Improve firewall core logic, add prompt support via notifications

This commit is contained in:
Daniel 2019-03-08 23:15:36 +01:00
parent d596bd07ca
commit 5f21f7bc60
5 changed files with 372 additions and 128 deletions

View file

@ -3,6 +3,7 @@ package core
import (
"github.com/Safing/portbase/database"
"github.com/Safing/portbase/modules"
"github.com/Safing/portbase/notifications"
// module dependencies
_ "github.com/Safing/portbase/database/dbmodule"
@ -11,6 +12,8 @@ import (
func init() {
modules.Register("core", nil, start, nil, "database")
notifications.SetPersistenceBasePath("core:notifications")
}
func start() error {

View file

@ -179,23 +179,8 @@ func initialHandler(pkt packet.Packet, link *network.Link) {
return
}
// check if communication needs reevaluation
if comm.NeedsReevaluation() {
comm.ResetVerdict()
}
// make a decision if not made already
switch comm.GetVerdict() {
case network.VerdictUndecided, network.VerdictUndeterminable:
DecideOnCommunication(comm, pkt)
}
switch comm.GetVerdict() {
case network.VerdictUndecided, network.VerdictUndeterminable, network.VerdictAccept:
DecideOnLink(comm, link, pkt)
default:
link.UpdateVerdict(comm.GetVerdict())
}
DecideOnCommunication(comm, pkt)
DecideOnLink(comm, link, pkt)
// log decision
logInitialVerdict(link)

View file

@ -5,8 +5,10 @@ import (
"net"
"os"
"strings"
"time"
"github.com/Safing/portbase/log"
"github.com/Safing/portbase/notifications"
"github.com/Safing/portmaster/intel"
"github.com/Safing/portmaster/network"
"github.com/Safing/portmaster/network/netutils"
@ -32,6 +34,16 @@ import (
// DecideOnCommunicationBeforeIntel makes a decision about a communication before the dns query is resolved and intel is gathered.
func DecideOnCommunicationBeforeIntel(comm *network.Communication, fqdn string) {
// check if communication needs reevaluation
if comm.NeedsReevaluation() {
comm.ResetVerdict()
}
// check if need to run
if comm.GetVerdict() != network.VerdictUndecided {
return
}
// grant self
if comm.Process().Pid == os.Getpid() {
log.Infof("firewall: granting own communication %s", comm)
@ -60,112 +72,155 @@ func DecideOnCommunicationBeforeIntel(comm *network.Communication, fqdn string)
switch result {
case profile.NoMatch:
comm.UpdateVerdict(network.VerdictUndecided)
if profileSet.GetProfileMode() == profile.Whitelist {
log.Infof("firewall: denying communication %s, domain is not whitelisted", comm)
comm.Deny("domain is not whitelisted")
}
case profile.Undeterminable:
comm.UpdateVerdict(network.VerdictUndeterminable)
return
case profile.Denied:
log.Infof("firewall: denying communication %s, endpoint is blacklisted: %s", comm, reason)
comm.Deny(fmt.Sprintf("endpoint is blacklisted: %s", reason))
return
case profile.Permitted:
log.Infof("firewall: permitting communication %s, endpoint is whitelisted: %s", comm, reason)
comm.Accept(fmt.Sprintf("endpoint is whitelisted: %s", reason))
}
}
// DecideOnCommunicationAfterIntel makes a decision about a communication after the dns query is resolved and intel is gathered.
func DecideOnCommunicationAfterIntel(comm *network.Communication, fqdn string, rrCache *intel.RRCache) {
// check if need to run
if comm.GetVerdict() != network.VerdictUndecided {
return
}
// grant self - should not get here
if comm.Process().Pid == os.Getpid() {
log.Infof("firewall: granting own communication %s", comm)
comm.Accept("")
return
}
// check if there is a profile
profileSet := comm.Process().ProfileSet()
if profileSet == nil {
log.Errorf("firewall: denying communication %s, no Profile Set", comm)
comm.Deny("no Profile Set")
return
}
profileSet.Update(status.ActiveSecurityLevel())
// TODO: Stamp integration
switch profileSet.GetProfileMode() {
case profile.Whitelist:
log.Infof("firewall: denying communication %s, domain is not whitelisted", comm)
comm.Deny("domain is not whitelisted")
return
case profile.Prompt:
// check Related flag
// TODO: improve this!
if profileSet.CheckFlag(profile.Related) {
matched := false
pathElements := strings.Split(comm.Process().Path, "/") // FIXME: path seperator
// only look at the last two path segments
if len(pathElements) > 2 {
pathElements = pathElements[len(pathElements)-2:]
}
domainElements := strings.Split(fqdn, ".")
var domainElement string
var processElement string
matchLoop:
for _, domainElement = range domainElements {
for _, pathElement := range pathElements {
if levenshtein.Match(domainElement, pathElement, nil) > 0.5 {
matched = true
processElement = pathElement
break matchLoop
}
}
if levenshtein.Match(domainElement, profileSet.UserProfile().Name, nil) > 0.5 {
matched = true
processElement = profileSet.UserProfile().Name
break matchLoop
}
if levenshtein.Match(domainElement, comm.Process().Name, nil) > 0.5 {
matched = true
processElement = comm.Process().Name
break matchLoop
}
if levenshtein.Match(domainElement, comm.Process().ExecName, nil) > 0.5 {
matched = true
processElement = comm.Process().ExecName
break matchLoop
}
}
if matched {
log.Infof("firewall: permitting communication %s, match to domain was found: %s ~== %s", comm, domainElement, processElement)
comm.Accept("domain is related to process")
}
}
if comm.GetVerdict() != network.VerdictAccept {
// TODO
log.Infof("firewall: permitting communication %s, domain permitted (prompting is not yet implemented)", comm)
comm.Accept("domain permitted (prompting is not yet implemented)")
}
return
case profile.Blacklist:
log.Infof("firewall: permitting communication %s, domain is not blacklisted", comm)
comm.Accept("domain is not blacklisted")
return
}
log.Infof("firewall: denying communication %s, no profile mode set", comm)
comm.Deny("no profile mode set")
}
// ProfileMode == Prompt
// DecideOnCommunicationAfterIntel makes a decision about a communication after the dns query is resolved and intel is gathered.
func DecideOnCommunicationAfterIntel(comm *network.Communication, fqdn string, rrCache *intel.RRCache) {
// check relation
if profileSet.CheckFlag(profile.Related) {
if checkRelation(comm, fqdn) {
return
}
}
// SUSPENDED until Stamp integration is finished
// prompt
// grant self - should not get here
// if comm.Process().Pid == os.Getpid() {
// log.Infof("firewall: granting own communication %s", comm)
// comm.Accept("")
// return
// }
// first check if there is an existing notification for this.
nID := fmt.Sprintf("firewall-prompt-%d-%s", comm.Process().Pid, comm.Domain)
nTTL := 15 * time.Second
n := notifications.Get(nID)
if n != nil {
// we were not here first, only get verdict, do not make changes
select {
case promptResponse := <-n.Response():
switch promptResponse {
case "permit-all", "permit-distinct":
comm.Accept("permitted by user")
default:
comm.Deny("denied by user")
}
case <-time.After(nTTL):
comm.SetReason("user did not respond to prompt")
}
return
}
// check if there is a profile
// profileSet := comm.Process().ProfileSet()
// if profileSet == nil {
// log.Errorf("firewall: denying communication %s, no Profile Set", comm)
// comm.Deny("no Profile Set")
// return
// }
// profileSet.Update(status.ActiveSecurityLevel())
// create new notification
n = (&notifications.Notification{
ID: nID,
Message: fmt.Sprintf("Application %s wants to connect to %s", comm.Process(), comm.Domain),
Type: notifications.Prompt,
AvailableActions: []*notifications.Action{
&notifications.Action{
ID: "permit-all",
Text: fmt.Sprintf("Permit all %s", comm.Domain),
},
&notifications.Action{
ID: "permit-distinct",
Text: fmt.Sprintf("Permit %s", comm.Domain),
},
&notifications.Action{
ID: "deny",
Text: "Deny",
},
},
Expires: time.Now().Add(nTTL).Unix(),
}).Init().Save()
// TODO: Stamp integration
// react
select {
case promptResponse := <-n.Response():
n.Cancel()
return
new := &profile.EndpointPermission{
Type: profile.EptDomain,
Value: comm.Domain,
Permit: true,
Created: time.Now().Unix(),
}
switch promptResponse {
case "permit-all":
new.Value = "." + new.Value
case "permit-distinct":
// everything already set
default:
// deny
new.Permit = false
}
if new.Permit {
log.Infof("firewall: user permitted communication %s -> %s", comm.Process(), new.Value)
comm.Accept("permitted by user")
} else {
log.Infof("firewall: user denied communication %s -> %s", comm.Process(), new.Value)
comm.Deny("denied by user")
}
profileSet.Lock()
defer profileSet.Unlock()
userProfile := profileSet.UserProfile()
userProfile.Lock()
defer userProfile.Unlock()
userProfile.Endpoints = append(userProfile.Endpoints, new)
go userProfile.Save("")
case <-time.After(nTTL):
n.Cancel()
comm.SetReason("user did not respond to prompt")
}
}
// FilterDNSResponse filters a dns response according to the application profile and settings.
@ -258,7 +313,7 @@ func FilterDNSResponse(comm *network.Communication, fqdn string, rrCache *intel.
}
// filter by endpoints
result, _ = profileSet.CheckEndpointIP("", ip, 0, 0, false)
result, _ = profileSet.CheckEndpointIP(fqdn, ip, 0, 0, false)
if result == profile.Denied {
addressesRemoved++
rrCache.FilteredEntries = append(rrCache.FilteredEntries, rr.String())
@ -298,6 +353,16 @@ func FilterDNSResponse(comm *network.Communication, fqdn string, rrCache *intel.
// DecideOnCommunication makes a decision about a communication with its first packet.
func DecideOnCommunication(comm *network.Communication, pkt packet.Packet) {
// check if communication needs reevaluation
if comm.NeedsReevaluation() {
comm.ResetVerdict()
}
// check if need to run
if comm.GetVerdict() != network.VerdictUndecided {
return
}
// grant self
if comm.Process().Pid == os.Getpid() {
log.Infof("firewall: granting own communication %s", comm)
@ -322,7 +387,7 @@ func DecideOnCommunication(comm *network.Communication, pkt packet.Packet) {
if comm.Domain == network.IncomingHost {
comm.Block("not a service")
} else {
comm.Drop("not a service")
comm.Deny("not a service")
}
return
}
@ -383,15 +448,19 @@ func DecideOnCommunication(comm *network.Communication, pkt packet.Packet) {
}
log.Infof("firewall: undeterminable verdict for communication %s", comm)
comm.UpdateVerdict(network.VerdictUndeterminable)
}
// DecideOnLink makes a decision about a link with the first packet.
func DecideOnLink(comm *network.Communication, link *network.Link, pkt packet.Packet) {
// check:
// Profile.Flags
// - network specific: Internet, LocalNet
// Profile.ConnectPorts
// Profile.ListenPorts
switch comm.GetVerdict() {
case network.VerdictUndecided, network.VerdictUndeterminable:
// continue
default:
link.UpdateVerdict(comm.GetVerdict())
return
}
// grant self
if comm.Process().Pid == os.Getpid() {
@ -410,9 +479,9 @@ func DecideOnLink(comm *network.Communication, link *network.Link, pkt packet.Pa
profileSet.Update(status.ActiveSecurityLevel())
// get domain
var domain string
var fqdn string
if strings.HasSuffix(comm.Domain, ".") {
domain = comm.Domain
fqdn = comm.Domain
}
// remoteIP
@ -432,10 +501,8 @@ func DecideOnLink(comm *network.Communication, link *network.Link, pkt packet.Pa
}
// check endpoints list
result, reason := profileSet.CheckEndpointIP(domain, remoteIP, protocol, dstPort, comm.Direction)
result, reason := profileSet.CheckEndpointIP(fqdn, remoteIP, protocol, dstPort, comm.Direction)
switch result {
// case profile.NoMatch, profile.Undeterminable:
// continue
case profile.Denied:
log.Infof("firewall: denying link %s, endpoint is blacklisted: %s", link, reason)
link.Deny(fmt.Sprintf("endpoint is blacklisted: %s", reason))
@ -446,21 +513,205 @@ func DecideOnLink(comm *network.Communication, link *network.Link, pkt packet.Pa
return
}
// TODO: Stamp integration
switch profileSet.GetProfileMode() {
case profile.Whitelist:
log.Infof("firewall: denying link %s: endpoint is not whitelisted", link)
link.Deny("endpoint is not whitelisted")
return
case profile.Prompt:
log.Infof("firewall: permitting link %s: endpoint is not blacklisted (prompting is not yet implemented)", link)
link.Accept("endpoint is not blacklisted (prompting is not yet implemented)")
return
case profile.Blacklist:
log.Infof("firewall: permitting link %s: endpoint is not blacklisted", link)
link.Accept("endpoint is not blacklisted")
return
}
log.Infof("firewall: denying link %s, no profile mode set", link)
link.Deny("no profile mode set")
// ProfileMode == Prompt
// check relation
if fqdn != "" && profileSet.CheckFlag(profile.Related) {
if checkRelation(comm, fqdn) {
return
}
}
// first check if there is an existing notification for this.
var nID string
switch {
case comm.Direction:
nID = fmt.Sprintf("firewall-prompt-%d-%s-%s-%d-%d", comm.Process().Pid, comm.Domain, remoteIP, protocol, dstPort)
case fqdn == "":
nID = fmt.Sprintf("firewall-prompt-%d-%s-%s-%d-%d", comm.Process().Pid, comm.Domain, remoteIP, protocol, dstPort)
default:
nID = fmt.Sprintf("firewall-prompt-%d-%s-%s-%d-%d", comm.Process().Pid, comm.Domain, remoteIP, protocol, dstPort)
}
nTTL := 15 * time.Second
n := notifications.Get(nID)
if n != nil {
// we were not here first, only get verdict, do not make changes
select {
case promptResponse := <-n.Response():
switch promptResponse {
case "permit-domain-all", "permit-domain-distinct", "permit-ip", "permit-ip-incoming":
link.Accept("permitted by user")
default:
link.Deny("denied by user")
}
case <-time.After(nTTL):
link.Deny("user did not respond to prompt")
}
return
}
// create new notification
n = (&notifications.Notification{
ID: nID,
Type: notifications.Prompt,
Expires: time.Now().Add(nTTL).Unix(),
})
switch {
case comm.Direction:
n.Message = fmt.Sprintf("Application %s wants to accept connections from %s (%d/%d)", comm.Process(), remoteIP, protocol, dstPort)
n.AvailableActions = []*notifications.Action{
&notifications.Action{
ID: "permit-ip-incoming",
Text: fmt.Sprintf("Permit serving to %s", remoteIP),
},
}
case fqdn == "":
n.Message = fmt.Sprintf("Application %s wants to connect to %s (%d/%d)", comm.Process(), remoteIP, protocol, dstPort)
n.AvailableActions = []*notifications.Action{
&notifications.Action{
ID: "permit-ip",
Text: fmt.Sprintf("Permit %s", remoteIP),
},
}
default:
n.Message = fmt.Sprintf("Application %s wants to connect to %s (%s %d/%d)", comm.Process(), comm.Domain, remoteIP, protocol, dstPort)
n.AvailableActions = []*notifications.Action{
&notifications.Action{
ID: "permit-domain-all",
Text: fmt.Sprintf("Permit all %s", comm.Domain),
},
&notifications.Action{
ID: "permit-domain-distinct",
Text: fmt.Sprintf("Permit %s", comm.Domain),
},
}
}
n.AvailableActions = append(n.AvailableActions, &notifications.Action{
ID: "deny",
Text: "deny",
})
n.Init().Save()
// react
select {
case promptResponse := <-n.Response():
n.Cancel()
new := &profile.EndpointPermission{
Type: profile.EptDomain,
Value: comm.Domain,
Permit: true,
Created: time.Now().Unix(),
}
switch promptResponse {
case "permit-domain-all":
new.Value = "." + new.Value
case "permit-domain-distinct":
// everything already set
case "permit-ip", "permit-ip-incoming":
if pkt.GetIPHeader().Version == packet.IPv4 {
new.Type = profile.EptIPv4
} else {
new.Type = profile.EptIPv6
}
new.Value = remoteIP.String()
default:
// deny
new.Permit = false
}
if new.Permit {
log.Infof("firewall: user permitted link %s -> %s", comm.Process(), new.Value)
link.Accept("permitted by user")
} else {
log.Infof("firewall: user denied link %s -> %s", comm.Process(), new.Value)
link.Deny("denied by user")
}
profileSet.Lock()
defer profileSet.Unlock()
userProfile := profileSet.UserProfile()
userProfile.Lock()
defer userProfile.Unlock()
if promptResponse == "permit-ip-incoming" {
userProfile.ServiceEndpoints = append(userProfile.ServiceEndpoints, new)
} else {
userProfile.Endpoints = append(userProfile.Endpoints, new)
}
go userProfile.Save("")
case <-time.After(nTTL):
n.Cancel()
link.Deny("user did not respond to prompt")
}
}
func checkRelation(comm *network.Communication, fqdn string) (related bool) {
profileSet := comm.Process().ProfileSet()
if profileSet == nil {
return
}
// TODO: add #AI
pathElements := strings.Split(comm.Process().Path, "/") // FIXME: path seperator
// only look at the last two path segments
if len(pathElements) > 2 {
pathElements = pathElements[len(pathElements)-2:]
}
domainElements := strings.Split(fqdn, ".")
var domainElement string
var processElement string
matchLoop:
for _, domainElement = range domainElements {
for _, pathElement := range pathElements {
if levenshtein.Match(domainElement, pathElement, nil) > 0.5 {
related = true
processElement = pathElement
break matchLoop
}
}
if levenshtein.Match(domainElement, profileSet.UserProfile().Name, nil) > 0.5 {
related = true
processElement = profileSet.UserProfile().Name
break matchLoop
}
if levenshtein.Match(domainElement, comm.Process().Name, nil) > 0.5 {
related = true
processElement = comm.Process().Name
break matchLoop
}
if levenshtein.Match(domainElement, comm.Process().ExecName, nil) > 0.5 {
related = true
processElement = comm.Process().ExecName
break matchLoop
}
}
if related {
log.Infof("firewall: permitting communication %s, match to domain was found: %s is related to %s", comm, domainElement, processElement)
comm.Accept(fmt.Sprintf("domain is related to process: %s is related to %s", domainElement, processElement))
}
return
}

View file

@ -137,17 +137,11 @@ func handleRequest(w dns.ResponseWriter, query *dns.Msg) {
// [2/2] use this to time how long it takes to get process info
// log.Tracef("nameserver: took %s to get connection/process of %s request", time.Now().Sub(timed).String(), fqdn)
// check if communication needs reevaluation
if comm.NeedsReevaluation() {
comm.ResetVerdict()
}
// check profile before we even get intel and rr
if comm.GetVerdict() == network.VerdictUndecided || comm.GetVerdict() == network.VerdictUndeterminable {
// start = time.Now()
firewall.DecideOnCommunicationBeforeIntel(comm, fqdn)
// log.Tracef("nameserver: took %s to make decision", time.Since(start))
}
// start = time.Now()
firewall.DecideOnCommunicationBeforeIntel(comm, fqdn)
// log.Tracef("nameserver: took %s to make decision", time.Since(start))
if comm.GetVerdict() == network.VerdictBlock || comm.GetVerdict() == network.VerdictDrop {
nxDomain(w, query)
return
@ -170,11 +164,10 @@ func handleRequest(w dns.ResponseWriter, query *dns.Msg) {
comm.Unlock()
comm.Save()
// do a full check with intel
if comm.GetVerdict() == network.VerdictUndecided || comm.GetVerdict() == network.VerdictUndeterminable {
firewall.DecideOnCommunicationAfterIntel(comm, fqdn, rrCache)
}
if comm.GetVerdict() == network.VerdictBlock || comm.GetVerdict() == network.VerdictDrop {
// check with intel
firewall.DecideOnCommunicationAfterIntel(comm, fqdn, rrCache)
switch comm.GetVerdict() {
case network.VerdictUndecided, network.VerdictBlock, network.VerdictDrop:
nxDomain(w, query)
return
}

View file

@ -51,6 +51,7 @@ func (comm *Communication) ResetVerdict() {
defer comm.Unlock()
comm.Verdict = VerdictUndecided
comm.Reason = ""
}
// GetVerdict returns the current verdict.
@ -99,6 +100,17 @@ func (comm *Communication) UpdateVerdict(newVerdict Verdict) {
}
}
// SetReason sets/replaces a human readable string as to why a certain verdict was set in regard to this communication.
func (comm *Communication) SetReason(reason string) {
if reason == "" {
return
}
comm.Lock()
defer comm.Unlock()
comm.Reason = reason
}
// AddReason adds a human readable string as to why a certain verdict was set in regard to this communication.
func (comm *Communication) AddReason(reason string) {
if reason == "" {