Android之RAS加密算法测试

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 {   

      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;
      }   

      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;
      }   

      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);   

      }   

}