lb: trust the host Caddy's X-Forwarded-Proto #145
Merged
admin_emi
merged 1 commit from 2026-08-01 16:25:16 +00:00
fix/lb-forwarded-proto into dev
1 commit
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Emi Griffith
|
3993b7552f |
lb: trust the host Caddy's X-Forwarded-Proto
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Every OAuth redirect URI the backend builds is currently http://, whatever scheme the user actually arrived with. There are two Caddy hops in front of the app: the host Caddy terminates TLS and sets X-Forwarded-Proto: https, then proxies to 127.0.0.1:8137 over plain HTTP; the stack LB is the second hop. Caddy preserves an incoming X-Forwarded-* header only when the immediate peer is a trusted proxy, and trusted_proxies was never set here -- so the LB overwrote the header with the scheme of the connection it had just received, which is http. accounts/oauth.py:_redirect_uri builds the callback from x-forwarded-proto, and that URI must match what is registered in the provider's console. Measured on vps2, same request to each hop: direct to web, XFP=https -> https://thermograph.org/api/v2/... through the LB, XFP=https -> http://thermograph.org/api/v2/... through the PATCHED LB -> https://thermograph.org/api/v2/... through the PATCHED LB, no XFP-> http://thermograph.org/api/v2/... The last line is the point of using trusted_proxies rather than hardcoding `header_up X-Forwarded-Proto https`: the LB still reports the truth when nothing in front of it claims otherwise. private_ranges covers 127.0.0.1/8 and the Docker bridge ranges, which is where the host Caddy reaches this container from. The LB binds loopback only, precisely so it cannot be reached un-fronted, so the only party that can set these headers is the host Caddy -- trusting the local peer widens nothing. Applied to beta's LB too. Beta is where a provider change gets tested before it reaches thermograph.org, so it needs the same behaviour or the test is not a test. |