RSA非对称加密Java实现

时间:2021-12-28 23:50:47

原文

加密基础方法类

 import java.security.MessageDigest;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class SecurityBase {
public static final String KEY_SHA="SHA";
public static final String KEY_MD5="MD5";
//BASE64解密
public static byte[] decryptBASE64(String key) throws Exception{
return (new BASE64Decoder()).decodeBuffer(key);
}
//BASE64加密
public static String encryptBASE64(byte[] key)throws Exception{
return (new BASE64Encoder()).encodeBuffer(key);
}
//MD5加密
public static byte[] encryptMD5(byte[] data)throws Exception{
MessageDigest md5 = MessageDigest.getInstance(KEY_MD5);
md5.update(data);
return md5.digest();
}
//SHA加密
public static byte[] encryptSHA(byte[] data)throws Exception{
MessageDigest sha = MessageDigest.getInstance(KEY_SHA);
sha.update(data);
return sha.digest();
}
}

RSA非对称加密实现类

 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.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.Cipher;
public class RSASecurity extends SecurityBase {
public static final String KEY_ALGORTHM="RSA";
public static final String SIGNATURE_ALGORITHM="MD5withRSA";
public static final String PUBLIC_KEY = "RSAPublicKey";//公钥
public static final String PRIVATE_KEY = "RSAPrivateKey";//私钥
/**
* 初始化密钥
* @return
* @throws Exception
*/
public static Map<String,Key> createKeys()throws Exception{
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_ALGORTHM);
keyPairGenerator.initialize(1024);
KeyPair keyPair = keyPairGenerator.generateKeyPair();
//公钥
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
//私钥
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
Map<String,Key> keyMap = new HashMap<String, Key>(2);
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return keyMap;
}
/**
* 取得公钥,并转化为String类型
* @param keyMap
* @return
* @throws Exception
*/
public static String getPublicKey(Map<String, Key> keyMap)throws Exception{
Key key = keyMap.get(PUBLIC_KEY);
return encryptBASE64(key.getEncoded());
}
/**
* 取得私钥,并转化为String类型
* @param keyMap
* @return
* @throws Exception
*/
public static String getPrivateKey(Map<String, Key> keyMap) throws Exception{
Key key = keyMap.get(PRIVATE_KEY);
return encryptBASE64(key.getEncoded());
}
/**
* 用私钥加密
* @param data 加密数据
* @param key 密钥
* @return
* @throws Exception
*/
public static byte[] encryptByPrivateKey(byte[] data,String key)throws Exception{
//解密密钥
byte[] keyBytes = decryptBASE64(key);
//取私钥
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
Key privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
//对数据加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
return cipher.doFinal(data);
}
/**
* 用私钥解密
* @param data 加密数据
* @param key 密钥
* @return
* @throws Exception
*/
public static byte[] decryptByPrivateKey(byte[] data,String key)throws Exception{
//对私钥解密
byte[] keyBytes = decryptBASE64(key);
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
Key privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
//对数据解密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateKey);
return cipher.doFinal(data);
}
/**
* 用公钥加密
* @param data 加密数据
* @param key 密钥
* @return
* @throws Exception
*/
public static byte[] encryptByPublicKey(byte[] data,String key)throws Exception{
//对公钥解密
byte[] keyBytes = decryptBASE64(key);
//取公钥
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
Key publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
//对数据解密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
return cipher.doFinal(data);
}
/**
* 用公钥解密
* @param data 加密数据
* @param key 密钥
* @return
* @throws Exception
*/
public static byte[] decryptByPublicKey(byte[] data,String key)throws Exception{
//对私钥解密
byte[] keyBytes = decryptBASE64(key);
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
Key publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
//对数据解密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicKey);
return cipher.doFinal(data);
}
/**
* 用私钥对信息生成数字签名
* @param data //加密数据
* @param privateKey //私钥
* @return
* @throws Exception
*/
public static String sign(byte[] data,String privateKey)throws Exception{
//解密私钥
byte[] keyBytes = decryptBASE64(privateKey);
//构造PKCS8EncodedKeySpec对象
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(keyBytes);
//指定加密算法
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
//取私钥匙对象
PrivateKey privateKey2 = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
//用私钥对信息生成数字签名
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(privateKey2);
signature.update(data);
return encryptBASE64(signature.sign());
}
/**
* 校验数字签名
* @param data 加密数据
* @param publicKey 公钥
* @param sign 数字签名
* @return
* @throws Exception
*/
public static boolean verify(byte[] data,String publicKey,String sign)throws Exception{
//解密公钥
byte[] keyBytes = decryptBASE64(publicKey);
//构造X509EncodedKeySpec对象
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(keyBytes);
//指定加密算法
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
//取公钥匙对象
PublicKey publicKey2 = keyFactory.generatePublic(x509EncodedKeySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(publicKey2);
signature.update(data);
//验证签名是否正常
return signature.verify(decryptBASE64(sign));
}
/**
*
* @Title: main
* @Description: 测试
* @param @param args
* @return void
* @throws
*/
public static void main(String[] args) {
try {
Map<String,Key> data = createKeys();
String content = "JavaRsaEncoder";
System.out.println("加密前:"+content);
String encode = encryptBASE64(encryptByPrivateKey(content.getBytes(), getPrivateKey(data)));
System.out.println("加密后:"+encode);
String decode = new String(decryptByPublicKey(decryptBASE64(encode), getPublicKey(data)));
System.out.println("解密后:"+decode);
} catch (Exception e) {
e.printStackTrace();
}
}
}

运行结果

 加密前:JavaRsaEncoder
加密后:l+vhbdRdq3dc5nr6m4jSIuW0ufKeCYBw4ds2Es9/SmPa/Dp298gZsT8KkZRwlKcm60+MV67fVMyG
OgwCZWbqQqmu8Mr+ZuqUWWnIZ0fIi1JAaqiwqsg7SaIkvixU35HHdsxmNMdK+1qPDWBE5sCjSCJ+
xaG0Y8BOpyGDlpL9bOc=
解密后:JavaRsaEncoder