Android之RAS加密算法测试实例

代码如下:

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);

}

}