Files
geniusrun/backend/internal/api/session.go
Christophe Vila 502e61e7b4 Fix OIDC login-gate cross-file wiring bugs from whole-branch review
Four bugs slipped through per-task review since each task only saw its
own diff:

- Logout was a plain <a href> GET against a POST-only backend route, so
  it 405'd and never cleared the session cookie or hit Keycloak's
  end-session redirect. Now a <form method="post"> with a submit button
  styled to match the old link (still a real full-page navigation, not
  a fetch, so the Keycloak redirect chain still works).
- Login/logout used origin-relative paths, unreachable from the Vite
  dev server (:5173) against the backend (:8080) with no proxy
  configured. Both now build their URL from client.ts's now-exported
  BASE_URL.
- handleSessionCallback's four failure paths redirected to
  /?auth_error=failed with no logging, making a real OIDC failure
  undiagnosable in production. Added log.Printf on each failure site.
- handleSessionLogout passed a bare "/" to EndSessionURL; Keycloak
  requires post_logout_redirect_uri to be an absolute, registered URL.
  Added SessionConfig.PublicBaseURL, wired from cfg.PublicBaseURL in
  main.go, and used to build an absolute redirect.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-07-24 22:03:02 +02:00

97 lines
3.2 KiB
Go

package api
import (
"log"
"net/http"
"time"
"geniusrun/backend/internal/auth"
)
// SessionConfig configures how the app-login session cookie is minted and
// validated. Secure should mirror config.Config.SessionSecure (true once
// the app is served over HTTPS).
type SessionConfig struct {
Secret []byte
Duration time.Duration
Secure bool
// PublicBaseURL is this app's own externally reachable origin (e.g.
// "https://geniusrun.example.com", no trailing slash), used to build an
// absolute post_logout_redirect_uri for the identity provider -- some
// providers, including Keycloak, require this to be an absolute URL
// matching one registered on the client, not a bare relative path.
PublicBaseURL string
}
type sessionMeResponse struct {
Name string `json:"name"`
Email string `json:"email"`
}
func (s *Server) handleSessionLogin(w http.ResponseWriter, r *http.Request) {
authURL, txn, err := s.Auth.BeginLogin()
if err != nil {
writeError(w, http.StatusBadGateway, err.Error())
return
}
cookie, err := auth.MintTxnCookie(txn, s.Session.Secret, s.Session.Secure)
if err != nil {
writeError(w, http.StatusInternalServerError, err.Error())
return
}
http.SetCookie(w, cookie)
http.Redirect(w, r, authURL, http.StatusFound)
}
func (s *Server) handleSessionCallback(w http.ResponseWriter, r *http.Request) {
txnCookie, err := r.Cookie(auth.TxnCookieName)
if err != nil {
log.Printf("session callback: missing txn cookie: %v", err)
http.Redirect(w, r, "/?auth_error=failed", http.StatusFound)
return
}
http.SetCookie(w, auth.ClearCookie(auth.TxnCookieName, s.Session.Secure))
txn, err := auth.ParseTxnCookie(txnCookie, s.Session.Secret)
if err != nil {
log.Printf("session callback: failed to parse txn cookie: %v", err)
http.Redirect(w, r, "/?auth_error=failed", http.StatusFound)
return
}
result, err := s.Auth.HandleCallback(r.Context(), txn, r.URL.Query())
if err != nil {
log.Printf("session callback: HandleCallback failed (state mismatch, code exchange, or ID-token verification): %v", err)
http.Redirect(w, r, "/?auth_error=failed", http.StatusFound)
return
}
if !result.Authorized {
http.Redirect(w, r, "/?auth_error=forbidden", http.StatusFound)
return
}
sessionCookie, err := auth.MintSessionCookie(result.Claims, s.Session.Secret, s.Session.Duration, s.Session.Secure)
if err != nil {
writeError(w, http.StatusInternalServerError, err.Error())
return
}
http.SetCookie(w, sessionCookie)
http.Redirect(w, r, "/", http.StatusFound)
}
func (s *Server) handleSessionLogout(w http.ResponseWriter, r *http.Request) {
http.SetCookie(w, auth.ClearCookie(auth.SessionCookieName, s.Session.Secure))
http.Redirect(w, r, s.Auth.EndSessionURL(s.Session.PublicBaseURL+"/"), http.StatusFound)
}
func (s *Server) handleSessionMe(w http.ResponseWriter, r *http.Request) {
claims, ok := auth.ClaimsFromContext(r.Context())
if !ok {
// Unreachable in practice -- RequireSession already 401s before this
// handler runs -- but fail closed rather than panic if that ever changes.
writeError(w, http.StatusUnauthorized, "not authenticated")
return
}
writeJSON(w, http.StatusOK, sessionMeResponse{Name: claims.Name, Email: claims.Email})
}