# Signature length error

**URL:** <https://devforum.zoom.us/t/signature-length-error/16134>\
**Category:** Web\
**Created:** [May 5, 2020, 4:31am UTC](https://devforum.zoom.us/t/signature-length-error/16134 "2020-05-05T04:31:26Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![mylevitz](https://avatars.discourse-cdn.com/v4/letter/m/c2a13f/32.png) [@mylevitz](https://devforum.zoom.us/u/mylevitz)\
**Post date:** [May 5, 2020, 4:31am UTC](https://devforum.zoom.us/t/signature-length-error/16134/1 "2020-05-05T04:31:26Z")

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Hi,  
I deployed the sample signature app to heroku and saved my api key and secret as variables there. I fetch from there ( passing in a meetingNumber from my account and role:0). However when trying to use the response I get the following error.

method: “join”, status: false, result: null, errorMessage: “{“signature”:”"} signatrue length error", errorCode: 4003}

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**Author:** ![mylevitz](https://avatars.discourse-cdn.com/v4/letter/m/c2a13f/32.png) [@mylevitz](https://devforum.zoom.us/u/mylevitz)\
**Post date:** [May 5, 2020, 4:33am UTC](https://devforum.zoom.us/t/signature-length-error/16134/2 "2020-05-05T04:33:57Z")

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just to add i tried the php code example (not live), with the same parameters and I was able to use the signature i got

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**Author:** ![tommy](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/tommy/32/72769_2.png) [@tommy](https://devforum.zoom.us/u/tommy)\
**Post date:** [May 6, 2020, 8:59pm UTC](https://devforum.zoom.us/t/signature-length-error/16134/3 "2020-05-06T20:59:12Z")

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Hey @mylevitz,

Did you get it working? Make sure to use the API Key and Secret from a [JWT App.](https://marketplace.zoom.us/docs/guides/build/jwt-app)

Thanks,  
Tommy

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**Author:** ![mylevitz](https://avatars.discourse-cdn.com/v4/letter/m/c2a13f/32.png) [@mylevitz](https://devforum.zoom.us/u/mylevitz)\
**Post date:** [May 6, 2020, 9:14pm UTC](https://devforum.zoom.us/t/signature-length-error/16134/4 "2020-05-06T21:14:41Z")

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unfortunately not. I did use the correct key and secret and I was able to test it in a php code. I was trying to use your sample app, because it seemed simpler to push to heroku. However although i was getting a response it seemed it was inaccurate ( why would it be a length error?)  
In the end I used your sample for php and pushed it myself, and that works for me.

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**Author:** ![tommy](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/tommy/32/72769_2.png) [@tommy](https://devforum.zoom.us/u/tommy)\
**Post date:** [May 12, 2020, 12:31am UTC](https://devforum.zoom.us/t/signature-length-error/16134/5 "2020-05-12T00:31:20Z")

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Hey @mylevitz,

Glad to hear you got it working. That being said, make sure you are [generating your Web SDK signature on the server side.](https://marketplace.zoom.us/docs/sdk/native-sdks/web/essential/signature) We have examples in PHP. If you use the Sample App to generate your Web SDK signature, it exposes your JWT Secret to the client.

> <https://github.com/zoom/sample-app-web/blob/master/CDN/js/index.js#L16>

Thanks,  
Tommy

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**Author:** ![DeveloperBot](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/developerbot/32/12632_2.png) [@DeveloperBot](https://devforum.zoom.us/u/DeveloperBot)\
**Post date:** [August 21, 2020, 9:15pm UTC](https://devforum.zoom.us/t/signature-length-error/16134/6 "2020-08-21T21:15:04Z")

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Closed on August 21, 2020, 9:15pm UTC