1、加密、解密流程
2、实现
（1）RSA加密工具类 RSACrypt.java
package club.easyshare.framework.utils; import java.security.InvalidKeyException; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.NoSuchAlgorithmException; import java.security.SecureRandom; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; import java.security.spec.InvalidKeySpecException; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; import java.util.HashMap; import java.util.Map; import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeException; import javax.crypto.NoSuchPaddingException; public class RSACrypt { /** * 生成RAS公钥与私钥字符串，直接返回 * * @return */ public static HashMap<String, String> getKeys() { HashMap<String, String> map = new HashMap<String, String>(); KeyPairGenerator keyPairGen = null; try { keyPairGen = KeyPairGenerator.getInstance("RSA"); } catch (NoSuchAlgorithmException e) { // TODO Auto-generated catch block e.printStackTrace(); } // 初始化密钥对生成器，密钥大小为96-1024位 keyPairGen.initialize(1024, new SecureRandom()); // 生成一个密钥对，保存在keyPair中 KeyPair keyPair = keyPairGen.generateKeyPair(); // 得到公钥字符串 String publicKey = base64ToStr(keyPair.getPublic().getEncoded()); // 得到私钥字符串 String privateKey = base64ToStr(keyPair.getPrivate().getEncoded()); map.put("publicKey", publicKey); map.put("privateKey", privateKey); return map; } /** * 根据公钥字符串加载公钥 * * @param publicKeyStr 公钥字符串 * @return * @throws Exception */ public static RSAPublicKey loadPublicKey(String publicKeyStr) throws Exception { try { byte[] buffer = javax.xml.bind.DatatypeConverter.parseBase64Binary(publicKeyStr); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer); return (RSAPublicKey) keyFactory.generatePublic(keySpec); } catch (NoSuchAlgorithmException e) { throw new Exception("无此算法", e); } catch (InvalidKeySpecException e) { throw new Exception("公钥非法", e); } catch (NullPointerException e) { throw new Exception("公钥数据为空", e); } } /** * 根据私钥字符串加载私钥 * * @param privateKeyStr 私钥字符串 * @return * @throws Exception */ public static RSAPrivateKey loadPrivateKey(String privateKeyStr) throws Exception { try { byte[] buffer = javax.xml.bind.DatatypeConverter.parseBase64Binary(privateKeyStr); PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); return (RSAPrivateKey) keyFactory.generatePrivate(keySpec); } catch (NoSuchAlgorithmException e) { throw new Exception("无此算法", e); } catch (InvalidKeySpecException e) { throw new Exception("私钥非法", e); } catch (NullPointerException e) { throw new Exception("私钥数据为空", e); } } /** * 公钥加密 * * @param publicKey 公钥 * @param plainTextData 明文数据 * @return * @throws Exception 加密过程中的异常信息 */ public static String encrypt(RSAPublicKey publicKey, byte[] plainTextData) throws Exception { if (publicKey == null) { throw new Exception("加密公钥为空, 请设置"); } Cipher cipher = null; try { // 使用默认RSA cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, publicKey); byte[] output = cipher.doFinal(plainTextData); return base64ToStr(output); } catch (NoSuchAlgorithmException e) { throw new Exception("无此加密算法"); } catch (NoSuchPaddingException e) { e.printStackTrace(); return null; } catch (InvalidKeyException e) { throw new Exception("加密公钥非法,请检查"); } catch (IllegalBlockSizeException e) { throw new Exception("明文长度非法"); } catch (BadPaddingException e) { throw new Exception("明文数据已损坏"); } } /** * 私钥解密 * * @param privateKey 私钥 * @param cipherData 密文数据 * @return 明文 * @throws Exception 解密过程中的异常信息 */ public static String decrypt(RSAPrivateKey privateKey, byte[] cipherData) throws Exception { if (privateKey == null) { throw new Exception("解密私钥为空, 请设置"); } Cipher cipher = null; try { // 使用默认RSA cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.DECRYPT_MODE, privateKey); byte[] output = cipher.doFinal(cipherData); return new String(output); } catch (NoSuchAlgorithmException e) { throw new Exception("无此解密算法"); } catch (NoSuchPaddingException e) { e.printStackTrace(); return null; } catch (InvalidKeyException e) { throw new Exception("解密私钥非法,请检查"); } catch (IllegalBlockSizeException e) { e.printStackTrace(); throw new Exception("密文长度非法"); } catch (BadPaddingException e) { e.printStackTrace(); throw new Exception("密文数据已损坏"); } } public static String base64ToStr(byte[] b) { return javax.xml.bind.DatatypeConverter.printBase64Binary(b); } public static byte[] strToBase64(String str) { return javax.xml.bind.DatatypeConverter.parseBase64Binary(str); } }
（2）生成秘钥对，加密数据、解密数据
public static void main(String[] args) throws Exception { //初始化阶段，初始化后生成秘钥对 //公钥发送给消息发送方用于加密传输数据；私钥严格保存于消息接收方，收到加密的消息之后进行解密 HashMap<String, String> map = RSACrypt.getKeys(); String privateKeyStr=map.get("privateKey"); String publicKeyStr=map.get("publicKey"); System.out.println("初始化私钥为："+privateKeyStr); System.out.println("初始化共钥为："+publicKeyStr); //消息发送方 String originData="周末约你看电影吧"; System.out.println("信息原文："+originData); String encryptData=RSACrypt.encrypt(RSACrypt.loadPublicKey(publicKeyStr),originData.getBytes()); System.out.println("加密后："+encryptData); //消息接收方 String decryptData=RSACrypt.decrypt(RSACrypt.loadPrivateKey(privateKeyStr),RSACrypt.strToBase64(encryptData)); System.out.println("解密后："+decryptData); }
结果输出
初始化私钥为：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 初始化共钥为：MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCNkskbzMWU65UceqB2r/JQhAh1+cGf6T5ALJdUSIfzTH1ecIzft5BmaxujRLyPsQrsMBRp/BsFA4Kguh8OZwNeXIbkaa2RQ2l2vYRawuq+o7UOjDzrKnWgyUn6SSGOuH2aqFSynYm1e/N5ny9e+Z/SJGg7sN5rLpicgzrIKZSCfwIDAQAB 信息原文：周末约你看电影吧 加密后：XeIAoNZlyn+Mk17wsdPpl8SDlaq0B8NbIvQFVg9Ja+YHxuKretNMu61IRY5EFyPL/dXC/6KiDDINglP2HRX4JNbRZgzZd1rkqExW219psHQOhFzbFYZ3yKuI72C7S4/sqIM1eqlnkvIGBhJNLwOfzF6VjplsbHAiQ4fDhA57XI8= 解密后：周末约你看电影吧
