RSA加密工具类(Java)

男娘i 2022-04-16 00:24 279阅读 0赞

## 干货 ##

package com.hht.exchange.utils;
    
    import javax.crypto.Cipher;
    import java.security.*;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    import java.util.Base64;
    
    public class RSAUtils { 
    
         /** * 缺省的2048位密钥对,可处理245个字节(81个汉字)的数据 */
         public static String PRIVATE_KEY = "MIIEv***XFu4=";
    
        public static String PUBLIC_KEY = "MIIB***DAQAB";
    
         /** * 字符集 */
         public static String CHARSET = "utf-8";
    
         /** * 签名算法 */
         public static final String SIGNATURE_INSTANCE = "SHA1WithRSA";
    
        /** * 生成密钥对 * @param keyLength * @return * @throws Exception */
        public static KeyPair getKeyPair(int keyLength) throws Exception { 
            KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
            keyPairGenerator.initialize(keyLength);
            return keyPairGenerator.generateKeyPair();
        }
    
        /** * 公钥字符串转PublicKey实例 * @param publicKey * @return * @throws Exception */
        public static PublicKey getPublicKey(String publicKey) throws Exception { 
             byte[] publicKeyBytes = Base64.getDecoder().decode(publicKey.getBytes());
             X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyBytes);
             KeyFactory keyFactory = KeyFactory.getInstance("RSA");
             return keyFactory.generatePublic(keySpec);
         }
    
        /** * 私钥字符串转PrivateKey实例 * @param privateKey * @return * @throws Exception */
        public static PrivateKey getPrivateKey(String privateKey) throws Exception { 
             byte[] privateKeyBytes = Base64.getDecoder().decode(privateKey.getBytes());
             PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(privateKeyBytes);
             KeyFactory keyFactory = KeyFactory.getInstance("RSA");
             return keyFactory.generatePrivate(keySpec);
         }
    
        /** * 公钥加密 * @param content * @param publicKey * @return * @throws Exception */
        public static byte[] encryptByPublicKey(byte[] content, PublicKey publicKey) throws Exception { 
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            return cipher.doFinal(content);
        }
    
        public static byte[] encryptByPublicKey(byte[] content) throws Exception { 
            return encryptByPublicKey(content, getPublicKey(PUBLIC_KEY));
        }
    
        public static String encryptByPublicKey(String content, String publicKey) throws Exception { 
           return new String(Base64.getEncoder().encode(encryptByPublicKey(content.getBytes(CHARSET), getPublicKey(publicKey))));
    
        }
    
        public static String encryptByPublicKey(String content) throws Exception { 
            return new String(Base64.getEncoder().encode(encryptByPublicKey(content.getBytes(CHARSET))));
        }
    
        /** * 私钥解密 * @param content * @param privateKey * @return * @throws Exception */
        public static byte[] decryptByPrivateKey(byte[] content, PrivateKey privateKey) throws Exception { 
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            return cipher.doFinal(content);
        }
    
        public static byte[] decryptByPrivateKey(byte[] content) throws Exception { 
            return decryptByPrivateKey(content, getPrivateKey(PRIVATE_KEY));
        }
    
        public static String decryptByPrivateKey(String content, String privateKey) throws Exception { 
            return new String(decryptByPrivateKey(Base64.getDecoder().decode(content), getPrivateKey(privateKey)), CHARSET);
    
        }
    
        public static String decryptByPrivateKey(String content) throws Exception { 
            return new String(decryptByPrivateKey(Base64.getDecoder().decode(content)), CHARSET);
        }
    
        /** * 私钥加密 * @param content * @param privateKey * @return * @throws Exception */
        public static byte[] encryptByPrivateKey(byte[] content, PrivateKey privateKey) throws Exception { 
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, privateKey);
            return cipher.doFinal(content);
        }
    
        public static byte[] encryptByPrivateKey(byte[] content) throws Exception { 
            return encryptByPrivateKey(content, getPrivateKey(PRIVATE_KEY));
        }
    
        public static String encryptByPrivateKey(String content, String privateKey) throws Exception { 
            return new String(encryptByPrivateKey(content.getBytes(CHARSET), getPrivateKey(privateKey)), CHARSET);
        }
    
        public static String encryptByPrivateKey(String content) throws Exception { 
            return new String(encryptByPrivateKey(content.getBytes(CHARSET)), CHARSET);
        }
    
        /** * 公钥解密 * @param content * @param publicKey * @return * @throws Exception */
        public static byte[] decrypByPublicKey(byte[] content, PublicKey publicKey) throws Exception { 
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, publicKey);
            return cipher.doFinal(content);
        }
    
        public static byte[] decrypByPublicKey(byte[] content) throws Exception { 
            return decrypByPublicKey(content, getPublicKey(PUBLIC_KEY));
        }
    
        public static String decrypByPublicKey(String content, String publicKey) throws Exception { 
            return new String(decrypByPublicKey(Base64.getDecoder().decode(content), getPublicKey(publicKey)), CHARSET);
    
        }
    
        public static String decrypByPublicKey(String content) throws Exception { 
            return new String(decrypByPublicKey(Base64.getDecoder().decode(content)), CHARSET);
        }
    
        /** * 签名 * @param content * @param privateKey * @return * @throws Exception */
        public static byte[] sign(byte[] content, PrivateKey privateKey) throws Exception { 
            Signature signature = Signature.getInstance(SIGNATURE_INSTANCE);
            signature.initSign(privateKey);
            signature.update(content);
            return signature.sign();
        }
    
        public static byte[] sign(byte[] content) throws Exception { 
            return sign(content, getPrivateKey(PRIVATE_KEY));
        }
    
        public static String sign(String content, String privateKey) throws Exception { 
            return new String(Base64.getEncoder().encode(sign(content.getBytes(CHARSET), getPrivateKey(privateKey))), CHARSET);
        }
    
        public static String sign(String content) throws Exception { 
            return new String(Base64.getEncoder().encode(sign(content.getBytes(CHARSET))), CHARSET);
        }
    
        /** * 验签 * @param content * @param sign * @param publicKey * @return * @throws Exception */
        public static boolean verify(byte[] content, byte[] sign,  PublicKey publicKey) throws Exception { 
            Signature signature = Signature.getInstance(SIGNATURE_INSTANCE);
            signature.initVerify(publicKey);
            signature.update(content);
            return signature.verify(sign);
        }
    
        public static boolean verify(byte[] content, byte[] sign) throws Exception { 
            return verify(content, sign, getPublicKey(PUBLIC_KEY));
        }
    
        public static boolean verify(String content, String sign, String publicKey) throws Exception { 
            return verify(content.getBytes(CHARSET), Base64.getDecoder().decode(sign), getPublicKey(publicKey));
        }
    
        public static boolean verify(String content, String sign) throws Exception { 
            return verify(content.getBytes(CHARSET), Base64.getDecoder().decode(sign), getPublicKey(PUBLIC_KEY));
        }
    }

缺省的密钥对可以用这段代码计算:

@Test
        public void testGetKeyPair() { 
            try { 
                KeyPair keyPair = RSAUtils.getKeyPair(1024);
                PublicKey publicKey = keyPair.getPublic();
                PrivateKey privateKey = keyPair.getPrivate();
                System.out.println(new String(Base64.getEncoder().encode(publicKey.getEncoded())));
                // MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDffzKfmLgZWc1cp0kMwky0Yd4upchGbKRS5a9L2Imw1m0BVpE1Vcg0i9tnBCYzRmuToeq+m30SQhMK+FvICMMvRX9zMyvvf50jMIV78xB6UBWJd5EIFwwPP900I/sSWE3fT09BwVDNP1ILPAAN2ZfjbUkDrIFPra8WKjVc5bTlWwIDAQAB
                System.out.println(new String(Base64.getEncoder().encode(privateKey.getEncoded())));
                // 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
            } catch (Exception e) { 
                e.printStackTrace();
            }
        }