feat(configuration): configurable default second factor method (#3081)

This allows configuring the default second factor method.

config.template.yml

@@ -27,6 +27,11 @@ jwt_secret: a_very_important_secret
 ## Note: this parameter is optional. If not provided, user won't be redirected upon successful authentication.
 default_redirection_url: https://home.example.com/
 
+## Set the default 2FA method for new users and for when a user has a preferred method configured that has been
+## disabled. This setting must be a method that is enabled.
+## Options are totp, webauthn, mobile_push.
+default_2fa_method: ""
+
 ##
 ## Server Configuration
 ##

docs/configuration/miscellaneous.md

@@ -59,3 +59,28 @@ redirected to that URL. If not defined, the user is not redirected after authent
 ```yaml
 default_redirection_url: https://home.example.com:8080/
 ```
+
+## default_2fa_method
+<div markdown="1">
+type: string
+{: .label .label-config .label-purple } 
+default: ""
+{: .label .label-config .label-blue }
+required: no
+{: .label .label-config .label-green }
+</div>
+
+Sets the default second factor method for users. This must be blank or one of the enabled methods. New users will by
+default have this method selected for them. In addition if this was configured to `webauthn` and a user had the `totp`
+method, and the `totp` method was disabled in the configuration, the users' method would automatically update to the
+`webauthn` method.
+
+Options are:
+
+- totp
+- webauthn
+- mobile_push
+
+```yaml
+default_2fa_method: totp
+```

docs/configuration/password_policy.md

@@ -2,7 +2,7 @@
 layout: default
 title: Password Policy
 parent: Configuration
-nav_order: 17
+nav_order: 18
 ---
 
 # Password Policy

docs/configuration/secrets.md

@@ -28,21 +28,21 @@ Here is the list of the environment variables which are considered secrets and c
 secrets can be loaded into the configuration if they end with one of the suffixes above, you can set the value of any
 other configuration using the environment but instead of loading a file the value of the environment variable is used.
 
-|Configuration Key                                |Environment Variable                                    |
+|                 Configuration Key                 |                   Environment Variable                   |
-|:-----------------------------------------------:|:------------------------------------------------------:|
+|:-------------------------------------------------:|:--------------------------------------------------------:|
-|tls_key                                          |AUTHELIA_TLS_KEY_FILE                                   |
+|                      tls_key                      |                  AUTHELIA_TLS_KEY_FILE                   |
-|jwt_secret                                       |AUTHELIA_JWT_SECRET_FILE                                |
+|                    jwt_secret                     |                 AUTHELIA_JWT_SECRET_FILE                 |
-|duo_api.secret_key                               |AUTHELIA_DUO_API_SECRET_KEY_FILE                        |
+|                duo_api.secret_key                 |             AUTHELIA_DUO_API_SECRET_KEY_FILE             |
-|session.secret                                   |AUTHELIA_SESSION_SECRET_FILE                            |
+|                  session.secret                   |               AUTHELIA_SESSION_SECRET_FILE               |
-|session.redis.password                           |AUTHELIA_SESSION_REDIS_PASSWORD_FILE                    |
+|              session.redis.password               |           AUTHELIA_SESSION_REDIS_PASSWORD_FILE           |
-|session.redis.high_availability.sentinel_password|AUTHELIA_REDIS_HIGH_AVAILABILITY_SENTINEL_PASSWORD_FILE |
+| session.redis.high_availability.sentinel_password | AUTHELIA_REDIS_HIGH_AVAILABILITY_SENTINEL_PASSWORD_FILE  |
-|storage.encryption_key                           |AUTHELIA_STORAGE_ENCRYPTION_KEY_FILE                    |
+|              storage.encryption_key               |           AUTHELIA_STORAGE_ENCRYPTION_KEY_FILE           |
-|storage.mysql.password                           |AUTHELIA_STORAGE_MYSQL_PASSWORD_FILE                    |
+|              storage.mysql.password               |           AUTHELIA_STORAGE_MYSQL_PASSWORD_FILE           |
-|storage.postgres.password                        |AUTHELIA_STORAGE_POSTGRES_PASSWORD_FILE                 |
+|             storage.postgres.password             |         AUTHELIA_STORAGE_POSTGRES_PASSWORD_FILE          |
-|notifier.smtp.password                           |AUTHELIA_NOTIFIER_SMTP_PASSWORD_FILE                    |
+|              notifier.smtp.password               |           AUTHELIA_NOTIFIER_SMTP_PASSWORD_FILE           |
-|authentication_backend.ldap.password             |AUTHELIA_AUTHENTICATION_BACKEND_LDAP_PASSWORD_FILE      |
+|       authentication_backend.ldap.password        |    AUTHELIA_AUTHENTICATION_BACKEND_LDAP_PASSWORD_FILE    |
-|identity_providers.oidc.issuer_private_key       |AUTHELIA_IDENTITY_PROVIDERS_OIDC_ISSUER_PRIVATE_KEY_FILE|
+|    identity_providers.oidc.issuer_private_key     | AUTHELIA_IDENTITY_PROVIDERS_OIDC_ISSUER_PRIVATE_KEY_FILE |
-|identity_providers.oidc.hmac_secret              |AUTHELIA_IDENTITY_PROVIDERS_OIDC_HMAC_SECRET_FILE       |
+|        identity_providers.oidc.hmac_secret        |    AUTHELIA_IDENTITY_PROVIDERS_OIDC_HMAC_SECRET_FILE     |
 
 ## Secrets in configuration file
 

docs/configuration/webauthn.md

@@ -2,7 +2,7 @@
 layout: default
 title: Webauthn
 parent: Configuration
-nav_order: 16
+nav_order: 17
 ---
 
 The Webauthn section has tunable options for the Webauthn implementation.

internal/configuration/config.template.yml

@@ -27,6 +27,11 @@ jwt_secret: a_very_important_secret
 ## Note: this parameter is optional. If not provided, user won't be redirected upon successful authentication.
 default_redirection_url: https://home.example.com/
 
+## Set the default 2FA method for new users and for when a user has a preferred method configured that has been
+## disabled. This setting must be a method that is enabled.
+## Options are totp, webauthn, mobile_push.
+default_2fa_method: ""
+
 ##
 ## Server Configuration
 ##

internal/configuration/schema/configuration.go

@@ -6,6 +6,7 @@ type Configuration struct {
 	CertificatesDirectory string `koanf:"certificates_directory"`
 	JWTSecret             string `koanf:"jwt_secret"`
 	DefaultRedirectionURL string `koanf:"default_redirection_url"`
+	Default2FAMethod      string `koanf:"default_2fa_method"`
 
 	Log                   LogConfiguration                   `koanf:"log"`
 	IdentityProviders     IdentityProvidersConfiguration     `koanf:"identity_providers"`

internal/configuration/schema/keys.go

@@ -12,6 +12,7 @@ var Keys = []string{
 	"certificates_directory",
 	"jwt_secret",
 	"default_redirection_url",
+	"default_2fa_method",
 	"log.level",
 	"log.format",
 	"log.file_path",

internal/configuration/schema/keys_test.go

@@ -1,253 +0,0 @@
-package schema
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-var ValidKeys = []string{
-	// Root Keys.
-	"certificates_directory",
-	"theme",
-	"default_redirection_url",
-	"jwt_secret",
-
-	// Log keys.
-	"log.level",
-	"log.format",
-	"log.file_path",
-	"log.keep_stdout",
-
-	// Server Keys.
-	"server.host",
-	"server.port",
-	"server.read_buffer_size",
-	"server.write_buffer_size",
-	"server.path",
-	"server.asset_path",
-	"server.enable_pprof",
-	"server.enable_expvars",
-	"server.disable_healthcheck",
-	"server.tls.key",
-	"server.tls.certificate",
-	"server.tls.client_certificates",
-	"server.headers.csp_template",
-
-	// TOTP Keys.
-	"totp.disable",
-	"totp.issuer",
-	"totp.algorithm",
-	"totp.digits",
-	"totp.period",
-	"totp.skew",
-	"totp.secret_size",
-
-	// Webauthn Keys.
-	"webauthn.disable",
-	"webauthn.display_name",
-	"webauthn.attestation_conveyance_preference",
-	"webauthn.user_verification",
-	"webauthn.timeout",
-
-	// DUO API Keys.
-	"duo_api.disable",
-	"duo_api.hostname",
-	"duo_api.enable_self_enrollment",
-	"duo_api.secret_key",
-	"duo_api.integration_key",
-
-	// Access Control Keys.
-	"access_control.default_policy",
-	"access_control.networks",
-	"access_control.networks[].name",
-	"access_control.networks[].networks",
-	"access_control.rules",
-	"access_control.rules[].domain",
-	"access_control.rules[].domain_regex",
-	"access_control.rules[].methods",
-	"access_control.rules[].networks",
-	"access_control.rules[].subject",
-	"access_control.rules[].policy",
-	"access_control.rules[].resources",
-
-	// Session Keys.
-	"session.name",
-	"session.domain",
-	"session.secret",
-	"session.same_site",
-	"session.expiration",
-	"session.inactivity",
-	"session.remember_me_duration",
-
-	// Redis Session Keys.
-	"session.redis.host",
-	"session.redis.port",
-	"session.redis.username",
-	"session.redis.password",
-	"session.redis.database_index",
-	"session.redis.maximum_active_connections",
-	"session.redis.minimum_idle_connections",
-	"session.redis.tls.minimum_version",
-	"session.redis.tls.skip_verify",
-	"session.redis.tls.server_name",
-	"session.redis.high_availability.sentinel_name",
-	"session.redis.high_availability.sentinel_username",
-	"session.redis.high_availability.sentinel_password",
-	"session.redis.high_availability.nodes",
-	"session.redis.high_availability.nodes[].host",
-	"session.redis.high_availability.nodes[].port",
-	"session.redis.high_availability.route_by_latency",
-	"session.redis.high_availability.route_randomly",
-
-	// Storage Keys.
-	"storage.encryption_key",
-
-	// Local Storage Keys.
-	"storage.local.path",
-
-	// MySQL Storage Keys.
-	"storage.mysql.host",
-	"storage.mysql.port",
-	"storage.mysql.database",
-	"storage.mysql.username",
-	"storage.mysql.password",
-	"storage.mysql.timeout",
-
-	// PostgreSQL Storage Keys.
-	"storage.postgres.host",
-	"storage.postgres.port",
-	"storage.postgres.database",
-	"storage.postgres.username",
-	"storage.postgres.password",
-	"storage.postgres.timeout",
-	"storage.postgres.schema",
-	"storage.postgres.ssl.mode",
-	"storage.postgres.ssl.root_certificate",
-	"storage.postgres.ssl.certificate",
-	"storage.postgres.ssl.key",
-
-	"storage.postgres.sslmode", // Deprecated. TODO: Remove in v4.36.0.
-
-	// FileSystem Notifier Keys.
-	"notifier.filesystem.filename",
-	"notifier.disable_startup_check",
-
-	// SMTP Notifier Keys.
-	"notifier.smtp.host",
-	"notifier.smtp.port",
-	"notifier.smtp.timeout",
-	"notifier.smtp.username",
-	"notifier.smtp.password",
-	"notifier.smtp.identifier",
-	"notifier.smtp.sender",
-	"notifier.smtp.subject",
-	"notifier.smtp.startup_check_address",
-	"notifier.smtp.disable_require_tls",
-	"notifier.smtp.disable_html_emails",
-	"notifier.smtp.tls.minimum_version",
-	"notifier.smtp.tls.skip_verify",
-	"notifier.smtp.tls.server_name",
-	"notifier.template_path",
-
-	// Regulation Keys.
-	"regulation.max_retries",
-	"regulation.find_time",
-	"regulation.ban_time",
-
-	// Authentication Backend Keys.
-	"authentication_backend.disable_reset_password",
-	"authentication_backend.password_reset.custom_url",
-	"authentication_backend.refresh_interval",
-
-	// LDAP Authentication Backend Keys.
-	"authentication_backend.ldap.implementation",
-	"authentication_backend.ldap.url",
-	"authentication_backend.ldap.timeout",
-	"authentication_backend.ldap.base_dn",
-	"authentication_backend.ldap.username_attribute",
-	"authentication_backend.ldap.additional_users_dn",
-	"authentication_backend.ldap.users_filter",
-	"authentication_backend.ldap.additional_groups_dn",
-	"authentication_backend.ldap.groups_filter",
-	"authentication_backend.ldap.group_name_attribute",
-	"authentication_backend.ldap.mail_attribute",
-	"authentication_backend.ldap.display_name_attribute",
-	"authentication_backend.ldap.user",
-	"authentication_backend.ldap.password",
-	"authentication_backend.ldap.start_tls",
-	"authentication_backend.ldap.tls.minimum_version",
-	"authentication_backend.ldap.tls.skip_verify",
-	"authentication_backend.ldap.tls.server_name",
-
-	// File Authentication Backend Keys.
-	"authentication_backend.file.path",
-	"authentication_backend.file.password.algorithm",
-	"authentication_backend.file.password.iterations",
-	"authentication_backend.file.password.key_length",
-	"authentication_backend.file.password.salt_length",
-	"authentication_backend.file.password.memory",
-	"authentication_backend.file.password.parallelism",
-
-	// Identity Provider Keys.
-	"identity_providers.oidc.hmac_secret",
-	"identity_providers.oidc.issuer_private_key",
-	"identity_providers.oidc.id_token_lifespan",
-	"identity_providers.oidc.access_token_lifespan",
-	"identity_providers.oidc.refresh_token_lifespan",
-	"identity_providers.oidc.authorize_code_lifespan",
-	"identity_providers.oidc.enforce_pkce",
-	"identity_providers.oidc.enable_pkce_plain_challenge",
-	"identity_providers.oidc.enable_client_debug_messages",
-	"identity_providers.oidc.minimum_parameter_entropy",
-	"identity_providers.oidc.cors.endpoints",
-	"identity_providers.oidc.cors.allowed_origins",
-	"identity_providers.oidc.cors.allowed_origins_from_client_redirect_uris",
-	"identity_providers.oidc.clients",
-	"identity_providers.oidc.clients[].id",
-	"identity_providers.oidc.clients[].description",
-	"identity_providers.oidc.clients[].secret",
-	"identity_providers.oidc.clients[].sector_identifier",
-	"identity_providers.oidc.clients[].public",
-	"identity_providers.oidc.clients[].redirect_uris",
-	"identity_providers.oidc.clients[].authorization_policy",
-	"identity_providers.oidc.clients[].pre_configured_consent_duration",
-	"identity_providers.oidc.clients[].scopes",
-	"identity_providers.oidc.clients[].audience",
-	"identity_providers.oidc.clients[].grant_types",
-	"identity_providers.oidc.clients[].response_types",
-	"identity_providers.oidc.clients[].response_modes",
-	"identity_providers.oidc.clients[].userinfo_signing_algorithm",
-
-	// NTP keys.
-	"ntp.address",
-	"ntp.version",
-	"ntp.max_desync",
-	"ntp.disable_startup_check",
-	"ntp.disable_failure",
-
-	// Password Policy keys.
-	"password_policy.standard.enabled",
-	"password_policy.standard.min_length",
-	"password_policy.standard.max_length",
-	"password_policy.standard.require_uppercase",
-	"password_policy.standard.require_lowercase",
-	"password_policy.standard.require_number",
-	"password_policy.standard.require_special",
-	"password_policy.zxcvbn.enabled",
-	"password_policy.zxcvbn.min_score",
-}
-
-func TestOldKeys(t *testing.T) {
-	for _, key := range ValidKeys {
-		assert.Contains(t, Keys, key)
-	}
-
-	for _, key := range Keys {
-		assert.Contains(t, ValidKeys, key)
-	}
-}
-
-func TestDuplicates(t *testing.T) {
-	assert.Equal(t, len(Keys), len(ValidKeys))
-}

internal/configuration/validator/configuration.go

@@ -33,6 +33,8 @@ func ValidateConfiguration(config *schema.Configuration, validator *schema.Struc
 		}
 	}
 
+	validateDefault2FAMethod(config, validator)
+
 	ValidateTheme(config, validator)
 
 	ValidateLog(config, validator)
@@ -65,3 +67,33 @@ func ValidateConfiguration(config *schema.Configuration, validator *schema.Struc
 
 	ValidatePasswordPolicy(&config.PasswordPolicy, validator)
 }
+
+func validateDefault2FAMethod(config *schema.Configuration, validator *schema.StructValidator) {
+	if config.Default2FAMethod == "" {
+		return
+	}
+
+	if !utils.IsStringInSlice(config.Default2FAMethod, validDefault2FAMethods) {
+		validator.Push(fmt.Errorf(errFmtInvalidDefault2FAMethod, config.Default2FAMethod, strings.Join(validDefault2FAMethods, "', '")))
+
+		return
+	}
+
+	var enabledMethods []string
+
+	if !config.TOTP.Disable {
+		enabledMethods = append(enabledMethods, "totp")
+	}
+
+	if !config.Webauthn.Disable {
+		enabledMethods = append(enabledMethods, "webauthn")
+	}
+
+	if !config.DuoAPI.Disable {
+		enabledMethods = append(enabledMethods, "mobile_push")
+	}
+
+	if !utils.IsStringInSlice(config.Default2FAMethod, enabledMethods) {
+		validator.Push(fmt.Errorf(errFmtInvalidDefault2FAMethodDisabled, config.Default2FAMethod, strings.Join(enabledMethods, "', '")))
+	}
+}

internal/configuration/validator/configuration_test.go

@@ -1,6 +1,7 @@
 package validator
 
 import (
+	"fmt"
 	"runtime"
 	"testing"
 
@@ -158,3 +159,114 @@ func TestShouldNotRaiseErrorOnValidCertificatesDirectory(t *testing.T) {
 
 	assert.EqualError(t, validator.Warnings()[0], "access control: no rules have been specified so the 'default_policy' of 'two_factor' is going to be applied to all requests")
 }
+
+func TestValidateDefault2FAMethod(t *testing.T) {
+	testCases := []struct {
+		desc         string
+		have         *schema.Configuration
+		expectedErrs []string
+	}{
+		{
+			desc: "ShouldAllowConfiguredMethodTOTP",
+			have: &schema.Configuration{
+				Default2FAMethod: "totp",
+				DuoAPI: schema.DuoAPIConfiguration{
+					SecretKey:      "a key",
+					IntegrationKey: "another key",
+					Hostname:       "none",
+				},
+			},
+		},
+		{
+			desc: "ShouldAllowConfiguredMethodWebauthn",
+			have: &schema.Configuration{
+				Default2FAMethod: "webauthn",
+				DuoAPI: schema.DuoAPIConfiguration{
+					SecretKey:      "a key",
+					IntegrationKey: "another key",
+					Hostname:       "none",
+				},
+			},
+		},
+		{
+			desc: "ShouldAllowConfiguredMethodMobilePush",
+			have: &schema.Configuration{
+				Default2FAMethod: "mobile_push",
+				DuoAPI: schema.DuoAPIConfiguration{
+					SecretKey:      "a key",
+					IntegrationKey: "another key",
+					Hostname:       "none",
+				},
+			},
+		},
+		{
+			desc: "ShouldNotAllowDisabledMethodTOTP",
+			have: &schema.Configuration{
+				Default2FAMethod: "totp",
+				DuoAPI: schema.DuoAPIConfiguration{
+					SecretKey:      "a key",
+					IntegrationKey: "another key",
+					Hostname:       "none",
+				},
+				TOTP: schema.TOTPConfiguration{Disable: true},
+			},
+			expectedErrs: []string{
+				"option 'default_2fa_method' is configured as 'totp' but must be one of the following enabled method values: 'webauthn', 'mobile_push'",
+			},
+		},
+		{
+			desc: "ShouldNotAllowDisabledMethodWebauthn",
+			have: &schema.Configuration{
+				Default2FAMethod: "webauthn",
+				DuoAPI: schema.DuoAPIConfiguration{
+					SecretKey:      "a key",
+					IntegrationKey: "another key",
+					Hostname:       "none",
+				},
+				Webauthn: schema.WebauthnConfiguration{Disable: true},
+			},
+			expectedErrs: []string{
+				"option 'default_2fa_method' is configured as 'webauthn' but must be one of the following enabled method values: 'totp', 'mobile_push'",
+			},
+		},
+		{
+			desc: "ShouldNotAllowDisabledMethodMobilePush",
+			have: &schema.Configuration{
+				Default2FAMethod: "mobile_push",
+				DuoAPI:           schema.DuoAPIConfiguration{Disable: true},
+			},
+			expectedErrs: []string{
+				"option 'default_2fa_method' is configured as 'mobile_push' but must be one of the following enabled method values: 'totp', 'webauthn'",
+			},
+		},
+		{
+			desc: "ShouldNotAllowInvalidMethodDuo",
+			have: &schema.Configuration{
+				Default2FAMethod: "duo",
+			},
+			expectedErrs: []string{
+				"option 'default_2fa_method' is configured as 'duo' but must be one of the following values: 'totp', 'webauthn', 'mobile_push'",
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			validator := schema.NewStructValidator()
+
+			validateDefault2FAMethod(tc.have, validator)
+
+			assert.Len(t, validator.Warnings(), 0)
+
+			errs := validator.Errors()
+
+			require.Len(t, errs, len(tc.expectedErrs))
+
+			for i, expected := range tc.expectedErrs {
+				t.Run(fmt.Sprintf("Err%d", i+1), func(t *testing.T) {
+					assert.EqualError(t, errs[i], expected)
+				})
+			}
+		})
+	}
+}

internal/configuration/validator/const.go

@@ -265,6 +265,11 @@ const (
 		TODO (cont): The main consideration is making sure we do not overwrite the destination key name if it already exists.
 	*/
 
+	errFmtInvalidDefault2FAMethod = "option 'default_2fa_method' is configured as '%s' but must be one of " +
+		"the following values: '%s'"
+	errFmtInvalidDefault2FAMethodDisabled = "option 'default_2fa_method' is configured as '%s' " +
+		"but must be one of the following enabled method values: '%s'"
+
 	errFmtReplacedConfigurationKey = "invalid configuration key '%s' was replaced by '%s'"
 
 	errFmtLoggingLevelInvalid = "log: option 'level' must be one of '%s' but it is configured as '%s'"
@@ -292,6 +297,8 @@ var validACLHTTPMethodVerbs = append(validRFC7231HTTPMethodVerbs, validRFC4918HT
 
 var validACLRulePolicies = []string{policyBypass, policyOneFactor, policyTwoFactor, policyDeny}
 
+var validDefault2FAMethods = []string{"totp", "webauthn", "mobile_push"}
+
 var validOIDCScopes = []string{oidc.ScopeOpenID, oidc.ScopeEmail, oidc.ScopeProfile, oidc.ScopeGroups, "offline_access"}
 var validOIDCGrantTypes = []string{"implicit", "refresh_token", "authorization_code", "password", "client_credentials"}
 var validOIDCResponseModes = []string{"form_post", "query", "fragment"}

internal/configuration/validator/identity_providers.go

@@ -10,7 +10,7 @@ import (
 	"github.com/authelia/authelia/v4/internal/utils"
 )
 
-// ValidateIdentityProviders validates and update IdentityProviders configuration.
+// ValidateIdentityProviders validates and updates the IdentityProviders configuration.
 func ValidateIdentityProviders(config *schema.IdentityProvidersConfiguration, validator *schema.StructValidator) {
 	validateOIDC(config.OIDC, validator)
 }

internal/handlers/handler_user_info.go

@@ -39,7 +39,7 @@ func UserInfoPOST(ctx *middlewares.AutheliaCtx) {
 		changed bool
 	)
 
-	if changed = userInfo.SetDefaultPreferred2FAMethod(ctx.AvailableSecondFactorMethods()); changed {
+	if changed = userInfo.SetDefaultPreferred2FAMethod(ctx.AvailableSecondFactorMethods(), ctx.Configuration.Default2FAMethod); changed {
 		if err = ctx.Providers.StorageProvider.SavePreferred2FAMethod(ctx, userSession.Username, userInfo.Method); err != nil {
 			ctx.Error(fmt.Errorf("unable to save user two factor method: %v", err), messageOperationFailed)
 			return

internal/model/user_info.go

@@ -23,7 +23,7 @@ type UserInfo struct {
 }
 
 // SetDefaultPreferred2FAMethod configures the default method based on what is configured as available and the users available methods.
-func (i *UserInfo) SetDefaultPreferred2FAMethod(methods []string) (changed bool) {
+func (i *UserInfo) SetDefaultPreferred2FAMethod(methods []string, fallback string) (changed bool) {
 	if len(methods) == 0 {
 		// No point attempting to change the method if no methods are available.
 		return false
@@ -33,11 +33,20 @@ func (i *UserInfo) SetDefaultPreferred2FAMethod(methods []string) (changed bool)
 
 	totp, webauthn, duo := utils.IsStringInSlice(SecondFactorMethodTOTP, methods), utils.IsStringInSlice(SecondFactorMethodWebauthn, methods), utils.IsStringInSlice(SecondFactorMethodDuo, methods)
 
-	if i.Method != "" && !utils.IsStringInSlice(i.Method, methods) {
+	if i.Method == "" && utils.IsStringInSlice(fallback, methods) {
+		i.Method = fallback
+	} else if i.Method != "" && !utils.IsStringInSlice(i.Method, methods) {
 		i.Method = ""
 	}
 
 	if i.Method == "" {
+		i.setMethod(totp, webauthn, duo, methods, fallback)
+	}
+
+	return before != i.Method
+}
+
+func (i *UserInfo) setMethod(totp, webauthn, duo bool, methods []string, fallback string) {
 	switch {
 	case i.HasTOTP && totp:
 		i.Method = SecondFactorMethodTOTP
@@ -45,6 +54,8 @@ func (i *UserInfo) SetDefaultPreferred2FAMethod(methods []string) (changed bool)
 		i.Method = SecondFactorMethodWebauthn
 	case i.HasDuo && duo:
 		i.Method = SecondFactorMethodDuo
+	case fallback != "" && utils.IsStringInSlice(fallback, methods):
+		i.Method = fallback
 	case totp:
 		i.Method = SecondFactorMethodTOTP
 	case webauthn:
@@ -52,7 +63,4 @@ func (i *UserInfo) SetDefaultPreferred2FAMethod(methods []string) (changed bool)
 	case duo:
 		i.Method = SecondFactorMethodDuo
 	}
-	}
-
-	return before != i.Method
 }

internal/model/user_info_test.go

@@ -8,10 +8,10 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
+func TestUserInfo_SetDefaultMethod(t *testing.T) {
 	none := "none"
 
-	testName := func(i int, have UserInfo, availableMethods []string) string {
+	testName := func(i int, have UserInfo, methods []string, fallback string) string {
 		method := have.Method
 
 		if method == "" {
@@ -37,18 +37,25 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 		}
 
 		available := none
-		if len(availableMethods) != 0 {
+		if len(methods) != 0 {
-			available = strings.Join(availableMethods, " ")
+			available = strings.Join(methods, " ")
 		}
 
-		return fmt.Sprintf("%d/method %s%s/available methods %s", i+1, method, has, available)
+		if fallback != "" {
+			fallback = "/fallback " + fallback
+		}
+
+		return fmt.Sprintf("%d/method %s%s/available methods %s%s", i+1, method, has, available, fallback)
 	}
 
 	testCases := []struct {
 		have UserInfo
-		availableMethods []string
-		changed          bool
 		want UserInfo
+
+		methods  []string
+		fallback string
+
+		changed bool
 	}{
 		{
 			have: UserInfo{
@@ -57,14 +64,14 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
-			availableMethods: []string{SecondFactorMethodWebauthn, SecondFactorMethodDuo},
-			changed:          true,
 			want: UserInfo{
 				Method:      SecondFactorMethodWebauthn,
 				HasDuo:      true,
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
+			methods: []string{SecondFactorMethodWebauthn, SecondFactorMethodDuo},
+			changed: true,
 		},
 		{
 			have: UserInfo{
@@ -72,14 +79,14 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
-			availableMethods: []string{SecondFactorMethodTOTP, SecondFactorMethodWebauthn, SecondFactorMethodDuo},
-			changed:          true,
 			want: UserInfo{
 				Method:      SecondFactorMethodTOTP,
 				HasDuo:      true,
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
+			methods: []string{SecondFactorMethodTOTP, SecondFactorMethodWebauthn, SecondFactorMethodDuo},
+			changed: true,
 		},
 		{
 			have: UserInfo{
@@ -88,14 +95,14 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 				HasTOTP:     false,
 				HasWebauthn: false,
 			},
-			availableMethods: []string{SecondFactorMethodTOTP},
-			changed:          true,
 			want: UserInfo{
 				Method:      SecondFactorMethodTOTP,
 				HasDuo:      true,
 				HasTOTP:     false,
 				HasWebauthn: false,
 			},
+			methods: []string{SecondFactorMethodTOTP},
+			changed: true,
 		},
 		{
 			have: UserInfo{
@@ -104,14 +111,14 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 				HasTOTP:     false,
 				HasWebauthn: false,
 			},
-			availableMethods: []string{SecondFactorMethodTOTP},
-			changed:          true,
 			want: UserInfo{
 				Method:      SecondFactorMethodTOTP,
 				HasDuo:      false,
 				HasTOTP:     false,
 				HasWebauthn: false,
 			},
+			methods: []string{SecondFactorMethodTOTP},
+			changed: true,
 		},
 		{
 			have: UserInfo{
@@ -120,14 +127,14 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 				HasTOTP:     false,
 				HasWebauthn: false,
 			},
-			availableMethods: []string{SecondFactorMethodWebauthn},
-			changed:          true,
 			want: UserInfo{
 				Method:      SecondFactorMethodWebauthn,
 				HasDuo:      false,
 				HasTOTP:     false,
 				HasWebauthn: false,
 			},
+			methods: []string{SecondFactorMethodWebauthn},
+			changed: true,
 		},
 		{
 			have: UserInfo{
@@ -136,14 +143,14 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 				HasTOTP:     false,
 				HasWebauthn: false,
 			},
-			availableMethods: []string{SecondFactorMethodDuo},
-			changed:          true,
 			want: UserInfo{
 				Method:      SecondFactorMethodDuo,
 				HasDuo:      false,
 				HasTOTP:     false,
 				HasWebauthn: false,
 			},
+			methods: []string{SecondFactorMethodDuo},
+			changed: true,
 		},
 		{
 			have: UserInfo{
@@ -152,14 +159,14 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
-			availableMethods: []string{SecondFactorMethodTOTP, SecondFactorMethodWebauthn, SecondFactorMethodDuo},
+			want: UserInfo{
+				Method:      SecondFactorMethodWebauthn,
+				HasDuo:      false,
+				HasTOTP:     true,
+				HasWebauthn: true,
+			},
+			methods: []string{SecondFactorMethodTOTP, SecondFactorMethodWebauthn, SecondFactorMethodDuo},
 			changed: false,
-			want: UserInfo{
-				Method:      SecondFactorMethodWebauthn,
-				HasDuo:      false,
-				HasTOTP:     true,
-				HasWebauthn: true,
-			},
 		},
 		{
 			have: UserInfo{
@@ -168,14 +175,14 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
-			availableMethods: []string{SecondFactorMethodWebauthn, SecondFactorMethodDuo},
-			changed:          true,
 			want: UserInfo{
 				Method:      SecondFactorMethodWebauthn,
 				HasDuo:      false,
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
+			methods: []string{SecondFactorMethodWebauthn, SecondFactorMethodDuo},
+			changed: true,
 		},
 		{
 			have: UserInfo{
@@ -184,14 +191,14 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
-			availableMethods: []string{SecondFactorMethodDuo},
-			changed:          true,
 			want: UserInfo{
 				Method:      SecondFactorMethodDuo,
 				HasDuo:      false,
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
+			methods: []string{SecondFactorMethodDuo},
+			changed: true,
 		},
 		{
 			have: UserInfo{
@@ -200,20 +207,104 @@ func TestUserInfo_SetDefaultMethod_ShouldConfigureConfigDefault(t *testing.T) {
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
-			availableMethods: nil,
-			changed:          false,
 			want: UserInfo{
 				Method:      "",
 				HasDuo:      false,
 				HasTOTP:     true,
 				HasWebauthn: true,
 			},
+			methods: nil,
+			changed: false,
+		},
+		{
+			have: UserInfo{
+				Method:      "",
+				HasDuo:      false,
+				HasTOTP:     false,
+				HasWebauthn: false,
+			},
+			want: UserInfo{
+				Method:      SecondFactorMethodDuo,
+				HasDuo:      false,
+				HasTOTP:     false,
+				HasWebauthn: false,
+			},
+			methods:  []string{SecondFactorMethodTOTP, SecondFactorMethodWebauthn, SecondFactorMethodDuo},
+			fallback: SecondFactorMethodDuo,
+			changed:  true,
+		},
+		{
+			have: UserInfo{
+				Method:      "",
+				HasDuo:      false,
+				HasTOTP:     false,
+				HasWebauthn: false,
+			},
+			want: UserInfo{
+				Method:      SecondFactorMethodTOTP,
+				HasDuo:      false,
+				HasTOTP:     false,
+				HasWebauthn: false,
+			},
+			methods:  []string{SecondFactorMethodTOTP, SecondFactorMethodWebauthn},
+			fallback: SecondFactorMethodDuo,
+			changed:  true,
+		},
+		{
+			have: UserInfo{
+				Method:      SecondFactorMethodTOTP,
+				HasDuo:      true,
+				HasTOTP:     false,
+				HasWebauthn: false,
+			},
+			want: UserInfo{
+				Method:      SecondFactorMethodDuo,
+				HasDuo:      true,
+				HasTOTP:     false,
+				HasWebauthn: false,
+			},
+			methods: []string{SecondFactorMethodWebauthn, SecondFactorMethodDuo},
+			changed: true,
+		},
+		{
+			have: UserInfo{
+				Method:      SecondFactorMethodTOTP,
+				HasDuo:      false,
+				HasTOTP:     false,
+				HasWebauthn: false,
+			},
+			want: UserInfo{
+				Method:      SecondFactorMethodWebauthn,
+				HasDuo:      false,
+				HasTOTP:     false,
+				HasWebauthn: false,
+			},
+			methods:  []string{SecondFactorMethodWebauthn, SecondFactorMethodDuo},
+			fallback: SecondFactorMethodWebauthn,
+			changed:  true,
+		},
+		{
+			have: UserInfo{
+				Method:      SecondFactorMethodWebauthn,
+				HasDuo:      false,
+				HasTOTP:     false,
+				HasWebauthn: false,
+			},
+			want: UserInfo{
+				Method:      SecondFactorMethodDuo,
+				HasDuo:      false,
+				HasTOTP:     false,
+				HasWebauthn: false,
+			},
+			methods:  []string{SecondFactorMethodTOTP, SecondFactorMethodDuo},
+			fallback: SecondFactorMethodDuo,
+			changed:  true,
 		},
 	}
 
 	for i, tc := range testCases {
-		t.Run(testName(i, tc.have, tc.availableMethods), func(t *testing.T) {
+		t.Run(testName(i, tc.have, tc.methods, tc.fallback), func(t *testing.T) {
-			changed := tc.have.SetDefaultPreferred2FAMethod(tc.availableMethods)
+			changed := tc.have.SetDefaultPreferred2FAMethod(tc.methods, tc.fallback)
 
 			assert.Equal(t, tc.changed, changed)
 			assert.Equal(t, tc.want, tc.have)