Allow U2F 2FA without TOTP (#11573)

This change enables the usage of U2F without being forced to enroll an TOTP authenticator.
The `/user/auth/u2f` has been changed to hide the "use TOTP instead" bar if TOTP is not enrolled.

Fixes #5410
Fixes #17495

12 files changed, 100 insertions, 57 deletions

diff --git a/models/fixtures/u2f_registration.yml b/models/fixtures/u2f_registration.yml
index 4a9d1d9624..60555c43f1 100644
--- a/models/fixtures/u2f_registration.yml
+++ b/models/fixtures/u2f_registration.yml
@@ -1,7 +1,7 @@
 -
   id: 1
   name: "U2F Key"
-  user_id: 1
+  user_id: 32
   counter: 0
   created_unix: 946684800
   updated_unix: 946684800
diff --git a/models/fixtures/user.yml b/models/fixtures/user.yml
index c49fe1b656..cf07542eed 100644
--- a/models/fixtures/user.yml
+++ b/models/fixtures/user.yml
@@ -542,3 +542,19 @@
   avatar_email: user31@example.com
   num_repos: 0
   is_active: true
+
+-
+  id: 32
+  lower_name: user32
+  name: user32
+  full_name: User 32 (U2F test)
+  email: user32@example.com
+  passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
+  type: 0 # individual
+  salt: ZogKvWdyEx
+  is_admin: false
+  is_restricted: false
+  avatar: avatar32
+  avatar_email: user30@example.com
+  num_repos: 0
+  is_active: true
diff --git a/models/login/twofactor.go b/models/login/twofactor.go
index 1c4d2734fc..acb5e1b2d5 100644
--- a/models/login/twofactor.go
+++ b/models/login/twofactor.go
@@ -136,6 +136,12 @@ func GetTwoFactorByUID(uid int64) (*TwoFactor, error) {
 	return twofa, nil
 }
 
+// HasTwoFactorByUID returns the two-factor authentication token associated with
+// the user, if any.
+func HasTwoFactorByUID(uid int64) (bool, error) {
+	return db.GetEngine(db.DefaultContext).Where("uid=?", uid).Exist(&TwoFactor{})
+}
+
 // DeleteTwoFactorByID deletes two-factor authentication token by given ID.
 func DeleteTwoFactorByID(id, userID int64) error {
 	cnt, err := db.GetEngine(db.DefaultContext).ID(id).Delete(&TwoFactor{
diff --git a/models/login/u2f.go b/models/login/u2f.go
index 05d39cc05e..8cea98463f 100644
--- a/models/login/u2f.go
+++ b/models/login/u2f.go
@@ -115,6 +115,11 @@ func GetU2FRegistrationsByUID(uid int64) (U2FRegistrationList, error) {
 	return getU2FRegistrationsByUID(db.GetEngine(db.DefaultContext), uid)
 }
 
+// HasU2FRegistrationsByUID returns whether a given user has U2F registrations
+func HasU2FRegistrationsByUID(uid int64) (bool, error) {
+	return db.GetEngine(db.DefaultContext).Where("user_id = ?", uid).Exist(&U2FRegistration{})
+}
+
 func createRegistration(e db.Engine, userID int64, name string, reg *u2f.Registration) (*U2FRegistration, error) {
 	raw, err := reg.MarshalBinary()
 	if err != nil {
diff --git a/models/login/u2f_test.go b/models/login/u2f_test.go
index 32505b62a6..8f5cea6150 100644
--- a/models/login/u2f_test.go
+++ b/models/login/u2f_test.go
@@ -29,7 +29,7 @@ func TestGetU2FRegistrationByID(t *testing.T) {
 func TestGetU2FRegistrationsByUID(t *testing.T) {
 	assert.NoError(t, db.PrepareTestDatabase())
 
-	res, err := GetU2FRegistrationsByUID(1)
+	res, err := GetU2FRegistrationsByUID(32)
 
 	assert.NoError(t, err)
 	assert.Len(t, res, 1)
diff --git a/models/user_test.go b/models/user_test.go
index 2dcca20346..3f3536dafa 100644
--- a/models/user_test.go
+++ b/models/user_test.go
@@ -147,13 +147,13 @@ func TestSearchUsers(t *testing.T) {
 	}
 
 	testUserSuccess(&SearchUserOptions{OrderBy: "id ASC", ListOptions: db.ListOptions{Page: 1}},
-		[]int64{1, 2, 4, 5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 21, 24, 27, 28, 29, 30})
+		[]int64{1, 2, 4, 5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 21, 24, 27, 28, 29, 30, 32})
 
 	testUserSuccess(&SearchUserOptions{ListOptions: db.ListOptions{Page: 1}, IsActive: util.OptionalBoolFalse},
 		[]int64{9})
 
 	testUserSuccess(&SearchUserOptions{OrderBy: "id ASC", ListOptions: db.ListOptions{Page: 1}, IsActive: util.OptionalBoolTrue},
-		[]int64{1, 2, 4, 5, 8, 10, 11, 12, 13, 14, 15, 16, 18, 20, 21, 24, 28, 29, 30})
+		[]int64{1, 2, 4, 5, 8, 10, 11, 12, 13, 14, 15, 16, 18, 20, 21, 24, 28, 29, 30, 32})
 
 	testUserSuccess(&SearchUserOptions{Keyword: "user1", OrderBy: "id ASC", ListOptions: db.ListOptions{Page: 1}, IsActive: util.OptionalBoolTrue},
 		[]int64{1, 10, 11, 12, 13, 14, 15, 16, 18})
diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index 4a9e3c3894..2632531e2f 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -714,7 +714,6 @@ twofa_enrolled = Your account has been enrolled into two-factor authentication.
 twofa_failed_get_secret = Failed to get secret.
 
 u2f_desc = Security keys are hardware devices containing cryptographic keys. They can be used for two-factor authentication. Security keys must support the <a rel="noreferrer" href="https://fidoalliance.org/">FIDO U2F</a> standard.
-u2f_require_twofa = Your account must be enrolled in two-factor authentication to use security keys.
 u2f_register_key = Add Security Key
 u2f_nickname = Nickname
 u2f_press_button = Press the button on your security key to register it.
diff --git a/routers/web/user/auth.go b/routers/web/user/auth.go
index 21d48e9834..55f304a7cb 100644
--- a/routers/web/user/auth.go
+++ b/routers/web/user/auth.go
@@ -211,38 +211,58 @@ func SignInPost(ctx *context.Context) {
 		return
 	}
 
-	// If this user is enrolled in 2FA, we can't sign the user in just yet.
+	// If this user is enrolled in 2FA TOTP, we can't sign the user in just yet.
 	// Instead, redirect them to the 2FA authentication page.
-	_, err = login.GetTwoFactorByUID(u.ID)
+	hasTOTPtwofa, err := login.HasTwoFactorByUID(u.ID)
 	if err != nil {
-		if login.IsErrTwoFactorNotEnrolled(err) {
-			handleSignIn(ctx, u, form.Remember)
-		} else {
-			ctx.ServerError("UserSignIn", err)
-		}
+		ctx.ServerError("UserSignIn", err)
 		return
 	}
 
-	// User needs to use 2FA, save data and redirect to 2FA page.
+	// Check if the user has u2f registration
+	hasU2Ftwofa, err := login.HasU2FRegistrationsByUID(u.ID)
+	if err != nil {
+		ctx.ServerError("UserSignIn", err)
+		return
+	}
+
+	if !hasTOTPtwofa && !hasU2Ftwofa {
+		// No two factor auth configured we can sign in the user
+		handleSignIn(ctx, u, form.Remember)
+		return
+	}
+
+	// User will need to use 2FA TOTP or U2F, save data
 	if err := ctx.Session.Set("twofaUid", u.ID); err != nil {
 		ctx.ServerError("UserSignIn: Unable to set twofaUid in session", err)
 		return
 	}
+
 	if err := ctx.Session.Set("twofaRemember", form.Remember); err != nil {
 		ctx.ServerError("UserSignIn: Unable to set twofaRemember in session", err)
 		return
 	}
+
+	if hasTOTPtwofa {
+		// User will need to use U2F, save data
+		if err := ctx.Session.Set("totpEnrolled", u.ID); err != nil {
+			ctx.ServerError("UserSignIn: Unable to set u2fEnrolled in session", err)
+			return
+		}
+	}
+
 	if err := ctx.Session.Release(); err != nil {
 		ctx.ServerError("UserSignIn: Unable to save session", err)
 		return
 	}
 
-	regs, err := login.GetU2FRegistrationsByUID(u.ID)
-	if err == nil && len(regs) > 0 {
+	// If we have U2F redirect there first
+	if hasU2Ftwofa {
 		ctx.Redirect(setting.AppSubURL + "/user/u2f")
 		return
 	}
 
+	// Fallback to 2FA
 	ctx.Redirect(setting.AppSubURL + "/user/two_factor")
 }
 
@@ -406,6 +426,11 @@ func U2F(ctx *context.Context) {
 		return
 	}
 
+	// See whether TOTP is also available.
+	if ctx.Session.Get("totpEnrolled") != nil {
+		ctx.Data["TOTPEnrolled"] = true
+	}
+
 	ctx.HTML(http.StatusOK, tplU2F)
 }
 
diff --git a/routers/web/user/setting/security.go b/routers/web/user/setting/security.go
index 53f672282d..65e9790d47 100644
--- a/routers/web/user/setting/security.go
+++ b/routers/web/user/setting/security.go
@@ -55,23 +55,17 @@ func DeleteAccountLink(ctx *context.Context) {
 }
 
 func loadSecurityData(ctx *context.Context) {
-	enrolled := true
-	_, err := login.GetTwoFactorByUID(ctx.User.ID)
+	enrolled, err := login.HasTwoFactorByUID(ctx.User.ID)
 	if err != nil {
-		if login.IsErrTwoFactorNotEnrolled(err) {
-			enrolled = false
-		} else {
-			ctx.ServerError("SettingsTwoFactor", err)
-			return
-		}
+		ctx.ServerError("SettingsTwoFactor", err)
+		return
 	}
-	ctx.Data["TwofaEnrolled"] = enrolled
-	if enrolled {
-		ctx.Data["U2FRegistrations"], err = login.GetU2FRegistrationsByUID(ctx.User.ID)
-		if err != nil {
-			ctx.ServerError("GetU2FRegistrationsByUID", err)
-			return
-		}
+	ctx.Data["TOTPEnrolled"] = enrolled
+
+	ctx.Data["U2FRegistrations"], err = login.GetU2FRegistrationsByUID(ctx.User.ID)
+	if err != nil {
+		ctx.ServerError("GetU2FRegistrationsByUID", err)
+		return
 	}
 
 	tokens, err := models.ListAccessTokens(models.ListAccessTokensOptions{UserID: ctx.User.ID})
diff --git a/templates/user/auth/u2f.tmpl b/templates/user/auth/u2f.tmpl
index 2013d14937..8b04866bbc 100644
--- a/templates/user/auth/u2f.tmpl
+++ b/templates/user/auth/u2f.tmpl
@@ -12,9 +12,11 @@
 				<p>{{.i18n.Tr "u2f_sign_in"}}</p>
 			</div>
 			<div id="wait-for-key" class="ui attached segment"><div class="ui active indeterminate inline loader"></div> {{.i18n.Tr "u2f_press_button"}} </div>
-			<div class="ui attached segment">
-				<a href="{{AppSubUrl}}/user/two_factor">{{.i18n.Tr "u2f_use_twofa"}}</a>
-			</div>
+			{{if .TOTPEnrolled}}
+				<div class="ui attached segment">
+					<a href="{{AppSubUrl}}/user/two_factor">{{.i18n.Tr "u2f_use_twofa"}}</a>
+				</div>
+			{{end}}
 		</div>
 	</div>
 </div>
diff --git a/templates/user/settings/security_twofa.tmpl b/templates/user/settings/security_twofa.tmpl
index f48b2f4cb2..3d6804d9c6 100644
--- a/templates/user/settings/security_twofa.tmpl
+++ b/templates/user/settings/security_twofa.tmpl
@@ -3,7 +3,7 @@
 </h4>
 <div class="ui attached segment">
 	<p>{{.i18n.Tr "settings.twofa_desc"}}</p>
-	{{if .TwofaEnrolled}}
+	{{if .TOTPEnrolled}}
 	<p>{{$.i18n.Tr "settings.twofa_is_enrolled" | Str2html }}</p>
 	<form class="ui form" action="{{AppSubUrl}}/user/settings/security/two_factor/regenerate_scratch" method="post" enctype="multipart/form-data">
 		{{.CsrfTokenHtml}}
diff --git a/templates/user/settings/security_u2f.tmpl b/templates/user/settings/security_u2f.tmpl
index 8fe01d8c70..a2ff6c2212 100644
--- a/templates/user/settings/security_u2f.tmpl
+++ b/templates/user/settings/security_u2f.tmpl
@@ -3,32 +3,28 @@
 </h4>
 <div class="ui attached segment">
 	<p>{{.i18n.Tr "settings.u2f_desc" | Str2html}}</p>
-	{{if .TwofaEnrolled}}
-		<div class="ui key list">
-			{{range .U2FRegistrations}}
-				<div class="item">
-					<div class="right floated content">
-						<button class="ui red tiny button delete-button" data-modal-id="delete-registration" data-url="{{$.Link}}/u2f/delete" data-id="{{.ID}}">
-						{{$.i18n.Tr "settings.delete_key"}}
-						</button>
-					</div>
-					<div class="content">
-						<strong>{{.Name}}</strong>
-					</div>
+	<div class="ui key list">
+		{{range .U2FRegistrations}}
+			<div class="item">
+				<div class="right floated content">
+					<button class="ui red tiny button delete-button" id="delete-registration" data-url="{{$.Link}}/u2f/delete" data-id="{{.ID}}">
+					{{$.i18n.Tr "settings.delete_key"}}
+					</button>
+				</div>
+				<div class="content">
+					<strong>{{.Name}}</strong>
 				</div>
-			{{end}}
-		</div>
-		<div class="ui form">
-			{{.CsrfTokenHtml}}
-			<div class="required field">
-				<label for="nickname">{{.i18n.Tr "settings.u2f_nickname"}}</label>
-				<input id="nickname" name="nickname" type="text" required>
 			</div>
-			<button id="register-security-key" class="ui green button">{{svg "octicon-key"}} {{.i18n.Tr "settings.u2f_register_key"}}</button>
+		{{end}}
+	</div>
+	<div class="ui form">
+		{{.CsrfTokenHtml}}
+		<div class="required field">
+			<label for="nickname">{{.i18n.Tr "settings.u2f_nickname"}}</label>
+			<input id="nickname" name="nickname" type="text" required>
 		</div>
-	{{else}}
-		<b>{{.i18n.Tr "settings.u2f_require_twofa"}}</b>
-	{{end}}
+		<button id="register-security-key" class="ui green button">{{svg "octicon-key"}} {{.i18n.Tr "settings.u2f_register_key"}}</button>
+	</div>
 </div>
 
 <div class="ui small modal" id="register-device">