Files
go-away/lib/challenge/dnsbl/dnsbl.go

146 lines
3.4 KiB
Go

package http
import (
"context"
"errors"
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/utils"
"github.com/goccy/go-yaml"
"github.com/goccy/go-yaml/ast"
"net"
"net/http"
"time"
)
func init() {
challenge.Runtimes[Key] = FillRegistration
}
const Key = "dnsbl"
type Parameters struct {
VerifyProbability float64 `yaml:"verify-probability"`
Host string `yaml:"dnsbl-host"`
Timeout time.Duration `yaml:"dnsbl-timeout"`
Decay time.Duration `yaml:"dnsbl-decay"`
}
var DefaultParameters = Parameters{
VerifyProbability: 0.10,
Timeout: time.Second * 1,
Decay: time.Hour * 1,
Host: "dnsbl.dronebl.org",
}
func lookup(ctx context.Context, decay, timeout time.Duration, dnsbl *utils.DNSBL, decayMap *utils.DecayMap[[net.IPv6len]byte, utils.DNSBLResponse], ip net.IP) (utils.DNSBLResponse, error) {
var key [net.IPv6len]byte
copy(key[:], ip.To16())
result, ok := decayMap.Get(key)
if ok {
return result, nil
}
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
result, err := dnsbl.Lookup(ctx, ip)
if err != nil {
}
decayMap.Set(key, result, decay)
return result, err
}
type closer chan struct{}
func (c closer) Close() error {
select {
case <-c:
default:
close(c)
}
return nil
}
func FillRegistration(state challenge.StateInterface, reg *challenge.Registration, parameters ast.Node) error {
params := DefaultParameters
if parameters != nil {
ymlData, err := parameters.MarshalYAML()
if err != nil {
return err
}
err = yaml.Unmarshal(ymlData, &params)
if err != nil {
return err
}
}
if params.Host == "" {
return errors.New("empty host")
}
reg.Class = challenge.ClassTransparent
if params.VerifyProbability <= 0 {
//20% default
params.VerifyProbability = 0.20
} else if params.VerifyProbability > 1.0 {
params.VerifyProbability = 1.0
}
reg.VerifyProbability = params.VerifyProbability
decayMap := utils.NewDecayMap[[net.IPv6len]byte, utils.DNSBLResponse]()
dnsbl := utils.NewDNSBL(params.Host, &net.Resolver{
PreferGo: true,
})
ob := make(closer)
go func() {
ticker := time.NewTicker(params.Timeout / 3)
defer ticker.Stop()
for {
select {
case <-ticker.C:
decayMap.Decay()
case <-ob:
return
}
}
}()
// allow freeing the ticker/decay map
reg.Object = ob
reg.IssueChallenge = func(w http.ResponseWriter, r *http.Request, key challenge.Key, expiry time.Time) challenge.VerifyResult {
data := challenge.RequestDataFromContext(r.Context())
result, err := lookup(r.Context(), params.Decay, params.Timeout, dnsbl, decayMap, data.RemoteAddress.Addr().Unmap().AsSlice())
if err != nil {
data.State.Logger(r).Debug("dnsbl lookup failed", "address", data.RemoteAddress.Addr().String(), "result", result, "err", err)
}
if result.Bad() {
token, err := reg.IssueChallengeToken(state.PrivateKey(), key, nil, expiry, false)
if err != nil {
return challenge.VerifyResultFail
}
utils.SetCookie(data.CookiePrefix+reg.Name, token, expiry, w, r)
return challenge.VerifyResultNotOK
} else {
token, err := reg.IssueChallengeToken(state.PrivateKey(), key, nil, expiry, true)
if err != nil {
return challenge.VerifyResultFail
}
utils.SetCookie(data.CookiePrefix+reg.Name, token, expiry, w, r)
return challenge.VerifyResultOK
}
}
return nil
}