Not able to pass JWKS URI as an environment variable

[vysyarajusantos]

Hi,

I am trying to pass JWKS URI as an environment variable as below but i am getting error. Is there a way to pass these values through env variables(KV Map)?

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<VerifyJWT continueOnError="false" enabled="true" name="VerifyJWT-AccessToken">
<DisplayName>VerifyJWT-AccessToken</DisplayName>
<Algorithm>RS256</Algorithm>
<PublicKey>
<JWKS uri="https://{okta_domain}/oauth2/{okta_client_id}/v1/keys"/>
</PublicKey>
<Audience>{env_jwt_audience}</Audience>
</VerifyJWT>

[dchiesa1 · Accepted solution]

Nope, you cannot use that syntax. The uri attribute is not interpreted as a message template, so string inside curly braces in that attribute will not be treated as references to variables. It's just a URI with curly braces!

There is a way to refer to a single variable, and that is with the yet-to-be-documented but currently supported (in Apigee X and hybrid) uriRef attribute. It looks like this:

<VerifyJWT name='VJWT-1'>
  <Algorithm>RS256</Algorithm>
  <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
  <PublicKey>
    <JWKS uriRef='variable-containing-jwks-endpoint-uri'/> <!-- new -->
  </PublicKey>
  <Source>request.header.token</Source>
</VerifyJWT>

So you will need to set a single variable to contain your URI. Probably with a preceding AssignMessage policy, configured like this:

<AssignMessage name='AV-JWKS-URI'>
  <AssignVariable>
    <Name>variable-containing-jwks-endpoint-uri</Name>
    <Template>https://{okta_domain}/oauth2/{okta_client_id}/v1/keys</Template>
  </AssignVariable>
</AssignMessage>

The request to document this new uriRef attribute is tracked under the internal reference b/230341213 .

One further note - the Audience element also does not get interpreted as a Message Template. You can specify a fixed value, or a reference to a variable. Per the documentation for the VerifyJWT policy:

It sort of frustrating that the message templates are not used everywhere but , .... that's the way it is.