OAuth 2.0 authentication and redirect uri wildcards

Questions OAuth/OIDC
7

Just closing the loop on this one if anyone stumbles across this, but Okta has implemented wildcards in subdomains for redirect_uris. More info in our docs here:

  • If wildcard_redirect is DISABLED, all redirect URIs must be absolute URIs and must not include a fragment component. If wildcard_redirect is SUBDOMAIN, then any configured redirect URIs may contain a single * character in the lowest-level domain (for example, https://redirect-*-domain.example.com/oidc/redirect) to act as a wildcard. The wildcard subdomain must have at least one subdomain between it and the top level domain.
  • The wildcard can match any valid hostname characters, but can’t span more than one domain. For example, if https://redirect-*-domain.example.com/oidc/redirect is configured as a redirect URI, then https://redirect-1-domain.example.com/oidc/redirect and https://redirect-sub-domain.example.com/oidc/redirect match, but https://redirect-1.sub-domain.example.com/oidc/redirect doesn’t match.
  • Only the https URI scheme can use wildcard redirect URIs.

Caution: The use of wildcard subdomains is discouraged as an insecure practice, since it may allow malicious actors to have tokens or authorization codes sent to unexpected or attacker-controlled pages. Exercise great caution if you decide to include a wildcard redirect URI in your configuration.

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