset = "utf-8";
    
        /**
         * 获取密钥对
         *
         * @return 密钥对
         */
        public static KeyPair getKeyPair() throws Exception {
            KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA");
            generator.initialize(1024);
            return generator.generateKeyPair();
        }
    
        /**
         * 获取私钥
         *
         * @param privateKey 私钥字符串
         * @return
         */
        public static PrivateKey getPrivateKey(String privateKey) throws Exception {
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            byte[] decodedKey = Base64.decodeBase64(privateKey.getBytes(charset));
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(decodedKey);
            return keyFactory.generatePrivate(keySpec);
        }
    
        /**
         * 获取公钥
         *
         * @param publicKey 公钥字符串
         * @return
         */
        public static PublicKey getPublicKey(String publicKey) throws Exception {
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            byte[] decodedKey = Base64.decodeBase64(publicKey.getBytes(charset));
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(decodedKey);
            return keyFactory.generatePublic(keySpec);
        }
    
        /**
         * RSA加密
         *
         * @param data 待加密数据
         * @param publicKey 公钥
         * @return
         */
        public static String encrypt(String data, PublicKey publicKey) throws Exception {
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            int inputLen = data.getBytes(charset).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.getBytes(charset), offset, MAX_ENCRYPT_BLOCK);
                } else {
                    cache = cipher.doFinal(data.getBytes(charset), offset, inputLen - offset);
                }
                out.write(cache, 0, cache.length);
                i++;
                offset = i * MAX_ENCRYPT_BLOCK;
            }
            byte[] encryptedData = out.toByteArray();
            out.close();
            // 获取加密内容使用base64进行编码,并以UTF-8为标准转化成字符串
            // 加密后的字符串
            return Base64.encodeBase64String(encryptedData);
        }
    
        /**
         * RSA解密
         *
         * @param data 待解密数据
         * @param privateKey 私钥
         * @return
         */
        public static String decrypt(String data, PrivateKey privateKey) throws Exception {
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            byte[] dataBytes = Base64.decodeBase64(data);
            int inputLen = dataBytes.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(dataBytes, offset, MAX_DECRYPT_BLOCK);
                } else {
                    cache = cipher.doFinal(dataBytes, offset, inputLen - offset);
                }
                out.write(cache, 0, cache.length);
                i++;
                offset = i * MAX_DECRYPT_BLOCK;
            }
            byte[] decryptedData = out.toByteArray();
            out.close();
            // 解密后的内容
            return new String(decryptedData, "UTF-8");
        }
    
        /**
         * 签名
         *
         * @param data 待签名数据
         * @param privateKey 私钥
         * @return 签名
         */
        public static String sign(String data, PrivateKey privateKey) throws Exception {
            byte[] keyBytes = privateKey.getEncoded();
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PrivateKey key = keyFactory.generatePrivate(keySpec);
            Signature signature = Signature.getInstance("MD5withRSA");
            signature.initSign(key);
            signature.update(data.getBytes(charset));
            return new String(Base64.encodeBase64(signature.sign()),charset);
        }
    
        /**
         * 验签
         *
         * @param srcData 原始字符串
         * @param publicKey 公钥
         * @param sign 签名
         * @return 是否验签通过
         */
        public static boolean verify(String srcData, PublicKey publicKey, String sign) throws Exception {
            byte[] keyBytes = publicKey.getEncoded();
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PublicKey key = keyFactory.generatePublic(keySpec);
            Signature signature = Signature.getInstance("MD5withRSA");
            signature.initVerify(key);
            signature.update(srcData.getBytes(charset));
            return signature.verify(Base64.decodeBase64(sign.getBytes(charset)));
        }
    
        public static void main(String[] args) {
            try {
                // 生成密钥对
                //KeyPair keyPair = getKeyPair();
                //String privateKey = new String(Base64.encodeBase64(keyPair.getPrivate().getEncoded()));
                //String publicKey = new String(Base64.encodeBase64(keyPair.getPublic().getEncoded()));
                //System.out.println("私钥:" + privateKey);
                //System.out.println("公钥:" + publicKey);
                // RSA加密
                String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCIDV8I1zpoazcFmv3VNtG/E9/QC14gDhBoW9Yq6o9UNLaOZC41yoGa7hjHqjuPOcmPJ61Wmv7i5UbB5BceGRl2i0pSyOzeAeYpoY5cNRStfQlXFlwV1Ig1P081rxBcCgkWZvhodsWp9yRdKOTTHUCj0FpgD94/2QhvqkxOaW9vAwIDAQAB";
                String privateKey = "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";
                String data = "12312aawevrdgr312332312312312";
                String encryptData = encrypt(data, getPublicKey(publicKey));
                System.out.println("加密后内容:" + encryptData);
                // RSA解密
                String decryptData = decrypt(encryptData, getPrivateKey(privateKey));
                System.out.println("解密后内容:" + decryptData);
    
                // RSA签名
                String sign = sign(data, getPrivateKey(privateKey));
                // RSA验签
                boolean result = verify(data, getPublicKey(publicKey), sign);
                System.out.print("验签结果:" + result);
            } catch (Exception e) {
                e.printStackTrace();
                System.out.print("加解密异常");
            }
        }
    
    }

转载于:https://www.cnblogs.com/chengyangyang/p/11302354.html