feat(BRIDGE-424): FIDO2 GUI support.

internal/frontend/grpc/fido.go

@@ -0,0 +1,111 @@
+// Copyright (c) 2025 Proton AG
+//
+// This file is part of Proton Mail Bridge.
+//
+// Proton Mail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Proton Mail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.
+
+//go:build linux || darwin
+
+package grpc
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/ProtonMail/gluon/async"
+	"github.com/ProtonMail/proton-bridge/v3/internal/fido"
+	"github.com/keys-pub/go-libfido2"
+	"google.golang.org/protobuf/types/known/emptypb"
+)
+
+func (s *Service) LoginFido(_ context.Context, login *LoginRequest) (*emptypb.Empty, error) {
+	s.log.WithField("username", login.Username).Debug("LoginFido")
+
+	go func() {
+		defer async.HandlePanic(s.panicHandler)
+
+		fidoCtx, cancelFido := context.WithCancel(context.Background())
+		s.fidoManager.SetCancel(cancelFido)
+		defer s.fidoManager.Clear()
+
+		if s.auth.UID == "" || s.authClient == nil {
+			s.log.Errorf("Login FIDO: authentication incomplete %s %p", s.auth.UID, s.authClient)
+			_ = s.SendEvent(NewLoginError(LoginErrorType_FIDO_ERROR, "Missing authentication, try again."))
+			s.loginClean()
+			return
+		}
+
+		pinSupported, err := fido.IsPinSupported()
+		if err != nil {
+			s.log.WithError(err).Warn("could not determine security key PIN requirements")
+			_ = s.SendEvent(NewLoginError(LoginErrorType_FIDO_ERROR, fmt.Sprintf("Could not obtain security key pin requirements: %s", err)))
+			s.loginClean()
+			return
+		}
+
+		if pinSupported && len(login.Password) == 0 {
+			_ = s.SendEvent(NewLoginFidoPinRequired(login.Username))
+			return
+		}
+
+		pin, err := base64Decode(login.Password)
+		if err != nil {
+			s.log.WithError(err).Error("cannot decode security key device pin")
+			_ = s.SendEvent(NewLoginError(LoginErrorType_FIDO_PIN_INVALID, "Could not decode security key PIN"))
+			return
+		}
+
+		touchCh := make(chan struct{})
+		touchConfirmCh := make(chan struct{})
+
+		defer func() {
+			close(touchCh)
+			close(touchConfirmCh)
+		}()
+
+		go func() {
+			if _, ok := <-touchCh; ok {
+				_ = s.SendEvent(NewLoginFidoTouchRequested(login.Username))
+				if _, ok := <-touchConfirmCh; ok {
+					_ = s.SendEvent(NewLoginFidoTouchCompleted(login.Username))
+				}
+			}
+		}()
+
+		if err := fido.AuthWithHardwareKeyGUI(fidoCtx, s.authClient, s.auth, touchCh, touchConfirmCh, string(pin)); err != nil {
+			s.log.WithError(err).Warn("Login FIDO: failed")
+			switch {
+			case errors.Is(err, libfido2.ErrPinAuthBlocked):
+				_ = s.SendEvent(NewLoginError(LoginErrorType_FIDO_PIN_BLOCKED, "Security key PIN code is blocked"))
+
+			case errors.Is(err, libfido2.ErrPinInvalid):
+				_ = s.SendEvent(NewLoginError(LoginErrorType_FIDO_PIN_INVALID, "Security key PIN code is incorrect"))
+
+			case errors.Is(err, fido.ErrAssertionCancelled): // User cancellation, they can click re-auth again.
+				return
+
+			default:
+				_ = s.SendEvent(NewLoginError(LoginErrorType_FIDO_ERROR, fmt.Sprintf("Security key authentication failed: %s", err)))
+				s.loginClean()
+			}
+
+			return
+		}
+
+		s.finishLogin()
+	}()
+
+	return &emptypb.Empty{}, nil
+}