[Openid-specs-mobile-profile] Issue #145: 7.3 expires_in and interval should be required to be integers (openid/mobile)

[Joseph Heenan]

New issue 145: 7.3 expires_in and interval should be required to be integers
https://bitbucket.org/openid/mobile/issues/145/73-expires_in-and-interval-should-be

Joseph Heenan:

expires_in and interval in the authentication response are (I believe) intended to integers, but it's not actually stated anywhere I could find.

We should probably be explicit that it's a positive integer, or alternatively we could use a more RFC6749 type definition:

> A.14.  "expires_in" Syntax
>
>   The "expires_in" element is defined in Sections 4.2.2 and 5.1:
>
>     expires-in = 1*DIGIT