fix(oidc): pre-conf consent skipped entirely for anon users (#3250)

This fixes an issue where pre-configured consent is entirely skipped if the process was initiated via an anonymous user.

internal/handlers/handler_oidc_authorization.go

@@ -101,8 +101,6 @@ func OpenIDConnectAuthorizationGET(ctx *middlewares.AutheliaCtx, rw http.Respons
 
 	ctx.Logger.Tracef("Authorization Request with id '%s' on client with id '%s' creating session for Authorization Response for subject '%s' with username '%s' with claims: %+v",
 		requester.GetID(), oidcSession.ClientID, oidcSession.Subject, oidcSession.Username, oidcSession.Claims)
-	ctx.Logger.Tracef("Authorization Request with id '%s' on client with id '%s' creating session for Authorization Response for subject '%s' with username '%s' with headers: %+v",
-		requester.GetID(), oidcSession.ClientID, oidcSession.Subject, oidcSession.Username, oidcSession.Headers)
 
 	if responder, err = ctx.Providers.OpenIDConnect.Fosite.NewAuthorizeResponse(ctx, requester, oidcSession); err != nil {
 		rfc := fosite.ErrorToRFC6749Error(err)

internal/handlers/handler_oidc_authorization_consent.go

@@ -117,9 +117,9 @@ func handleOIDCAuthorizationConsentOrGenerate(ctx *middlewares.AutheliaCtx, root
 		err error
 	)
 
-	scopes, audience := getExpectedScopesAndAudience(requester)
+	scopes, audience := getOIDCExpectedScopesAndAudienceFromRequest(requester)
 
-	if consent, err = getOIDCPreconfiguredConsent(ctx, client.GetID(), subject.UUID, scopes, audience); err != nil {
+	if consent, err = getOIDCPreConfiguredConsent(ctx, client.GetID(), subject.UUID, scopes, audience); err != nil {
 		ctx.Logger.Errorf("Authorization Request with id '%s' on client with id '%s' had error looking up pre-configured consent sessions: %+v", requester.GetID(), requester.GetClient().GetID(), err)
 
 		ctx.Providers.OpenIDConnect.Fosite.WriteAuthorizeError(rw, requester, fosite.ErrServerError.WithHint("Could not lookup the consent session."))
@@ -182,16 +182,32 @@ func handleOIDCAuthorizationConsentRedirect(destination string, client *oidc.Cli
 	http.Redirect(rw, r, destination, http.StatusFound)
 }
 
-func getExpectedScopesAndAudience(requester fosite.Requester) (scopes, audience []string) {
-	audience = requester.GetRequestedAudience()
-	if !utils.IsStringInSlice(requester.GetClient().GetID(), audience) {
-		audience = append(audience, requester.GetClient().GetID())
+func getOIDCExpectedScopesAndAudienceFromRequest(requester fosite.Requester) (scopes, audience []string) {
+	return getOIDCExpectedScopesAndAudience(requester.GetClient().GetID(), requester.GetRequestedScopes(), requester.GetRequestedAudience())
 }
 
-	return requester.GetRequestedScopes(), audience
+func getOIDCExpectedScopesAndAudience(clientID string, scopes, audience []string) (expectedScopes, expectedAudience []string) {
+	if !utils.IsStringInSlice(clientID, audience) {
+		audience = append(audience, clientID)
 	}
 
-func getOIDCPreconfiguredConsent(ctx *middlewares.AutheliaCtx, clientID string, subject uuid.UUID, scopes, audience []string) (consent *model.OAuth2ConsentSession, err error) {
+	return scopes, audience
+}
+
+func getOIDCPreConfiguredConsentFromClientAndConsent(ctx *middlewares.AutheliaCtx, client fosite.Client, consent *model.OAuth2ConsentSession) (preConfigConsent *model.OAuth2ConsentSession, err error) {
+	if consent == nil || !consent.Subject.Valid {
+		return nil, fmt.Errorf("invalid consent provided for pre-configured consent lookup")
+	}
+
+	scopes, audience := getOIDCExpectedScopesAndAudience(client.GetID(), consent.RequestedScopes, consent.RequestedAudience)
+
+	// We can skip this error as it's handled at the authorization endpoint.
+	preConfigConsent, _ = getOIDCPreConfiguredConsent(ctx, client.GetID(), consent.Subject.UUID, scopes, audience)
+
+	return preConfigConsent, nil
+}
+
+func getOIDCPreConfiguredConsent(ctx *middlewares.AutheliaCtx, clientID string, subject uuid.UUID, scopes, audience []string) (consent *model.OAuth2ConsentSession, err error) {
 	var (
 		rows *storage.ConsentSessionRows
 	)

internal/handlers/response.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/authelia/authelia/v4/internal/authorization"
 	"github.com/authelia/authelia/v4/internal/middlewares"
+	"github.com/authelia/authelia/v4/internal/model"
 	"github.com/authelia/authelia/v4/internal/oidc"
 	"github.com/authelia/authelia/v4/internal/utils"
 )
@@ -59,16 +60,50 @@ func handleOIDCWorkflowResponse(ctx *middlewares.AutheliaCtx) {
 		return
 	}
 
-	if userSession.ConsentChallengeID != nil {
+	if consent.Subject.UUID, err = ctx.Providers.OpenIDConnect.Store.GetSubject(ctx, client.GetSectorIdentifier(), userSession.Username); err != nil {
+		ctx.Logger.Errorf("Unable to find subject for the consent session: %v", err)
+
+		respondUnauthorized(ctx, messageOperationFailed)
+
+		return
+	}
+
+	consent.Subject.Valid = true
+
+	var preConsent *model.OAuth2ConsentSession
+
+	if preConsent, err = getOIDCPreConfiguredConsentFromClientAndConsent(ctx, client, consent); err != nil {
+		ctx.Logger.Errorf("Unable to lookup pre-configured consent for the consent session: %v", err)
+
+		respondUnauthorized(ctx, messageOperationFailed)
+
+		return
+	}
+
+	if userSession.ConsentChallengeID != nil && preConsent == nil {
 		if err = ctx.SetJSONBody(redirectResponse{Redirect: fmt.Sprintf("%s/consent", externalRootURL)}); err != nil {
 			ctx.Logger.Errorf("Unable to set default redirection URL in body: %s", err)
 		}
-	} else {
+
+		return
+	}
+
+	if userSession.ConsentChallengeID != nil {
+		userSession.ConsentChallengeID = nil
+
+		if err = ctx.SaveSession(userSession); err != nil {
+			ctx.Logger.Errorf("Unable to update user session: %v", err)
+
+			respondUnauthorized(ctx, messageOperationFailed)
+
+			return
+		}
+	}
+
 	if err = ctx.SetJSONBody(redirectResponse{Redirect: fmt.Sprintf("%s%s?%s", externalRootURL, oidc.AuthorizationPath, consent.Form)}); err != nil {
 		ctx.Logger.Errorf("Unable to set default redirection URL in body: %s", err)
 	}
 }
-}
 
 // Handle1FAResponse handle the redirection upon 1FA authentication.
 func Handle1FAResponse(ctx *middlewares.AutheliaCtx, targetURI, requestMethod string, username string, groups []string) {