I have a jwt token that I have retrieved from cognito after my user logs in.
I have a specific api end point in my application and I want only users with a valid jwt to be able to access this end point. I tried looking at various resources on the web but I couldn't understand anything. I am new to the jwt concept.
PS I have a Java application (spring boot ). I would really appreciate if someone would describe in detail the steps that i need to follow to verify my jwt. Please provide the code if possible.
@CrossOrigin
@RequestMapping(value= "/login", method=RequestMethod.POST,consumes="application/json")
@ResponseBody
public String authenticate(@RequestBody SignInDTO signInDetails)
{
//boolean isAuthenticated=false;
CognitoHelper cognitoHelper=new CognitoHelper();
String authResult=cognitoHelper.ValidateUser(signInDetails.getEmailId(), signInDetails.getPassword());
.....
.....
.....
authResult is the jwt that i get from cognito. After this I am completely clueless about what needs to be done.
Spring Security 5.1 introduced support for this, making it much easier to implement. See https://docs.spring.io/spring-security/site/docs/current/reference/html/jc.html#oauth2resourceserver
Basically:
https://cognito-idp.<region>.amazonaws.com/<YOUR_USER_POOL_ID>Use a library like java-jwt (I guess you are using Maven)
<dependency>
<groupId>com.auth0</groupId>
<artifactId>java-jwt</artifactId>
<version>3.3.0</version>
</dependency>
Then:
String token = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXUyJ9.eyJpc3MiOiJhdXRoMCJ9.AbIJTDMFc7yUa5MhvcP03nJPyCPzZtQcGEp-zWfOkEE";
try {
Algorithm algorithm = Algorithm.HMAC256("secret");
// or
Algorithm algorithm = Algorithm.RSA256(publicKey, privateKey);
JWTVerifier verifier = JWT.require(algorithm)
.withIssuer("auth0")
.build(); //Reusable verifier instance
DecodedJWT jwt = verifier.verify(token);
} catch (UnsupportedEncodingException exception){
//UTF-8 encoding not supported
} catch (JWTVerificationException exception){
//Invalid signature/claims
}
You can manually decode a jwt-token here: https://jwt.io
More info about java-jwt here: https://github.com/auth0/java-jwt
Step 1: Confirm the Structure of the JWT
Step 2: Validate the JWT Signature
Step 3: Verify the Claims
Goto https://docs.aws.amazon.com/cognito/latest/developerguide/amazon-cognito-user-pools-using-tokens-verifying-a-jwt.html for more information.