fleet/server/service/appconfig.go

package service

import (
	"bytes"
	"context"
	"crypto/tls"
	"crypto/x509"
	"encoding/json"
	"encoding/pem"
	"errors"
	"fmt"
	"io"
	"net"
	"net/http"
	"net/url"

	"github.com/fleetdm/fleet/v4/server/authz"
	"github.com/fleetdm/fleet/v4/server/config"
	authz_ctx "github.com/fleetdm/fleet/v4/server/contexts/authz"
	"github.com/fleetdm/fleet/v4/server/contexts/ctxerr"
	"github.com/fleetdm/fleet/v4/server/contexts/license"
	"github.com/fleetdm/fleet/v4/server/contexts/viewer"
	"github.com/fleetdm/fleet/v4/server/fleet"
	"github.com/go-kit/kit/log/level"
	"github.com/kolide/kit/version"
)

////////////////////////////////////////////////////////////////////////////////
// Get AppConfig
////////////////////////////////////////////////////////////////////////////////

type appConfigResponse struct {
	fleet.AppConfig
	appConfigResponseFields
}

// appConfigResponseFields are grouped separately to aid with JSON unmarshaling
type appConfigResponseFields struct {
	UpdateInterval  *fleet.UpdateIntervalConfig  `json:"update_interval"`
	Vulnerabilities *fleet.VulnerabilitiesConfig `json:"vulnerabilities"`

	// License is loaded from the service
	License *fleet.LicenseInfo `json:"license,omitempty"`
	// Logging is loaded on the fly rather than from the database.
	Logging *fleet.Logging `json:"logging,omitempty"`
	// Email is returned when the email backend is something other than SMTP, for example SES
	Email *fleet.EmailConfig `json:"email,omitempty"`
	// SandboxEnabled is true if fleet serve was ran with server.sandbox_enabled=true
	SandboxEnabled bool  `json:"sandbox_enabled,omitempty"`
	Err            error `json:"error,omitempty"`

	// MDMEnabled is true if fleet serve was started with
	// FLEET_DEV_MDM_ENABLED=1.
	//
	// Undocumented feature flag for Windows MDM, used to determine if the
	// Windows MDM feature is visible in the UI and can be enabled. More details
	// here: https://github.com/fleetdm/fleet/issues/12257
	//
	// TODO: remove this flag once the Windows MDM feature is ready for
	// release.
	MDMEnabled bool `json:"mdm_enabled,omitempty"`
}

// UnmarshalJSON implements the json.Unmarshaler interface to make sure we serialize
// both AppConfig and appConfigResponseFields properly:
//
// - If this function is not defined, AppConfig.UnmarshalJSON gets promoted and
// will be called instead.
// - If we try to unmarshal everything in one go, AppConfig.UnmarshalJSON doesn't get
// called.
func (r *appConfigResponse) UnmarshalJSON(data []byte) error {
	if err := json.Unmarshal(data, &r.AppConfig); err != nil {
		return err
	}
	if err := json.Unmarshal(data, &r.appConfigResponseFields); err != nil {
		return err
	}
	return nil
}

func (r appConfigResponse) error() error { return r.Err }

func getAppConfigEndpoint(ctx context.Context, request interface{}, svc fleet.Service) (errorer, error) {
	vc, ok := viewer.FromContext(ctx)
	if !ok {
		return nil, errors.New("could not fetch user")
	}
	appConfig, err := svc.AppConfigObfuscated(ctx)
	if err != nil {
		return nil, err
	}
	license, err := svc.License(ctx)
	if err != nil {
		return nil, err
	}
	loggingConfig, err := svc.LoggingConfig(ctx)
	if err != nil {
		return nil, err
	}
	emailConfig, err := svc.EmailConfig(ctx)
	if err != nil {
		return nil, err
	}
	updateIntervalConfig, err := svc.UpdateIntervalConfig(ctx)
	if err != nil {
		return nil, err
	}
	vulnConfig, err := svc.VulnerabilitiesConfig(ctx)
	if err != nil {
		return nil, err
	}

	// Only the Global Admin should be able to see see SMTP, SSO and osquery agent settings.
	var smtpSettings *fleet.SMTPSettings
	var ssoSettings *fleet.SSOSettings
	var agentOptions *json.RawMessage
	if vc.User.GlobalRole != nil && *vc.User.GlobalRole == fleet.RoleAdmin {
		smtpSettings = appConfig.SMTPSettings
		ssoSettings = appConfig.SSOSettings
		agentOptions = appConfig.AgentOptions
	}

	transparencyURL := fleet.DefaultTransparencyURL
	// Fleet Premium license is required for custom transparency url
	if license.IsPremium() && appConfig.FleetDesktop.TransparencyURL != "" {
		transparencyURL = appConfig.FleetDesktop.TransparencyURL
	}
	fleetDesktop := fleet.FleetDesktopSettings{TransparencyURL: transparencyURL}

	if appConfig.OrgInfo.ContactURL == "" {
		appConfig.OrgInfo.ContactURL = fleet.DefaultOrgInfoContactURL
	}

	features := appConfig.Features
	response := appConfigResponse{
		AppConfig: fleet.AppConfig{
			OrgInfo:               appConfig.OrgInfo,
			ServerSettings:        appConfig.ServerSettings,
			Features:              features,
			VulnerabilitySettings: appConfig.VulnerabilitySettings,
			HostExpirySettings:    appConfig.HostExpirySettings,

			SMTPSettings: smtpSettings,
			SSOSettings:  ssoSettings,
			AgentOptions: agentOptions,

			FleetDesktop: fleetDesktop,

			WebhookSettings: appConfig.WebhookSettings,
			Integrations:    appConfig.Integrations,
			MDM:             appConfig.MDM,
		},
		appConfigResponseFields: appConfigResponseFields{
			UpdateInterval:  updateIntervalConfig,
			Vulnerabilities: vulnConfig,
			License:         license,
			Logging:         loggingConfig,
			Email:           emailConfig,
			SandboxEnabled:  svc.SandboxEnabled(),
			MDMEnabled:      config.IsMDMFeatureFlagEnabled(),
		},
	}
	return response, nil
}

func (svc *Service) SandboxEnabled() bool {
	return svc.config.Server.SandboxEnabled
}

func (svc *Service) AppConfigObfuscated(ctx context.Context) (*fleet.AppConfig, error) {
	if !svc.authz.IsAuthenticatedWith(ctx, authz_ctx.AuthnDeviceToken) {
		if err := svc.authz.Authorize(ctx, &fleet.AppConfig{}, fleet.ActionRead); err != nil {
			return nil, err
		}
	}

	ac, err := svc.ds.AppConfig(ctx)
	if err != nil {
		return nil, err
	}

	ac.Obfuscate()

	return ac, nil
}

// //////////////////////////////////////////////////////////////////////////////
// Modify AppConfig
// //////////////////////////////////////////////////////////////////////////////

type modifyAppConfigRequest struct {
	Force  bool `json:"-" query:"force,optional"`   // if true, bypass strict incoming json validation
	DryRun bool `json:"-" query:"dry_run,optional"` // if true, apply validation but do not save changes
	json.RawMessage
}

func modifyAppConfigEndpoint(ctx context.Context, request interface{}, svc fleet.Service) (errorer, error) {
	req := request.(*modifyAppConfigRequest)
	appConfig, err := svc.ModifyAppConfig(ctx, req.RawMessage, fleet.ApplySpecOptions{
		Force:  req.Force,
		DryRun: req.DryRun,
	})
	if err != nil {
		return appConfigResponse{appConfigResponseFields: appConfigResponseFields{Err: err}}, nil
	}

	// We do not use svc.License(ctx) to allow roles (like GitOps) write but not read access to AppConfig.
	license, _ := license.FromContext(ctx)

	loggingConfig, err := svc.LoggingConfig(ctx)
	if err != nil {
		return nil, err
	}
	response := appConfigResponse{
		AppConfig: *appConfig,
		appConfigResponseFields: appConfigResponseFields{
			License:    license,
			Logging:    loggingConfig,
			MDMEnabled: config.IsMDMFeatureFlagEnabled(),
		},
	}

	response.Obfuscate()

	if (!license.IsPremium()) || response.FleetDesktop.TransparencyURL == "" {
		response.FleetDesktop.TransparencyURL = fleet.DefaultTransparencyURL
	}

	return response, nil
}

func (svc *Service) ModifyAppConfig(ctx context.Context, p []byte, applyOpts fleet.ApplySpecOptions) (*fleet.AppConfig, error) {
	if err := svc.authz.Authorize(ctx, &fleet.AppConfig{}, fleet.ActionWrite); err != nil {
		return nil, err
	}

	// we need the config from the datastore because API tokens are obfuscated at the service layer
	// we will retrieve the obfuscated config before we return
	appConfig, err := svc.ds.AppConfig(ctx)
	if err != nil {
		return nil, err
	}
	oldAppConfig := appConfig.Copy()

	// We do not use svc.License(ctx) to allow roles (like GitOps) write but not read access to AppConfig.
	license, _ := license.FromContext(ctx)

	var oldSMTPSettings fleet.SMTPSettings
	if appConfig.SMTPSettings != nil {
		oldSMTPSettings = *appConfig.SMTPSettings
	} else {
		// SMTPSettings used to be a non-pointer on previous iterations,
		// so if current SMTPSettings are not present (with empty values),
		// then this is a bug, let's log an error.
		level.Error(svc.logger).Log("smtp_settings are not present")
	}

	oldAgentOptions := ""
	if appConfig.AgentOptions != nil {
		oldAgentOptions = string(*appConfig.AgentOptions)
	}

	storedJiraByProjectKey, err := fleet.IndexJiraIntegrations(appConfig.Integrations.Jira)
	if err != nil {
		return nil, ctxerr.Wrap(ctx, err, "modify AppConfig")
	}

	storedZendeskByGroupID, err := fleet.IndexZendeskIntegrations(appConfig.Integrations.Zendesk)
	if err != nil {
		return nil, ctxerr.Wrap(ctx, err, "modify AppConfig")
	}

	invalid := &fleet.InvalidArgumentError{}
	var newAppConfig fleet.AppConfig
	if err := json.Unmarshal(p, &newAppConfig); err != nil {
		return nil, ctxerr.Wrap(ctx, &fleet.BadRequestError{
			Message:     "failed to decode app config",
			InternalErr: err,
		})
	}

	// default transparency URL is https://fleetdm.com/transparency so you are allowed to apply as long as it's not changing
	if newAppConfig.FleetDesktop.TransparencyURL != "" && newAppConfig.FleetDesktop.TransparencyURL != fleet.DefaultTransparencyURL {
		if !license.IsPremium() {
			invalid.Append("transparency_url", ErrMissingLicense.Error())
			return nil, ctxerr.Wrap(ctx, invalid)
		}
		if _, err := url.Parse(newAppConfig.FleetDesktop.TransparencyURL); err != nil {
			invalid.Append("transparency_url", err.Error())
			return nil, ctxerr.Wrap(ctx, invalid)
		}
	}

	if newAppConfig.SSOSettings != nil {
		validateSSOSettings(newAppConfig, appConfig, invalid, license)
		if invalid.HasErrors() {
			return nil, ctxerr.Wrap(ctx, invalid)
		}
	}

	// We apply the config that is incoming to the old one
	appConfig.EnableStrictDecoding()
	if err := json.Unmarshal(p, &appConfig); err != nil {
		err = fleet.NewUserMessageError(err, http.StatusBadRequest)
		return nil, ctxerr.Wrap(ctx, err)
	}
	var legacyUsedWarning error
	if legacyKeys := appConfig.DidUnmarshalLegacySettings(); len(legacyKeys) > 0 {
		// this "warning" is returned only in dry-run mode, and if no other errors
		// were encountered.
		legacyUsedWarning = &fleet.BadRequestError{
			Message: fmt.Sprintf("warning: deprecated settings were used in the configuration: %v; consider updating to the new settings: https://fleetdm.com/docs/using-fleet/configuration-files#settings", legacyKeys),
		}
	}

	// required fields must be set, ensure they haven't been removed by applying
	// the new config
	if appConfig.OrgInfo.OrgName == "" {
		invalid.Append("org_name", "organization name must be present")
	}
	if appConfig.ServerSettings.ServerURL == "" {
		invalid.Append("server_url", "Fleet server URL must be present")
	}

	if appConfig.OrgInfo.ContactURL == "" {
		appConfig.OrgInfo.ContactURL = fleet.DefaultOrgInfoContactURL
	}

	if newAppConfig.AgentOptions != nil {
		// if there were Agent Options in the new app config, then it replaced the
		// agent options in the resulting app config, so validate those.
		if err := fleet.ValidateJSONAgentOptions(*appConfig.AgentOptions); err != nil {
			err = fleet.NewUserMessageError(err, http.StatusBadRequest)
			if applyOpts.Force && !applyOpts.DryRun {
				level.Info(svc.logger).Log("err", err, "msg", "force-apply appConfig agent options with validation errors")
			}
			if !applyOpts.Force {
				return nil, ctxerr.Wrap(ctx, err, "validate agent options")
			}
		}
	}

	fleet.ValidateEnabledVulnerabilitiesIntegrations(appConfig.WebhookSettings.VulnerabilitiesWebhook, appConfig.Integrations, invalid)
	fleet.ValidateEnabledFailingPoliciesIntegrations(appConfig.WebhookSettings.FailingPoliciesWebhook, appConfig.Integrations, invalid)
	fleet.ValidateEnabledHostStatusIntegrations(appConfig.WebhookSettings.HostStatusWebhook, invalid)
	svc.validateMDM(ctx, license, &oldAppConfig.MDM, &appConfig.MDM, invalid)

	if invalid.HasErrors() {
		return nil, ctxerr.Wrap(ctx, invalid)
	}

	// ignore MDM.EnabledAndConfigured MDM.AppleBMTermsExpired, and MDM.AppleBMEnabledAndConfigured
	// if provided in the modify payload we don't return an error in this case because it would
	// prevent using the output of fleetctl get config as input to fleetctl apply or this endpoint.
	appConfig.MDM.AppleBMTermsExpired = oldAppConfig.MDM.AppleBMTermsExpired
	appConfig.MDM.AppleBMEnabledAndConfigured = oldAppConfig.MDM.AppleBMEnabledAndConfigured
	appConfig.MDM.EnabledAndConfigured = oldAppConfig.MDM.EnabledAndConfigured

	// do not send a test email in dry-run mode, so this is a good place to stop
	// (we also delete the removed integrations after that, which we don't want
	// to do in dry-run mode).
	if applyOpts.DryRun {
		if legacyUsedWarning != nil {
			return nil, legacyUsedWarning
		}
		// must reload to get the unchanged app config
		return svc.AppConfigObfuscated(ctx)
	}

	// Perform validation of the applied SMTP settings.
	if newAppConfig.SMTPSettings != nil {
		// Ignore the values for SMTPEnabled and SMTPConfigured.
		oldSMTPSettings.SMTPEnabled = appConfig.SMTPSettings.SMTPEnabled
		oldSMTPSettings.SMTPConfigured = appConfig.SMTPSettings.SMTPConfigured

		// If we enable SMTP and the settings have changed, then we send a test email.
		if appConfig.SMTPSettings.SMTPEnabled {
			if oldSMTPSettings != *appConfig.SMTPSettings || !appConfig.SMTPSettings.SMTPConfigured {
				if err = svc.sendTestEmail(ctx, appConfig); err != nil {
					return nil, fleet.NewInvalidArgumentError("SMTP Options", err.Error())
				}
			}
			appConfig.SMTPSettings.SMTPConfigured = true
		} else {
			appConfig.SMTPSettings.SMTPConfigured = false
		}
	}

	delJira, err := fleet.ValidateJiraIntegrations(ctx, storedJiraByProjectKey, newAppConfig.Integrations.Jira)
	if err != nil {
		if errors.As(err, &fleet.IntegrationTestError{}) {
			return nil, ctxerr.Wrap(ctx, &fleet.BadRequestError{
				Message: err.Error(),
			})
		}
		return nil, ctxerr.Wrap(ctx, fleet.NewInvalidArgumentError("Jira integration", err.Error()))
	}
	appConfig.Integrations.Jira = newAppConfig.Integrations.Jira

	delZendesk, err := fleet.ValidateZendeskIntegrations(ctx, storedZendeskByGroupID, newAppConfig.Integrations.Zendesk)
	if err != nil {
		if errors.As(err, &fleet.IntegrationTestError{}) {
			return nil, ctxerr.Wrap(ctx, &fleet.BadRequestError{
				Message: err.Error(),
			})
		}
		return nil, ctxerr.Wrap(ctx, fleet.NewInvalidArgumentError("Zendesk integration", err.Error()))
	}
	appConfig.Integrations.Zendesk = newAppConfig.Integrations.Zendesk

	// if any integration was deleted, remove it from any team that uses it
	if len(delJira)+len(delZendesk) > 0 {
		if err := svc.ds.DeleteIntegrationsFromTeams(ctx, fleet.Integrations{Jira: delJira, Zendesk: delZendesk}); err != nil {
			return nil, ctxerr.Wrap(ctx, err, "delete integrations from teams")
		}
	}

	if !license.IsPremium() {
		// reset transparency url to empty for downgraded licenses
		appConfig.FleetDesktop.TransparencyURL = ""
	}

	if err := svc.ds.SaveAppConfig(ctx, appConfig); err != nil {
		return nil, err
	}

	if oldAppConfig.MDM.MacOSSetup.MacOSSetupAssistant.Value != appConfig.MDM.MacOSSetup.MacOSSetupAssistant.Value &&
		appConfig.MDM.MacOSSetup.MacOSSetupAssistant.Value == "" {
		// clear macos setup assistant for no team - note that we cannot call
		// svc.DeleteMDMAppleSetupAssistant here as it would call the (non-premium)
		// current service implementation. We have to go through the Enterprise
		// extensions.
		if err := svc.EnterpriseOverrides.DeleteMDMAppleSetupAssistant(ctx, nil); err != nil {
			return nil, ctxerr.Wrap(ctx, err, "delete macos setup assistant")
		}
	}

	if oldAppConfig.MDM.MacOSSetup.BootstrapPackage.Value != appConfig.MDM.MacOSSetup.BootstrapPackage.Value &&
		appConfig.MDM.MacOSSetup.BootstrapPackage.Value == "" {
		// clear bootstrap package for no team - note that we cannot call
		// svc.DeleteMDMAppleBootstrapPackage here as it would call the (non-premium)
		// current service implementation. We have to go through the Enterprise
		// extensions.
		if err := svc.EnterpriseOverrides.DeleteMDMAppleBootstrapPackage(ctx, nil); err != nil {
			return nil, ctxerr.Wrap(ctx, err, "delete Apple bootstrap package")
		}
	}

	// retrieve new app config with obfuscated secrets
	obfuscatedAppConfig, err := svc.ds.AppConfig(ctx)
	if err != nil {
		return nil, err
	}
	obfuscatedAppConfig.Obfuscate()

	// if the agent options changed, create the corresponding activity
	newAgentOptions := ""
	if obfuscatedAppConfig.AgentOptions != nil {
		newAgentOptions = string(*obfuscatedAppConfig.AgentOptions)
	}
	if oldAgentOptions != newAgentOptions {
		if err := svc.ds.NewActivity(
			ctx,
			authz.UserFromContext(ctx),
			fleet.ActivityTypeEditedAgentOptions{
				Global: true,
			},
		); err != nil {
			return nil, ctxerr.Wrap(ctx, err, "create activity for app config agent options modification")
		}
	}

	// if the macOS minimum version requirement changed, create the corresponding
	// activity
	if oldAppConfig.MDM.MacOSUpdates.MinimumVersion.Value != appConfig.MDM.MacOSUpdates.MinimumVersion.Value ||
		oldAppConfig.MDM.MacOSUpdates.Deadline.Value != appConfig.MDM.MacOSUpdates.Deadline.Value {
		if err := svc.ds.NewActivity(
			ctx,
			authz.UserFromContext(ctx),
			fleet.ActivityTypeEditedMacOSMinVersion{
				MinimumVersion: appConfig.MDM.MacOSUpdates.MinimumVersion.Value,
				Deadline:       appConfig.MDM.MacOSUpdates.Deadline.Value,
			},
		); err != nil {
			return nil, ctxerr.Wrap(ctx, err, "create activity for app config macos min version modification")
		}
	}

	if oldAppConfig.MDM.MacOSSettings.EnableDiskEncryption != appConfig.MDM.MacOSSettings.EnableDiskEncryption {
		var act fleet.ActivityDetails
		if appConfig.MDM.MacOSSettings.EnableDiskEncryption {
			act = fleet.ActivityTypeEnabledMacosDiskEncryption{}
			if err := svc.EnterpriseOverrides.MDMAppleEnableFileVaultAndEscrow(ctx, nil); err != nil {
				return nil, ctxerr.Wrap(ctx, err, "enable no-team filevault and escrow")
			}
		} else {
			act = fleet.ActivityTypeDisabledMacosDiskEncryption{}
			if err := svc.EnterpriseOverrides.MDMAppleDisableFileVaultAndEscrow(ctx, nil); err != nil {
				return nil, ctxerr.Wrap(ctx, err, "disable no-team filevault and escrow")
			}
		}
		if err := svc.ds.NewActivity(ctx, authz.UserFromContext(ctx), act); err != nil {
			return nil, ctxerr.Wrap(ctx, err, "create activity for app config macos disk encryption")
		}
	}

	mdmEnableEndUserAuthChanged := oldAppConfig.MDM.MacOSSetup.EnableEndUserAuthentication != appConfig.MDM.MacOSSetup.EnableEndUserAuthentication
	if mdmEnableEndUserAuthChanged {
		var act fleet.ActivityDetails
		if appConfig.MDM.MacOSSetup.EnableEndUserAuthentication {
			act = fleet.ActivityTypeEnabledMacosSetupEndUserAuth{}
		} else {
			act = fleet.ActivityTypeDisabledMacosSetupEndUserAuth{}
		}
		if err := svc.ds.NewActivity(ctx, authz.UserFromContext(ctx), act); err != nil {
			return nil, ctxerr.Wrap(ctx, err, "create activity for macos enable end user auth change")
		}
	}

	mdmSSOSettingsChanged := oldAppConfig.MDM.EndUserAuthentication.SSOProviderSettings !=
		appConfig.MDM.EndUserAuthentication.SSOProviderSettings
	serverURLChanged := oldAppConfig.ServerSettings.ServerURL != appConfig.ServerSettings.ServerURL
	if (mdmEnableEndUserAuthChanged || mdmSSOSettingsChanged || serverURLChanged) && license.IsPremium() {
		if err := svc.EnterpriseOverrides.MDMAppleSyncDEPProfiles(ctx); err != nil {
			return nil, ctxerr.Wrap(ctx, err, "sync DEP profiles")
		}
	}

	// if Windows MDM was enabled or disabled, create the corresponding activity
	if oldAppConfig.MDM.WindowsEnabledAndConfigured != appConfig.MDM.WindowsEnabledAndConfigured {
		var act fleet.ActivityDetails
		if appConfig.MDM.WindowsEnabledAndConfigured {
			act = fleet.ActivityTypeEnabledWindowsMDM{}
		} else {
			act = fleet.ActivityTypeDisabledWindowsMDM{}
		}
		if err := svc.ds.NewActivity(ctx, authz.UserFromContext(ctx), act); err != nil {
			return nil, ctxerr.Wrapf(ctx, err, "create activity %s", act.ActivityName())
		}
	}

	return obfuscatedAppConfig, nil
}

func (svc *Service) validateMDM(
	ctx context.Context,
	license *fleet.LicenseInfo,
	oldMdm *fleet.MDM,
	mdm *fleet.MDM,
	invalid *fleet.InvalidArgumentError,
) {
	if mdm.MacOSSettings.EnableDiskEncryption && !license.IsPremium() {
		invalid.Append("macos_settings.enable_disk_encryption", ErrMissingLicense.Error())
	}
	if oldMdm.MacOSSetup.MacOSSetupAssistant.Value != mdm.MacOSSetup.MacOSSetupAssistant.Value && !license.IsPremium() {
		invalid.Append("macos_setup.macos_setup_assistant", ErrMissingLicense.Error())
	}
	if oldMdm.MacOSSetup.BootstrapPackage.Value != mdm.MacOSSetup.BootstrapPackage.Value && !license.IsPremium() {
		invalid.Append("macos_setup.bootstrap_package", ErrMissingLicense.Error())
	}
	if oldMdm.MacOSSetup.EnableEndUserAuthentication != mdm.MacOSSetup.EnableEndUserAuthentication && !license.IsPremium() {
		invalid.Append("macos_setup.enable_end_user_authentication", ErrMissingLicense.Error())
	}

	// we want to use `oldMdm` here as this boolean is set by the fleet
	// server at startup and can't be modified by the user
	if !oldMdm.EnabledAndConfigured {
		if len(mdm.MacOSSettings.CustomSettings) != len(oldMdm.MacOSSettings.CustomSettings) {
			invalid.Append("macos_settings.custom_settings",
				`Couldn't update macos_settings because MDM features aren't turned on in Fleet. Use fleetctl generate mdm-apple and then fleet serve with mdm configuration to turn on MDM features.`)
		}

		if mdm.MacOSSettings.EnableDiskEncryption {
			invalid.Append("macos_settings.enable_disk_encryption",
				`Couldn't update macos_settings because MDM features aren't turned on in Fleet. Use fleetctl generate mdm-apple and then fleet serve with mdm configuration to turn on MDM features.`)
		}

		if oldMdm.MacOSSetup.MacOSSetupAssistant.Value != mdm.MacOSSetup.MacOSSetupAssistant.Value {
			invalid.Append("macos_setup.macos_setup_assistant",
				`Couldn't update macos_setup because MDM features aren't turned on in Fleet. Use fleetctl generate mdm-apple and then fleet serve with mdm configuration to turn on MDM features.`)
		}

		if oldMdm.MacOSSetup.BootstrapPackage.Value != mdm.MacOSSetup.BootstrapPackage.Value {
			invalid.Append("macos_setup.bootstrap_package",
				`Couldn't update macos_setup because MDM features aren't turned on in Fleet. Use fleetctl generate mdm-apple and then fleet serve with mdm configuration to turn on MDM features.`)
		}
		if oldMdm.MacOSSetup.EnableEndUserAuthentication != mdm.MacOSSetup.EnableEndUserAuthentication {
			invalid.Append("macos_setup.enable_end_user_authentication",
				`Couldn't update macos_setup because MDM features aren't turned on in Fleet. Use fleetctl generate mdm-apple and then fleet serve with mdm configuration to turn on MDM features.`)
		}
	}

	if name := mdm.AppleBMDefaultTeam; name != "" && name != oldMdm.AppleBMDefaultTeam {
		if !license.IsPremium() {
			invalid.Append("mdm.apple_bm_default_team", ErrMissingLicense.Error())
			return
		}
		if _, err := svc.ds.TeamByName(ctx, name); err != nil {
			invalid.Append("apple_bm_default_team", "team name not found")
		}
	}

	// MacOSUpdates
	updatingVersion := mdm.MacOSUpdates.MinimumVersion.Value != "" &&
		mdm.MacOSUpdates.MinimumVersion != oldMdm.MacOSUpdates.MinimumVersion
	updatingDeadline := mdm.MacOSUpdates.Deadline.Value != "" &&
		mdm.MacOSUpdates.Deadline != oldMdm.MacOSUpdates.Deadline

	if updatingVersion || updatingDeadline {
		if !license.IsPremium() {
			invalid.Append("macos_updates.minimum_version", ErrMissingLicense.Error())
			return
		}
	}
	if err := mdm.MacOSUpdates.Validate(); err != nil {
		invalid.Append("macos_updates", err.Error())
	}

	// EndUserAuthentication
	// only validate SSO settings if they changed
	if mdm.EndUserAuthentication.SSOProviderSettings != oldMdm.EndUserAuthentication.SSOProviderSettings {
		if !license.IsPremium() {
			invalid.Append("end_user_authentication", ErrMissingLicense.Error())
			return
		}

		validateSSOProviderSettings(mdm.EndUserAuthentication.SSOProviderSettings, oldMdm.EndUserAuthentication.SSOProviderSettings, invalid)
	}

	// MacOSSetup validation
	if mdm.MacOSSetup.EnableEndUserAuthentication {
		if mdm.EndUserAuthentication.IsEmpty() {
			// TODO: update this error message to include steps to resolve the issue once docs for IdP
			// config are available
			invalid.Append("macos_setup.enable_end_user_authentication",
				`Couldn't enable macos_setup.enable_end_user_authentication because no IdP is configured for MDM features.`)
		}
	}

	updatingMacOSMigration := mdm.MacOSMigration.Enable != oldMdm.MacOSMigration.Enable ||
		mdm.MacOSMigration.Mode != oldMdm.MacOSMigration.Mode ||
		mdm.MacOSMigration.WebhookURL != oldMdm.MacOSMigration.WebhookURL

	// MacOSMigration validation
	if updatingMacOSMigration {
		if mdm.MacOSMigration.Enable {
			if license.Tier != fleet.TierPremium {
				invalid.Append("macos_migration.enable", ErrMissingLicense.Error())
				return
			}
			if !mdm.MacOSMigration.Mode.IsValid() {
				invalid.Append("macos_migration.mode", "mode must be one of 'voluntary' or 'forced'")
			}
			// TODO: improve url validation generally
			if u, err := url.ParseRequestURI(mdm.MacOSMigration.WebhookURL); err != nil {
				invalid.Append("macos_migration.webhook_url", err.Error())
			} else if u.Scheme != "https" && u.Scheme != "http" {
				invalid.Append("macos_migration.webhook_url", "webhook_url must be https or http")
			}
		}
	}

	// Windows validation
	if !config.IsMDMFeatureFlagEnabled() {
		if mdm.WindowsEnabledAndConfigured {
			invalid.Append("mdm.windows_enabled_and_configured", "cannot enable Windows MDM without the feature flag explicitly enabled")
			return
		}
	}
}

func validateSSOProviderSettings(incoming, existing fleet.SSOProviderSettings, invalid *fleet.InvalidArgumentError) {
	if incoming.Metadata == "" && incoming.MetadataURL == "" {
		if existing.Metadata == "" && existing.MetadataURL == "" {
			invalid.Append("metadata", "either metadata or metadata_url must be defined")
		}
	}
	if incoming.Metadata != "" && incoming.MetadataURL != "" {
		invalid.Append("metadata", "both metadata and metadata_url are defined, only one is allowed")
	}
	if incoming.EntityID == "" {
		if existing.EntityID == "" {
			invalid.Append("entity_id", "required")
		}
	} else if len(incoming.EntityID) < 5 {
		invalid.Append("entity_id", "must be 5 or more characters")
	}
	if incoming.IDPName == "" {
		if existing.IDPName == "" {
			invalid.Append("idp_name", "required")
		}
	}

	if incoming.MetadataURL != "" {
		if u, err := url.ParseRequestURI(incoming.MetadataURL); err != nil {
			invalid.Append("metadata_url", err.Error())
		} else if u.Scheme != "https" && u.Scheme != "http" {
			invalid.Append("metadata_url", "must be either https or http")
		}
	}
}

func validateSSOSettings(p fleet.AppConfig, existing *fleet.AppConfig, invalid *fleet.InvalidArgumentError, license *fleet.LicenseInfo) {
	if p.SSOSettings != nil && p.SSOSettings.EnableSSO {

		var existingSSOProviderSettings fleet.SSOProviderSettings
		if existing.SSOSettings != nil {
			existingSSOProviderSettings = existing.SSOSettings.SSOProviderSettings
		}
		validateSSOProviderSettings(p.SSOSettings.SSOProviderSettings, existingSSOProviderSettings, invalid)

		if !license.IsPremium() {
			if p.SSOSettings.EnableJITProvisioning {
				invalid.Append("enable_jit_provisioning", ErrMissingLicense.Error())
			}
		}
	}
}

// //////////////////////////////////////////////////////////////////////////////
// Apply enroll secret spec
// //////////////////////////////////////////////////////////////////////////////

type applyEnrollSecretSpecRequest struct {
	Spec *fleet.EnrollSecretSpec `json:"spec"`
}

type applyEnrollSecretSpecResponse struct {
	Err error `json:"error,omitempty"`
}

func (r applyEnrollSecretSpecResponse) error() error { return r.Err }

func applyEnrollSecretSpecEndpoint(ctx context.Context, request interface{}, svc fleet.Service) (errorer, error) {
	req := request.(*applyEnrollSecretSpecRequest)
	err := svc.ApplyEnrollSecretSpec(ctx, req.Spec)
	if err != nil {
		return applyEnrollSecretSpecResponse{Err: err}, nil
	}
	return applyEnrollSecretSpecResponse{}, nil
}

func (svc *Service) ApplyEnrollSecretSpec(ctx context.Context, spec *fleet.EnrollSecretSpec) error {
	if err := svc.authz.Authorize(ctx, &fleet.EnrollSecret{}, fleet.ActionWrite); err != nil {
		return err
	}
	if len(spec.Secrets) > fleet.MaxEnrollSecretsCount {
		return ctxerr.Wrap(ctx, fleet.NewInvalidArgumentError("secrets", "too many secrets"))
	}

	for _, s := range spec.Secrets {
		if s.Secret == "" {
			return ctxerr.New(ctx, "enroll secret must not be empty")
		}
	}

	if svc.config.Packaging.GlobalEnrollSecret != "" {
		return ctxerr.New(ctx, "enroll secret cannot be changed when fleet_packaging.global_enroll_secret is set")
	}

	return svc.ds.ApplyEnrollSecrets(ctx, nil, spec.Secrets)
}

// //////////////////////////////////////////////////////////////////////////////
// Get enroll secret spec
// //////////////////////////////////////////////////////////////////////////////

type getEnrollSecretSpecResponse struct {
	Spec *fleet.EnrollSecretSpec `json:"spec"`
	Err  error                   `json:"error,omitempty"`
}

func (r getEnrollSecretSpecResponse) error() error { return r.Err }

func getEnrollSecretSpecEndpoint(ctx context.Context, request interface{}, svc fleet.Service) (errorer, error) {
	specs, err := svc.GetEnrollSecretSpec(ctx)
	if err != nil {
		return getEnrollSecretSpecResponse{Err: err}, nil
	}
	return getEnrollSecretSpecResponse{Spec: specs}, nil
}

func (svc *Service) GetEnrollSecretSpec(ctx context.Context) (*fleet.EnrollSecretSpec, error) {
	if err := svc.authz.Authorize(ctx, &fleet.EnrollSecret{}, fleet.ActionRead); err != nil {
		return nil, err
	}

	secrets, err := svc.ds.GetEnrollSecrets(ctx, nil)
	if err != nil {
		return nil, err
	}
	return &fleet.EnrollSecretSpec{Secrets: secrets}, nil
}

// //////////////////////////////////////////////////////////////////////////////
// Version
// //////////////////////////////////////////////////////////////////////////////

type versionResponse struct {
	*version.Info
	Err error `json:"error,omitempty"`
}

func (r versionResponse) error() error { return r.Err }

func versionEndpoint(ctx context.Context, request interface{}, svc fleet.Service) (errorer, error) {
	info, err := svc.Version(ctx)
	if err != nil {
		return versionResponse{Err: err}, nil
	}
	return versionResponse{Info: info}, nil
}

func (svc *Service) Version(ctx context.Context) (*version.Info, error) {
	if err := svc.authz.Authorize(ctx, &fleet.Version{}, fleet.ActionRead); err != nil {
		return nil, err
	}

	info := version.Version()
	return &info, nil
}

// //////////////////////////////////////////////////////////////////////////////
// Get Certificate Chain
// //////////////////////////////////////////////////////////////////////////////

type getCertificateResponse struct {
	CertificateChain []byte `json:"certificate_chain"`
	Err              error  `json:"error,omitempty"`
}

func (r getCertificateResponse) error() error { return r.Err }

func getCertificateEndpoint(ctx context.Context, request interface{}, svc fleet.Service) (errorer, error) {
	chain, err := svc.CertificateChain(ctx)
	if err != nil {
		return getCertificateResponse{Err: err}, nil
	}
	return getCertificateResponse{CertificateChain: chain}, nil
}

// Certificate returns the PEM encoded certificate chain for osqueryd TLS termination.
func (svc *Service) CertificateChain(ctx context.Context) ([]byte, error) {
	config, err := svc.AppConfigObfuscated(ctx)
	if err != nil {
		return nil, err
	}

	u, err := url.Parse(config.ServerSettings.ServerURL)
	if err != nil {
		return nil, ctxerr.Wrap(ctx, err, "parsing serverURL")
	}

	conn, err := connectTLS(ctx, u)
	if err != nil {
		return nil, err
	}

	return chain(ctx, conn.ConnectionState(), u.Hostname())
}

func connectTLS(ctx context.Context, serverURL *url.URL) (*tls.Conn, error) {
	var hostport string
	if serverURL.Port() == "" {
		hostport = net.JoinHostPort(serverURL.Host, "443")
	} else {
		hostport = serverURL.Host
	}

	// attempt dialing twice, first with a secure conn, and then
	// if that fails, use insecure
	dial := func(insecure bool) (*tls.Conn, error) {
		conn, err := tls.Dial("tcp", hostport, &tls.Config{
			InsecureSkipVerify: insecure,
		})
		if err != nil {
			return nil, ctxerr.Wrap(ctx, err, "dial tls")
		}
		defer conn.Close()
		return conn, nil
	}

	var (
		conn *tls.Conn
		err  error
	)

	conn, err = dial(false)
	if err == nil {
		return conn, nil
	}
	conn, err = dial(true)
	return conn, err
}

// chain builds a PEM encoded certificate chain using the PeerCertificates
// in tls.ConnectionState. chain uses the hostname to omit the Leaf certificate
// from the chain.
func chain(ctx context.Context, cs tls.ConnectionState, hostname string) ([]byte, error) {
	buf := bytes.NewBuffer([]byte(""))

	verifyEncode := func(chain []*x509.Certificate) error {
		for _, cert := range chain {
			if len(chain) > 1 {
				// drop the leaf certificate from the chain. osqueryd does not
				// need it to establish a secure connection
				if err := cert.VerifyHostname(hostname); err == nil {
					continue
				}
			}
			if err := encodePEMCertificate(buf, cert); err != nil {
				return err
			}
		}
		return nil
	}

	// use verified chains if available(which adds the root CA), otherwise
	// use the certificate chain offered by the server (if terminated with
	// self-signed certs)
	if len(cs.VerifiedChains) != 0 {
		for _, chain := range cs.VerifiedChains {
			if err := verifyEncode(chain); err != nil {
				return nil, ctxerr.Wrap(ctx, err, "encode verified chains pem")
			}
		}
	} else {
		if err := verifyEncode(cs.PeerCertificates); err != nil {
			return nil, ctxerr.Wrap(ctx, err, "encode peer certificates pem")
		}
	}
	return buf.Bytes(), nil
}

func encodePEMCertificate(buf io.Writer, cert *x509.Certificate) error {
	block := &pem.Block{
		Type:  "CERTIFICATE",
		Bytes: cert.Raw,
	}
	return pem.Encode(buf, block)
}

func (svc *Service) HostFeatures(ctx context.Context, host *fleet.Host) (*fleet.Features, error) {
	if svc.EnterpriseOverrides != nil {
		return svc.EnterpriseOverrides.HostFeatures(ctx, host)
	}

	appConfig, err := svc.ds.AppConfig(ctx)
	if err != nil {
		return nil, err
	}
	return &appConfig.Features, nil
}