Remove "--prn" option or make it optional on encode

[erhhung]

Summary

According to the latest JWT spec (https://tools.ietf.org/html/rfc7519#page-9), the "prn" claim is not even mentioned, and according to an earlier JWT draft spec (https://tools.ietf.org/html/draft-ietf-oauth-json-web-token-05#page-9), the "prn" claim is optional.

Steps to reproduce

On encode, I get an error that the "--prn" required argument was not provided:

error: The following required arguments were not provided:
    --prn <principal>

USAGE:
    jwt encode --alg <algorithm> --aud <audience> --exp <expires> --iss <issuer> --payload <payload>... --prn <principal> --secret <secret> --sub <subject>

Expected behavior

The "--prn" option should either be removed entirely or at least be made optional.

[kljensen]

@erhhung I didn't experience that argument as required. Can you post an example usage?

[erhhung]

The version I ran was v3.2.1 as that was the latest published in Homebrew (and still is).
I just manually pulled down v3.3.0 and ran my example again, and I still see the issue:

./jwt --version
jwt 3.3.0

Full example:

$ ./jwt encode \
  --iss https://foo.com \
  --aud https://bar.com \
  --sub john.doe \
  -P "jti=$(uuidgen)" \
  -P "email=john.doe@foo.com" \
  --exp "+1 hr" \
  --secret secret

error: The following required arguments were not provided:
    --prn <principal>

USAGE:
    jwt encode --alg <algorithm> --aud <audience> --exp <expires> --iss <issuer> --prn <principal> --secret <secret> --sub <subject>

Minimal example:

$ ./jwt encode --aud https://bar.com --secret secret

error: The following required arguments were not provided:
    --prn <principal>

USAGE:
    jwt encode --alg <algorithm> --aud <audience> --exp <expires> --prn <principal> --secret <secret>

Full example without --aud option:

$ ./jwt encode \
  --iss https://foo.com \
  --sub john.doe \
  -P "jti=$(uuidgen)" \
  -P "email=john.doe@foo.com" \
  --exp "+1 hr" \
  --secret secret

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[mike-engel]

Thanks @erhhung! I'm not sure which spec I read when I first created this tool, but prn was required if aud was present at the time. According to the current spec that you mentioned, however, it doesn't even seem to be specified. I'll remove it.

[mike-engel]

Removed in 4.0.0