import javax.crypto.Cipher;
import javax.crypto.spec.OAEPParameterSpec;
import javax.crypto.spec.PSource;
import java.security.*;
import java.security.spec.MGF1ParameterSpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
public class RSACipher {
/**
* 加密方法
*
* @param publicKey 公钥
* @param raw 待加密明文
* @return 加密后的密文
* @throws Exception
*/
public static byte[] encrypt(String publicKey, byte[] raw) throws Exception {
Key key = getPublicKey(publicKey);
Cipher cipher = Cipher.getInstance(Config.RSA_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, key, new OAEPParameterSpec("SHA-256", "MGF1", MGF1ParameterSpec.SHA256, PSource.PSpecified.DEFAULT));
byte[] b1 = cipher.doFinal(raw);
return Base64.encodeBase64(b1);
}
/**
* 解密方法
*
* @param privateKey 私钥
* @param enc 待解密密文
* @return 解密后的明文
* @throws Exception
*/
public static byte[] decrypt(String privateKey, byte[] enc) throws Exception {
Key key = getPrivateKey(privateKey);
Cipher cipher = Cipher.getInstance(Config.RSA_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, key, new OAEPParameterSpec("SHA-256", "MGF1", MGF1ParameterSpec.SHA256, PSource.PSpecified.DEFAULT));
return cipher.doFinal(Base64.decodeBase64(enc));
}
/**
* 获取公钥
*
* @param key 密钥字符串（经过base64编码）
* @return 公钥
* @throws Exception
*/
public static PublicKey getPublicKey(String key) throws Exception {
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(Base64.decodeBase64(key.getBytes()));
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PublicKey publicKey = keyFactory.generatePublic(keySpec);
return publicKey;
}
/**
* 获取私钥
*
* @param key 密钥字符串（经过base64编码）
* @return 私钥
* @throws Exception
*/
public static PrivateKey getPrivateKey(String key) throws Exception {
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(Base64.decodeBase64(key.getBytes()));
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
return privateKey;
}
/**
* 签名
*
* @param privateKey 私钥
* @param content 要进行签名的内容
* @return 签名
*/
public static String sign(String privateKey, byte[] content) {
try {
PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKey.getBytes()));
KeyFactory keyf = KeyFactory.getInstance("RSA");
PrivateKey priKey = keyf.generatePrivate(priPKCS8);
Signature signature = Signature.getInstance("SHA256WithRSA");
signature.initSign(priKey);
signature.update(content);
byte[] signed = signature.sign();
return new String(Base64.encodeBase64(signed));
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 验签
*
* @param publicKey 公钥
* @param content 要验签的内容
* @param sign 签名
* @return 验签结果
*/
public static boolean checkSign(String publicKey, byte[] content, String sign) {
try {
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
byte[] encodedKey = Base64.decode2(publicKey);
PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));
java.security.Signature signature = java.security.Signature.getInstance("SHA256WithRSA");
signature.initVerify(pubKey);
signature.update(content);
return signature.verify(Base64.decode2(sign));
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
public static void main(String[] args) throws Exception {
//客户端代码
String text = "hello";
//使用服务端公钥加密
byte[] encryptText = RSACipher.encrypt(Config.SERVER_PUBLIC_KEY, text.getBytes());
System.out.println("加密后:\n" + new String(encryptText));
//使用客户端私钥签名
String signature = RSACipher.sign(Config.CLIENT_PRIVATE_KEY, encryptText);
System.out.println("签名:\n" + signature);
//服务端代码
//使用客户端公钥验签
boolean result = RSACipher.checkSign(Config.CLIENT_PUBLIC_KEY, encryptText, signature);
System.out.println("验签:\n" + result);
//使用服务端私钥解密
byte[] decryptText = RSACipher.decrypt(Config.SERVER_PRIVATE_KEY, encryptText);
System.out.println("解密后:\n" + new String(decryptText));
}
}
RSA 加密签名验签解密的相关教程结束。
