1. 什么是RSA加密算法？
1.1 对称加密和非对称加密
对称加密：对称加密指的就是加密和解密使用同一个秘钥，所以叫做对称加密。对称加密只有一个秘钥，作为私钥。常见的对称加密算法：DES，AES，3DES等等。非对称加密：非对称加密指的是：加密和解密使用不同的秘钥，一把作为公开的公钥，另一把作为私钥。公钥加密的信息，只有私钥才能解密。私钥加密的信息，只有公钥才能解密。常见的非对称加密算法：RSA，ECC1.2 RSA加密算法
RSA加密算法是一种非对称加密算法，是通过两个密钥（公钥-私钥）来实现对数据的加密和解密的。公钥用于加密，私钥用于解密。
2. scala实现RSA加密
Object Rsa{/*** 公钥加密* 传入参数为需要加密的字符串origStr，返回结果为加密后的字符串和私钥的元组（encodeStr,privateKeyStr）*/def rsaEncryPtion(origStr:String):(String,String)={//生成公钥和私钥val keyPairGenerator = KeyPairGenerator.getInstance("RSA")keyPairGenerator.initialize(1024, new SecureRandom())val keyPair = keyPairGenerator.generateKeyPair()val privateKey = keyPair.getPrivateval privateKeyStr = new String(Base64.encode(privateKey.getEncoded))val publicKey = keyPair.getPublicval publicKeyStr = new String(Base64.encode(publicKey.getEncoded))//进行加密处理val encoded = Base64.decode(publicKeyStr)val rsaPublicKey = KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(encoded))val cipher = Cipher.getInstance("RSA")cipher.init(Cipher.ENCRYPT_MODE, rsaPublicKey)val encodeStr = Base64.encode(cipher.doFinal(origStr.getBytes("UTF-8")))(encodeStr,privateKeyStr)}/*** 私钥解密* 传入参数为加密过后的字符串encodeStr、私钥privateStr，返回结果为解密后的数据*/def rsaDecryPtion(encodeStr:String,privateKeyStr:String):String={val bytes = Base64.decode(encodeStr)val decoded = Base64.decode(privateKey)val rsaPrivateKey = KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded))val cipher = Cipher.getInstance("RSA")cipher.init(Cipher.DECRYPT_MODE, rsaPrivateKey)val codeStr = new String(cipher.doFinal(bytes))codeStr}def main(args: Array[String]) {//待加密的数据val origData = "RSA from korry24"//加密val origDecry = rsaEncryPtion(origData)//加密后的数据val encodeStr = origDecry._1//私钥val privateKeyStr = origDecry._2//解密val codeStr = rsaDecryPtion(encodeStr,privateKeyStr)}}
3. java实现RSA加密
public class RSACrypt {private static Map<Integer, String> keyMap = new HashMap<Integer, String>();/*** 初始化生成公钥和私钥* */public static void init() throws NoSuchAlgorithmException{/*** KeyPairGenerator用于生成公钥和私钥对，基于RSA算法生成对象*/KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");/*** 初始化秘钥对生成器，秘钥大小为1024位*/keyPairGen.initialize(1024, new SecureRandom());/*** 生成秘钥*/KeyPair keyPair = keyPairGen.generateKeyPair();/*** 获取私钥*/RSAPrivateKey privateKey = (RSAPrivateKey)keyPair.getPrivate();String privateKeyStr = new String(Base64.encodeBase64(privateKey.getEncoded()));/** * 获取公钥*/RSAPublicKey publicKey = (RSAPublicKey)keyPair.getPublic();String publicKeyStr = new String(Base64.encodeBase64(publicKey.getEncoded()));/*** 保存公钥，私钥*/keyMap.put(0, publicKeyStr); // 公钥keyMap.put(1, privateKeyStr);// 私钥}/*** 公钥加密* @throws NoSuchAlgorithmException * @throws InvalidKeySpecException * @throws Exception */public static String rsaEncrypt(String content, String publicKey) throws InvalidKeySpecException, NoSuchAlgorithmException, Exception{//base64编码的公钥byte[] encoded = Base64.decodeBase64(publicKey);RSAPublicKey rsaPublicKey = (RSAPublicKey)KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(encoded));// RSA加密Cipher cipher = Cipher.getInstance("RSA");cipher.init(Cipher.ENCRYPT_MODE, rsaPublicKey);String outPublicKey = Base64.encodeBase64String(cipher.doFinal(content.getBytes("UTF-8")));return outPublicKey;}/*** 私钥解密* @throws UnsupportedEncodingException * @throws NoSuchAlgorithmException * @throws InvalidKeySpecException * @throws NoSuchPaddingException * @throws InvalidKeyException * @throws BadPaddingException * @throws IllegalBlockSizeException * @throws Exception*/public static String rsaDecrypt(String content, String privateKey) throws UnsupportedEncodingException, InvalidKeySpecException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException{//base64位解码加密后的字符串byte[] inputByte = Base64.decodeBase64(content.getBytes("UTF-8"));//base64编码的私钥byte[] decoded = Base64.decodeBase64(privateKey);RSAPrivateKey rsaPrivateKey = (RSAPrivateKey)KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));//RSA解密Cipher cipher = Cipher.getInstance("RSA");cipher.init(Cipher.DECRYPT_MODE, rsaPrivateKey);String outPrivateKey = new String(cipher.doFinal(inputByte));return outPrivateKey;}public static void main(String[] args) throws Exception {/*** 初始化生成公钥，私钥*/init();/*** 加密数据*/String message = "abc123";System.out.println("随机生成的公钥为：" + keyMap.get(0));System.out.println("随机生成的私钥为：" + keyMap.get(1));System.out.println("加密前的数据：" + message);String messageEncrypt = rsaEncrypt(message, keyMap.get(0));System.out.println("加密后的数据：" + messageEncrypt);//String mid = "MIIc" + keyMap.get(1).substring(4, keyMap.get(1).length());//System.out.println("随机生成的私钥为：" + mid);String messageDecrypt = rsaDecrypt(messageEncrypt, keyMap.get(1));System.out.println("解密后的数据：" + messageDecrypt);}}
