Skip to content

Metadata: require issuer to match the URL it was fetched from #17

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
rohanharikr wants to merge 1 commit into
base: main
Choose a base branch
from
Open

Metadata: require issuer to match the URL it was fetched from #17

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions draft-hardt-aauth-protocol.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2120,6 +2120,10 @@ The `jwks_uri`, `tos_uri`, `policy_uri`, `logo_uri`, and `logo_dark_uri` values

Participants publish metadata at well-known URLs ([@!RFC8615]) to enable discovery.

When fetching a metadata document, implementations MUST verify that the `issuer` value in the document matches the URL the document was retrieved from (the URL minus the `/.well-known/{dwk}` suffix). If the values do not match, the metadata document MUST be rejected.

This check prevents host-poisoned metadata: an attacker hosting a metadata document at one domain that claims an `issuer` of a different domain. Without it, a permissive verifier following the `jwks_uri` in such a document could end up trusting attacker-controlled keys for tokens claiming the impersonated issuer.

### Agent Server Metadata

Published at `/.well-known/aauth-agent.json`:
Expand Down