常见签名算法之SHA256withRSA
作者：互联网
SHA256withRSA 完美工具类 RSAUtils，包含：
1、签名
2、验签
3、公钥加密
4、钥加密私
RSAUtils工具类：
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.KeyStore;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.Signature;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang3.ArrayUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class RSAUtils {
private static final Logger logger = LoggerFactory.getLogger(RSAUtils.class);
// MAX_DECRYPT_BLOCK应等于密钥长度/8（1byte=8bit），所以当密钥位数为2048时，最大解密长度应为256.
// 128 对应 1024，256对应2048
private static final int KEYSIZE = 2048;
// RSA最大加密明文大小
private static final int MAX_ENCRYPT_BLOCK = 117;
// RSA最大解密密文大小
private static final int MAX_DECRYPT_BLOCK = 128;
// 不仅可以使用DSA算法，同样也可以使用RSA算法做数字签名
private static final String KEY_ALGORITHM = "RSA";
private static final String SIGNATURE_ALGORITHM = "SHA256withRSA";
public static final String DEFAULT_SEED = "$%^*%^()(ED47d784sde78"; // 默认种子
public static final String PUBLIC_KEY = "PublicKey";
public static final String PRIVATE_KEY = "PrivateKey";
/**
*
* 生成密钥
*
* @param seed 种子
*
* @return 密钥对象
* @throws Exception
*
*/
public static Map<String, Key> initKey(String seed) throws Exception {
logger.info("生成密钥");
KeyPairGenerator keygen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
SecureRandom secureRandom = new SecureRandom();
// 如果指定seed，那么secureRandom结果是一样的，所以生成的公私钥也永远不会变
// secureRandom.setSeed(seed.getBytes());
// Modulus size must range from 512 to 1024 and be a multiple of 64
keygen.initialize(KEYSIZE, secureRandom);
KeyPair keys = keygen.genKeyPair();
PrivateKey privateKey = keys.getPrivate();
PublicKey publicKey = keys.getPublic();
Map<String, Key> map = new HashMap<>(2);
map.put(PUBLIC_KEY, publicKey);
map.put(PRIVATE_KEY, privateKey);
return map;
}
/**
*
* 生成默认密钥
*
*
* @return 密钥对象
* @throws Exception
*
*/
public static Map<String, Key> initKey() throws Exception {
return initKey(DEFAULT_SEED);
}
/**
*
* 取得私钥
*
* @param keyMap
*
* @return
* @throws Exception
*
*/
public static String getPrivateKey(Map<String, Key> keyMap) throws Exception {
Key key = (Key) keyMap.get(PRIVATE_KEY);
return encryptBASE64(key.getEncoded()); // base64加密私钥
}
/**
*
* 取得公钥
*
* @param keyMap
*
* @return
* @throws Exception
*
*/
public static String getPublicKey(Map<String, Key> keyMap) throws Exception {
Key key = (Key) keyMap.get(PUBLIC_KEY);
return encryptBASE64(key.getEncoded()); // base64加密公钥
}
/**
*
* 用私钥对信息进行数字签名
*
* @param data 加密数据
*
* @param privateKey 私钥-base64加密的
*
* @return
*
* @throws Exception
*
*/
public static String signByPrivateKey(byte[] data, String privateKey) throws Exception {
logger.info("用私钥对信息进行数字签名");
byte[] keyBytes = decryptBASE64(privateKey);
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory factory = KeyFactory.getInstance(KEY_ALGORITHM);
PrivateKey priKey = factory.generatePrivate(keySpec);// 生成私钥
// 用私钥对信息进行数字签名
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(priKey);
signature.update(data);
return encryptBASE64(signature.sign());
}
/**
*
* BASE64Encoder 加密
*
* @param data 要加密的数据
*
* @return 加密后的字符串
*
*/
private static String encryptBASE64(byte[] data) {
// BASE64Encoder encoder = new BASE64Encoder();
// String encode = encoder.encode(data);
// return encode;
return new String(Base64.encodeBase64(data));
}
private static byte[] decryptBASE64(String data) {
// BASE64Decoder 每76个字符换行
// BASE64Decoder decoder = new BASE64Decoder();
// byte[] buffer = decoder.decodeBuffer(data);
// return buffer;
// codec 的 Base64 不换行
return Base64.decodeBase64(data);
}
public static boolean verifyByPublicKey(byte[] data, String publicKey, String sign) throws Exception {
byte[] keyBytes = decryptBASE64(publicKey);
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PublicKey pubKey = keyFactory.generatePublic(keySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(pubKey);
signature.update(data);
return signature.verify(decryptBASE64(sign)); // 验证签名
}
/**
* RSA公钥加密
*
* @param str 加密字符串
* @param publicKey 公钥
* @return 密文
* @throws NoSuchAlgorithmException
* @throws InvalidKeySpecException
* @throws NoSuchPaddingException
* @throws InvalidKeyException
* @throws UnsupportedEncodingException
* @throws BadPaddingException
* @throws IllegalBlockSizeException
* @throws Exception 加密过程中的异常信息
*/
public static String encryptByPublicKey(String str, String publicKey)
throws InvalidKeySpecException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
// base64编码的公钥
byte[] keyBytes = decryptBASE64(publicKey);
RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance(KEY_ALGORITHM)
.generatePublic(new X509EncodedKeySpec(keyBytes));
// RSA加密
Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, pubKey);
byte[] data = str.getBytes("UTF-8");
// 加密时超过117字节就报错。为此采用分段加密的办法来加密
byte[] enBytes = null;
for (int i = 0; i < data.length; i += MAX_ENCRYPT_BLOCK) {
// 注意要使用2的倍数，否则会出现加密后的内容再解密时为乱码
byte[] doFinal = cipher.doFinal(ArrayUtils.subarray(data, i, i + MAX_ENCRYPT_BLOCK));
enBytes = ArrayUtils.addAll(enBytes, doFinal);
}
String outStr = encryptBASE64(enBytes);
return outStr;
}
/**
* RSA私钥加密
*
* @param str 加密字符串
* @param privateKey 公钥
* @return 密文
* @throws NoSuchAlgorithmException
* @throws InvalidKeySpecException
* @throws NoSuchPaddingException
* @throws InvalidKeyException
* @throws UnsupportedEncodingException
* @throws BadPaddingException
* @throws IllegalBlockSizeException
* @throws Exception 加密过程中的异常信息
*/
public static String encryptByPrivateKey(String str, String privateKey)
throws InvalidKeySpecException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
// base64编码的公钥
byte[] keyBytes = decryptBASE64(privateKey);
RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance(KEY_ALGORITHM)
.generatePrivate(new PKCS8EncodedKeySpec(keyBytes));
// RSA加密
Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, priKey);
byte[] data = str.getBytes("UTF-8");
// 加密时超过117字节就报错。为此采用分段加密的办法来加密
byte[] enBytes = null;
for (int i = 0; i < data.length; i += MAX_ENCRYPT_BLOCK) {
// 注意要使用2的倍数，否则会出现加密后的内容再解密时为乱码
byte[] doFinal = cipher.doFinal(ArrayUtils.subarray(data, i, i + MAX_ENCRYPT_BLOCK));
enBytes = ArrayUtils.addAll(enBytes, doFinal);
}
String outStr = encryptBASE64(enBytes);
return outStr;
}
/**
* 读取公钥
*
* @param publicKeyPath
* @return
*/
public static PublicKey readPublic(String publicKeyPath) {
if (publicKeyPath != null) {
try (FileInputStream bais = new FileInputStream(publicKeyPath)) {
CertificateFactory certificatefactory = CertificateFactory.getInstance("X.509");
X509Certificate cert = (X509Certificate) certificatefactory.generateCertificate(bais);
return cert.getPublicKey();
} catch (CertificateException e) {
logger.error(e.getMessage(), e);
} catch (FileNotFoundException e) {
logger.error(e.getMessage(), e);
} catch (IOException e) {
logger.error(e.getMessage(), e);
}
}
return null;
}
/**
* 读取私钥
*
* @param path
* @return
*/
public static PrivateKey readPrivate(String privateKeyPath, String privateKeyPwd) {
if (privateKeyPath == null || privateKeyPwd == null) {
return null;
}
try (InputStream stream = new FileInputStream(new File(privateKeyPath));) {
// 获取JKS 服务器私有证书的私钥，取得标准的JKS的 KeyStore实例
KeyStore store = KeyStore.getInstance("JKS");// JKS，二进制格式，同时包含证书和私钥，一般有密码保护；PKCS12，二进制格式，同时包含证书和私钥，一般有密码保护。
// jks文件密码，根据实际情况修改
store.load(stream, privateKeyPwd.toCharArray());
// 获取jks证书别名
Enumeration<String> en = store.aliases();
String pName = null;
while (en.hasMoreElements()) {
String n = (String) en.nextElement();
if (store.isKeyEntry(n)) {
pName = n;
}
}
// 获取证书的私钥
PrivateKey key = (PrivateKey) store.getKey(pName, privateKeyPwd.toCharArray());
return key;
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
return null;
}
/**
* RSA私钥解密
*
* @param encryStr 加密字符串
* @param privateKey 私钥
* @return 铭文
* @throws NoSuchAlgorithmException
* @throws InvalidKeySpecException
* @throws NoSuchPaddingException
* @throws BadPaddingException
* @throws IllegalBlockSizeException
* @throws InvalidKeyException
* @throws Exception 解密过程中的异常信息
*/
public static String decryptByPrivateKey(String encryStr, String privateKey)
throws InvalidKeySpecException, NoSuchAlgorithmException, NoSuchPaddingException, IllegalBlockSizeException,
BadPaddingException, InvalidKeyException {
// base64编码的私钥
byte[] decoded = decryptBASE64(privateKey);
RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance(KEY_ALGORITHM)
.generatePrivate(new PKCS8EncodedKeySpec(decoded));
// RSA解密
Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, priKey);
// 64位解码加密后的字符串
byte[] data = decryptBASE64(encryStr);
// 解密时超过128字节报错。为此采用分段解密的办法来解密
StringBuilder sb = new StringBuilder();
for (int i = 0; i < data.length; i += MAX_DECRYPT_BLOCK) {
byte[] doFinal = cipher.doFinal(ArrayUtils.subarray(data, i, i + MAX_DECRYPT_BLOCK));
sb.append(new String(doFinal));
}
return sb.toString();
}
/**
* RSA公钥解密
*
* @param encryStr 加密字符串
* @param privateKey 私钥
* @return 铭文
* @throws NoSuchAlgorithmException
* @throws InvalidKeySpecException
* @throws NoSuchPaddingException
* @throws BadPaddingException
* @throws IllegalBlockSizeException
* @throws InvalidKeyException
* @throws Exception 解密过程中的异常信息
*/
public static String decryptByPublicKey(String encryStr, String publicKey)
throws InvalidKeySpecException, NoSuchAlgorithmException, NoSuchPaddingException, IllegalBlockSizeException,
BadPaddingException, InvalidKeyException {
// base64编码的私钥
byte[] decoded = decryptBASE64(publicKey);
RSAPublicKey priKey = (RSAPublicKey) KeyFactory.getInstance(KEY_ALGORITHM)
.generatePublic(new X509EncodedKeySpec(decoded));
// RSA解密
Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, priKey);
// 64位解码加密后的字符串
byte[] data = decryptBASE64(encryStr);
// 解密时超过128字节报错。为此采用分段解密的办法来解密
StringBuilder sb = new StringBuilder();
for (int i = 0; i < data.length; i += MAX_DECRYPT_BLOCK) {
byte[] doFinal = cipher.doFinal(ArrayUtils.subarray(data, i, i + MAX_DECRYPT_BLOCK));
sb.append(new String(doFinal));
}
return sb.toString();
}
/**
* main方法测试 第一种用法：公钥加密，私钥解密。---用于加解密 第二种用法：私钥签名，公钥验签。---用于签名
*
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
String ss = "hello";
byte[] data = ss.getBytes();
Map<String, Key> keyMap = initKey();// 构建密钥
PublicKey publicKey = (PublicKey) keyMap.get(PUBLIC_KEY);
PrivateKey privateKey = (PrivateKey) keyMap.get(PRIVATE_KEY);
logger.info("私钥format：{}", privateKey.getFormat());
logger.info("公钥format：{}", publicKey.getFormat());
logger.info("私钥string：{}", getPrivateKey(keyMap));
logger.info("公钥string：{}", getPublicKey(keyMap));
// 产生签名
String sign = signByPrivateKey(data, getPrivateKey(keyMap));
logger.info("签名sign={}", sign);
// 验证签名
boolean verify1 = verifyByPublicKey(ss.getBytes(), getPublicKey(keyMap), sign);
logger.info("经验证数据和签名匹配：{} ", verify1);
boolean verify = verifyByPublicKey(data, getPublicKey(keyMap), sign);
logger.error("经验证数据和签名匹配：{} ", verify);
// logger.info("数字签名为"+sign);
String s = "测试，e8986ae53e76e7514ebc7e8a42e81e6cea5b6280fb5d3259d5f0a46f9f6e090c";
String encryStr = encryptByPublicKey(s, getPublicKey(keyMap));
logger.info("字符串 {} 的公钥加密结果为：{}", s, encryStr);
String decryStr = decryptByPrivateKey(encryStr, getPrivateKey(keyMap));
logger.info("私钥解密结果为：{}", decryStr);
logger.info("========================================================================================");
String s2 = "测试222，e8986ae53e76e7514ebc7e8a42e81e6cea5b6280fb5d3259d5f0a46f9f6e090c";
String encryStr2 = encryptByPrivateKey(s, getPrivateKey(keyMap));
logger.info("字符串 {} 的私钥加密结果为：{}", s2, encryStr2);
String decryStr2 = decryptByPublicKey(encryStr2, getPublicKey(keyMap));
logger.info("公钥解密结果为：{}", decryStr2);
}
}当我在使用springcloud的oauth2时，经常会用到jwt作为用户身份的确认和鉴权。而我们知道jwt是由三部分组成，其中第三部分就是数字签名了，而springcloud的oauth2中的默认jwt签名算法为SHA256withRSA。
下面通过调用OauthServer的{/oauth/token_key}接口来看一下返回情况：
HMAC与SHA256withRSA
hmac做签名时需要指定一个secret和指定hamc算法，常见的hmac算法有hamcsha1、hamcsha256等，通常用hmac生成信息摘要后会再用RSA算法对其进行加密
SHA256withRSA做签名则一步到位，需要先生成RSA密钥对，其中私钥用于签名，公钥用于验签。
为了方便理解：
hmac数字签名 = rsa_encrypt(hmac(信息) + RSA私钥)
SHA256withRSA数字签名 = SHA256withRSA_encrypt(信息 + RSA私钥)
RSA密钥之PKCS#1、PKCS#8
pkcs时密钥的语法标准，细心的同学应该会经常遇到PKCS#1,PKCS#8,PKCS#12等标准，具体所代表的含义这里不做赘述了。通常我们生成密钥对时，会对私钥进行加密，加密后的格式为PKCS#1或PKCS#8格式，而一般不会对公钥进行加密。对于开发者而言，JAVA中通常使用的是PKCS8格式的私钥，php、.net使用的是PKCS1格式的私钥。简单例子： 用openssl生成PKCS#1格式的私钥：openssl genrsa -des3 -out test.key 1024
通过文件首尾部能判断:
JAVA示例
1.签名示例
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.openssl.PEMWriter;
import org.bouncycastle.util.encoders.Base64;
import java.io.IOException;
import java.io.StringWriter;
import java.security.InvalidKeyException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.Security;
import java.security.Signature;
import java.security.SignatureException;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.util.HashMap;
import java.util.Map;
public class SignTest {
/**
* 生成没有加密的密钥对
* @param algorithm
* @param keysize
* @return
* @throws Exception
*/
public static Map<String, Object> createKey(String algorithm,int keysize) throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(algorithm);
keyPairGen.initialize(keysize);
KeyPair keyPair = keyPairGen.generateKeyPair();
//通过对象 KeyPair 获取RSA公私钥对象RSAPublicKey RSAPrivateKey
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
//公私钥对象存入map中
Map<String, Object> keyMap = new HashMap<String, Object>(2);
keyMap.put("publicKey", publicKey);
keyMap.put("privateKey", privateKey);
return keyMap;
}
/**
* 生成加过密的密钥对 pkcs#1格式私钥 pkcs#8格式公钥
*
* @param algorithm
* @param keysize
* @param privateKeyPwd
* @return
* @throws Exception
*/
public static Map<String, Object> createEncryKeyStr(String algorithm, int keysize, String privateKeyPwd) throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(algorithm);
keyPairGen.initialize(keysize);
KeyPair keyPair = keyPairGen.generateKeyPair();
//通过对象 KeyPair 获取RSA公私钥对象RSAPublicKey RSAPrivateKey
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
String pubKeyStr = new String(Base64.encode(publicKey.getEncoded())); //pkcs8格式
String priKeyStr = new String(Base64.encode(privateKey.getEncoded())); //pkcs8格式
System.out.println(priKeyStr);//从输出结果可以知道是PKCS#8格式的
//私钥加密
String privateKeyStr = privateKeyPwdToPKCS1(privateKey, privateKeyPwd);//使用BC加密私钥格式会被转为PKSC#1格式
System.out.println(privateKeyStr);
System.out.println(privateKeyNoPwdToPKCS1(privateKey));
//公私钥对象存入map中
Map<String, Object> keyMap = new HashMap<String, Object>(2);
keyMap.put("publicKeyStr", pubKeyStr);
keyMap.put("privateKeyStr", privateKeyStr);
return keyMap;
}
/**
* 将私钥转为PKCS#1格式私钥（加密）
*
* @param privateKey
* @param filePasswd
* @return
*/
private static String privateKeyPwdToPKCS1(PrivateKey privateKey, String filePasswd) {
Security.addProvider(new BouncyCastleProvider());
StringWriter sw = new StringWriter();
PEMWriter writer = new PEMWriter(sw);
try {
writer.writeObject(privateKey, "DESEDE", filePasswd.toCharArray(),
new SecureRandom());
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (writer != null) {
writer.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return sw.toString();
}
/**
* 将私钥转为PKCS#1格式私钥（没有加密）
* @param privateKey
* @return
*/
private static String privateKeyNoPwdToPKCS1(PrivateKey privateKey){
Security.addProvider(new BouncyCastleProvider());
StringWriter sw = new StringWriter();
PEMWriter writer = new PEMWriter(sw);
try {
writer.writeObject(privateKey);
} catch (IOException e) {
e.printStackTrace();
}finally{
try {
if(writer !=null){
writer.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return sw.toString();
}
public static final String SIGNATURE_ALGORITHM = "SHA256withRSA";
public static final String ENCODE_ALGORITHM = "SHA-256";
public static final String PLAIN_TEXT = "test string";
/**
* 签名
* @param privateKey 私钥
* @param plainText 明文
* @return
*/
public static byte[] sign(PrivateKey privateKey, String plainText) {
MessageDigest messageDigest;
byte[] signed = null;
try {
messageDigest = MessageDigest.getInstance(ENCODE_ALGORITHM);
messageDigest.update(plainText.getBytes());
byte[] outputDigest_sign = messageDigest.digest();
System.out.println("SHA-256编码后-----》"
+ org.apache.commons.codec.binary.Base64.encodeBase64String(outputDigest_sign));
Signature Sign = Signature.getInstance(SIGNATURE_ALGORITHM);
Sign.initSign(privateKey);
Sign.update(outputDigest_sign);
signed = Sign.sign();
System.out.println("SHA256withRSA签名后-----》"
+ org.apache.commons.codec.binary.Base64.encodeBase64String(signed));
} catch (NoSuchAlgorithmException | InvalidKeyException | SignatureException e) {
e.printStackTrace();
}
return signed;
}
/**
* 验签
* @param publicKey 公钥
* @param plain_text 明文
* @param signed 签名
*/
public static boolean verifySign(PublicKey publicKey, String plain_text, byte[] signed) {
MessageDigest messageDigest;
boolean SignedSuccess=false;
try {
messageDigest = MessageDigest.getInstance(ENCODE_ALGORITHM);
messageDigest.update(plain_text.getBytes());
byte[] outputDigest_verify = messageDigest.digest();
//System.out.println("SHA-256加密后-----》" +bytesToHexString(outputDigest_verify));
Signature verifySign = Signature.getInstance(SIGNATURE_ALGORITHM);
verifySign.initVerify(publicKey);
verifySign.update(outputDigest_verify);
SignedSuccess = verifySign.verify(signed);
System.out.println("验证成功？---" + SignedSuccess);
} catch (NoSuchAlgorithmException | InvalidKeyException | SignatureException e) {
e.printStackTrace();
}
return SignedSuccess;
}
/**
* bytes[]换成16进制字符串
*
* @param src
* @return
*/
public static String bytesToHexString(byte[] src) {
StringBuilder stringBuilder = new StringBuilder("");
if (src == null || src.length <= 0) {
return null;
}
for (int i = 0; i < src.length; i++) {
int v = src[i] & 0xFF;
String hv = Integer.toHexString(v);
if (hv.length() < 2) {
stringBuilder.append(0);
}
stringBuilder.append(hv);
}
return stringBuilder.toString();
}
public static void main(String[] args) throws Exception {
Map<String, Object> keyMap = createKey("RSA", 2048);
PublicKey publicKey = (PublicKey) keyMap.get("publicKey");
PrivateKey privateKey = (PrivateKey) keyMap.get("privateKey");
byte[] signBytes = sign(privateKey, PLAIN_TEXT);
System.out.println(verifySign(publicKey, PLAIN_TEXT, signBytes));
}
}2.签发JWT示例
import com.cyq.CheckResult;
import io.jsonwebtoken.Claims;
import io.jsonwebtoken.ExpiredJwtException;
import io.jsonwebtoken.JwtBuilder;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import io.jsonwebtoken.SignatureException;
import org.bouncycastle.util.encoders.Base64;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.time.OffsetDateTime;
import java.time.ZoneId;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
/**
* maven依赖
*
* <dependency>
* <groupId>io.jsonwebtoken</groupId>
* <artifactId>jjwt</artifactId>
* <version>0.9.0</version>
* </dependency>
*/
/**
* @author cyq
*/
public class JwtUtils {
public static void main(String[] args) throws Exception {
// 签发jwt(签名算法hmac256)
System.out.println("签发jwt(签名算法hmac256):");
String jwt = createJWT("123", "jwt_hmac256", 60);
System.out.println(jwt);
// 解析
SecretKey secretKey = generalKey();
Claims claims = parseJWT(jwt, secretKey);
System.out.println(claims);
// 签发jwt(签名算法SHA256withRSA)
System.out.println("\n签发jwt(签名算法SHA256withRSA):");
Map<String, Object> keyMaps = createRSAKey(2048);
String jwt2 = createJWT2("456", "jwt_SHA256withRSA", 60, (RSAPrivateKey) keyMaps.get("privateKey"));
System.out.println(jwt2);
// 解析
Claims claims2 = parseJWT(jwt2, (RSAPublicKey) keyMaps.get("publicKey"));
System.out.println(claims2);
}
/**
* 签发JWT
* @param id
* @param subject 可以是JSON数据 尽可能少
* @param ttlMillis
* @return String
*
*/
public static String createJWT(String id, String subject, long ttlMillis) {
SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.HS256;// HmacSha256
OffsetDateTime now = OffsetDateTime.now(ZoneId.of("Asia/Shanghai"));
//Date now = new Date(nowMillis);
SecretKey secretKey = generalKey();
JwtBuilder builder = Jwts.builder()
.setId(id)
.setSubject(subject) // 主题
.setIssuer("user") // 签发者
.setIssuedAt(Date.from(now.toInstant())) // 签发时间
.signWith(signatureAlgorithm, secretKey); // 签名算法以及密匙
if (ttlMillis >= 0) {
OffsetDateTime expTime = now.plusSeconds(ttlMillis);
builder.setExpiration(Date.from(expTime.toInstant())); // 过期时间
}
return builder.compact();
}
/**
* 签发JWT
* @param id
* @param subject 可以是JSON数据 尽可能少
* @param ttlMillis
* @return String
*
*/
public static String createJWT2(String id, String subject, long ttlMillis, RSAPrivateKey privateKey) {
SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.RS256;// SHA256withRSA
OffsetDateTime now = OffsetDateTime.now(ZoneId.of("Asia/Shanghai"));
JwtBuilder builder = Jwts.builder()
.setId(id)
.setSubject(subject) // 主题
.setIssuer("user") // 签发者
.setIssuedAt(Date.from(now.toInstant())) // 签发时间
.signWith(signatureAlgorithm, privateKey); // 签名算法以及密匙
if (ttlMillis >= 0) {
OffsetDateTime expTime = now.plusSeconds(ttlMillis);
builder.setExpiration(Date.from(expTime.toInstant())); // 过期时间
}
return builder.compact();
}
/**
* 生成没有加密的密钥对
* @param keysize
* @return
* @throws Exception
*/
public static Map<String, Object> createRSAKey(int keysize) throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("rsa");
keyPairGen.initialize(keysize);
KeyPair keyPair = keyPairGen.generateKeyPair();
//通过对象 KeyPair 获取RSA公私钥对象RSAPublicKey RSAPrivateKey
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
//公私钥对象存入map中
Map<String, Object> keyMap = new HashMap<String, Object>(2);
keyMap.put("publicKey", publicKey);
keyMap.put("privateKey", privateKey);
return keyMap;
}
public static SecretKey generalKey() {
byte[] encodedKey = Base64.decode("testjwt");
SecretKey key = new SecretKeySpec(encodedKey, 0, encodedKey.length, "AES");
return key;
}
/**
*
* 解析JWT字符串
* @param jwt
* @return
* @throws Exception
*/
public static Claims parseJWT(String jwt, Key key) throws Exception {
return Jwts.parser()
.setSigningKey(key)
.parseClaimsJws(jwt)
.getBody();
}
/**
* 验证JWT
* @param jwtStr
* @return
*/
public static CheckResult validateJWT(String jwtStr, Key key) {
CheckResult checkResult = new CheckResult();
Claims claims = null;
try {
claims = parseJWT(jwtStr, key);
checkResult.setSuccess(true);
checkResult.setClaims(claims);
} catch (ExpiredJwtException e) {
e.printStackTrace();
checkResult.setErrCode("JWT_ERRCODE_EXPIRE");
checkResult.setSuccess(false);
} catch (SignatureException e) {
e.printStackTrace();
checkResult.setErrCode("JWT_ERRCODE_FAIL");
checkResult.setSuccess(false);
} catch (Exception e) {
e.printStackTrace();
checkResult.setErrCode("JWT_ERRCODE_FAIL");
checkResult.setSuccess(false);
}
return checkResult;
}
}标签：SHA256withRSA,java,String,return,算法,static,签名,import,throws 来源： https://blog.csdn.net/weixin_45442296/article/details/123111454