From fa8b8c055d3131fd3dff1b943ed1a20f7044088f Mon Sep 17 00:00:00 2001
From: David Jimenez <dvejmz@users.noreply.github.com>
Date: Thu, 14 Oct 2021 17:37:35 +0100
Subject: [PATCH] Don't panic if we fail to parse U2FRegistration data (#17304)

* Don't panic if we fail to parse a U2FRegistration data

Downgrade logging statement from Fatal to Error so that errors parsing
U2FRegistration data does not panic; instead, the invalid key will be
skipped and we will attempt to parse the next one, if available.

Signed-off-by: David Jimenez <dvejmz@sgfault.com>
---
 models/login/u2f.go      |  2 +-
 models/login/u2f_test.go | 26 ++++++++++++++++++++++++++
 routers/web/user/auth.go |  2 +-
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/models/login/u2f.go b/models/login/u2f.go
index 64b1fb322..05d39cc05 100644
--- a/models/login/u2f.go
+++ b/models/login/u2f.go
@@ -81,7 +81,7 @@ func (list U2FRegistrationList) ToRegistrations() []u2f.Registration {
 	for _, reg := range list {
 		r, err := reg.Parse()
 		if err != nil {
-			log.Fatal("parsing u2f registration: %v", err)
+			log.Error("parsing u2f registration: %v", err)
 			continue
 		}
 		regs = append(regs, *r)
diff --git a/models/login/u2f_test.go b/models/login/u2f_test.go
index b0305775c..32505b62a 100644
--- a/models/login/u2f_test.go
+++ b/models/login/u2f_test.go
@@ -5,6 +5,7 @@
 package login
 
 import (
+	"encoding/hex"
 	"testing"
 
 	"code.gitea.io/gitea/models/db"
@@ -29,6 +30,7 @@ func TestGetU2FRegistrationsByUID(t *testing.T) {
 	assert.NoError(t, db.PrepareTestDatabase())
 
 	res, err := GetU2FRegistrationsByUID(1)
+
 	assert.NoError(t, err)
 	assert.Len(t, res, 1)
 	assert.Equal(t, "U2F Key", res[0].Name)
@@ -72,3 +74,27 @@ func TestDeleteRegistration(t *testing.T) {
 	assert.NoError(t, DeleteRegistration(reg))
 	db.AssertNotExistsBean(t, &U2FRegistration{ID: 1})
 }
+
+const validU2FRegistrationResponseHex = "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"
+
+func TestToRegistrations_SkipInvalidItemsWithoutCrashing(t *testing.T) {
+	regKeyRaw, _ := hex.DecodeString(validU2FRegistrationResponseHex)
+	regs := U2FRegistrationList{
+		&U2FRegistration{ID: 1},
+		&U2FRegistration{ID: 2, Name: "U2F Key", UserID: 2, Counter: 0, Raw: regKeyRaw, CreatedUnix: 946684800, UpdatedUnix: 946684800},
+	}
+
+	actual := regs.ToRegistrations()
+	assert.Len(t, actual, 1)
+}
+
+func TestToRegistrations(t *testing.T) {
+	regKeyRaw, _ := hex.DecodeString(validU2FRegistrationResponseHex)
+	regs := U2FRegistrationList{
+		&U2FRegistration{ID: 1, Name: "U2F Key", UserID: 1, Counter: 0, Raw: regKeyRaw, CreatedUnix: 946684800, UpdatedUnix: 946684800},
+		&U2FRegistration{ID: 2, Name: "U2F Key", UserID: 2, Counter: 0, Raw: regKeyRaw, CreatedUnix: 946684800, UpdatedUnix: 946684800},
+	}
+
+	actual := regs.ToRegistrations()
+	assert.Len(t, actual, 2)
+}
diff --git a/routers/web/user/auth.go b/routers/web/user/auth.go
index 65515402c..99885e5ce 100644
--- a/routers/web/user/auth.go
+++ b/routers/web/user/auth.go
@@ -462,7 +462,7 @@ func U2FSign(ctx *context.Context) {
 	for _, reg := range regs {
 		r, err := reg.Parse()
 		if err != nil {
-			log.Fatal("parsing u2f registration: %v", err)
+			log.Error("parsing u2f registration: %v", err)
 			continue
 		}
 		newCounter, authErr := r.Authenticate(*signResp, *challenge, reg.Counter)