# JWT Token signature error

**URL:** <https://devforum.zoom.us/t/jwt-token-signature-error/66433>\
**Category:** Authentication\
**Created:** [March 25, 2022, 11:59am UTC](https://devforum.zoom.us/t/jwt-token-signature-error/66433 "2022-03-25T11:59:51Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dctesting](https://avatars.discourse-cdn.com/v4/letter/d/b5e925/32.png) [@dctesting](https://devforum.zoom.us/u/dctesting)\
**Post date:** [March 25, 2022, 11:59am UTC](https://devforum.zoom.us/t/jwt-token-signature-error/66433/1 "2022-03-25T11:59:51Z")

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I have faced JWT token generation error while implementing HMACSHA256.  
But this method is nor reconized by Springboot JWT library. com.auth0:java-jwt:3.19.0  
Below is the code snippent:  
Long expTime = System.currentTimeMillis() + TimeUnit.MINUTES.toMillis(90);  
String jwtHeader = “{“alg”: “HS256”,“typ”: “JWT”}”;  
String jwtPayload = “{\n”  
+ " “iss”: “XXXXXXXXXX”,\n"  
+ " “exp”: “+expTime+”\n"  
+ “}”;  
System.out.println(“expTime”+ expTime);  
String API\_SECRET = “XXXXXXXXl”;  
String token = “”;  
try {  
Algorithm algorithm = Algorithm.HMACSHA256(  
base64UrlEncode(jwtHeader) + “.” +  
base64UrlEncode(jwtPayload));  
token = JWT.create()  
.withIssuer(“iss”)  
.sign(algorithm);  
} catch (JWTCreationException exception){  
//Invalid Signing configuration / Couldn’t convert Claims.  
}

Kindly help regarding this  
Thanks

---

<div class="post-metadata">

**Author:** ![donte.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/donte.zoom/32/24412_2.png) [@donte.zoom](https://devforum.zoom.us/u/donte.zoom)\
**Post date:** [April 28, 2022, 7:25pm UTC](https://devforum.zoom.us/t/jwt-token-signature-error/66433/2 "2022-04-28T19:25:47Z")

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@dctesting,

Welcome to the Developer Forum and thank you for posting! We have signature code samples and a Sample App you can reference for your implementation. I’ve linked those resources below for your reference:

# Generate Signature

[https://marketplace.zoom.us/docs/sdk/native-sdks/web/signature](https://marketplace.zoom.us/docs/sdk/native-sdks/web/signature)

# [Signature Sample App](https://github.com/zoom/meetingsdk-sample-signature-node.js).

> **[GitHub - zoom/meetingsdk-auth-endpoint-sample: Generate a Meeting SDK JWT to join Zoom meetings...](https://github.com/zoom/meetingsdk-auth-endpoint-sample)**
>
> Generate a Meeting SDK JWT to join Zoom meetings and webinars with the Meeting SDK.

Let us know if you have any questions.

Regards,  
Donte