java rsa加密解密
Coder.java
package com.sign.utils.rsa; import java.security.MessageDigest; import sun.misc.BASE64Decoder; import sun.misc.BASE64Encoder; public class Coder { public static final String KEY_SHA="SHA"; public static final String KEY_MD5="MD5"; /** * BASE64解密 * @param key * @return * @throws Exception */ public static byte[] decryptBASE64(String key) throws Exception{ return (new BASE64Decoder()).decodeBuffer(key); } /** * BASE64加密 * @param key * @return * @throws Exception */ public static String encryptBASE64(byte[] key)throws Exception{ return (new BASE64Encoder()).encodeBuffer(key); } /** * MD5加密 * @param data * @return * @throws Exception */ public static byte[] encryptMD5(byte[] data)throws Exception{ MessageDigest md5 = MessageDigest.getInstance(KEY_MD5); md5.update(data); return md5.digest(); } /** * SHA加密 * @param data * @return * @throws Exception */ public static byte[] encryptSHA(byte[] data)throws Exception{ MessageDigest sha = MessageDigest.getInstance(KEY_SHA); sha.update(data); return sha.digest(); } }
Rsa.java
package com.sign.utils.rsa; 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.Signature; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; import java.util.HashMap; import java.util.Map; import javax.crypto.Cipher; import org.junit.Test; public class Rsa extends Coder { public static final String KEY_ALGORTHM="RSA";//秘钥算法 public static final String SIGNATURE_ALGORITHM="MD5withRSA";//签名算法 public static final String PUBLIC_KEY = "RSAPublicKey";//公钥 public static final String PRIVATE_KEY = "RSAPrivateKey";//私钥 /* * 初始化密钥 * @return * @throws Exception * RSA加密解密的实现，需要有一对公私密钥，公私密钥的初始化如下： */ public static Map<String,Object> initKey()throws Exception{ KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_ALGORTHM); keyPairGenerator.initialize(1024); KeyPair keyPair = keyPairGenerator.generateKeyPair(); //公钥 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); //私钥 RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); Map<String,Object> keyMap = new HashMap<String, Object>(2); keyMap.put(PUBLIC_KEY, publicKey); keyMap.put(PRIVATE_KEY, privateKey); return keyMap; } /** * 取得公钥，并转化为String类型 * @param keyMap * @return * @throws Exception */ public static String getPublicKey(Map<String, Object> keyMap)throws Exception{ Key key = (Key) keyMap.get(PUBLIC_KEY); return encryptBASE64(key.getEncoded()); } /** * 取得私钥，并转化为String类型 * @param keyMap * @return * @throws Exception */ public static String getPrivateKey(Map<String, Object> keyMap) throws Exception{ Key key = (Key) keyMap.get(PRIVATE_KEY); return encryptBASE64(key.getEncoded()); } //两种加密形式 //方法一 /* * 用私钥加密 * @param data 加密数据 * @param key 密钥 * @return * @throws Exception */ public static byte[] encryptByPrivateKey(byte[] data,String key)throws Exception{ //解密密钥 byte[] keyBytes = decryptBASE64(key); //取私钥 PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM); Key privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec); //对数据加密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, privateKey); return cipher.doFinal(data); } /** * 私钥解密 * @param data 加密数据 * @param key 密钥 * @return * @throws Exception */ public static byte[] decryptByPrivateKey(byte[] data,String key)throws Exception{ //对私钥解密 byte[] keyBytes = decryptBASE64(key); PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM); Key privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec); //对数据解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, privateKey); return cipher.doFinal(data); } //方式二 /** * 用公钥加密 * @param data 加密数据 * @param key 密钥 * @return * @throws Exception */ public static byte[] encryptByPublicKey(byte[] data,String key)throws Exception{ //对公钥解密 byte[] keyBytes = decryptBASE64(key); //取公钥 X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM); Key publicKey = keyFactory.generatePublic(x509EncodedKeySpec); //对数据解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, publicKey); return cipher.doFinal(data); } /** * 私钥加密 * 用公钥解密 * @param data 加密数据 * @param key 密钥 * @return * @throws Exception */ public static byte[] decryptByPublicKey(byte[] data,String key)throws Exception{ //对私钥解密 byte[] keyBytes = decryptBASE64(key); X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM); Key publicKey = keyFactory.generatePublic(x509EncodedKeySpec); //对数据解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, publicKey); return cipher.doFinal(data); } /** * 私钥签名 * 用私钥对信息生成数字签名 * @param data //加密数据 * @param privateKey //私钥 * @return * @throws Exception */ public static String sign(byte[] data,String privateKey)throws Exception{ //解密私钥 byte[] keyBytes = decryptBASE64(privateKey); //构造PKCS8EncodedKeySpec对象 PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(keyBytes); //指定加密算法 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM); //取私钥匙对象 PrivateKey privateKey2 = keyFactory.generatePrivate(pkcs8EncodedKeySpec); //用私钥对信息生成数字签名 Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); signature.initSign(privateKey2); signature.update(data); return encryptBASE64(signature.sign()); } /** * 公钥校验 * 校验数字签名 * @param data 加密数据 * @param publicKey 公钥 * @param sign 数字签名 * @return * @throws Exception */ public static boolean verify(byte[] data,String publicKey,String sign)throws Exception{ //解密公钥 byte[] keyBytes = decryptBASE64(publicKey); //构造X509EncodedKeySpec对象 X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(keyBytes); //指定加密算法 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM); //取公钥匙对象 PublicKey publicKey2 = keyFactory.generatePublic(x509EncodedKeySpec); Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); signature.initVerify(publicKey2); signature.update(data); //验证签名是否正常 return signature.verify(decryptBASE64(sign)); } @Test public void testRsa(){ try { //test(); testSign(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } public void test() throws Exception { Map<String, Object> keyMap = initKey(); String publicKey =getPublicKey(keyMap); String privateKey = getPrivateKey(keyMap); System.err.println("公钥加密——私钥解密"); String source = "这是一行没有任何意义的文字，你看完了等于没看，不是吗？"; System.out.println("\r加密前文字：\r\n" + source); byte[] data = source.getBytes(); byte[] encodedData = encryptByPublicKey(data, publicKey); System.out.println("加密后文字：\r\n" + new String(encodedData)); byte[] decodedData =decryptByPrivateKey(encodedData, privateKey); String target = new String(decodedData); System.out.println("解密后文字: \r\n" + target); } public void testSign() throws Exception { Map<String, Object> keyMap = initKey(); String publicKey =getPublicKey(keyMap); System.out.println(publicKey+"==================================="); String privateKey = getPrivateKey(keyMap); System.err.println("私钥加密——公钥解密"); String source = "这是一行测试RSA数字签名的无意义文字"; System.out.println("原文字：\r\n" + source); byte[] data = source.getBytes(); byte[] encodedData = encryptByPrivateKey(data, privateKey); System.out.println("加密后：\r\n" + new String(encodedData)); byte[] decodedData = decryptByPublicKey(encodedData, publicKey); String target = new String(decodedData); System.out.println("解密后: \r\n" + target); System.err.println("私钥签名——公钥验证签名"); String sign = sign(encodedData, privateKey); System.err.println("签名:\r" + sign); boolean status = verify(encodedData, publicKey, sign); System.err.println("验证结果:\r" + status); } }
上面生成秘钥对的时候每次都生成的不一样，一般后台和app或其他设备交互只需要两对，写在配置文件中。
