java RSA公私钥与其base64编码之间的转换

太过爱你忘了你带给我的痛 2022-06-09 07:11 576阅读 0赞

import Java.security.Key;
    
    import java.security.KeyFactory;
    import java.security.KeyPair;
    import java.security.KeyPairGenerator;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.interfaces.RSAPrivateKey;
    import java.security.interfaces.RSAPublicKey;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
     
    import javax.crypto.Cipher;
     
    import sun.misc.BASE64Decoder;
    import sun.misc.BASE64Encoder;
     
     
    public class RSAHelper {
     
          /**
           * 得到公钥
           * @param key 密钥字符串（经过base64编码）
           * @throws Exception
           */
          public static PublicKey getPublicKey(String key) throws Exception {
                byte[] keyBytes;
                keyBytes = (new BASE64Decoder()).decodeBuffer(key);
     
                X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
                KeyFactory keyFactory = KeyFactory.getInstance("RSA");
                PublicKey publicKey = keyFactory.generatePublic(keySpec);
                return publicKey;
          }
          /**
           * 得到私钥
           * @param key 密钥字符串（经过base64编码）
           * @throws Exception
           */
          public static PrivateKey getPrivateKey(String key) throws Exception {
                byte[] keyBytes;
                keyBytes = (new BASE64Decoder()).decodeBuffer(key);
     
                PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
                KeyFactory keyFactory = KeyFactory.getInstance("RSA");
                PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
                return privateKey;
          }
     
          /**
           * 得到密钥字符串（经过base64编码）
           * @return
           */
          public static String getKeyString(Key key) throws Exception {
                byte[] keyBytes = key.getEncoded();
                String s = (new BASE64Encoder()).encode(keyBytes);
                return s;
          }
     
     
          public static void main(String[] args) throws Exception {
     
                KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
                //密钥位数
                keyPairGen.initialize(1024);
                //密钥对
                KeyPair keyPair = keyPairGen.generateKeyPair();
     
                // 公钥
                PublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
     
                // 私钥
                PrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
     
                String publicKeyString = getKeyString(publicKey);
                System.out.println("public:\n" + publicKeyString);
     
                String privateKeyString = getKeyString(privateKey);
                System.out.println("private:\n" + privateKeyString);
     
                //加解密类
                Cipher cipher = Cipher.getInstance("RSA");//Cipher.getInstance("RSA/ECB/PKCS1Padding");
     
                //明文
                byte[] plainText = "我们都很好！邮件：@sina.com".getBytes();
     
                //加密
                cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    			byte[] enBytes = cipher.doFinal(plainText);
     
    			//通过密钥字符串得到密钥
                publicKey = getPublicKey(publicKeyString);
                privateKey = getPrivateKey(privateKeyString);
     
                //解密
                cipher.init(Cipher.DECRYPT_MODE, privateKey);
                byte[]deBytes = cipher.doFinal(enBytes);
     
                publicKeyString = getKeyString(publicKey);
                System.out.println("public:\n" +publicKeyString);
     
                privateKeyString = getKeyString(privateKey);
                System.out.println("private:\n" + privateKeyString);
     
                String s = new String(deBytes);
                System.out.println(s);
     
     
          }
     
    }
    
    
    
    通过modulus \public exponent \private exponent生成 RSA Key 
    import java.math.BigInteger;
    import java.security.KeyFactory;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.spec.RSAPrivateKeySpec;
    import java.security.spec.RSAPublicKeySpec;
    import javax.crypto.Cipher;
    
    public class RsaKey {
    
          public PublicKey getPublicKey(String modulus,String publicExponent) throws Exception {
                BigInteger m = new BigInteger(modulus);
                BigInteger e = new BigInteger(publicExponent);
                RSAPublicKeySpec keySpec = new RSAPublicKeySpec(m,e);
                KeyFactory keyFactory = KeyFactory.getInstance("RSA");
                PublicKey publicKey = keyFactory.generatePublic(keySpec);
                return publicKey;
          }
    
          public PrivateKey getPrivateKey(String modulus,String privateExponent) throws Exception {
                BigInteger m = new BigInteger(modulus);
                BigInteger e = new BigInteger(privateExponent);
                RSAPrivateKeySpec keySpec = new RSAPrivateKeySpec(m,e);
                KeyFactory keyFactory = KeyFactory.getInstance("RSA");
                PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
                return privateKey;
          }
    
          public static void main(String[] args) throws Exception {
                String modulus = "10103166745709600780215616551837697832816413714471062522342538060943596036859967333870827790358555455232243383580565187280643159050869924436081447583051139";
                String publicExponent = "65537";
                String privateExponet = "367979294475011322800474185715497882523349856362702385535371444397399388741997039894583483410120364529325888461124714276674612930833020362278754665756193";
                RsaKey key = new RsaKey();
                PublicKey publicKey = key.getPublicKey(modulus, publicExponent);
                PrivateKey privateKey = key.getPrivateKey(modulus, privateExponet);
                //加解密类
                Cipher cipher = Cipher.getInstance("RSA");
                //明文
                byte[] plainText = "我们都很好！邮件：@sina.com".getBytes();
                //加密
                cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            byte[] enBytes = cipher.doFinal(plainText);
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
                byte[]deBytes = cipher.doFinal(enBytes);
                String s = new String(deBytes);
                System.out.println(s);
    
          }
    }

本文转载自csdn文章：[java RSA公私钥与其base64编码之间的转换][java RSA_base64]

[java RSA_base64]: http://blog.csdn.net/kirrin/article/details/7063790