Merge pull request #37 from safing/feature/firefox-doh

Add support for firefox canary domain for disabling DoH

firewall/bypassing.go

@@ -0,0 +1,19 @@
+package firewall
+
+import (
+	"strings"
+
+	"github.com/safing/portmaster/network"
+	"github.com/safing/portmaster/profile/endpoints"
+)
+
+// PreventBypassing checks if the connection should be denied or permitted
+// based on some bypass protection checks.
+func PreventBypassing(conn *network.Connection) (endpoints.EPResult, string) {
+	// Block firefox canary domain to disable DoH
+	if strings.ToLower(conn.Entity.Domain) == "use-application-dns.net." {
+		return endpoints.Denied, "blocked canary domain to prevent enabling DNS-over-HTTPs"
+	}
+
+	return endpoints.NoMatch, ""
+}

firewall/master.go

@@ -141,9 +141,24 @@ func DecideOnConnection(conn *network.Connection, pkt packet.Packet) { //nolint:
 		}
 	}
 
-	// check endpoints list
 	var result endpoints.EPResult
 	var reason string
+
+	if p.PreventBypassing() {
+		// check for bypass protection
+		result, reason := PreventBypassing(conn)
+		switch result {
+		case endpoints.Denied:
+			conn.Block("bypass prevention: " + reason)
+			return
+		case endpoints.Permitted:
+			conn.Accept("bypass prevention: " + reason)
+			return
+		case endpoints.NoMatch:
+		}
+	}
+
+	// check endpoints list
 	if conn.Inbound {
 		result, reason = p.MatchServiceEndpoint(conn.Entity)
 	} else {

intel/entity.go

@@ -151,7 +151,6 @@ func (e *Entity) getLocation() {
 	e.fetchLocationOnce.Do(func() {
 		// need IP!
 		if e.IP == nil {
-			log.Warningf("intel: cannot get location for %s data without IP", e.Domain)
 			return
 		}
 
@@ -224,11 +223,11 @@ func (e *Entity) getDomainLists() {
 		var domains = []string{domain}
 		if e.resolveSubDomainLists {
 			domains = splitDomain(domain)
-			log.Debugf("intel: subdomain list resolving is enabled, checking %v", domains)
+			log.Tracef("intel: subdomain list resolving is enabled, checking %v", domains)
 		}
 
 		for _, d := range domains {
-			log.Debugf("intel: loading domain list for %s", d)
+			log.Tracef("intel: loading domain list for %s", d)
 			list, err := filterlists.LookupDomain(d)
 			if err != nil {
 				log.Errorf("intel: failed to get domain blocklists for %s: %s", d, err)
@@ -278,7 +277,7 @@ func (e *Entity) getASNLists() {
 		return
 	}
 
-	log.Debugf("intel: loading ASN list for %d", asn)
+	log.Tracef("intel: loading ASN list for %d", asn)
 	e.loadAsnListOnce.Do(func() {
 		list, err := filterlists.LookupASNString(fmt.Sprintf("%d", asn))
 		if err != nil {
@@ -302,7 +301,7 @@ func (e *Entity) getCountryLists() {
 		return
 	}
 
-	log.Debugf("intel: loading country list for %s", country)
+	log.Tracef("intel: loading country list for %s", country)
 	e.loadCoutryListOnce.Do(func() {
 		list, err := filterlists.LookupCountry(country)
 		if err != nil {
@@ -335,7 +334,7 @@ func (e *Entity) getIPLists() {
 		return
 	}
 
-	log.Debugf("intel: loading IP list for %s", ip)
+	log.Tracef("intel: loading IP list for %s", ip)
 	e.loadIPListOnce.Do(func() {
 		list, err := filterlists.LookupIP(ip)
 

profile/config.go

@@ -53,6 +53,9 @@ var (
 
 	CfgOptionRemoveBlockedDNSKey = "filter/removeBlockedDNS"
 	cfgOptionRemoveBlockedDNS    config.IntOption // security level option
+
+	CfgOptionPreventBypassingKey = "filter/preventBypassing"
+	cfgOptionPreventBypassing    config.IntOption // security level option
 )
 
 func registerConfiguration() error {
@@ -325,5 +328,22 @@ Examples:
 	cfgOptionRemoveBlockedDNS = config.Concurrent.GetAsInt(CfgOptionRemoveBlockedDNSKey, int64(status.SecurityLevelsAll))
 	cfgIntOptions[CfgOptionRemoveBlockedDNSKey] = cfgOptionRemoveBlockedDNS
 
+	err = config.Register(&config.Option{
+		Name:            "Prevent Bypassing",
+		Key:             CfgOptionPreventBypassingKey,
+		Description:     "Prevent apps from bypassing the privacy filter: Firefox by disabling DNS-over-HTTPs",
+		OptType:         config.OptTypeInt,
+		ExpertiseLevel:  config.ExpertiseLevelUser,
+		ReleaseLevel:    config.ReleaseLevelBeta,
+		ExternalOptType: "security level",
+		DefaultValue:    status.SecurityLevelsAll,
+		ValidationRegex: "^(7|6|4)",
+	})
+	if err != nil {
+		return err
+	}
+	cfgOptionPreventBypassing = config.Concurrent.GetAsInt((CfgOptionPreventBypassingKey), int64(status.SecurityLevelsAll))
+	cfgIntOptions[CfgOptionPreventBypassingKey] = cfgOptionPreventBypassing
+
 	return nil
 }

profile/profile-layered.go

@@ -43,6 +43,7 @@ type LayeredProfile struct {
 	RemoveOutOfScopeDNS config.BoolOption
 	RemoveBlockedDNS    config.BoolOption
 	FilterSubDomains    config.BoolOption
+	PreventBypassing    config.BoolOption
 }
 
 // NewLayeredProfile returns a new layered profile based on the given local profile.
@@ -98,6 +99,10 @@ func NewLayeredProfile(localProfile *Profile) *LayeredProfile {
 		CfgOptionFilterSubDomainsKey,
 		cfgOptionFilterSubDomains,
 	)
+	new.PreventBypassing = new.wrapSecurityLevelOption(
+		CfgOptionPreventBypassingKey,
+		cfgOptionPreventBypassing,
+	)
 
 	// TODO: load linked profiles.
 
@@ -224,7 +229,7 @@ func (lp *LayeredProfile) MatchServiceEndpoint(entity *intel.Entity) (result end
 
 // MatchFilterLists matches the entity against the set of filter
 // lists.
-func (lp *LayeredProfile) MatchFilterLists(entity *intel.Entity) (result endpoints.EPResult, reason string) {
+func (lp *LayeredProfile) MatchFilterLists(entity *intel.Entity) (endpoints.EPResult, string) {
 	entity.ResolveSubDomainLists(lp.FilterSubDomains())
 
 	lookupMap, hasLists := entity.GetListsMap()