OAuth 2.0 unable to get access token

1

Hello everyone, I am new to the community and I faced some error and hope that I can get some help here!

What I want to do is to get authenticated via OAuth and retrieve the access token so that I can call the APIs

But I keep facing the error of invalid client when I try to do a POST Request to https://fhir.epic.com/interconnect-fhir-oauth/oauth2/token

My steps:

  1. Created an application through build apps tab on fhir epic and its currently not on production mode yet.
  2. Created a rsa private/public key pair using openssl
  3. Use jwt.io website to create a JWT
    image
    image680×522 21.3 KB

Note: I tried the request at around 13:15:40pm GMT+8. JTI’s guid value is randomly generated. ISS/Sub is non-production clientID
4. Copied the encoded value into the postman’s parameter of “client_assertion”

Result:
400 Bad Request
{“error”: “invalid_client”, “error_description”: null}

I am not sure what have I missed/done wrong, I have been stuck at this for 3 days… Created new pair of public/private key, created multiple apps (have 3 now) to make sure that the public key that I link to is the right one. Please do provide assistance, thank you!

2

Please help me thank you

3

Have you tried reaching out to Epic?

4

Hello, thank you so much for the reply. I am actually not sure how do I reach out to Epic, is their email open@epic.com or? I am sorry if I asked such a stupid question but I hope you can help me.

5

https://open.epic.com/Home/Contact

6

Was this issue resolved? I am also facing the same issue.

7

Lloyd,

I’m having the same issue as the original poster. I used your contact referral to ask for help from Epic. So thanks for that. From your experience, how long would you guess it would be before I heard from epic.com/home/contact? The error message I’m getting says Protocol error. I forced TLS 1.2 and HTTP/1.1 but those were already the defaults. Maybe protocol doesn’t mean what I think it means.

Jim Tolonen

8

If you don’t hear a response in a couple of business days, raise the question on http://chat.fhir.org noting that you’ve reached out on Epic’s preferred channel and haven’t had a response and I can try to grab the attention of some folks who might be able to help.

9

Hi ,
You have to set only exp time exact 05 min from your time now. It works.you don’t set iat and nbf.

10

Hi Gowtham,

How do I make sure the exp time is exactly 5 minutes from the time you submit the request?
You can’t include the JWT token generation time. By the time I generate the token on jwt.io and
copied and pasted it into Postman, seconds would have passed. The doc says as long as the
exp is < 5 minutes from now, it’s OK.