Android编程加密算法小结(AES、Base64、RAS加密算法)

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);