RSA 加密在編程中很常見恼策，iOS 安卓要用潮剪，Java 也要用，最近因為大數(shù)據(jù)的項目要用到狮斗，就寫了一份弧蝇，這里備份一下折砸，也希望能幫到要用的朋友們沙峻。
以下是整體代碼：
import org.apache.commons.codec.binary.Base64;
import javax.crypto.Cipher;
import java.security.*;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
/**
* Hello RSA!
*
*/
public class RSAUtils
{
private static Map<Integer,String> keyMap=new HashMap<>();
public static void main( String[] args ) throws Exception {
//生成公鑰和私鑰
getKeyPair();
//加密字符串
String password="liupengkun";
System.out.println("隨機生成的公鑰為："+keyMap.get(0));
System.out.println("隨機生成的私鑰為："+keyMap.get(1));
String passwordEn=encrypt(password,keyMap.get(0));
System.out.println(password+"\t加密后的字符串為："+passwordEn);
String passwordDe=decrypt(passwordEn,keyMap.get(1));
System.out.println("還原后的字符串為："+passwordDe);
}
/**
* 隨機生成密鑰對
* @throws NoSuchAlgorithmException
*/
public static void getKeyPair() throws Exception {
//KeyPairGenerator類用于生成公鑰和密鑰對摔寨，基于RSA算法生成對象
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
//初始化密鑰對生成器是复，密鑰大小為96-1024位
keyPairGen.initialize(1024,new SecureRandom());
//生成一個密鑰對，保存在keyPair中
KeyPair keyPair = keyPairGen.generateKeyPair();
PrivateKey privateKey = keyPair.getPrivate();//得到私鑰
PublicKey publicKey = keyPair.getPublic();//得到公鑰
//得到公鑰字符串
String publicKeyString=new String(Base64.encodeBase64(publicKey.getEncoded()));
//得到私鑰字符串
String privateKeyString=new String(Base64.encodeBase64(privateKey.getEncoded()));
//將公鑰和私鑰保存到Map
keyMap.put(0,publicKeyString);//0表示公鑰
keyMap.put(1,privateKeyString);//1表示私鑰
}
/**
* RSA公鑰加密
*
* @param str
* 加密字符串
* @param publicKey
* 公鑰
* @return 密文
* @throws Exception
* 加密過程中的異常信息
*/
public static String encrypt(String str,String publicKey) throws Exception {
//base64編碼的公鑰
byte[] decoded = Base64.decodeBase64(publicKey);
RSAPublicKey pubKey= (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
//RAS加密
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE,pubKey);
String outStr=Base64.encodeBase64String(cipher.doFinal(str.getBytes("UTF-8")));
return outStr;
}
/**
* RSA私鑰解密
*
* @param str
* 加密字符串
* @param privateKey
* 私鑰
* @return 銘文
* @throws Exception
* 解密過程中的異常信息
*/
public static String decrypt(String str,String privateKey) throws Exception {
//Base64解碼加密后的字符串
byte[] inputByte = Base64.decodeBase64(str.getBytes("UTF-8"));
//Base64編碼的私鑰
byte[] decoded = Base64.decodeBase64(privateKey);
PrivateKey priKey = KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));
//RSA解密
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.DECRYPT_MODE,priKey);
String outStr=new String(cipher.doFinal(inputByte));
return outStr;
}
}
在程序中，我們首先利用 getKeyPair() 函數(shù)生成公鑰和私鑰并將其保存到 Map 集合中季惩。然后，基于產(chǎn)生的公鑰對明文進行加密。針對已經(jīng)已經(jīng)加密的密文碾阁，我們再次使用私鑰解密些楣，得到明文。
上述程序的輸出結(jié)果為：
隨機生成的公鑰為：MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCs+QkIaMuogm99lcRjV1xT+AuTHlgIT65svpG8MrPnfjApnkQAdT++VwubdU9ULwVthc6GLuXORxakN/Odd+/jd8WY2IJMVttkYR1mhAZQkx9AU2frNbq97gS9menvL7pQk2ji42Sl1gcZ7tY5+XXGN7EYS52+JGdgfuxGoWNMQwIDAQAB
隨機生成的私鑰為：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
liupengkun 加密后的字符串為：EUz2Goo0m5mNk0al87dsrcqIuzIzNAEvzTBJOXUOiujubJgqVPmsM880aahLbKrNjl5ArJPtguznJ9PruwSBUnGoPpAMetHp+23RBkXB2DwAA200qejLyKt1PkeTLJjDrQVhohlsF+K48TaGpTSfDMoPli3E6eTdS+dk1Xib4SI=
還原后的字符串為：liupengkun
