java-jwt通过公钥字符串验证解析token

旧城等待， 2023-09-23 22:57 35阅读 0赞

### 引言 ###

本文主要示例如何通过已知的`公钥（字符串）`，来使用`java-jwt`校验token所。

由于java-jwt中校验时所需要的公钥是`RSAPublicKey`对象而我们目前的公钥是`字符串`，所以我们需要进行转化，本篇文章主要就是记录如何进行这个转化

如果需要了解公钥、私钥的概念，请百度其它文章。

### 代码 ###

<dependency>
        <groupId>com.auth0</groupId>
        <artifactId>java-jwt</artifactId>
        <version>4.2.1</version>
    </dependency>

/**
     * 根据公钥字符串生成PublicKey对象
     * @return
     * @throws NoSuchAlgorithmException
     * @throws InvalidKeySpecException
     */
    private static PublicKey getPublicKey()
            throws NoSuchAlgorithmException, InvalidKeySpecException {
        
    
        String pem = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuWCkZn1ksPM+DBLzgaffe2je6/Kr168fDI/CAM23Ardh4+w5yprtCmNfibCLcNZ66OzPC164p4ufboc9fxXqd5mv0ZtaHGG2pATH5e7z+Gla3Bd3QX8WqJi5LkAtsdP23IQqhz8UHA+Vmd6pTzobcQBhF1K7K/zcK9QDTFon4tCxL12wSOl40CDlWnaHortvljmJ5T3zD1iPjHjpVejI5YQReqxXEuqFVTqu2nhdTWAmfX8KrlVbPGPCevruKFmNvnl09N0Kk2CZGRlLq5aE7UZxH3GOkNWKkVWMO7tUgoJK9r8v/EIrIcuO5SX7RuyyhyY0/fsx3f+CTrUATkfgVwIDAQAB";
        X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(Base64.decodeBase64(pem));
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        PublicKey publicKey = keyFactory.generatePublic(pubKeySpec);
        System.out.println(publicKey);
        return publicKey;
    }
    
    /**
     * 校验token
     * @param token
     * @return
     * @throws Exception
     */
    public static DecodedJWT verifierToken(String token)throws Exception{
        
    
        
        //其实按照规定只需要传递 publicKey 来校验即可，这可能是auth0 的缺点
        Algorithm algorithm = Algorithm.RSA256((RSAPublicKey) getPublicKey(),null);
        JWTVerifier verifier = JWT.require(algorithm)
                //.withIssuer(ISSUER)
                .build(); //Reusable verifier instance 可复用的验证实例
        DecodedJWT jwt = verifier.verify(token);
    
    
        return jwt;
    
    }

### 测试 ###

@SpringBootTest(classes = KeycloakdemoApplication.class)
    @RunWith(SpringRunner.class)
    public class DemoTest {
        
    
        @Test
        public void testGetInstance() throws Exception {
        
            DecodedJWT verify = JWTUtils.verifierToken("eyJhbGciOiJSUzI1NiIsInR5cCIgOiAiSldUIiwia2lkIiA6ICIxdGtoMFBXanE1SmpOalVjc1hNYnJ1TldQVngtM2tQekJpekJGTDZfUDFJIn0.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.sGblDdBIkwnDDUcGd7-2QlCeA17gnmuvXosqpZ0T_zGlKtr6Ta-z1QSgwdc8K5ivekyIQmcYAIh-eHmfVxjCLKZ6fR-AdTeqenXdkNJuMREzwKpnOFx1Wq2LZUb-hqWKJimBKi2iUPlu4ENAVbFOWxcMwIedySpN74RHF3yP4BKr4YfAmr5u9CSX3EYw0LMiMVlt6l_FKNssKnTLlBq0IPDlBdwV9D1l6qpDXu_uIbvUzb_w8rnSoUGMqqqxI-RNF6m5dit29KWinFfkat5-g-lvbiVz8l0wYfMBGb9ESwC0aXJARcEG7PdhtqYLPjsGFVrjqHMq1ci_BVivAt3Htw");
            System.out.println(verify);
            System.out.println(verify.getExpiresAt());
            System.out.println(verify.getClaim("scope"));
            System.out.println(verify.getExpiresAtAsInstant());
            System.out.println(verify.getClaims());
        }
    }

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[image-20230112012631377]: https://img-blog.csdnimg.cn/img_convert/4d52ca1033ddb7ca43c57dd405db8bd9.png