Unable to get expiration date

[tobiasbp]

I'm parsing a token as seen below. I'm unable to get the correct value of exp in the token header. When I inspect my token with other tools (like https://jwt.io/#debugger-io) , I see this header for the token:

{
  "ver": 2,
  "kid": "*****",
  "exp": 1716447235,
  "alg": "RS256",
  "jku": "**********"
}

Here is my demo code:

t, _ := jwt.ParseHeader(
    r.Header,
    "x-jws-signature",
    jwt.WithVerify(false),
)

fmt.Printf("%s\n", t.Expiration())

I get the following output:

0001-01-01 00:00:00 +0000 UTC

[lestrrat]

Without the actual token, it's hard to say. But here's what I can cob together as a minimal test case, and I can't reproduce it.

func TestGH1136(t *testing.T) {
	const src = `{
		"ver": 2,
		"kid": "*****",
		"exp": 1716447235,
		"alg": "RS256",
		"jku": "**********"
	}`

	token := jwt.New()
	require.NoError(t, json.Unmarshal([]byte(src), token), `json.Unmarshal should succeed`)

	require.NotEqual(t, token.Expiration(), time.Time{}, `token.Expiration should not be zero`)

	t.Logf("%#v", token.Expiration())
}

The above test produces this result

$ go test -run=GH1136 -v
=== RUN   TestGH1136
    jwt_test.go:1870: time.Date(2024, time.May, 23, 6, 53, 55, 0, time.UTC)
--- PASS: TestGH1136 (0.00s)
PASS
ok      github.com/lestrrat-go/jwx/v2/jwt       0.003s

I could be off, but with the test results I'm inclined to think that the token that is producing a zero time.Time is NOT the same as the token you pasted on jwt.io. I'd need more info if you're sure it's the library that is at fault.

[tobiasbp]

I have realized, that the problem is that my token, has the exp in the header, not in the payload (like everyone else in the world).

Sorry for the noise, and thank you for this package.

[lestrrat]

no prob. thanks for getting back