Condition, rules, state and action refactor / rewrite

Add nested rules
Add backend action, allow wildcard in backends
Remove poison from tree, update README with action table

Allow defining pass/fail actions on challenge,

Remove redirect/referer parameters on backend pass

Set challenge cookie tied to host

Rewrite DNSBL condition into a challenge

Allow passing an arbitrary path for assets to js challenges

Optimize programs exhaustively on compilation

Activation instead of map for CEL context, faster map access, new network override

Return valid host on cookie setting in case Host is an IP address.
bug: does not work with IPv6, see https://github.com/golang/go/issues/65521

Apply TLS fingerprinter on GetConfigForClient instead of GetCertificate

Cleanup go-away cookies before passing to backend

Code action for specifically replying with an HTTP code
This commit is contained in:
WeebDataHoarder
2025-04-19 00:42:18 +02:00
committed by WeebDataHoarder
parent 1c7fe1bed9
commit ead41055ca
58 changed files with 3258 additions and 2048 deletions

80
lib/action/backend.go Normal file
View File

@@ -0,0 +1,80 @@
package action
import (
"fmt"
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/goccy/go-yaml"
"github.com/goccy/go-yaml/ast"
"log/slog"
"net/http"
"regexp"
)
func init() {
Register[policy.RuleActionPROXY] = func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node) (Handler, error) {
params := ProxyDefaultSettings
if settings != nil {
ymlData, err := settings.MarshalYAML()
if err != nil {
return nil, err
}
err = yaml.Unmarshal(ymlData, &params)
if err != nil {
return nil, err
}
}
if params.Match != "" {
expr, err := regexp.Compile(params.Match)
if err != nil {
return nil, err
}
return Proxy{
Match: expr,
Rewrite: params.Rewrite,
Backend: params.Backend,
}, nil
}
return Proxy{
Backend: params.Backend,
}, nil
}
}
var ProxyDefaultSettings = ProxySettings{}
type ProxySettings struct {
Match string `yaml:"proxy-match"`
Rewrite string `yaml:"proxy-rewrite"`
Backend string `yaml:"proxy-backend"`
}
type Proxy struct {
Match *regexp.Regexp
Rewrite string
Backend string
}
func (a Proxy) Handle(logger *slog.Logger, w http.ResponseWriter, r *http.Request, done func() (backend http.Handler)) (next bool, err error) {
data := challenge.RequestDataFromContext(r.Context())
backend := data.State.GetBackend(a.Backend)
if backend == nil {
return false, fmt.Errorf("backend for %s not found", a.Backend)
}
if a.Match != nil {
// rewrite query
r.URL.Path = a.Match.ReplaceAllString(r.URL.Path, a.Rewrite)
}
// set headers, ignore reply
_ = done()
backend.ServeHTTP(w, r)
return false, nil
}

36
lib/action/block.go Normal file
View File

@@ -0,0 +1,36 @@
package action
import (
"fmt"
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/goccy/go-yaml/ast"
"log/slog"
"net/http"
)
func init() {
Register[policy.RuleActionBLOCK] = func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node) (Handler, error) {
return Block{
Code: http.StatusForbidden,
RuleHash: ruleHash,
}, nil
}
}
type Block struct {
Code int
RuleHash string
}
func (a Block) Handle(logger *slog.Logger, w http.ResponseWriter, r *http.Request, done func() (backend http.Handler)) (next bool, err error) {
logger.Info("request blocked")
data := challenge.RequestDataFromContext(r.Context())
w.Header().Set("Content-Type", "text/plain")
w.Header().Set("Connection", "close")
w.WriteHeader(a.Code)
_, _ = w.Write([]byte(fmt.Errorf("access blocked: blocked by administrative rule %s/%s", data.Id.String(), a.RuleHash).Error()))
return false, nil
}

178
lib/action/challenge.go Normal file
View File

@@ -0,0 +1,178 @@
package action
import (
"fmt"
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/goccy/go-yaml"
"github.com/goccy/go-yaml/ast"
"log/slog"
"net/http"
"strings"
)
func init() {
i := func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node, cont bool) (Handler, error) {
params := ChallengeDefaultSettings
if settings != nil {
ymlData, err := settings.MarshalYAML()
if err != nil {
return nil, err
}
err = yaml.Unmarshal(ymlData, &params)
if err != nil {
return nil, err
}
}
if params.Code == 0 {
params.Code = state.Settings().ChallengeResponseCode
}
var regs []*challenge.Registration
for _, regName := range params.Challenges {
if reg, ok := state.GetChallengeByName(regName); ok {
regs = append(regs, reg)
} else {
return nil, fmt.Errorf("challenge %s not found", regName)
}
}
if len(regs) == 0 {
return nil, fmt.Errorf("no registered challenges found in rule %s", ruleName)
}
passHandler, ok := Register[policy.RuleAction(strings.ToUpper(params.PassAction))]
if !ok {
return nil, fmt.Errorf("unknown pass action %s", params.PassAction)
}
passActionHandler, err := passHandler(state, ruleName, ruleHash, params.PassSettings)
if err != nil {
return nil, err
}
failHandler, ok := Register[policy.RuleAction(strings.ToUpper(params.FailAction))]
if !ok {
return nil, fmt.Errorf("unknown pass action %s", params.FailAction)
}
failActionHandler, err := failHandler(state, ruleName, ruleHash, params.FailSettings)
if err != nil {
return nil, err
}
return Challenge{
RuleHash: ruleHash,
Code: params.Code,
Continue: cont,
Challenges: regs,
PassAction: passActionHandler,
FailAction: failActionHandler,
}, nil
}
Register[policy.RuleActionCHALLENGE] = func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node) (Handler, error) {
return i(state, ruleName, ruleHash, settings, false)
}
Register[policy.RuleActionCHECK] = func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node) (Handler, error) {
return i(state, ruleName, ruleHash, settings, true)
}
}
var ChallengeDefaultSettings = ChallengeSettings{
PassAction: string(policy.RuleActionPASS),
FailAction: string(policy.RuleActionDENY),
}
type ChallengeSettings struct {
Code int `yaml:"http-code"`
Challenges []string `yaml:"challenges"`
PassAction string `yaml:"pass"`
PassSettings ast.Node `yaml:"pass-settings"`
// FailAction Executed in case no challenges match or
FailAction string `yaml:"fail"`
FailSettings ast.Node `yaml:"fail-settings"`
}
type Challenge struct {
RuleHash string
Code int
Continue bool
Challenges []*challenge.Registration
PassAction Handler
FailAction Handler
}
func (a Challenge) Handle(logger *slog.Logger, w http.ResponseWriter, r *http.Request, done func() (backend http.Handler)) (next bool, err error) {
data := challenge.RequestDataFromContext(r.Context())
for _, reg := range a.Challenges {
if data.HasValidChallenge(reg.Id()) {
if a.Continue {
return true, nil
}
// we passed!
return a.PassAction.Handle(logger.With("challenge", reg.Name), w, r, done)
}
}
// none matched, issue challenges in sequential priority
for _, reg := range a.Challenges {
result := data.ChallengeVerify[reg.Id()]
state := data.ChallengeState[reg.Id()]
if result.Ok() || result == challenge.VerifyResultSkip || state == challenge.VerifyStatePass {
// skip already ok'd challenges for some reason (TODO: why)
// also skip skipped challenges due to preconditions
continue
}
expiry := data.Expiration(reg.Duration)
key := challenge.GetChallengeKeyForRequest(data.State, reg, expiry, r)
data.State.ChallengeIssued(r, reg, r.URL.String(), logger)
result = reg.IssueChallenge(w, r, key, expiry)
data.ChallengeVerify[reg.Id()] = result
data.ChallengeState[reg.Id()] = challenge.VerifyStatePass
switch result {
case challenge.VerifyResultOK:
data.State.ChallengePassed(r, reg, r.URL.String(), logger)
if a.Continue {
return true, nil
}
return a.PassAction.Handle(logger.With("challenge", reg.Name), w, r, done)
case challenge.VerifyResultNotOK:
// we have had the challenge checked, but it's not ok!
// safe to continue
continue
case challenge.VerifyResultFail:
err := fmt.Errorf("challenge %s failed on issuance", reg.Name)
data.State.ChallengeFailed(r, reg, err, r.URL.String(), logger)
if reg.Class == challenge.ClassTransparent {
// allow continuing transparent challenges
continue
}
return a.FailAction.Handle(logger, w, r, done)
case challenge.VerifyResultNone:
// challenge was issued
if reg.Class == challenge.ClassTransparent {
// allow continuing transparent challenges
continue
}
// we cannot continue after issuance
return false, nil
case challenge.VerifyResultSkip:
// continue onto next one due to precondition
continue
}
}
// nothing matched, execute default action
return a.FailAction.Handle(logger, w, r, done)
}

47
lib/action/code.go Normal file
View File

@@ -0,0 +1,47 @@
package action
import (
"errors"
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/goccy/go-yaml"
"github.com/goccy/go-yaml/ast"
"log/slog"
"net/http"
)
func init() {
Register[policy.RuleActionCODE] = func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node) (Handler, error) {
params := CodeDefaultSettings
if settings != nil {
ymlData, err := settings.MarshalYAML()
if err != nil {
return nil, err
}
err = yaml.Unmarshal(ymlData, &params)
if err != nil {
return nil, err
}
}
if params.Code == 0 {
return nil, errors.New("http-code not set")
}
return Code(params.Code), nil
}
}
var CodeDefaultSettings = CodeSettings{}
type CodeSettings struct {
Code int `yaml:"http-code"`
}
type Code int
func (a Code) Handle(logger *slog.Logger, w http.ResponseWriter, r *http.Request, done func() (backend http.Handler)) (next bool, err error) {
w.WriteHeader(int(a))
return false, nil
}

31
lib/action/deny.go Normal file
View File

@@ -0,0 +1,31 @@
package action
import (
"fmt"
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/goccy/go-yaml/ast"
"log/slog"
"net/http"
)
func init() {
Register[policy.RuleActionDENY] = func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node) (Handler, error) {
return Deny{
Code: http.StatusForbidden,
RuleHash: ruleHash,
}, nil
}
}
type Deny struct {
Code int
RuleHash string
}
func (a Deny) Handle(logger *slog.Logger, w http.ResponseWriter, r *http.Request, done func() (backend http.Handler)) (next bool, err error) {
logger.Info("request denied")
data := challenge.RequestDataFromContext(r.Context())
data.State.ErrorPage(w, r, a.Code, fmt.Errorf("access denied: denied by administrative rule %s/%s", data.Id.String(), a.RuleHash), "")
return false, nil
}

39
lib/action/drop.go Normal file
View File

@@ -0,0 +1,39 @@
package action
import (
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/goccy/go-yaml/ast"
"log/slog"
"net/http"
)
func init() {
Register[policy.RuleActionDROP] = func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node) (Handler, error) {
return Drop{}, nil
}
}
type Drop struct {
}
func (a Drop) Handle(logger *slog.Logger, w http.ResponseWriter, r *http.Request, done func() (backend http.Handler)) (next bool, err error) {
logger.Info("request dropped")
if hj, ok := w.(http.Hijacker); ok {
if conn, _, err := hj.Hijack(); err == nil {
// drop without sending data
_ = conn.Close()
return false, nil
}
}
// fallback
w.Header().Set("Content-Type", "text/plain")
w.Header().Set("Content-Length", "0")
w.Header().Set("Connection", "close")
w.WriteHeader(http.StatusForbidden)
return false, nil
}

21
lib/action/none.go Normal file
View File

@@ -0,0 +1,21 @@
package action
import (
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/goccy/go-yaml/ast"
"log/slog"
"net/http"
)
func init() {
Register[policy.RuleActionNONE] = func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node) (Handler, error) {
return None{}, nil
}
}
type None struct{}
func (a None) Handle(logger *slog.Logger, w http.ResponseWriter, r *http.Request, done func() (backend http.Handler)) (next bool, err error) {
return true, nil
}

23
lib/action/pass.go Normal file
View File

@@ -0,0 +1,23 @@
package action
import (
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/goccy/go-yaml/ast"
"log/slog"
"net/http"
)
func init() {
Register[policy.RuleActionPASS] = func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node) (Handler, error) {
return Pass{}, nil
}
}
type Pass struct{}
func (a Pass) Handle(logger *slog.Logger, w http.ResponseWriter, r *http.Request, done func() (backend http.Handler)) (next bool, err error) {
logger.Debug("request passed")
done().ServeHTTP(w, r)
return false, nil
}

20
lib/action/register.go Normal file
View File

@@ -0,0 +1,20 @@
package action
import (
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/goccy/go-yaml/ast"
"log/slog"
"net/http"
)
type Handler interface {
// Handle An incoming request.
// If next is true, continue processing
// If next is false, stop processing. If passing to a backend, done() must be called beforehand to set headers.
Handle(logger *slog.Logger, w http.ResponseWriter, r *http.Request, done func() (backend http.Handler)) (next bool, err error)
}
type NewFunc func(state challenge.StateInterface, ruleName, ruleHash string, settings ast.Node) (Handler, error)
var Register = make(map[policy.RuleAction]NewFunc)

View File

@@ -1,125 +1,13 @@
package lib
import (
"crypto/sha256"
"encoding/binary"
"encoding/hex"
"errors"
"github.com/go-jose/go-jose/v4/jwt"
"net"
"net/http"
"strings"
"time"
_ "git.gammaspectra.live/git/go-away/lib/challenge/cookie"
_ "git.gammaspectra.live/git/go-away/lib/challenge/dnsbl"
_ "git.gammaspectra.live/git/go-away/lib/challenge/http"
_ "git.gammaspectra.live/git/go-away/lib/challenge/preload-link"
_ "git.gammaspectra.live/git/go-away/lib/challenge/refresh"
_ "git.gammaspectra.live/git/go-away/lib/challenge/resource-load"
_ "git.gammaspectra.live/git/go-away/lib/challenge/wasm"
)
type ChallengeInformation struct {
Name string `json:"name"`
Key []byte `json:"key"`
Result []byte `json:"result"`
Expiry *jwt.NumericDate `json:"exp,omitempty"`
NotBefore *jwt.NumericDate `json:"nbf,omitempty"`
IssuedAt *jwt.NumericDate `json:"iat,omitempty"`
}
func getRequestScheme(r *http.Request) string {
if proto := r.Header.Get("X-Forwarded-Proto"); proto == "http" || proto == "https" {
return proto
}
if r.TLS != nil {
return "https"
}
return "http"
}
func getRequestAddress(r *http.Request, clientHeader string) net.IP {
var ipStr string
if clientHeader != "" {
ipStr = r.Header.Get(clientHeader)
}
if ipStr != "" {
// handle X-Forwarded-For
ipStr = strings.Split(ipStr, ",")[0]
}
// fallback
if ipStr == "" {
parts := strings.Split(r.RemoteAddr, ":")
// drop port
ipStr = strings.Join(parts[:len(parts)-1], ":")
}
ipStr = strings.Trim(ipStr, "[]")
return net.ParseIP(ipStr)
}
type ChallengeKey []byte
const ChallengeKeySize = sha256.Size
func (k *ChallengeKey) Set(flags ChallengeKeyFlags) {
(*k)[0] |= uint8(flags)
}
func (k *ChallengeKey) Get(flags ChallengeKeyFlags) ChallengeKeyFlags {
return ChallengeKeyFlags((*k)[0] & uint8(flags))
}
func (k *ChallengeKey) Unset(flags ChallengeKeyFlags) {
(*k)[0] = (*k)[0] & ^(uint8(flags))
}
type ChallengeKeyFlags uint8
const (
ChallengeKeyFlagIsIPv4 = ChallengeKeyFlags(1 << iota)
)
func ChallengeKeyFromString(s string) (ChallengeKey, error) {
b, err := hex.DecodeString(s)
if err != nil {
return nil, err
}
if len(b) != ChallengeKeySize {
return nil, errors.New("invalid challenge key")
}
return ChallengeKey(b), nil
}
func (state *State) GetChallengeKeyForRequest(challengeName string, until time.Time, r *http.Request) ChallengeKey {
data := RequestDataFromContext(r.Context())
address := data.RemoteAddress
hasher := sha256.New()
hasher.Write([]byte("challenge\x00"))
hasher.Write([]byte(challengeName))
hasher.Write([]byte{0})
hasher.Write(address.To16())
hasher.Write([]byte{0})
// specific headers
for _, k := range []string{
"Accept-Language",
// General browser information
"User-Agent",
// TODO: not sent in preload
//"Sec-Ch-Ua",
//"Sec-Ch-Ua-Platform",
} {
hasher.Write([]byte(r.Header.Get(k)))
hasher.Write([]byte{0})
}
hasher.Write([]byte{0})
_ = binary.Write(hasher, binary.LittleEndian, until.UTC().Unix())
hasher.Write([]byte{0})
hasher.Write(state.publicKey)
hasher.Write([]byte{0})
sum := ChallengeKey(hasher.Sum(nil))
sum[0] = 0
if address.To4() != nil {
// Is IPv4, mark
sum.Set(ChallengeKeyFlagIsIPv4)
}
return ChallengeKey(sum)
}
// This file loads embedded challenge runtimes so their init() is called

47
lib/challenge/awaiter.go Normal file
View File

@@ -0,0 +1,47 @@
package challenge
import (
"context"
"github.com/alphadose/haxmap"
"sync/atomic"
)
type awaiterCallback func(result VerifyResult)
type Awaiter[K ~string | ~int64 | ~uint64] haxmap.Map[K, awaiterCallback]
func NewAwaiter[T ~string | ~int64 | ~uint64]() *Awaiter[T] {
return (*Awaiter[T])(haxmap.New[T, awaiterCallback]())
}
func (a *Awaiter[T]) Await(key T, ctx context.Context) VerifyResult {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
var result atomic.Int64
a.m().Set(key, func(receivedResult VerifyResult) {
result.Store(int64(receivedResult))
cancel()
})
// cleanup
defer a.m().Del(key)
<-ctx.Done()
return VerifyResult(result.Load())
}
func (a *Awaiter[T]) Solve(key T, result VerifyResult) {
if f, ok := a.m().GetAndDel(key); ok && f != nil {
f(result)
}
}
func (a *Awaiter[T]) m() *haxmap.Map[T, awaiterCallback] {
return (*haxmap.Map[T, awaiterCallback])(a)
}
func (a *Awaiter[T]) Close() error {
return nil
}

View File

@@ -0,0 +1,38 @@
package cookie
import (
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/utils"
"github.com/goccy/go-yaml/ast"
"net/http"
"time"
)
func init() {
challenge.Runtimes[Key] = FillRegistration
}
const Key = "cookie"
func FillRegistration(state challenge.StateInterface, reg *challenge.Registration, parameters ast.Node) error {
reg.Class = challenge.ClassBlocking
reg.IssueChallenge = func(w http.ResponseWriter, r *http.Request, key challenge.Key, expiry time.Time) challenge.VerifyResult {
token, err := reg.IssueChallengeToken(state.PrivateKey(), key, nil, expiry, true)
if err != nil {
return challenge.VerifyResultFail
}
utils.SetCookie(utils.CookiePrefix+reg.Name, token, expiry, w, r)
uri, err := challenge.RedirectUrl(r, reg)
if err != nil {
return challenge.VerifyResultFail
}
http.Redirect(w, r, uri.String(), http.StatusTemporaryRedirect)
return challenge.VerifyResultNone
}
return nil
}

171
lib/challenge/data.go Normal file
View File

@@ -0,0 +1,171 @@
package challenge
import (
"context"
"crypto/rand"
"encoding/hex"
"errors"
"fmt"
"git.gammaspectra.live/git/go-away/lib/condition"
"git.gammaspectra.live/git/go-away/utils"
"github.com/google/cel-go/cel"
"github.com/google/cel-go/common/types"
"github.com/google/cel-go/common/types/traits"
"net"
"net/http"
"net/textproto"
"time"
)
type requestDataContextKey struct {
}
func RequestDataFromContext(ctx context.Context) *RequestData {
return ctx.Value(requestDataContextKey{}).(*RequestData)
}
type RequestId [16]byte
func (id RequestId) String() string {
return hex.EncodeToString(id[:])
}
type RequestData struct {
Id RequestId
Time time.Time
ChallengeVerify map[Id]VerifyResult
ChallengeState map[Id]VerifyState
RemoteAddress net.IP
State StateInterface
r *http.Request
fp map[string]string
header traits.Mapper
query traits.Mapper
}
func CreateRequestData(r *http.Request, state StateInterface) (*http.Request, *RequestData) {
var data RequestData
// generate random id, todo: is this fast?
_, _ = rand.Read(data.Id[:])
data.RemoteAddress = utils.GetRequestAddress(r, state.Settings().ClientIpHeader)
data.ChallengeVerify = make(map[Id]VerifyResult, len(state.GetChallenges()))
data.ChallengeState = make(map[Id]VerifyState, len(state.GetChallenges()))
data.Time = time.Now().UTC()
data.State = state
data.r = r
data.fp = make(map[string]string, 2)
if fp := utils.GetTLSFingerprint(r); fp != nil {
if ja3nPtr := fp.JA3N(); ja3nPtr != nil {
ja3n := ja3nPtr.String()
data.fp["ja3n"] = ja3n
r.Header.Set("X-TLS-Fingerprint-JA3N", ja3n)
}
if ja4Ptr := fp.JA4(); ja4Ptr != nil {
ja4 := ja4Ptr.String()
data.fp["ja4"] = ja4
r.Header.Set("X-TLS-Fingerprint-JA4", ja4)
}
}
data.query = condition.NewValuesMap(r.URL.Query())
data.header = condition.NewMIMEMap(textproto.MIMEHeader(r.Header))
r = r.WithContext(context.WithValue(r.Context(), requestDataContextKey{}, &data))
return r, &data
}
func (d *RequestData) ResolveName(name string) (any, bool) {
switch name {
case "host":
return d.r.Host, true
case "method":
return d.r.Method, true
case "remoteAddress":
return d.RemoteAddress, true
case "userAgent":
return d.r.UserAgent(), true
case "path":
return d.r.URL.Path, true
case "query":
return d.query, true
case "headers":
return d.header, true
case "fp":
return d.fp, true
default:
return nil, false
}
}
func (d *RequestData) Parent() cel.Activation {
return nil
}
func (d *RequestData) EvaluateChallenges(w http.ResponseWriter, r *http.Request) {
for _, reg := range d.State.GetChallenges() {
key := GetChallengeKeyForRequest(d.State, reg, d.Expiration(reg.Duration), r)
verifyResult, verifyState, err := reg.VerifyChallengeToken(d.State.PublicKey(), key, r)
if err != nil && !errors.Is(err, http.ErrNoCookie) {
// clear invalid cookie
utils.ClearCookie(utils.CookiePrefix+reg.Name, w, r)
}
// prevent evaluating the challenge if not solved
if !verifyResult.Ok() && reg.Condition != nil {
out, _, err := reg.Condition.Eval(d)
// verify eligibility
if err != nil {
d.State.Logger(r).Error(err.Error(), "challenge", reg.Name)
} else if out != nil && out.Type() == types.BoolType {
if out.Equal(types.True) != types.True {
// skip challenge match due to precondition!
verifyResult = VerifyResultSkip
continue
}
}
}
d.ChallengeVerify[reg.Id()] = verifyResult
d.ChallengeState[reg.Id()] = verifyState
}
if d.State.Settings().BackendIpHeader != "" {
if d.State.Settings().ClientIpHeader != "" {
r.Header.Del(d.State.Settings().ClientIpHeader)
}
r.Header.Set(d.State.Settings().BackendIpHeader, d.RemoteAddress.String())
}
// send these to client so we consistently get the headers
//w.Header().Set("Accept-CH", "Sec-CH-UA, Sec-CH-UA-Platform")
//w.Header().Set("Critical-CH", "Sec-CH-UA, Sec-CH-UA-Platform")
}
func (d *RequestData) Expiration(duration time.Duration) time.Time {
return d.Time.Add(duration).Round(duration)
}
func (d *RequestData) HasValidChallenge(id Id) bool {
return d.ChallengeVerify[id].Ok()
}
func (d *RequestData) Headers(headers http.Header) {
headers.Set("X-Away-Id", d.Id.String())
for id, result := range d.ChallengeVerify {
if result.Ok() {
c, ok := d.State.GetChallenge(id)
if !ok {
panic("challenge not found")
}
headers.Set(fmt.Sprintf("X-Away-Challenge-%s-Result", c.Name), result.String())
headers.Set(fmt.Sprintf("X-Away-Challenge-%s-State", c.Name), d.ChallengeState[id].String())
}
}
}

View File

@@ -0,0 +1,149 @@
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)
if err != nil {
data.State.Logger(r).Debug("dnsbl lookup failed", "address", data.RemoteAddress.String(), "result", result, "err", err)
}
if err != nil {
return challenge.VerifyResultFail
}
if result.Bad() {
token, err := reg.IssueChallengeToken(state.PrivateKey(), key, nil, expiry, false)
if err != nil {
return challenge.VerifyResultFail
}
utils.SetCookie(utils.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(utils.CookiePrefix+reg.Name, token, expiry, w, r)
return challenge.VerifyResultOK
}
}
return nil
}

164
lib/challenge/helper.go Normal file
View File

@@ -0,0 +1,164 @@
package challenge
import (
"crypto/subtle"
"encoding/hex"
"errors"
"fmt"
"git.gammaspectra.live/git/go-away/utils"
"net/http"
"net/url"
)
func NewKeyVerifier() (verify VerifyFunc, issue func(key Key) string) {
return func(key Key, token []byte, r *http.Request) (VerifyResult, error) {
expectedKey, err := hex.DecodeString(string(token))
if err != nil {
return VerifyResultFail, err
}
if subtle.ConstantTimeCompare(key[:], expectedKey) == 1 {
return VerifyResultOK, nil
}
return VerifyResultFail, errors.New("invalid token")
}, func(key Key) string {
return hex.EncodeToString(key[:])
}
}
const (
QueryArgPrefix = "__goaway"
QueryArgReferer = QueryArgPrefix + "_referer"
QueryArgRedirect = QueryArgPrefix + "_redirect"
QueryArgRequestId = QueryArgPrefix + "_id"
QueryArgChallenge = QueryArgPrefix + "_challenge"
QueryArgToken = QueryArgPrefix + "_token"
)
const MakeChallengeUrlSuffix = "/make-challenge"
const VerifyChallengeUrlSuffix = "/verify-challenge"
func GetVerifyInformation(r *http.Request, reg *Registration) (requestId RequestId, redirect, token string, err error) {
if r.FormValue(QueryArgChallenge) != reg.Name {
return RequestId{}, "", "", fmt.Errorf("unexpected challenge: got %s", r.FormValue(QueryArgChallenge))
}
requestIdHex := r.FormValue(QueryArgRequestId)
if len(requestId) != hex.DecodedLen(len(requestIdHex)) {
return RequestId{}, "", "", errors.New("invalid request id")
}
n, err := hex.Decode(requestId[:], []byte(requestIdHex))
if err != nil {
return RequestId{}, "", "", err
} else if n != len(requestId) {
return RequestId{}, "", "", errors.New("invalid request id")
}
token = r.FormValue(QueryArgToken)
redirect, err = utils.EnsureNoOpenRedirect(r.FormValue(QueryArgRedirect))
if err != nil {
return RequestId{}, "", "", err
}
return
}
func VerifyUrl(r *http.Request, reg *Registration, token string) (*url.URL, error) {
redirectUrl, err := RedirectUrl(r, reg)
if err != nil {
return nil, err
}
uri := new(url.URL)
uri.Path = reg.Path + VerifyChallengeUrlSuffix
data := RequestDataFromContext(r.Context())
values := uri.Query()
values.Set(QueryArgRequestId, data.Id.String())
values.Set(QueryArgRedirect, redirectUrl.String())
values.Set(QueryArgToken, token)
values.Set(QueryArgChallenge, reg.Name)
uri.RawQuery = values.Encode()
return uri, nil
}
func RedirectUrl(r *http.Request, reg *Registration) (*url.URL, error) {
uri, err := url.ParseRequestURI(r.URL.String())
if err != nil {
return nil, err
}
data := RequestDataFromContext(r.Context())
values := uri.Query()
values.Set(QueryArgRequestId, data.Id.String())
values.Set(QueryArgReferer, r.Referer())
values.Set(QueryArgChallenge, reg.Name)
uri.RawQuery = values.Encode()
return uri, nil
}
func VerifyHandlerChallengeResponseFunc(state StateInterface, data *RequestData, w http.ResponseWriter, r *http.Request, verifyResult VerifyResult, err error, redirect string) {
if err != nil {
state.ErrorPage(w, r, http.StatusBadRequest, err, redirect)
return
} else if !verifyResult.Ok() {
state.ErrorPage(w, r, http.StatusForbidden, fmt.Errorf("access denied: failed challenge"), redirect)
return
}
http.Redirect(w, r, redirect, http.StatusTemporaryRedirect)
}
func VerifyHandlerFunc(state StateInterface, reg *Registration, verify VerifyFunc, responseFunc func(state StateInterface, data *RequestData, w http.ResponseWriter, r *http.Request, verifyResult VerifyResult, err error, redirect string)) http.HandlerFunc {
if verify == nil {
verify = reg.Verify
}
if responseFunc == nil {
responseFunc = VerifyHandlerChallengeResponseFunc
}
return func(w http.ResponseWriter, r *http.Request) {
data := RequestDataFromContext(r.Context())
requestId, redirect, token, err := GetVerifyInformation(r, reg)
if err != nil {
state.ChallengeFailed(r, reg, err, "", nil)
responseFunc(state, data, w, r, VerifyResultFail, fmt.Errorf("internal error: %w", err), "")
return
}
data.Id = requestId
err = func() (err error) {
expiration := data.Expiration(reg.Duration)
key := GetChallengeKeyForRequest(state, reg, expiration, r)
verifyResult, err := verify(key, []byte(token), r)
if err != nil {
return err
} else if !verifyResult.Ok() {
utils.ClearCookie(utils.CookiePrefix+reg.Name, w, r)
state.ChallengeFailed(r, reg, nil, redirect, nil)
responseFunc(state, data, w, r, verifyResult, nil, redirect)
return nil
}
challengeToken, err := reg.IssueChallengeToken(state.PrivateKey(), key, []byte(token), expiration, true)
if err != nil {
utils.ClearCookie(utils.CookiePrefix+reg.Name, w, r)
} else {
utils.SetCookie(utils.CookiePrefix+reg.Name, challengeToken, expiration, w, r)
}
data.ChallengeVerify[reg.id] = verifyResult
state.ChallengePassed(r, reg, redirect, nil)
responseFunc(state, data, w, r, verifyResult, nil, redirect)
return nil
}()
if err != nil {
utils.ClearCookie(utils.CookiePrefix+reg.Name, w, r)
state.ChallengeFailed(r, reg, err, redirect, nil)
responseFunc(state, data, w, r, VerifyResultFail, fmt.Errorf("access denied: error in challenge %s: %w", reg.Name, err), redirect)
return
}
}
}

158
lib/challenge/http/http.go Normal file
View File

@@ -0,0 +1,158 @@
package http
import (
"crypto/sha256"
"crypto/subtle"
"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"
"io"
"net/http"
"slices"
"time"
)
func init() {
challenge.Runtimes[Key] = FillRegistration
}
const Key = "http"
type Parameters struct {
VerifyProbability float64 `yaml:"verify-probability"`
HttpMethod string `yaml:"http-method"`
HttpCode int `yaml:"http-code"`
HttpCookie string `yaml:"http-cookie"`
Url string `yaml:"http-url"`
}
var DefaultParameters = Parameters{
VerifyProbability: 0.20,
HttpMethod: http.MethodGet,
HttpCode: http.StatusOK,
}
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.Url == "" {
return errors.New("empty url")
}
reg.Class = challenge.ClassTransparent
bindAuthValue := func(key challenge.Key, r *http.Request) ([]byte, error) {
var cookieValue string
if cookie, err := r.Cookie(params.HttpCookie); err != nil || cookie == nil {
// skip check if we don't have cookie or it's expired
return nil, http.ErrNoCookie
} else {
cookieValue = cookie.Value
}
// bind hash of cookie contents
sum := sha256.New()
sum.Write([]byte(cookieValue))
sum.Write([]byte{0})
sum.Write(key[:])
return sum.Sum(nil), nil
}
if params.VerifyProbability <= 0 {
//20% default
params.VerifyProbability = 0.20
} else if params.VerifyProbability > 1.0 {
params.VerifyProbability = 1.0
}
reg.VerifyProbability = params.VerifyProbability
if params.HttpCookie != "" {
// re-verify the cookie value
// TODO: configure to verify with backend
reg.Verify = func(key challenge.Key, token []byte, r *http.Request) (challenge.VerifyResult, error) {
sum, err := bindAuthValue(key, r)
if err != nil {
return challenge.VerifyResultFail, err
}
if subtle.ConstantTimeCompare(sum, token) == 1 {
return challenge.VerifyResultOK, nil
}
return challenge.VerifyResultFail, errors.New("invalid cookie value")
}
}
reg.IssueChallenge = func(w http.ResponseWriter, r *http.Request, key challenge.Key, expiry time.Time) challenge.VerifyResult {
var sum []byte
if params.HttpCookie != "" {
if c, err := r.Cookie(params.HttpCookie); err != nil || c == nil {
// skip check if we don't have cookie or it's expired
return challenge.VerifyResultSkip
} else {
sum, err = bindAuthValue(key, r)
if err != nil {
return challenge.VerifyResultFail
}
}
}
request, err := http.NewRequest(params.HttpMethod, params.Url, nil)
if err != nil {
return challenge.VerifyResultFail
}
var excludeHeaders = []string{"Host", "Content-Length"}
for k, v := range r.Header {
if slices.Contains(excludeHeaders, k) {
// skip these parameters
continue
}
request.Header[k] = v
}
// set id
request.Header.Set("X-Away-Id", challenge.RequestDataFromContext(r.Context()).Id.String())
// set request info in X headers
request.Header.Set("X-Away-Host", r.Host)
request.Header.Set("X-Away-Path", r.URL.Path)
request.Header.Set("X-Away-Query", r.URL.RawQuery)
response, err := state.Client().Do(request)
if err != nil {
return challenge.VerifyResultFail
}
defer response.Body.Close()
defer io.Copy(io.Discard, response.Body)
if response.StatusCode != params.HttpCode {
token, err := reg.IssueChallengeToken(state.PrivateKey(), key, sum, expiry, false)
if err != nil {
return challenge.VerifyResultFail
}
utils.SetCookie(utils.CookiePrefix+reg.Name, token, expiry, w, r)
return challenge.VerifyResultNotOK
} else {
token, err := reg.IssueChallengeToken(state.PrivateKey(), key, sum, expiry, true)
if err != nil {
return challenge.VerifyResultFail
}
utils.SetCookie(utils.CookiePrefix+reg.Name, token, expiry, w, r)
return challenge.VerifyResultOK
}
}
return nil
}

80
lib/challenge/key.go Normal file
View File

@@ -0,0 +1,80 @@
package challenge
import (
"crypto/sha256"
"encoding/binary"
"encoding/hex"
"errors"
"net/http"
"time"
)
type Key [KeySize]byte
const KeySize = sha256.Size
func (k *Key) Set(flags KeyFlags) {
(*k)[0] |= uint8(flags)
}
func (k *Key) Get(flags KeyFlags) KeyFlags {
return KeyFlags((*k)[0] & uint8(flags))
}
func (k *Key) Unset(flags KeyFlags) {
(*k)[0] = (*k)[0] & ^(uint8(flags))
}
type KeyFlags uint8
const (
KeyFlagIsIPv4 = KeyFlags(1 << iota)
)
func KeyFromString(s string) (Key, error) {
b, err := hex.DecodeString(s)
if err != nil {
return Key{}, err
}
if len(b) != KeySize {
return Key{}, errors.New("invalid challenge key")
}
return Key(b), nil
}
func GetChallengeKeyForRequest(state StateInterface, reg *Registration, until time.Time, r *http.Request) Key {
data := RequestDataFromContext(r.Context())
address := data.RemoteAddress
hasher := sha256.New()
hasher.Write([]byte("challenge\x00"))
hasher.Write([]byte(reg.Name))
hasher.Write([]byte{0})
hasher.Write(address.To16())
hasher.Write([]byte{0})
// specific headers
for _, k := range []string{
"Accept-Language",
// General browser information
"User-Agent",
// TODO: not sent in preload
//"Sec-Ch-Ua",
//"Sec-Ch-Ua-Platform",
} {
hasher.Write([]byte(r.Header.Get(k)))
hasher.Write([]byte{0})
}
hasher.Write([]byte{0})
_ = binary.Write(hasher, binary.LittleEndian, until.UTC().Unix())
hasher.Write([]byte{0})
hasher.Write(state.PublicKey())
hasher.Write([]byte{0})
sum := Key(hasher.Sum(nil))
sum[0] = 0
if address.To4() != nil {
// Is IPv4, mark
sum.Set(KeyFlagIsIPv4)
}
return Key(sum)
}

View File

@@ -0,0 +1,128 @@
package preload_link
import (
"context"
"fmt"
"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/http"
"time"
)
func init() {
challenge.Runtimes[Key] = FillRegistration
}
const Key = "preload-link"
type Parameters struct {
Deadline time.Duration `yaml:"preload-early-hint-deadline"`
}
var DefaultParameters = Parameters{
Deadline: time.Second * 3,
}
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
}
}
verifier, issuer := challenge.NewKeyVerifier()
reg.Verify = verifier
reg.Class = challenge.ClassTransparent
ob := challenge.NewAwaiter[string]()
reg.Object = ob
reg.IssueChallenge = func(w http.ResponseWriter, r *http.Request, key challenge.Key, expiry time.Time) challenge.VerifyResult {
// this only works on HTTP/2 and HTTP/3
if r.ProtoMajor < 2 {
// this can happen if we are an upgraded request from HTTP/1.1 to HTTP/2 in H2C
if _, ok := w.(http.Pusher); !ok {
return challenge.VerifyResultSkip
}
}
issuerKey := issuer(key)
uri, err := challenge.VerifyUrl(r, reg, issuerKey)
if err != nil {
return challenge.VerifyResultFail
}
// remove redirect args
values := uri.Query()
values.Del(challenge.QueryArgRedirect)
uri.RawQuery = values.Encode()
// Redirect URI must be absolute to work
uri.Scheme = utils.GetRequestScheme(r)
uri.Host = r.Host
w.Header().Set("Link", fmt.Sprintf("<%s>; rel=\"preload\"; as=\"style\"; fetchpriority=high", uri.String()))
defer func() {
// remove old header so it won't show on response!
w.Header().Del("Link")
}()
w.WriteHeader(http.StatusEarlyHints)
ctx, cancel := context.WithTimeout(r.Context(), params.Deadline)
defer cancel()
if result := ob.Await(issuerKey, ctx); result.Ok() {
// this should serve!
return challenge.VerifyResultOK
} else if result == challenge.VerifyResultNone {
// we hit timeout
return challenge.VerifyResultFail
} else {
return result
}
}
mux := http.NewServeMux()
mux.HandleFunc("GET "+reg.Path+challenge.VerifyChallengeUrlSuffix, func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/css; charset=utf-8")
w.Header().Set("Content-Length", "0")
data := challenge.RequestDataFromContext(r.Context())
key := challenge.GetChallengeKeyForRequest(state, reg, data.Expiration(reg.Duration), r)
issuerKey := issuer(key)
_, _, token, err := challenge.GetVerifyInformation(r, reg)
if err != nil {
w.WriteHeader(http.StatusBadRequest)
}
verifyResult, _ := verifier(key, []byte(token), r)
if !verifyResult.Ok() {
w.WriteHeader(http.StatusUnauthorized)
} else {
w.WriteHeader(http.StatusOK)
}
ob.Solve(issuerKey, verifyResult)
if !verifyResult.Ok() {
// also give data on other failure when mismatched
ob.Solve(token, verifyResult)
}
})
reg.Handler = mux
return nil
}

View File

@@ -0,0 +1,64 @@
package refresh
import (
"git.gammaspectra.live/git/go-away/lib/challenge"
"github.com/goccy/go-yaml"
"github.com/goccy/go-yaml/ast"
"net/http"
"time"
)
func init() {
challenge.Runtimes["refresh"] = FillRegistration
}
type Parameters struct {
Mode string `yaml:"refresh-mode"`
}
var DefaultParameters = Parameters{
Mode: "header",
}
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
}
}
reg.Class = challenge.ClassBlocking
verifier, issuer := challenge.NewKeyVerifier()
reg.Verify = verifier
reg.IssueChallenge = func(w http.ResponseWriter, r *http.Request, key challenge.Key, expiry time.Time) challenge.VerifyResult {
uri, err := challenge.VerifyUrl(r, reg, issuer(key))
if err != nil {
return challenge.VerifyResultFail
}
if params.Mode == "meta" {
state.ChallengePage(w, r, state.Settings().ChallengeResponseCode, reg, map[string]any{
"Meta": map[string]string{
"refresh": "0; url=" + uri.String(),
},
})
} else {
// self redirect!
w.Header().Set("Refresh", "0; url="+uri.String())
state.ChallengePage(w, r, state.Settings().ChallengeResponseCode, reg, nil)
}
return challenge.VerifyResultNone
}
return nil
}

252
lib/challenge/register.go Normal file
View File

@@ -0,0 +1,252 @@
package challenge
import (
"bytes"
"crypto/ed25519"
"errors"
"fmt"
"git.gammaspectra.live/git/go-away/lib/condition"
"git.gammaspectra.live/git/go-away/lib/policy"
"git.gammaspectra.live/git/go-away/utils"
"github.com/go-jose/go-jose/v4"
"github.com/go-jose/go-jose/v4/jwt"
"github.com/goccy/go-yaml/ast"
"github.com/google/cel-go/cel"
"io"
"math/rand/v2"
"net/http"
"path"
"strings"
"time"
)
type Register map[Id]*Registration
func (r Register) Get(id Id) (*Registration, bool) {
c, ok := r[id]
return c, ok
}
func (r Register) GetByName(name string) (*Registration, Id, bool) {
for id, c := range r {
if c.Name == name {
return c, id, true
}
}
return nil, 0, false
}
var idCounter Id
// DefaultDuration TODO: adjust
const DefaultDuration = time.Hour * 24 * 7
func (r Register) Create(state StateInterface, name string, pol policy.Challenge, replacer *strings.Replacer) (*Registration, Id, error) {
runtime, ok := Runtimes[pol.Runtime]
if !ok {
return nil, 0, fmt.Errorf("unknown challenge runtime %s", pol.Runtime)
}
reg := &Registration{
Name: name,
Path: path.Join(state.UrlPath(), "challenge", name),
Duration: pol.Duration,
}
if reg.Duration == 0 {
reg.Duration = DefaultDuration
}
// allow nesting
var conditions []string
for _, cond := range pol.Conditions {
if replacer != nil {
cond = replacer.Replace(cond)
}
conditions = append(conditions, cond)
}
if len(conditions) > 0 {
ast, err := condition.FromStrings(state.ProgramEnv(), condition.OperatorOr, conditions...)
if err != nil {
return nil, 0, fmt.Errorf("error compiling conditions: %v", err)
}
reg.Condition, err = condition.Program(state.ProgramEnv(), ast)
if err != nil {
return nil, 0, fmt.Errorf("error compiling program: %v", err)
}
}
if _, oldId, ok := r.GetByName(reg.Name); ok {
reg.id = oldId
} else {
idCounter++
reg.id = idCounter
}
err := runtime(state, reg, pol.Parameters)
if err != nil {
return nil, 0, fmt.Errorf("error filling registration: %v", err)
}
r[reg.id] = reg
return reg, reg.id, nil
}
func (r Register) Add(c *Registration) Id {
if _, oldId, ok := r.GetByName(c.Name); ok {
c.id = oldId
r[oldId] = c
return oldId
} else {
idCounter++
c.id = idCounter
r[idCounter] = c
return idCounter
}
}
type Registration struct {
// id The assigned internal identifier
id Id
// Name The unique name for this challenge
Name string
// Class whether this challenge is transparent or otherwise
Class Class
// Condition A CEL condition which is passed the same environment as general rules.
// If nil, always true
// If non-nil, must return true for this challenge to be allowed to be executed
Condition cel.Program
// Path The url path that this challenge is hosted under for the Handler to be called.
Path string
// Duration How long this challenge will be valid when passed
Duration time.Duration
// Handler An HTTP handler for all requests coming on the Path
// This handler will need to handle MakeChallengeUrlSuffix and VerifyChallengeUrlSuffix as well if needed
// Recommended to use http.ServeMux
Handler http.Handler
// Verify Verify an issued token
Verify VerifyFunc
VerifyProbability float64
// IssueChallenge Issues a challenge to a request.
// If Class is ClassTransparent and VerifyResult is !VerifyResult.Ok(), continue with other challenges
// TODO: have this return error as well
IssueChallenge func(w http.ResponseWriter, r *http.Request, key Key, expiry time.Time) VerifyResult
// Object used to handle state or similar
// Can be nil if no state is needed
// If non-nil must implement io.Closer even if there's nothing to do
Object io.Closer
}
type VerifyFunc func(key Key, token []byte, r *http.Request) (VerifyResult, error)
type Token struct {
Name string `json:"name"`
Key []byte `json:"key"`
Result []byte `json:"result,omitempty"`
Ok bool `json:"ok"`
Expiry jwt.NumericDate `json:"exp,omitempty"`
NotBefore jwt.NumericDate `json:"nbf,omitempty"`
IssuedAt jwt.NumericDate `json:"iat,omitempty"`
}
func (reg Registration) Id() Id {
return reg.id
}
func (reg Registration) IssueChallengeToken(privateKey ed25519.PrivateKey, key Key, result []byte, until time.Time, ok bool) (token string, err error) {
signer, err := jose.NewSigner(jose.SigningKey{
Algorithm: jose.EdDSA,
Key: privateKey,
}, nil)
if err != nil {
return "", err
}
token, err = jwt.Signed(signer).Claims(Token{
Name: reg.Name,
Key: key[:],
Result: result,
Ok: ok,
Expiry: jwt.NumericDate(until.Unix()),
NotBefore: jwt.NumericDate(time.Now().UTC().AddDate(0, 0, -1).Unix()),
IssuedAt: jwt.NumericDate(time.Now().UTC().Unix()),
}).Serialize()
if err != nil {
return "", err
}
return token, nil
}
var ErrVerifyKeyMismatch = errors.New("verify: key mismatch")
var ErrVerifyVerifyMismatch = errors.New("verify: verification mismatch")
var ErrTokenExpired = errors.New("token: expired")
func (reg Registration) VerifyChallengeToken(publicKey ed25519.PublicKey, expectedKey Key, r *http.Request) (VerifyResult, VerifyState, error) {
cookie, err := r.Cookie(utils.CookiePrefix + reg.Name)
if err != nil {
return VerifyResultNone, VerifyStateNone, err
}
if cookie == nil {
return VerifyResultNone, VerifyStateNone, http.ErrNoCookie
}
token, err := jwt.ParseSigned(cookie.Value, []jose.SignatureAlgorithm{jose.EdDSA})
if err != nil {
return VerifyResultFail, VerifyStateNone, err
}
var i Token
err = token.Claims(publicKey, &i)
if err != nil {
return VerifyResultFail, VerifyStateNone, err
}
if i.Name != reg.Name {
return VerifyResultFail, VerifyStateNone, errors.New("token invalid name")
}
if i.Expiry.Time().Compare(time.Now()) < 0 {
return VerifyResultFail, VerifyStateNone, ErrTokenExpired
}
if i.NotBefore.Time().Compare(time.Now()) > 0 {
return VerifyResultFail, VerifyStateNone, errors.New("token not valid yet")
}
if bytes.Compare(expectedKey[:], i.Key) != 0 {
return VerifyResultFail, VerifyStateNone, ErrVerifyKeyMismatch
}
if reg.Verify != nil {
if rand.Float64() < reg.VerifyProbability {
// random spot check
if ok, err := reg.Verify(expectedKey, i.Result, r); err != nil {
return VerifyResultFail, VerifyStateFull, err
} else if ok == VerifyResultNotOK {
return VerifyResultNotOK, VerifyStateFull, nil
} else if !ok.Ok() {
return ok, VerifyStateFull, ErrVerifyVerifyMismatch
} else {
return ok, VerifyStateFull, nil
}
}
}
if !i.Ok {
return VerifyResultNotOK, VerifyStateBrief, nil
}
return VerifyResultOK, VerifyStateBrief, nil
}
type FillRegistration func(state StateInterface, reg *Registration, parameters ast.Node) error
var Runtimes = make(map[string]FillRegistration)

View File

@@ -0,0 +1,55 @@
package resource_load
import (
"fmt"
"git.gammaspectra.live/git/go-away/lib/challenge"
"github.com/goccy/go-yaml/ast"
"html/template"
"net/http"
"time"
)
func init() {
challenge.Runtimes["resource-load"] = FillRegistrationHeader
}
func FillRegistrationHeader(state challenge.StateInterface, reg *challenge.Registration, parameters ast.Node) error {
reg.Class = challenge.ClassBlocking
verifier, issuer := challenge.NewKeyVerifier()
reg.Verify = verifier
reg.IssueChallenge = func(w http.ResponseWriter, r *http.Request, key challenge.Key, expiry time.Time) challenge.VerifyResult {
uri, err := challenge.VerifyUrl(r, reg, issuer(key))
if err != nil {
return challenge.VerifyResultFail
}
// self redirect!
//TODO: adjust deadline
w.Header().Set("Refresh", "2; url="+r.URL.String())
state.ChallengePage(w, r, state.Settings().ChallengeResponseCode, reg, map[string]any{
"HeaderTags": []template.HTML{
template.HTML(fmt.Sprintf("<link href=\"%s\" rel=\"stylesheet\" crossorigin=\"use-credentials\">", uri.String())),
},
})
return challenge.VerifyResultNone
}
mux := http.NewServeMux()
mux.HandleFunc("GET "+reg.Path+challenge.VerifyChallengeUrlSuffix, challenge.VerifyHandlerFunc(state, reg, nil, func(state challenge.StateInterface, data *challenge.RequestData, w http.ResponseWriter, r *http.Request, verifyResult challenge.VerifyResult, err error, redirect string) {
//TODO: add other types inside css that need to be loaded!
w.Header().Set("Content-Type", "text/css; charset=utf-8")
w.Header().Set("Content-Length", "0")
if !verifyResult.Ok() {
w.WriteHeader(http.StatusForbidden)
} else {
w.WriteHeader(http.StatusOK)
}
}))
reg.Handler = mux
return nil
}

41
lib/challenge/script.go Normal file
View File

@@ -0,0 +1,41 @@
package challenge
import (
_ "embed"
"encoding/json"
"git.gammaspectra.live/git/go-away/utils"
"net/http"
"text/template"
)
//go:embed script.mjs
var scriptData []byte
var scriptTemplate = template.Must(template.New("script.mjs").Parse(string(scriptData)))
func ServeChallengeScript(w http.ResponseWriter, r *http.Request, reg *Registration, params any, script string) {
data := RequestDataFromContext(r.Context())
w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
w.Header().Set("Content-Type", "text/javascript; charset=utf-8")
paramData, err := json.Marshal(params)
if err != nil {
//TODO: log
panic(err)
}
w.WriteHeader(http.StatusOK)
err = scriptTemplate.Execute(w, map[string]any{
"Id": data.Id.String(),
"Path": reg.Path,
"Parameters": paramData,
"Random": utils.CacheBust(),
"Challenge": reg.Name,
"ChallengeScript": script,
})
if err != nil {
//TODO: log
panic(err)
}
}

70
lib/challenge/script.mjs Normal file
View File

@@ -0,0 +1,70 @@
import {setup, challenge} from "{{ .ChallengeScript }}";
// from Xeact
const u = (url = "", params = {}) => {
let result = new URL(url, window.location.href);
Object.entries(params).forEach((kv) => {
let [k, v] = kv;
result.searchParams.set(k, v);
});
return result.toString();
};
(async () => {
const status = document.getElementById('status');
const title = document.getElementById('title');
const spinner = document.getElementById('spinner');
status.innerText = 'Starting challenge {{ .Challenge }}...';
try {
const info = await setup({
Path: "{{ .Path }}",
Parameters: "{{ .Parameters }}"
});
if (info != "") {
status.innerText = 'Calculating... ' + info
} else {
status.innerText = 'Calculating...';
}
} catch (err) {
title.innerHTML = "Oh no!";
status.innerHTML = `Failed to initialize: ${err.message}`;
spinner.innerHTML = "";
spinner.style.display = "none";
return
}
try {
const t0 = Date.now();
const { result, info } = await challenge();
const t1 = Date.now();
console.log({ result, info });
title.innerHTML = "Challenge success!";
if (info != "") {
status.innerHTML = `Done! Took ${t1 - t0}ms, ${info}`;
} else {
status.innerHTML = `Done! Took ${t1 - t0}ms`;
}
setTimeout(() => {
const redir = window.location.href;
window.location.href = u("{{ .Path }}/verify-challenge", {
__goaway_token: result,
__goaway_challenge: "{{ .Challenge }}",
__goaway_redirect: redir,
__goaway_id: "{{ .Id }}",
__goaway_elapsedTime: t1 - t0,
});
}, 500);
} catch (err) {
title.innerHTML = "Oh no!";
status.innerHTML = `Failed to challenge: ${err.message}`;
spinner.innerHTML = "";
spinner.style.display = "none";
}
})();

View File

@@ -1,176 +0,0 @@
package challenge
import (
"bytes"
"crypto/ed25519"
"errors"
"git.gammaspectra.live/git/go-away/utils"
"github.com/go-jose/go-jose/v4"
"github.com/go-jose/go-jose/v4/jwt"
"github.com/google/cel-go/cel"
"math/rand/v2"
"net/http"
"time"
)
type Result int
const (
// ResultStop Stop testing other challenges and return
ResultStop = Result(iota)
// ResultContinue Test next
ResultContinue
// ResultPass passed, return and proxy
ResultPass
)
type Id int
type Challenge struct {
Id Id
Program cel.Program
Name string
Path string
Verify func(key []byte, result string, r *http.Request) (bool, error)
VerifyProbability float64
ServeStatic http.Handler
ServeChallenge func(w http.ResponseWriter, r *http.Request, key []byte, expiry time.Time) Result
ServeScript http.Handler
ServeScriptPath string
ServeMakeChallenge http.Handler
ServeVerifyChallenge http.Handler
}
type Token struct {
Name string `json:"name"`
Key []byte `json:"key"`
Result []byte `json:"result,omitempty"`
Expiry *jwt.NumericDate `json:"exp,omitempty"`
NotBefore *jwt.NumericDate `json:"nbf,omitempty"`
IssuedAt *jwt.NumericDate `json:"iat,omitempty"`
}
func (c Challenge) IssueChallengeToken(privateKey ed25519.PrivateKey, key, result []byte, until time.Time) (token string, err error) {
signer, err := jose.NewSigner(jose.SigningKey{
Algorithm: jose.EdDSA,
Key: privateKey,
}, nil)
if err != nil {
return "", err
}
expiry := jwt.NumericDate(until.Unix())
notBefore := jwt.NumericDate(time.Now().UTC().AddDate(0, 0, -1).Unix())
issuedAt := jwt.NumericDate(time.Now().UTC().Unix())
token, err = jwt.Signed(signer).Claims(Token{
Name: c.Name,
Key: key,
Result: result,
Expiry: &expiry,
NotBefore: &notBefore,
IssuedAt: &issuedAt,
}).Serialize()
if err != nil {
return "", err
}
return token, nil
}
type VerifyResult int
const (
VerifyResultNONE = VerifyResult(iota)
VerifyResultFAIL
VerifyResultSKIP
// VerifyResultPASS Client just passed this challenge
VerifyResultPASS
VerifyResultOK
VerifyResultBRIEF
VerifyResultFULL
)
func (r VerifyResult) Ok() bool {
return r >= VerifyResultPASS
}
func (r VerifyResult) String() string {
switch r {
case VerifyResultNONE:
return "NONE"
case VerifyResultFAIL:
return "FAIL"
case VerifyResultSKIP:
return "SKIP"
case VerifyResultPASS:
return "PASS"
case VerifyResultOK:
return "OK"
case VerifyResultBRIEF:
return "BRIEF"
case VerifyResultFULL:
return "FULL"
default:
panic("unsupported")
}
}
var ErrVerifyKeyMismatch = errors.New("verify: key mismatch")
var ErrVerifyVerifyMismatch = errors.New("verify: verification mismatch")
func (c Challenge) VerifyChallengeToken(publicKey ed25519.PublicKey, expectedKey []byte, r *http.Request) (VerifyResult, error) {
cookie, err := r.Cookie(utils.CookiePrefix + c.Name)
if err != nil {
return VerifyResultNONE, err
}
if cookie == nil {
return VerifyResultNONE, http.ErrNoCookie
}
token, err := jwt.ParseSigned(cookie.Value, []jose.SignatureAlgorithm{jose.EdDSA})
if err != nil {
return VerifyResultFAIL, err
}
var i Token
err = token.Claims(publicKey, &i)
if err != nil {
return VerifyResultFAIL, err
}
if i.Name != c.Name {
return VerifyResultFAIL, errors.New("token invalid name")
}
if i.Expiry == nil && i.Expiry.Time().Compare(time.Now()) < 0 {
return VerifyResultFAIL, errors.New("token expired")
}
if i.NotBefore == nil && i.NotBefore.Time().Compare(time.Now()) > 0 {
return VerifyResultFAIL, errors.New("token not valid yet")
}
if bytes.Compare(expectedKey, i.Key) != 0 {
return VerifyResultFAIL, ErrVerifyKeyMismatch
}
if c.Verify != nil {
if rand.Float64() < c.VerifyProbability {
// random spot check
if ok, err := c.Verify(expectedKey, string(i.Result), r); err != nil {
return VerifyResultFAIL, err
} else if !ok {
return VerifyResultFAIL, ErrVerifyVerifyMismatch
}
return VerifyResultFULL, nil
} else {
return VerifyResultBRIEF, nil
}
}
return VerifyResultOK, nil
}

112
lib/challenge/types.go Normal file
View File

@@ -0,0 +1,112 @@
package challenge
import (
"crypto/ed25519"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/google/cel-go/cel"
"log/slog"
"net/http"
)
type Id int64
type Class uint8
const (
// ClassTransparent Transparent challenges work inline in the execution process.
// These can pass or continue, so more challenges or requests can ve served afterward.
ClassTransparent = Class(iota)
// ClassBlocking Blocking challenges must serve a different response to challenge the requester.
// These can pass or stop, for example, due to serving a challenge
ClassBlocking
)
type VerifyState uint8
const (
VerifyStateNone = VerifyState(iota)
// VerifyStatePass Challenge was just passed on this request
VerifyStatePass
// VerifyStateBrief Challenge token was verified but didn't check the challenge
VerifyStateBrief
// VerifyStateFull Challenge token was verified and challenge verification was done
VerifyStateFull
)
func (r VerifyState) String() string {
switch r {
case VerifyStatePass:
return "PASS"
case VerifyStateBrief:
return "BRIEF"
case VerifyStateFull:
return "FULL"
default:
panic("unsupported")
}
}
type VerifyResult uint8
const (
// VerifyResultNone A negative pass result, without a token
VerifyResultNone = VerifyResult(iota)
// VerifyResultFail A negative pass result, with an invalid token
VerifyResultFail
// VerifyResultSkip Challenge was skipped due to precondition
VerifyResultSkip
// VerifyResultNotOK A negative pass result, with a valid token
VerifyResultNotOK
// VerifyResultOK A positive pass result, with a valid token
VerifyResultOK
)
func (r VerifyResult) Ok() bool {
return r >= VerifyResultOK
}
func (r VerifyResult) String() string {
switch r {
case VerifyResultNone:
return "None"
case VerifyResultFail:
return "Fail"
case VerifyResultSkip:
return "Skip"
case VerifyResultNotOK:
return "NotOK"
case VerifyResultOK:
return "OK"
default:
panic("unsupported")
}
}
type StateInterface interface {
ProgramEnv() *cel.Env
Client() *http.Client
PrivateKey() ed25519.PrivateKey
PublicKey() ed25519.PublicKey
UrlPath() string
ChallengeFailed(r *http.Request, reg *Registration, err error, redirect string, logger *slog.Logger)
ChallengePassed(r *http.Request, reg *Registration, redirect string, logger *slog.Logger)
ChallengeIssued(r *http.Request, reg *Registration, redirect string, logger *slog.Logger)
Logger(r *http.Request) *slog.Logger
ChallengePage(w http.ResponseWriter, r *http.Request, status int, reg *Registration, params map[string]any)
ErrorPage(w http.ResponseWriter, r *http.Request, status int, err error, redirect string)
GetChallenge(id Id) (*Registration, bool)
GetChallengeByName(name string) (*Registration, bool)
GetChallenges() Register
Settings() policy.Settings
GetBackend(host string) http.Handler
}

View File

@@ -111,6 +111,7 @@ type VerifyChallengeInput struct {
type VerifyChallengeOutput uint64
// TODO: expand allowed values
const (
VerifyChallengeOutputOK = VerifyChallengeOutput(iota)
VerifyChallengeOutputFailed

View File

@@ -0,0 +1,186 @@
package wasm
import (
"codeberg.org/meta/gzipped/v2"
"context"
"errors"
"fmt"
"git.gammaspectra.live/git/go-away/embed"
"git.gammaspectra.live/git/go-away/lib/challenge"
_interface "git.gammaspectra.live/git/go-away/lib/challenge/wasm/interface"
"git.gammaspectra.live/git/go-away/utils"
"git.gammaspectra.live/git/go-away/utils/inline"
"github.com/goccy/go-yaml"
"github.com/goccy/go-yaml/ast"
"github.com/tetratelabs/wazero/api"
"html/template"
"io"
"io/fs"
"net/http"
"path"
"time"
)
func init() {
challenge.Runtimes["js"] = FillJavaScriptRegistration
}
type Parameters struct {
Path string `yaml:"path"`
// Loader path to js/mjs file to use as challenge issuer
Loader string `yaml:"js-loader"`
// Runtime path to WASM wasip1 runtime
Runtime string `yaml:"wasm-runtime"`
Settings map[string]string `yaml:"wasm-runtime-settings"`
NativeCompiler bool `yaml:"wasm-native-compiler"`
VerifyProbability float64 `yaml:"verify-probability"`
}
var DefaultParameters = Parameters{
VerifyProbability: 0.1,
NativeCompiler: true,
}
func FillJavaScriptRegistration(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
}
}
reg.Class = challenge.ClassBlocking
mux := http.NewServeMux()
if params.Path == "" {
params.Path = reg.Name
}
assetsFs, err := embed.GetFallbackFS(embed.ChallengeFs, params.Path)
if err != nil {
return err
}
if params.VerifyProbability <= 0 {
//10% default
params.VerifyProbability = 0.1
} else if params.VerifyProbability > 1.0 {
params.VerifyProbability = 1.0
}
reg.VerifyProbability = params.VerifyProbability
ob := NewRunner(params.NativeCompiler)
reg.Object = ob
wasmData, err := assetsFs.ReadFile(path.Join("runtime", params.Runtime))
if err != nil {
return fmt.Errorf("could not load runtime: %w", err)
}
err = ob.Compile("runtime", wasmData)
if err != nil {
return fmt.Errorf("compiling runtime: %w", err)
}
reg.IssueChallenge = func(w http.ResponseWriter, r *http.Request, key challenge.Key, expiry time.Time) challenge.VerifyResult {
state.ChallengePage(w, r, state.Settings().ChallengeResponseCode, reg, map[string]any{
"EndTags": []template.HTML{
template.HTML(fmt.Sprintf("<script async type=\"module\" src=\"%s?cacheBust=%s\"></script>", reg.Path+"/script.mjs", utils.CacheBust())),
},
})
return challenge.VerifyResultNone
}
reg.Verify = func(key challenge.Key, token []byte, r *http.Request) (challenge.VerifyResult, error) {
var ok bool
err = ob.Instantiate("runtime", func(ctx context.Context, mod api.Module) (err error) {
in := _interface.VerifyChallengeInput{
Key: key[:],
Parameters: params.Settings,
Result: token,
}
out, err := VerifyChallengeCall(ctx, mod, in)
if err != nil {
return err
}
if out == _interface.VerifyChallengeOutputError {
return errors.New("error checking challenge")
}
ok = out == _interface.VerifyChallengeOutputOK
return nil
})
if err != nil {
return challenge.VerifyResultFail, err
}
if ok {
return challenge.VerifyResultOK, nil
}
return challenge.VerifyResultFail, nil
}
// serve assets if existent
if staticFs, err := fs.Sub(assetsFs, "static"); err != nil {
return fmt.Errorf("no static assets: %w", err)
} else {
mux.Handle("GET "+reg.Path+"/static/", http.StripPrefix(reg.Path+"/static/", gzipped.FileServer(gzipped.FS(staticFs))))
}
mux.HandleFunc(reg.Path+challenge.MakeChallengeUrlSuffix, func(w http.ResponseWriter, r *http.Request) {
data := challenge.RequestDataFromContext(r.Context())
err := ob.Instantiate("runtime", func(ctx context.Context, mod api.Module) (err error) {
key := challenge.GetChallengeKeyForRequest(state, reg, data.Expiration(reg.Duration), r)
in := _interface.MakeChallengeInput{
Key: key[:],
Parameters: params.Settings,
Headers: inline.MIMEHeader(r.Header),
}
in.Data, err = io.ReadAll(r.Body)
if err != nil {
return err
}
out, err := MakeChallengeCall(ctx, mod, in)
if err != nil {
return err
}
// set output headers
for k, v := range out.Headers {
w.Header()[k] = v
}
w.Header().Set("Content-Length", fmt.Sprintf("%d", len(out.Data)))
w.WriteHeader(out.Code)
_, _ = w.Write(out.Data)
return nil
})
if err != nil {
state.ErrorPage(w, r, http.StatusInternalServerError, err, "")
return
}
})
mux.HandleFunc(reg.Path+challenge.VerifyChallengeUrlSuffix, challenge.VerifyHandlerFunc(state, reg, nil, nil))
mux.HandleFunc("GET "+reg.Path+"/script.mjs", func(w http.ResponseWriter, r *http.Request) {
challenge.ServeChallengeScript(w, r, reg, params.Settings, path.Join(reg.Path, "static", params.Loader))
})
reg.Handler = mux
return nil
}

View File

@@ -94,11 +94,13 @@ func (r *Runner) Compile(key string, binary []byte) error {
return nil
}
func (r *Runner) Close() {
func (r *Runner) Close() error {
for _, module := range r.modules {
module.Close(r.context)
if err := module.Close(r.context); err != nil {
return err
}
}
r.runtime.Close(r.context)
return r.runtime.Close(r.context)
}
var ErrModuleNotFound = errors.New("module not found")

View File

@@ -3,6 +3,12 @@ package condition
import (
"fmt"
"github.com/google/cel-go/cel"
"github.com/google/cel-go/common/types"
"github.com/google/cel-go/common/types/ref"
"github.com/google/cel-go/ext"
"github.com/yl2chen/cidranger"
"log/slog"
"net"
"strings"
)
@@ -15,6 +21,124 @@ const (
OperatorAnd = "&&"
)
func NewRulesEnvironment(networks map[string]cidranger.Ranger) (*cel.Env, error) {
return cel.NewEnv(
ext.Strings(
ext.StringsLocale("en_US"),
ext.StringsValidateFormatCalls(true),
),
cel.DefaultUTCTimeZone(true),
//TODO: custom type for remoteAddress
cel.Variable("remoteAddress", cel.BytesType),
cel.Variable("host", cel.StringType),
cel.Variable("method", cel.StringType),
cel.Variable("userAgent", cel.StringType),
cel.Variable("path", cel.StringType),
cel.Variable("query", cel.MapType(cel.StringType, cel.StringType)),
cel.Variable("fp", cel.MapType(cel.StringType, cel.StringType)),
// http.Header
cel.Variable("headers", cel.MapType(cel.StringType, cel.StringType)),
//TODO: dynamic type?
cel.Function("inDNSBL",
cel.Overload("inDNSBL_ip",
[]*cel.Type{cel.AnyType},
cel.BoolType,
cel.UnaryBinding(func(val ref.Val) ref.Val {
slog.Error("inDNSBL function has been deprecated, replace with dnsbl challenge")
return types.Bool(false)
}),
),
),
cel.Function("network",
cel.MemberOverload("netIP_network_string",
[]*cel.Type{cel.BytesType, cel.StringType},
cel.BoolType,
cel.BinaryBinding(func(lhs ref.Val, rhs ref.Val) ref.Val {
var ip net.IP
switch v := lhs.Value().(type) {
case []byte:
ip = v
case net.IP:
ip = v
}
if ip == nil {
panic(fmt.Errorf("invalid ip %v", lhs.Value()))
}
val, ok := rhs.Value().(string)
if !ok {
panic(fmt.Errorf("invalid network value %v", rhs.Value()))
}
network, ok := networks[val]
if !ok {
_, ipNet, err := net.ParseCIDR(val)
if err != nil {
panic("network not found")
}
return types.Bool(ipNet.Contains(ip))
} else {
ok, err := network.Contains(ip)
if err != nil {
panic(err)
}
return types.Bool(ok)
}
}),
),
),
cel.Function("inNetwork",
cel.Overload("inNetwork_string_ip",
[]*cel.Type{cel.StringType, cel.BytesType},
cel.BoolType,
cel.BinaryBinding(func(lhs ref.Val, rhs ref.Val) ref.Val {
var ip net.IP
switch v := rhs.Value().(type) {
case []byte:
ip = v
case net.IP:
ip = v
}
if ip == nil {
panic(fmt.Errorf("invalid ip %v", rhs.Value()))
}
val, ok := lhs.Value().(string)
if !ok {
panic(fmt.Errorf("invalid value %v", lhs.Value()))
}
slog.Debug(fmt.Sprintf("inNetwork function has been deprecated and will be removed in a future release, use remoteAddress.network(\"%s\") instead", val))
network, ok := networks[val]
if !ok {
_, ipNet, err := net.ParseCIDR(val)
if err != nil {
panic("network not found")
}
return types.Bool(ipNet.Contains(ip))
} else {
ok, err := network.Contains(ip)
if err != nil {
panic(err)
}
return types.Bool(ok)
}
}),
),
),
)
}
func Program(env *cel.Env, ast *cel.Ast) (cel.Program, error) {
return env.Program(ast,
cel.EvalOptions(cel.OptOptimize),
)
}
func FromStrings(env *cel.Env, operator string, conditions ...string) (*cel.Ast, error) {
var asts []*cel.Ast
for _, c := range conditions {

158
lib/condition/map.go Normal file
View File

@@ -0,0 +1,158 @@
package condition
import (
"fmt"
"github.com/google/cel-go/common/types"
"github.com/google/cel-go/common/types/ref"
"github.com/google/cel-go/common/types/traits"
"net/textproto"
"reflect"
"strings"
)
type mimeLike struct {
m textproto.MIMEHeader
}
func (a mimeLike) ConvertToNative(typeDesc reflect.Type) (any, error) {
return nil, fmt.Errorf("type conversion error from map to '%v'", typeDesc)
}
func (a mimeLike) ConvertToType(typeVal ref.Type) ref.Val {
switch typeVal {
case types.MapType:
return a
case types.TypeType:
return types.MapType
}
return types.NewErr("type conversion error from '%s' to '%s'", types.MapType, typeVal)
}
func (a mimeLike) Equal(other ref.Val) ref.Val {
return types.Bool(false)
}
func (a mimeLike) Type() ref.Type {
return types.MapType
}
func (a mimeLike) Value() any {
return a.m
}
func (a mimeLike) Contains(key ref.Val) ref.Val {
_, found := a.Find(key)
return types.Bool(found)
}
func (a mimeLike) Get(key ref.Val) ref.Val {
v, found := a.Find(key)
if !found {
return types.ValOrErr(v, "no such key: %v", key)
}
return v
}
func (a mimeLike) Iterator() traits.Iterator {
panic("implement me")
}
func (a mimeLike) IsZeroValue() bool {
return len(a.m) == 0
}
func (a mimeLike) Size() ref.Val {
return types.Int(len(a.m))
}
func (a mimeLike) Find(key ref.Val) (ref.Val, bool) {
k, ok := key.(types.String)
if !ok {
return nil, false
}
return singleVal(a.m.Values(string(k)), true)
}
type valuesLike struct {
m map[string][]string
}
func (a valuesLike) ConvertToNative(typeDesc reflect.Type) (any, error) {
return nil, fmt.Errorf("type conversion error from map to '%v'", typeDesc)
}
func (a valuesLike) ConvertToType(typeVal ref.Type) ref.Val {
switch typeVal {
case types.MapType:
return a
case types.TypeType:
return types.MapType
}
return types.NewErr("type conversion error from '%s' to '%s'", types.MapType, typeVal)
}
func (a valuesLike) Equal(other ref.Val) ref.Val {
return types.Bool(false)
}
func (a valuesLike) Type() ref.Type {
return types.MapType
}
func (a valuesLike) Value() any {
return a.m
}
func (a valuesLike) Contains(key ref.Val) ref.Val {
_, found := a.Find(key)
return types.Bool(found)
}
func (a valuesLike) Get(key ref.Val) ref.Val {
v, found := a.Find(key)
if !found {
return types.ValOrErr(v, "no such key: %v", key)
}
return v
}
func (a valuesLike) Iterator() traits.Iterator {
panic("implement me")
}
func (a valuesLike) IsZeroValue() bool {
return len(a.m) == 0
}
func (a valuesLike) Size() ref.Val {
return types.Int(len(a.m))
}
func (a valuesLike) Find(key ref.Val) (ref.Val, bool) {
k, ok := key.(types.String)
if !ok {
return nil, false
}
val, ok := a.m[string(k)]
return singleVal(val, ok)
}
func singleVal(values []string, ok bool) (ref.Val, bool) {
if len(values) == 0 || !ok {
return nil, false
}
if len(values) > 1 {
return types.String(strings.Join(values, ",")), true
}
return types.String(values[0]), true
}
func NewMIMEMap(m textproto.MIMEHeader) traits.Mapper {
return mimeLike{m: m}
}
func NewValuesMap(m map[string][]string) traits.Mapper {
return mimeLike{m: m}
}

View File

@@ -1,118 +1,11 @@
package lib
import (
"context"
"fmt"
"github.com/google/cel-go/cel"
"github.com/google/cel-go/common/types"
"github.com/google/cel-go/common/types/ref"
"log/slog"
"net"
"time"
"git.gammaspectra.live/git/go-away/lib/condition"
)
func (state *State) initConditions() (err error) {
state.RulesEnv, err = cel.NewEnv(
cel.DefaultUTCTimeZone(true),
cel.Variable("remoteAddress", cel.BytesType),
cel.Variable("host", cel.StringType),
cel.Variable("method", cel.StringType),
cel.Variable("userAgent", cel.StringType),
cel.Variable("path", cel.StringType),
cel.Variable("query", cel.MapType(cel.StringType, cel.StringType)),
cel.Variable("fpJA3N", cel.StringType),
cel.Variable("fpJA4", cel.StringType),
// http.Header
cel.Variable("headers", cel.MapType(cel.StringType, cel.StringType)),
//TODO: dynamic type?
cel.Function("inDNSBL",
cel.Overload("inDNSBL_ip",
[]*cel.Type{cel.AnyType},
cel.BoolType,
cel.UnaryBinding(func(val ref.Val) ref.Val {
if state.Settings.DNSBL == nil {
return types.Bool(false)
}
var ip net.IP
switch v := val.Value().(type) {
case []byte:
ip = v
case net.IP:
ip = v
case string:
ip = net.ParseIP(v)
}
if ip == nil {
panic(fmt.Errorf("invalid ip %v", val.Value()))
}
var key [net.IPv6len]byte
copy(key[:], ip.To16())
result, ok := state.DecayMap.Get(key)
if ok {
return types.Bool(result.Bad())
}
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
defer cancel()
result, err := state.Settings.DNSBL.Lookup(ctx, ip)
if err != nil {
slog.Debug("dnsbl lookup failed", "address", ip.String(), "result", result, "err", err)
} else {
slog.Debug("dnsbl lookup", "address", ip.String(), "result", result)
}
//TODO: configure decay
state.DecayMap.Set(key, result, time.Hour)
return types.Bool(result.Bad())
}),
),
),
cel.Function("inNetwork",
cel.Overload("inNetwork_string_ip",
[]*cel.Type{cel.StringType, cel.AnyType},
cel.BoolType,
cel.BinaryBinding(func(lhs ref.Val, rhs ref.Val) ref.Val {
var ip net.IP
switch v := rhs.Value().(type) {
case []byte:
ip = v
case net.IP:
ip = v
case string:
ip = net.ParseIP(v)
}
if ip == nil {
panic(fmt.Errorf("invalid ip %v", rhs.Value()))
}
val, ok := lhs.Value().(string)
if !ok {
panic(fmt.Errorf("invalid value %v", lhs.Value()))
}
network, ok := state.Networks[val]
if !ok {
_, ipNet, err := net.ParseCIDR(val)
if err != nil {
panic("network not found")
}
return types.Bool(ipNet.Contains(ip))
} else {
ok, err := network.Contains(ip)
if err != nil {
panic(err)
}
return types.Bool(ok)
}
}),
),
),
)
state.programEnv, err = condition.NewRulesEnvironment(state.networks)
if err != nil {
return err
}

View File

@@ -1,28 +1,16 @@
package lib
import (
"bytes"
"codeberg.org/meta/gzipped/v2"
"context"
"crypto/rand"
"encoding/base64"
"encoding/hex"
"errors"
"fmt"
"git.gammaspectra.live/git/go-away/embed"
"git.gammaspectra.live/git/go-away/lib/action"
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"git.gammaspectra.live/git/go-away/utils"
"github.com/google/cel-go/common/types"
"html/template"
"io"
"log/slog"
"maps"
"net"
"net/http"
"net/http/pprof"
"path"
"path/filepath"
"strconv"
"strings"
"time"
@@ -30,20 +18,11 @@ import (
var templates map[string]*template.Template
var cacheBust string
// DefaultValidity TODO: adjust
const DefaultValidity = time.Hour * 24 * 7
func init() {
buf := make([]byte, 16)
_, _ = rand.Read(buf)
cacheBust = base64.RawURLEncoding.EncodeToString(buf)
templates = make(map[string]*template.Template)
dir, err := embed.TemplatesFs.ReadDir("templates")
dir, err := embed.TemplatesFs.ReadDir(".")
if err != nil {
panic(err)
}
@@ -51,7 +30,7 @@ func init() {
if e.IsDir() {
continue
}
data, err := embed.TemplatesFs.ReadFile(filepath.Join("templates", e.Name()))
data, err := embed.TemplatesFs.ReadFile(e.Name())
if err != nil {
panic(err)
}
@@ -72,69 +51,16 @@ func initTemplate(name, data string) error {
return nil
}
func (state *State) challengePage(w http.ResponseWriter, id string, status int, challenge string, params map[string]any) error {
input := make(map[string]any)
input["Id"] = id
input["Random"] = cacheBust
input["Challenge"] = challenge
input["Path"] = state.UrlPath
input["Theme"] = state.Settings.ChallengeTemplateTheme
maps.Copy(input, params)
if _, ok := input["Title"]; !ok {
input["Title"] = "Checking you are not a bot"
}
w.Header().Set("Content-Type", "text/html; charset=utf-8")
buf := bytes.NewBuffer(make([]byte, 0, 8192))
err := templates["challenge-"+state.Settings.ChallengeTemplate+".gohtml"].Execute(buf, input)
if err != nil {
_ = state.errorPage(w, id, http.StatusInternalServerError, err, "")
} else {
w.WriteHeader(status)
_, _ = w.Write(buf.Bytes())
}
return nil
}
func (state *State) errorPage(w http.ResponseWriter, id string, status int, err error, redirect string) error {
w.Header().Set("Content-Type", "text/html; charset=utf-8")
buf := bytes.NewBuffer(make([]byte, 0, 8192))
err2 := templates["challenge-"+state.Settings.ChallengeTemplate+".gohtml"].Execute(buf, map[string]any{
"Id": id,
"Random": cacheBust,
"Error": err.Error(),
"Path": state.UrlPath,
"Theme": state.Settings.ChallengeTemplateTheme,
"Title": "Oh no! " + http.StatusText(status),
"HideSpinner": true,
"Challenge": "",
"Redirect": redirect,
})
if err2 != nil {
panic(err2)
} else {
w.WriteHeader(status)
_, _ = w.Write(buf.Bytes())
}
return nil
}
func (state *State) addTiming(w http.ResponseWriter, name, desc string, duration time.Duration) {
if state.Settings.Debug {
if state.Settings().Debug {
w.Header().Add("Server-Timing", fmt.Sprintf("%s;desc=%s;dur=%d", name, strconv.Quote(desc), duration.Milliseconds()))
}
}
func GetLoggerForRequest(r *http.Request) *slog.Logger {
data := RequestDataFromContext(r.Context())
data := challenge.RequestDataFromContext(r.Context())
args := []any{
"request_id", hex.EncodeToString(data.Id[:]),
"request_id", data.Id.String(),
"remote_address", data.RemoteAddress.String(),
"user_agent", r.UserAgent(),
"host", r.Host,
@@ -153,272 +79,95 @@ func GetLoggerForRequest(r *http.Request) *slog.Logger {
return slog.With(args...)
}
func (state *State) logger(r *http.Request) *slog.Logger {
return GetLoggerForRequest(r)
}
func (state *State) handleRequest(w http.ResponseWriter, r *http.Request) {
host := r.Host
data := RequestDataFromContext(r.Context())
data := challenge.RequestDataFromContext(r.Context())
backend, ok := state.Settings.Backends[host]
if !ok {
backend := state.GetBackend(host)
if backend == nil {
http.Error(w, http.StatusText(http.StatusServiceUnavailable), http.StatusServiceUnavailable)
return
}
lg := state.logger(r)
lg := state.Logger(r)
start := time.Now()
state.addTiming(w, "rule-env", "Setup the rule environment", time.Since(start))
var (
ruleEvalDuration time.Duration
)
serve := func() {
state.addTiming(w, "rule-eval", "Evaluate access rules", ruleEvalDuration)
backend.ServeHTTP(w, r)
}
fail := func(code int, err error) {
state.addTiming(w, "rule-eval", "Evaluate access rules", ruleEvalDuration)
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), code, err, "")
}
setAwayState := func(rule RuleState) {
r.Header.Set("X-Away-Rule", rule.Name)
r.Header.Set("X-Away-Hash", rule.Hash)
r.Header.Set("X-Away-Action", string(rule.Action))
data.Headers(state, r.Header)
}
for _, rule := range state.Rules {
// skip rules that have host match
if rule.Host != nil && *rule.Host != host {
continue
cleanupRequest := func(r *http.Request, fromChallenge bool) {
if fromChallenge {
r.Header.Del("Referer")
}
if ref := r.FormValue(challenge.QueryArgReferer); ref != "" {
r.Header.Set("Referer", ref)
}
start = time.Now()
out, _, err := rule.Program.Eval(data.ProgramEnv)
ruleEvalDuration += time.Since(start)
if err != nil {
fail(http.StatusInternalServerError, err)
lg.Error(err.Error(), "rule", rule.Name, "rule_hash", rule.Hash)
panic(err)
return
} else if out != nil && out.Type() == types.BoolType {
if out.Equal(types.True) == types.True {
switch rule.Action {
default:
panic(fmt.Errorf("unknown action %s", rule.Action))
case policy.RuleActionPASS:
lg.Debug("request passed", "rule", rule.Name, "rule_hash", rule.Hash)
setAwayState(rule)
serve()
return
case policy.RuleActionCHALLENGE, policy.RuleActionCHECK:
for _, challengeId := range rule.Challenges {
if result := data.Challenges[challengeId]; !result.Ok() {
continue
} else {
if rule.Action == policy.RuleActionCHECK {
goto nextRule
}
// we passed the challenge!
lg.Debug("request passed", "rule", rule.Name, "rule_hash", rule.Hash, "challenge", state.Challenges[challengeId].Name)
setAwayState(rule)
serve()
return
}
}
// none matched, issue first challenge in priority
for _, challengeId := range rule.Challenges {
result := data.Challenges[challengeId]
if result.Ok() || result == challenge.VerifyResultSKIP {
// skip already ok'd challenges for some reason, and also skip skipped challenges
continue
}
c := state.Challenges[challengeId]
if c.ServeChallenge != nil {
result := c.ServeChallenge(w, r, state.GetChallengeKeyForRequest(c.Name, data.Expires, r), data.Expires)
switch result {
case challenge.ResultStop:
lg.Info("request challenged", "rule", rule.Name, "rule_hash", rule.Hash, "challenge", c.Name)
return
case challenge.ResultContinue:
continue
case challenge.ResultPass:
if rule.Action == policy.RuleActionCHECK {
goto nextRule
}
state.logger(r).Warn("challenge passed", "rule", rule.Name, "rule_hash", rule.Hash, "challenge", c.Name)
// set pass if caller didn't set one
if !data.Challenges[c.Id].Ok() {
data.Challenges[c.Id] = challenge.VerifyResultPASS
}
// we pass the challenge early!
lg.Debug("request passed", "rule", rule.Name, "rule_hash", rule.Hash, "challenge", c.Name)
setAwayState(rule)
serve()
return
}
} else {
panic("challenge not found")
}
}
case policy.RuleActionDENY:
lg.Info("request denied", "rule", rule.Name, "rule_hash", rule.Hash)
//TODO: config error code
fail(http.StatusForbidden, fmt.Errorf("access denied: denied by administrative rule %s/%s", r.Header.Get("X-Away-Id"), rule.Hash))
return
case policy.RuleActionBLOCK:
lg.Info("request blocked", "rule", rule.Name, "rule_hash", rule.Hash)
//TODO: config error code
//TODO: configure block
fail(http.StatusForbidden, fmt.Errorf("access denied: blocked by administrative rule %s/%s", r.Header.Get("X-Away-Id"), rule.Hash))
return
case policy.RuleActionPOISON:
lg.Info("request poisoned", "rule", rule.Name, "rule_hash", rule.Hash)
mime := "text/html"
switch path.Ext(r.URL.Path) {
case ".css":
case ".json", ".js", ".mjs":
}
encodings := strings.Split(r.Header.Get("Accept-Encoding"), ",")
for i, encoding := range encodings {
encodings[i] = strings.TrimSpace(strings.ToLower(encoding))
}
reader, encoding := state.getPoison(mime, encodings)
if reader == nil {
mime = "application/octet-stream"
reader, encoding = state.getPoison(mime, encodings)
}
if reader != nil {
defer reader.Close()
w.Header().Set("Cache-Control", "max-age=0, private, must-revalidate, no-transform")
w.Header().Set("Vary", "Accept-Encoding")
w.Header().Set("Content-Type", mime)
w.Header().Set("X-Content-Type-Options", "nosniff")
if encoding != "" {
w.Header().Set("Content-Encoding", encoding)
}
w.WriteHeader(http.StatusOK)
if flusher, ok := w.(http.Flusher); ok {
// trigger chunked encoding
flusher.Flush()
}
if r != nil {
_, _ = io.Copy(w, reader)
}
} else {
http.Error(w, http.StatusText(http.StatusForbidden), http.StatusForbidden)
}
return
}
q := r.URL.Query()
// delete query parameters that were set by go-away
for k := range q {
if strings.HasPrefix(k, challenge.QueryArgPrefix) {
q.Del(k)
}
}
r.URL.RawQuery = q.Encode()
nextRule:
data.Headers(r.Header)
// delete cookies set by go-away to prevent user tracking that way
cookies := r.Cookies()
r.Header.Del("Cookie")
for _, c := range cookies {
if !strings.HasPrefix(c.Name, utils.CookiePrefix) {
r.AddCookie(c)
}
}
}
serve()
return
for _, rule := range state.rules {
next, err := rule.Evaluate(lg, w, r, func() http.Handler {
cleanupRequest(r, true)
return backend
})
if err != nil {
state.ErrorPage(w, r, http.StatusInternalServerError, err, "")
panic(err)
return
}
if !next {
return
}
}
// default pass
_, _ = action.Pass{}.Handle(lg, w, r, func() http.Handler {
r.Header.Set("X-Away-Rule", "DEFAULT")
r.Header.Set("X-Away-Action", "PASS")
cleanupRequest(r, false)
return backend
})
}
func (state *State) setupRoutes() error {
state.Mux.HandleFunc("/", state.handleRequest)
if state.Settings.Debug {
http.HandleFunc(state.UrlPath+"/debug/pprof/", pprof.Index)
http.HandleFunc(state.UrlPath+"/debug/pprof/profile", pprof.Profile)
http.HandleFunc(state.UrlPath+"/debug/pprof/symbol", pprof.Symbol)
http.HandleFunc(state.UrlPath+"/debug/pprof/trace", pprof.Trace)
if state.Settings().Debug {
//TODO: split this to a different listener, metrics listener
http.HandleFunc(state.urlPath+"/debug/pprof/", pprof.Index)
http.HandleFunc(state.urlPath+"/debug/pprof/profile", pprof.Profile)
http.HandleFunc(state.urlPath+"/debug/pprof/symbol", pprof.Symbol)
http.HandleFunc(state.urlPath+"/debug/pprof/trace", pprof.Trace)
}
state.Mux.Handle("GET "+state.UrlPath+"/assets/", http.StripPrefix(state.UrlPath, gzipped.FileServer(gzipped.FS(embed.AssetsFs))))
state.Mux.Handle("GET "+state.urlPath+"/assets/", http.StripPrefix(state.UrlPath()+"/assets/", gzipped.FileServer(gzipped.FS(embed.AssetsFs))))
for _, c := range state.Challenges {
if c.ServeStatic != nil {
state.Mux.Handle("GET "+c.Path+"/static/", c.ServeStatic)
}
for _, reg := range state.challenges {
if c.ServeScript != nil {
state.Mux.Handle("GET "+c.ServeScriptPath, c.ServeScript)
}
if c.ServeMakeChallenge != nil {
state.Mux.Handle(fmt.Sprintf("POST %s/make-challenge", c.Path), c.ServeMakeChallenge)
}
if c.ServeVerifyChallenge != nil {
state.Mux.Handle(fmt.Sprintf("GET %s/verify-challenge", c.Path), c.ServeVerifyChallenge)
} else if c.Verify != nil {
state.Mux.HandleFunc(fmt.Sprintf("GET %s/verify-challenge", c.Path), func(w http.ResponseWriter, r *http.Request) {
redirect, err := utils.EnsureNoOpenRedirect(r.FormValue("redirect"))
if redirect == "" {
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), http.StatusInternalServerError, err, "")
return
}
err = func() (err error) {
data := RequestDataFromContext(r.Context())
key := state.GetChallengeKeyForRequest(c.Name, data.Expires, r)
result := r.FormValue("result")
requestId, err := hex.DecodeString(r.FormValue("requestId"))
if err == nil {
// override
r.Header.Set("X-Away-Id", hex.EncodeToString(requestId))
}
start := time.Now()
ok, err := c.Verify(key, result, r)
state.addTiming(w, "challenge-verify", "Verify client challenge", time.Since(start))
if err != nil {
state.logger(r).Error(fmt.Errorf("challenge error: %w", err).Error(), "challenge", c.Name, "redirect", redirect)
return err
} else if !ok {
state.logger(r).Warn("challenge failed", "challenge", c.Name, "redirect", redirect)
utils.ClearCookie(utils.CookiePrefix+c.Name, w)
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), http.StatusForbidden, fmt.Errorf("access denied: failed challenge %s", c.Name), redirect)
return nil
}
state.logger(r).Info("challenge passed", "challenge", c.Name, "redirect", redirect)
token, err := c.IssueChallengeToken(state.privateKey, key, []byte(result), data.Expires)
if err != nil {
utils.ClearCookie(utils.CookiePrefix+c.Name, w)
} else {
utils.SetCookie(utils.CookiePrefix+c.Name, token, data.Expires, w)
}
data.Challenges[c.Id] = challenge.VerifyResultPASS
http.Redirect(w, r, redirect, http.StatusTemporaryRedirect)
return nil
}()
if err != nil {
utils.ClearCookie(utils.CookiePrefix+c.Name, w)
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), http.StatusInternalServerError, err, redirect)
return
}
})
if reg.Handler != nil {
state.Mux.Handle(reg.Path+"/", reg.Handler)
} else if reg.Verify != nil {
// default verify
state.Mux.HandleFunc(reg.Path+challenge.VerifyChallengeUrlSuffix, challenge.VerifyHandlerFunc(state, reg, nil, nil))
}
}
@@ -426,116 +175,12 @@ func (state *State) setupRoutes() error {
}
func (state *State) ServeHTTP(w http.ResponseWriter, r *http.Request) {
r, data := challenge.CreateRequestData(r, state)
var data RequestData
// generate random id, todo: is this fast?
_, _ = rand.Read(data.Id[:])
data.RemoteAddress = getRequestAddress(r, state.Settings.ClientIpHeader)
data.Challenges = make(map[challenge.Id]challenge.VerifyResult, len(state.Challenges))
data.Expires = time.Now().UTC().Add(DefaultValidity).Round(DefaultValidity)
data.EvaluateChallenges(w, r)
var ja3n, ja4 string
if fp := utils.GetTLSFingerprint(r); fp != nil {
if ja3nPtr := fp.JA3N(); ja3nPtr != nil {
ja3n = ja3nPtr.String()
r.Header.Set("X-TLS-Fingerprint-JA3N", ja3n)
}
if ja4Ptr := fp.JA4(); ja4Ptr != nil {
ja4 = ja4Ptr.String()
r.Header.Set("X-TLS-Fingerprint-JA4", ja4)
}
}
data.ProgramEnv = map[string]any{
"host": r.Host,
"method": r.Method,
"remoteAddress": data.RemoteAddress,
"userAgent": r.UserAgent(),
"path": r.URL.Path,
"fpJA3N": ja3n,
"fpJA4": ja4,
"query": func() map[string]string {
result := make(map[string]string)
for k, v := range r.URL.Query() {
result[k] = strings.Join(v, ",")
}
return result
}(),
"headers": func() map[string]string {
result := make(map[string]string)
for k, v := range r.Header {
result[k] = strings.Join(v, ",")
}
return result
}(),
}
r = r.WithContext(context.WithValue(r.Context(), "_goaway_data", &data))
for _, c := range state.Challenges {
key := state.GetChallengeKeyForRequest(c.Name, data.Expires, r)
result, err := c.VerifyChallengeToken(state.publicKey, key, r)
if err != nil && !errors.Is(err, http.ErrNoCookie) {
// clear invalid cookie
utils.ClearCookie(utils.CookiePrefix+c.Name, w)
}
// prevent the challenge if not solved
if !result.Ok() && c.Program != nil {
out, _, err := c.Program.Eval(data.ProgramEnv)
// verify eligibility
if err != nil {
state.logger(r).Error(err.Error(), "challenge", c.Name)
} else if out != nil && out.Type() == types.BoolType {
if out.Equal(types.True) != types.True {
// skip challenge match!
result = challenge.VerifyResultSKIP
continue
}
}
}
data.Challenges[c.Id] = result
}
r.Header.Set("X-Away-Id", hex.EncodeToString(data.Id[:]))
if state.Settings.BackendIpHeader != "" {
r.Header.Del(state.Settings.ClientIpHeader)
r.Header.Set(state.Settings.BackendIpHeader, data.RemoteAddress.String())
}
// TODO: make this configurable!
w.Header().Add("Via", fmt.Sprintf("%s %s", r.Proto, "go-away"))
// send these to client so we consistently get the headers
//w.Header().Set("Accept-CH", "Sec-CH-UA, Sec-CH-UA-Platform")
//w.Header().Set("Critical-CH", "Sec-CH-UA, Sec-CH-UA-Platform")
state.Mux.ServeHTTP(w, r)
}
func RequestDataFromContext(ctx context.Context) *RequestData {
return ctx.Value("_goaway_data").(*RequestData)
}
type RequestData struct {
Id [16]byte
ProgramEnv map[string]any
Expires time.Time
Challenges map[challenge.Id]challenge.VerifyResult
RemoteAddress net.IP
}
func (d *RequestData) HasValidChallenge(id challenge.Id) bool {
return d.Challenges[id].Ok()
}
func (d *RequestData) Headers(state *State, headers http.Header) {
for id, result := range d.Challenges {
if result.Ok() {
c, ok := state.Challenges[id]
if !ok {
panic("challenge not found")
}
headers.Set(fmt.Sprintf("X-Away-Challenge-%s-Result", c.Name), result.String())
}
}
}

158
lib/interface.go Normal file
View File

@@ -0,0 +1,158 @@
package lib
import (
"bytes"
"crypto/ed25519"
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/policy"
"git.gammaspectra.live/git/go-away/utils"
"github.com/google/cel-go/cel"
"log/slog"
"maps"
"net/http"
"strings"
)
// Defines challenge.StateInterface
var _ challenge.StateInterface
func (state *State) ProgramEnv() *cel.Env {
return state.programEnv
}
func (state *State) Client() *http.Client {
return state.client
}
func (state *State) PrivateKey() ed25519.PrivateKey {
return state.privateKey
}
func (state *State) PublicKey() ed25519.PublicKey {
return state.publicKey
}
func (state *State) UrlPath() string {
return state.urlPath
}
func (state *State) ChallengeFailed(r *http.Request, reg *challenge.Registration, err error, redirect string, logger *slog.Logger) {
if logger == nil {
logger = state.Logger(r)
}
logger.Warn("challenge failed", "challenge", reg.Name, "err", err, "redirect", redirect)
//TODO: metrics
}
func (state *State) ChallengePassed(r *http.Request, reg *challenge.Registration, redirect string, logger *slog.Logger) {
if logger == nil {
logger = state.Logger(r)
}
logger.Warn("challenge passed", "challenge", reg.Name, "redirect", redirect)
//TODO: metrics
}
func (state *State) ChallengeIssued(r *http.Request, reg *challenge.Registration, redirect string, logger *slog.Logger) {
if logger == nil {
logger = state.Logger(r)
}
logger.Info("challenge issued", "challenge", reg.Name, "redirect", redirect)
//TODO: metrics
}
func (state *State) Logger(r *http.Request) *slog.Logger {
return GetLoggerForRequest(r)
}
func (state *State) ChallengePage(w http.ResponseWriter, r *http.Request, status int, reg *challenge.Registration, params map[string]any) {
data := challenge.RequestDataFromContext(r.Context())
input := make(map[string]any)
input["Id"] = data.Id.String()
input["Random"] = utils.CacheBust()
if reg != nil {
input["Challenge"] = reg.Name
input["Path"] = state.UrlPath()
}
input["Theme"] = state.Settings().ChallengeTemplateTheme
maps.Copy(input, params)
if _, ok := input["Title"]; !ok {
input["Title"] = "Checking you are not a bot"
}
w.Header().Set("Content-Type", "text/html; charset=utf-8")
buf := bytes.NewBuffer(make([]byte, 0, 8192))
err := templates["challenge-"+state.Settings().ChallengeTemplate+".gohtml"].Execute(buf, input)
if err != nil {
state.ErrorPage(w, r, http.StatusInternalServerError, err, "")
} else {
w.WriteHeader(status)
_, _ = w.Write(buf.Bytes())
}
}
func (state *State) ErrorPage(w http.ResponseWriter, r *http.Request, status int, err error, redirect string) {
data := challenge.RequestDataFromContext(r.Context())
w.Header().Set("Content-Type", "text/html; charset=utf-8")
buf := bytes.NewBuffer(make([]byte, 0, 8192))
err2 := templates["challenge-"+state.Settings().ChallengeTemplate+".gohtml"].Execute(buf, map[string]any{
"Id": data.Id.String(),
"Random": utils.CacheBust(),
"Error": err.Error(),
"Path": state.UrlPath(),
"Theme": state.Settings().ChallengeTemplateTheme,
"Title": "Oh no! " + http.StatusText(status),
"HideSpinner": true,
"Challenge": "",
"Redirect": redirect,
})
if err2 != nil {
// nested errors!
panic(err2)
} else {
w.WriteHeader(status)
_, _ = w.Write(buf.Bytes())
}
}
func (state *State) GetChallenge(id challenge.Id) (*challenge.Registration, bool) {
reg, ok := state.challenges.Get(id)
return reg, ok
}
func (state *State) GetChallenges() challenge.Register {
return state.challenges
}
func (state *State) GetChallengeByName(name string) (*challenge.Registration, bool) {
reg, _, ok := state.challenges.GetByName(name)
return reg, ok
}
func (state *State) Settings() policy.Settings {
return state.settings
}
func (state *State) GetBackend(host string) http.Handler {
backend, ok := state.Settings().Backends[host]
if !ok {
// do wildcard match
wildcard := "*." + strings.Join(strings.Split(host, ".")[1:], ".")
backend, ok = state.Settings().Backends[wildcard]
if !ok {
// return fallback
backend = state.Settings().Backends["*"]
}
}
//TODO: dynamic
return backend
}

View File

@@ -1,26 +0,0 @@
package lib
import (
"git.gammaspectra.live/git/go-away/embed"
"io"
"path"
"slices"
"strings"
)
var poisonEncodings = []string{"br", "zstd", "gzip"}
func (state *State) getPoison(mime string, encodings []string) (r io.ReadCloser, encoding string) {
for _, encoding = range poisonEncodings {
if !slices.Contains(encodings, encoding) {
continue
}
p := path.Join("poison", strings.ReplaceAll(mime, "/", "_")+"."+encoding+".poison")
f, err := embed.PoisonFs.Open(p)
if err == nil {
return f, encoding
}
}
return nil, ""
}

View File

@@ -1,15 +1,15 @@
package policy
import (
"github.com/goccy/go-yaml/ast"
"time"
)
type Challenge struct {
Conditions []string `yaml:"conditions"`
Mode string `yaml:"mode"`
Asset *string `yaml:"asset,omitempty"`
Url *string `yaml:"url,omitempty"`
Runtime string `yaml:"runtime"`
Parameters map[string]string `json:"parameters,omitempty"`
Runtime struct {
Mode string `yaml:"mode,omitempty"`
Asset string `yaml:"asset,omitempty"`
Probability float64 `yaml:"probability,omitempty"`
} `yaml:"runtime"`
Duration time.Duration `yaml:"duration"`
Parameters ast.Node `yaml:"parameters,omitempty"`
}

18
lib/policy/options.go Normal file
View File

@@ -0,0 +1,18 @@
package policy
import (
"net/http"
)
type Settings struct {
Backends map[string]http.Handler
PrivateKeySeed []byte
Debug bool
PackageName string
ChallengeTemplate string
ChallengeTemplateTheme string
ClientIpHeader string
BackendIpHeader string
ChallengeResponseCode int
}

View File

@@ -1,22 +1,40 @@
package policy
import "github.com/goccy/go-yaml/ast"
type RuleAction string
const (
RuleActionPASS RuleAction = "PASS"
RuleActionDENY RuleAction = "DENY"
RuleActionBLOCK RuleAction = "BLOCK"
// RuleActionNONE Does nothing. Useful for parent rules when children want to be specified
RuleActionNONE RuleAction = "NONE"
// RuleActionPASS Passes the connection immediately
RuleActionPASS RuleAction = "PASS"
// RuleActionDENY Denies the connection with a fancy page
RuleActionDENY RuleAction = "DENY"
// RuleActionBLOCK Denies the connection with a response code
RuleActionBLOCK RuleAction = "BLOCK"
// RuleActionCODE Returns a specified HTTP code
RuleActionCODE RuleAction = "CODE"
// RuleActionDROP Drops the connection without sending a reply
RuleActionDROP RuleAction = "DROP"
// RuleActionCHALLENGE Issues a challenge that when passed, passes the connection
RuleActionCHALLENGE RuleAction = "CHALLENGE"
RuleActionCHECK RuleAction = "CHECK"
RuleActionPOISON RuleAction = "POISON"
// RuleActionCHECK Issues a challenge that when passed, continues checking rules
RuleActionCHECK RuleAction = "CHECK"
// RuleActionPROXY Proxies request to a backend, with optional path replacements
RuleActionPROXY RuleAction = "PROXY"
)
type Rule struct {
Name string `yaml:"name"`
Host *string `yaml:"host"`
Conditions []string `yaml:"conditions"`
Action string `yaml:"action"`
Challenges []string `yaml:"challenges"`
Settings ast.Node `yaml:"settings"`
Children []Rule `yaml:"children"`
}

141
lib/rule.go Normal file
View File

@@ -0,0 +1,141 @@
package lib
import (
"crypto/sha256"
"encoding/hex"
"fmt"
"git.gammaspectra.live/git/go-away/lib/action"
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/condition"
"git.gammaspectra.live/git/go-away/lib/policy"
"github.com/google/cel-go/cel"
"github.com/google/cel-go/common/types"
"github.com/google/cel-go/common/types/ref"
"log/slog"
"net/http"
"strings"
)
type RuleState struct {
Name string
Hash string
Condition cel.Program
Action policy.RuleAction
Handler action.Handler
Children []RuleState
}
func NewRuleState(state challenge.StateInterface, r policy.Rule, replacer *strings.Replacer, parent *RuleState) (RuleState, error) {
fp := sha256.Sum256(state.PrivateKey())
hasher := sha256.New()
if parent != nil {
hasher.Write([]byte(parent.Name))
hasher.Write([]byte{0})
r.Name = fmt.Sprintf("%s/%s", parent.Name, r.Name)
}
hasher.Write([]byte(r.Name))
hasher.Write([]byte{0})
hasher.Write(fp[:])
sum := hasher.Sum(nil)
rule := RuleState{
Name: r.Name,
Hash: hex.EncodeToString(sum[:10]),
Action: policy.RuleAction(strings.ToUpper(r.Action)),
}
newHandler, ok := action.Register[rule.Action]
if !ok {
return RuleState{}, fmt.Errorf("unknown action %s", r.Action)
}
actionHandler, err := newHandler(state, rule.Name, rule.Hash, r.Settings)
if err != nil {
return RuleState{}, err
}
rule.Handler = actionHandler
if len(r.Conditions) > 0 {
// allow nesting
var conditions []string
for _, cond := range r.Conditions {
cond = replacer.Replace(cond)
conditions = append(conditions, cond)
}
ast, err := condition.FromStrings(state.ProgramEnv(), condition.OperatorOr, conditions...)
if err != nil {
return RuleState{}, fmt.Errorf("error compiling conditions: %w", err)
}
program, err := condition.Program(state.ProgramEnv(), ast)
if err != nil {
return RuleState{}, fmt.Errorf("error compiling program: %w", err)
}
rule.Condition = program
}
if len(r.Children) > 0 {
for _, child := range r.Children {
childRule, err := NewRuleState(state, child, replacer, &rule)
if err != nil {
return RuleState{}, fmt.Errorf("child %s: %w", child.Name, err)
}
rule.Children = append(rule.Children, childRule)
}
}
return rule, nil
}
func (rule RuleState) Evaluate(logger *slog.Logger, w http.ResponseWriter, r *http.Request, done func() http.Handler) (next bool, err error) {
data := challenge.RequestDataFromContext(r.Context())
var out ref.Val
lg := logger.With("rule", rule.Name, "rule_hash", rule.Hash, "action", string(rule.Action))
if rule.Condition != nil {
out, _, err = rule.Condition.Eval(data)
} else {
// default true
out = types.Bool(true)
}
if err != nil {
lg.Error(err.Error())
return false, fmt.Errorf("error: evaluating administrative rule %s/%s: %w", data.Id.String(), rule.Hash, err)
} else if out != nil && out.Type() == types.BoolType {
if out.Equal(types.True) == types.True {
next, err = rule.Handler.Handle(lg, w, r, func() http.Handler {
r.Header.Set("X-Away-Rule", rule.Name)
r.Header.Set("X-Away-Hash", rule.Hash)
r.Header.Set("X-Away-Action", string(rule.Action))
return done()
})
if err != nil {
lg.Error(err.Error())
return false, fmt.Errorf("error: executing administrative rule %s/%s: %w", data.Id.String(), rule.Hash, err)
}
if !next {
return next, nil
}
for _, child := range rule.Children {
next, err = child.Evaluate(logger, w, r, done)
if err != nil {
lg.Error(err.Error())
return false, fmt.Errorf("error: executing administrative rule %s/%s: %w", data.Id.String(), rule.Hash, err)
}
if !next {
return next, nil
}
}
}
}
return true, nil
}

View File

@@ -1,157 +1,76 @@
package lib
import (
"codeberg.org/meta/gzipped/v2"
"context"
"crypto/ed25519"
"crypto/rand"
"crypto/sha256"
"crypto/subtle"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"git.gammaspectra.live/git/go-away/embed"
"git.gammaspectra.live/git/go-away/lib/challenge"
"git.gammaspectra.live/git/go-away/lib/challenge/wasm"
"git.gammaspectra.live/git/go-away/lib/challenge/wasm/interface"
"git.gammaspectra.live/git/go-away/lib/condition"
"git.gammaspectra.live/git/go-away/lib/policy"
"git.gammaspectra.live/git/go-away/utils"
"git.gammaspectra.live/git/go-away/utils/inline"
"github.com/google/cel-go/cel"
"github.com/tetratelabs/wazero/api"
"github.com/yl2chen/cidranger"
"html/template"
"io"
"io/fs"
"log/slog"
"net"
"net/http"
"net/http/httputil"
"net/url"
"os"
"path"
"strconv"
"strings"
"sync"
"sync/atomic"
"time"
)
type State struct {
Client *http.Client
Settings StateSettings
UrlPath string
Mux *http.ServeMux
client *http.Client
urlPath string
Networks map[string]cidranger.Ranger
Wasm *wasm.Runner
Challenges map[challenge.Id]challenge.Challenge
RulesEnv *cel.Env
Rules []RuleState
programEnv *cel.Env
publicKey ed25519.PublicKey
privateKey ed25519.PrivateKey
Poison map[string][]byte
settings policy.Settings
ChallengeSolve sync.Map
networks map[string]cidranger.Ranger
DecayMap *utils.DecayMap[[net.IPv6len]byte, utils.DNSBLResponse]
challenges challenge.Register
rules []RuleState
close chan struct{}
Mux *http.ServeMux
}
func (state *State) AwaitChallenge(key []byte, ctx context.Context) challenge.VerifyResult {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
var result atomic.Int64
state.ChallengeSolve.Store(string(key), ChallengeCallback(func(receivedResult challenge.VerifyResult) {
result.Store(int64(receivedResult))
cancel()
}))
<-ctx.Done()
return challenge.VerifyResult(result.Load())
}
func (state *State) SolveChallenge(key []byte, result challenge.VerifyResult) {
if f, ok := state.ChallengeSolve.LoadAndDelete(string(key)); ok && f != nil {
if cb, ok := f.(ChallengeCallback); ok {
cb(result)
}
}
}
type ChallengeCallback func(result challenge.VerifyResult)
type RuleState struct {
Name string
Hash string
Host *string
Program cel.Program
Action policy.RuleAction
Challenges []challenge.Id
}
type StateSettings struct {
Backends map[string]http.Handler
PrivateKeySeed []byte
Debug bool
PackageName string
ChallengeTemplate string
ChallengeTemplateTheme string
ClientIpHeader string
BackendIpHeader string
DNSBL *utils.DNSBL
}
func NewState(p policy.Policy, settings StateSettings) (handler http.Handler, err error) {
func NewState(p policy.Policy, settings policy.Settings) (handler http.Handler, err error) {
state := new(State)
state.close = make(chan struct{})
state.Settings = settings
state.Client = &http.Client{
state.settings = settings
state.client = &http.Client{
CheckRedirect: func(req *http.Request, via []*http.Request) error {
return http.ErrUseLastResponse
},
}
state.UrlPath = "/.well-known/." + state.Settings.PackageName
if state.Settings.DNSBL != nil {
state.DecayMap = utils.NewDecayMap[[net.IPv6len]byte, utils.DNSBLResponse]()
}
state.urlPath = "/.well-known/." + state.Settings().PackageName
// set a reasonable configuration for default http proxy if there is none
for _, backend := range state.Settings.Backends {
for _, backend := range state.Settings().Backends {
if proxy, ok := backend.(*httputil.ReverseProxy); ok {
if proxy.ErrorHandler == nil {
proxy.ErrorHandler = func(w http.ResponseWriter, r *http.Request, err error) {
state.logger(r).Error(err.Error())
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), http.StatusBadGateway, err, "")
state.Logger(r).Error(err.Error())
state.ErrorPage(w, r, http.StatusBadGateway, err, "")
}
}
}
}
if len(state.Settings.PrivateKeySeed) > 0 {
if len(state.Settings.PrivateKeySeed) != ed25519.SeedSize {
return nil, fmt.Errorf("invalid private key seed length: %d", len(state.Settings.PrivateKeySeed))
if len(state.Settings().PrivateKeySeed) > 0 {
if len(state.Settings().PrivateKeySeed) != ed25519.SeedSize {
return nil, fmt.Errorf("invalid private key seed length: %d", len(state.Settings().PrivateKeySeed))
}
state.privateKey = ed25519.NewKeyFromSeed(state.Settings.PrivateKeySeed)
state.privateKey = ed25519.NewKeyFromSeed(state.Settings().PrivateKeySeed)
state.publicKey = state.privateKey.Public().(ed25519.PublicKey)
clear(state.Settings.PrivateKeySeed)
clear(state.settings.PrivateKeySeed)
} else {
state.publicKey, state.privateKey, err = ed25519.GenerateKey(rand.Reader)
@@ -160,34 +79,32 @@ func NewState(p policy.Policy, settings StateSettings) (handler http.Handler, er
}
}
privateKeyFingerprint := sha256.Sum256(state.privateKey)
if state.Settings.ChallengeTemplate == "" {
state.Settings.ChallengeTemplate = "anubis"
if state.Settings().ChallengeTemplate == "" {
state.settings.ChallengeTemplate = "anubis"
}
if templates["challenge-"+state.Settings.ChallengeTemplate+".gohtml"] == nil {
if templates["challenge-"+state.Settings().ChallengeTemplate+".gohtml"] == nil {
if data, err := os.ReadFile(state.Settings.ChallengeTemplate); err == nil && len(data) > 0 {
name := path.Base(state.Settings.ChallengeTemplate)
if data, err := os.ReadFile(state.Settings().ChallengeTemplate); err == nil && len(data) > 0 {
name := path.Base(state.Settings().ChallengeTemplate)
err := initTemplate(name, string(data))
if err != nil {
return nil, fmt.Errorf("error loading template %s: %w", settings.ChallengeTemplate, err)
}
state.Settings.ChallengeTemplate = name
state.settings.ChallengeTemplate = name
}
return nil, fmt.Errorf("no template defined for %s", settings.ChallengeTemplate)
}
state.Networks = make(map[string]cidranger.Ranger)
state.networks = make(map[string]cidranger.Ranger)
for k, network := range p.Networks {
ranger := cidranger.NewPCTrieRanger()
for _, e := range network {
if e.Url != nil {
slog.Debug("loading network url list", "network", k, "url", *e.Url)
}
prefixes, err := e.FetchPrefixes(state.Client)
prefixes, err := e.FetchPrefixes(state.client)
if err != nil {
slog.Error("error fetching network url list", "network", k, "url", *e.Url)
continue
@@ -202,11 +119,9 @@ func NewState(p policy.Policy, settings StateSettings) (handler http.Handler, er
slog.Warn("loaded network prefixes", "network", k, "count", ranger.Len())
state.Networks[k] = ranger
state.networks[k] = ranger
}
state.Wasm = wasm.NewRunner(true)
err = state.initConditions()
if err != nil {
return nil, err
@@ -214,7 +129,7 @@ func NewState(p policy.Policy, settings StateSettings) (handler http.Handler, er
var replacements []string
for k, entries := range p.Conditions {
ast, err := condition.FromStrings(state.RulesEnv, condition.OperatorOr, entries...)
ast, err := condition.FromStrings(state.programEnv, condition.OperatorOr, entries...)
if err != nil {
return nil, fmt.Errorf("conditions %s: error compiling conditions: %v", k, err)
}
@@ -229,563 +144,26 @@ func NewState(p policy.Policy, settings StateSettings) (handler http.Handler, er
}
conditionReplacer := strings.NewReplacer(replacements...)
state.Challenges = make(map[challenge.Id]challenge.Challenge)
idCounter := challenge.Id(1)
state.challenges = make(challenge.Register)
//TODO: move this to self-contained challenge files
for challengeName, p := range p.Challenges {
// allow nesting
var conditions []string
for _, cond := range p.Conditions {
cond = conditionReplacer.Replace(cond)
conditions = append(conditions, cond)
for challengeName, pol := range p.Challenges {
_, _, err := state.challenges.Create(state, challengeName, pol, conditionReplacer)
if err != nil {
return nil, fmt.Errorf("challenge %s: %w", challengeName, err)
}
var program cel.Program
if len(conditions) > 0 {
ast, err := condition.FromStrings(state.RulesEnv, condition.OperatorOr, conditions...)
if err != nil {
return nil, fmt.Errorf("challenge %s: error compiling conditions: %v", challengeName, err)
}
program, err = state.RulesEnv.Program(ast)
if err != nil {
return nil, fmt.Errorf("challenge %s: error compiling program: %v", challengeName, err)
}
}
c := challenge.Challenge{
Id: idCounter,
Program: program,
Name: challengeName,
Path: fmt.Sprintf("%s/challenge/%s", state.UrlPath, challengeName),
VerifyProbability: p.Runtime.Probability,
}
idCounter++
if c.VerifyProbability <= 0 {
//10% default
c.VerifyProbability = 0.1
} else if c.VerifyProbability > 1.0 {
c.VerifyProbability = 1.0
}
assetPath := c.Path + "/static/"
subFs, err := fs.Sub(embed.ChallengeFs, fmt.Sprintf("challenge/%s/static", challengeName))
if err == nil {
c.ServeStatic = http.StripPrefix(
assetPath,
gzipped.FileServer(gzipped.FS(subFs)),
)
}
switch p.Mode {
default:
return nil, fmt.Errorf("unknown challenge mode: %s", p.Mode)
case "http":
if p.Url == nil {
return nil, fmt.Errorf("challenge %s: missing url", challengeName)
}
method := p.Parameters["http-method"]
if method == "" {
method = "GET"
}
httpCode, _ := strconv.Atoi(p.Parameters["http-code"])
if httpCode == 0 {
httpCode = http.StatusOK
}
expectedCookie := p.Parameters["http-cookie"]
c.Verify = func(key []byte, result string, r *http.Request) (bool, error) {
var cookieValue string
if expectedCookie != "" {
if cookie, err := r.Cookie(expectedCookie); err != nil || cookie == nil {
// skip check if we don't have cookie or it's expired
return false, nil
} else {
cookieValue = cookie.Value
}
}
// bind hash of cookie contents
sum := sha256.New()
sum.Write([]byte(cookieValue))
sum.Write([]byte{0})
sum.Write(key)
sum.Write([]byte{0})
sum.Write(state.publicKey)
if subtle.ConstantTimeCompare(sum.Sum(nil), []byte(result)) == 1 {
return true, nil
}
return false, nil
}
c.ServeChallenge = func(w http.ResponseWriter, r *http.Request, key []byte, expiry time.Time) challenge.Result {
data := RequestDataFromContext(r.Context())
if result := data.Challenges[c.Id]; result.Ok() {
return challenge.ResultPass
}
var cookieValue string
if expectedCookie != "" {
if cookie, err := r.Cookie(expectedCookie); err != nil || cookie == nil {
// skip check if we don't have cookie or it's expired
return challenge.ResultContinue
} else {
cookieValue = cookie.Value
}
}
request, err := http.NewRequest(method, *p.Url, nil)
if err != nil {
return challenge.ResultContinue
}
request.Header = r.Header
response, err := state.Client.Do(request)
if err != nil {
return challenge.ResultContinue
}
defer response.Body.Close()
defer io.Copy(io.Discard, response.Body)
if response.StatusCode != httpCode {
utils.ClearCookie(utils.CookiePrefix+c.Name, w)
// continue other challenges!
//TODO: negatively cache failure
return challenge.ResultContinue
} else {
// bind hash of cookie contents
sum := sha256.New()
sum.Write([]byte(cookieValue))
sum.Write([]byte{0})
sum.Write(key)
sum.Write([]byte{0})
sum.Write(state.publicKey)
token, err := c.IssueChallengeToken(state.privateKey, key, sum.Sum(nil), expiry)
if err != nil {
utils.ClearCookie(utils.CookiePrefix+c.Name, w)
} else {
utils.SetCookie(utils.CookiePrefix+challengeName, token, expiry, w)
}
data.Challenges[c.Id] = challenge.VerifyResultPASS
// we passed it!
return challenge.ResultPass
}
}
case "cookie":
c.ServeChallenge = func(w http.ResponseWriter, r *http.Request, key []byte, expiry time.Time) challenge.Result {
if chall := r.URL.Query().Get("__goaway_challenge"); chall == challengeName {
state.logger(r).Warn("challenge failed", "challenge", c.Name)
utils.ClearCookie(utils.CookiePrefix+c.Name, w)
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), http.StatusForbidden, fmt.Errorf("access denied: failed challenge %s", c.Name), "")
return challenge.ResultStop
}
token, err := c.IssueChallengeToken(state.privateKey, key, nil, expiry)
if err != nil {
utils.ClearCookie(utils.CookiePrefix+challengeName, w)
} else {
utils.SetCookie(utils.CookiePrefix+challengeName, token, expiry, w)
}
// self redirect!
uri, err := url.ParseRequestURI(r.URL.String())
values := uri.Query()
values.Set("__goaway_challenge", challengeName)
uri.RawQuery = values.Encode()
http.Redirect(w, r, uri.String(), http.StatusTemporaryRedirect)
return challenge.ResultStop
}
case "meta-refresh":
c.ServeChallenge = func(w http.ResponseWriter, r *http.Request, key []byte, expiry time.Time) challenge.Result {
redirectUri := new(url.URL)
redirectUri.Path = c.Path + "/verify-challenge"
values := make(url.Values)
values.Set("result", hex.EncodeToString(key))
values.Set("redirect", r.URL.String())
values.Set("requestId", r.Header.Get("X-Away-Id"))
redirectUri.RawQuery = values.Encode()
_ = state.challengePage(w, r.Header.Get("X-Away-Id"), http.StatusTeapot, "", map[string]any{
"Meta": map[string]string{
"refresh": "0; url=" + redirectUri.String(),
},
})
return challenge.ResultStop
}
case "header-refresh":
c.ServeChallenge = func(w http.ResponseWriter, r *http.Request, key []byte, expiry time.Time) challenge.Result {
redirectUri := new(url.URL)
redirectUri.Path = c.Path + "/verify-challenge"
values := make(url.Values)
values.Set("result", hex.EncodeToString(key))
values.Set("redirect", r.URL.String())
values.Set("requestId", r.Header.Get("X-Away-Id"))
redirectUri.RawQuery = values.Encode()
// self redirect!
w.Header().Set("Refresh", "0; url="+redirectUri.String())
_ = state.challengePage(w, r.Header.Get("X-Away-Id"), http.StatusTeapot, "", nil)
return challenge.ResultStop
}
case "preload-link":
deadline, _ := time.ParseDuration(p.Parameters["preload-early-hint-deadline"])
if deadline == 0 {
deadline = time.Second * 3
}
c.ServeChallenge = func(w http.ResponseWriter, r *http.Request, key []byte, expiry time.Time) challenge.Result {
// this only works on HTTP/2 and HTTP/3
if r.ProtoMajor < 2 {
// this can happen if we are an upgraded request from HTTP/1.1 to HTTP/2 in H2C
if _, ok := w.(http.Pusher); !ok {
return challenge.ResultContinue
}
}
data := RequestDataFromContext(r.Context())
redirectUri := new(url.URL)
redirectUri.Scheme = getRequestScheme(r)
redirectUri.Host = r.Host
redirectUri.Path = c.Path + "/verify-challenge"
values := make(url.Values)
values.Set("result", hex.EncodeToString(key))
values.Set("requestId", r.Header.Get("X-Away-Id"))
redirectUri.RawQuery = values.Encode()
w.Header().Set("Link", fmt.Sprintf("<%s>; rel=\"preload\"; as=\"style\"; fetchpriority=high", redirectUri.String()))
defer func() {
// remove old header so it won't show on response!
w.Header().Del("Link")
}()
w.WriteHeader(http.StatusEarlyHints)
ctx, cancel := context.WithTimeout(r.Context(), deadline)
defer cancel()
if result := state.AwaitChallenge(key, ctx); result.Ok() {
data.Challenges[c.Id] = challenge.VerifyResultPASS
// this should serve!
return challenge.ResultPass
}
data.Challenges[c.Id] = challenge.VerifyResultFAIL
// we failed, continue
return challenge.ResultContinue
}
case "resource-load":
c.ServeChallenge = func(w http.ResponseWriter, r *http.Request, key []byte, expiry time.Time) challenge.Result {
redirectUri := new(url.URL)
redirectUri.Path = c.Path + "/verify-challenge"
values := make(url.Values)
values.Set("result", hex.EncodeToString(key))
values.Set("requestId", r.Header.Get("X-Away-Id"))
redirectUri.RawQuery = values.Encode()
// self redirect!
w.Header().Set("Refresh", "2; url="+r.URL.String())
_ = state.challengePage(w, r.Header.Get("X-Away-Id"), http.StatusTeapot, "", map[string]any{
"Tags": []template.HTML{
template.HTML(fmt.Sprintf("<link href=\"%s\" rel=\"stylesheet\" crossorigin=\"use-credentials\">", redirectUri.String())),
},
})
return challenge.ResultStop
}
case "js":
c.ServeChallenge = func(w http.ResponseWriter, r *http.Request, key []byte, expiry time.Time) challenge.Result {
_ = state.challengePage(w, r.Header.Get("X-Away-Id"), http.StatusTeapot, challengeName, nil)
return challenge.ResultStop
}
c.ServeScriptPath = c.Path + "/challenge.mjs"
c.ServeScript = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
params, _ := json.Marshal(p.Parameters)
//TODO: move this to http.go as a template
w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
w.Header().Set("Content-Type", "text/javascript; charset=utf-8")
w.WriteHeader(http.StatusOK)
err := templates["challenge.mjs"].Execute(w, map[string]any{
"Path": c.Path,
"Parameters": string(params),
"Random": cacheBust,
"Challenge": challengeName,
"ChallengeScript": func() string {
if p.Asset != nil {
return assetPath + *p.Asset
} else if p.Url != nil {
return *p.Url
} else {
panic("not implemented")
}
}(),
})
if err != nil {
//TODO: log
}
})
}
// how to runtime
switch p.Runtime.Mode {
default:
return nil, fmt.Errorf("unknown challenge runtime mode: %s", p.Runtime.Mode)
case "":
case "http":
case "key":
mimeType := p.Parameters["key-mime"]
if mimeType == "" {
mimeType = "text/html; charset=utf-8"
}
httpCode, _ := strconv.Atoi(p.Parameters["key-code"])
if httpCode == 0 {
httpCode = http.StatusTemporaryRedirect
}
var content []byte
if data, ok := p.Parameters["key-content"]; ok {
content = []byte(data)
}
c.Verify = func(key []byte, result string, r *http.Request) (bool, error) {
resultBytes, err := hex.DecodeString(result)
if err != nil {
return false, err
}
if subtle.ConstantTimeCompare(resultBytes, key) != 1 {
return false, nil
}
return true, nil
}
c.ServeVerifyChallenge = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
redirect, err := utils.EnsureNoOpenRedirect(r.FormValue("redirect"))
if err != nil {
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), http.StatusBadRequest, err, "")
return
}
err = func() (err error) {
data := RequestDataFromContext(r.Context())
key := state.GetChallengeKeyForRequest(challengeName, data.Expires, r)
result := r.FormValue("result")
requestId, err := hex.DecodeString(r.FormValue("requestId"))
if err == nil {
r.Header.Set("X-Away-Id", hex.EncodeToString(requestId))
}
if ok, err := c.Verify(key, result, r); err != nil {
return err
} else if !ok {
utils.ClearCookie(utils.CookiePrefix+challengeName, w)
data.Challenges[c.Id] = challenge.VerifyResultFAIL
state.SolveChallenge(key, challenge.VerifyResultFAIL)
state.logger(r).Warn("challenge failed", "challenge", challengeName, "redirect", redirect)
// catch happy eyeballs IPv4 -> IPv6 migration, re-direct to try again
if resultKey, err := ChallengeKeyFromString(result); err == nil && resultKey.Get(ChallengeKeyFlagIsIPv4) > 0 && key.Get(ChallengeKeyFlagIsIPv4) == 0 {
} else {
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), http.StatusForbidden, fmt.Errorf("access denied: failed challenge %s", challengeName), redirect)
return nil
}
} else {
state.logger(r).Warn("challenge passed", "challenge", challengeName, "redirect", redirect)
token, err := c.IssueChallengeToken(state.privateKey, key, []byte(result), data.Expires)
if err != nil {
utils.ClearCookie(utils.CookiePrefix+challengeName, w)
} else {
utils.SetCookie(utils.CookiePrefix+challengeName, token, data.Expires, w)
}
data.Challenges[c.Id] = challenge.VerifyResultPASS
state.SolveChallenge(key, challenge.VerifyResultPASS)
}
switch httpCode {
case http.StatusMovedPermanently, http.StatusFound, http.StatusSeeOther, http.StatusTemporaryRedirect, http.StatusPermanentRedirect:
if redirect == "" {
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), http.StatusBadRequest, errors.New("no redirect found"), "")
return nil
}
http.Redirect(w, r, redirect, httpCode)
default:
w.Header().Set("Content-Type", mimeType)
w.WriteHeader(httpCode)
if content != nil {
_, _ = w.Write(content)
}
}
return nil
}()
if err != nil {
utils.ClearCookie(utils.CookiePrefix+challengeName, w)
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), http.StatusInternalServerError, err, redirect)
return
}
})
case "wasm":
wasmData, err := embed.ChallengeFs.ReadFile(fmt.Sprintf("challenge/%s/runtime/%s", challengeName, p.Runtime.Asset))
if err != nil {
return nil, fmt.Errorf("c %s: could not load runtime: %w", challengeName, err)
}
err = state.Wasm.Compile(challengeName, wasmData)
if err != nil {
return nil, fmt.Errorf("c %s: compiling runtime: %w", challengeName, err)
}
c.ServeMakeChallenge = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
err := state.Wasm.Instantiate(challengeName, func(ctx context.Context, mod api.Module) (err error) {
data := RequestDataFromContext(r.Context())
in := _interface.MakeChallengeInput{
Key: state.GetChallengeKeyForRequest(challengeName, data.Expires, r),
Parameters: p.Parameters,
Headers: inline.MIMEHeader(r.Header),
}
in.Data, err = io.ReadAll(r.Body)
if err != nil {
return err
}
out, err := wasm.MakeChallengeCall(ctx, mod, in)
if err != nil {
return err
}
// set output headers
for k, v := range out.Headers {
w.Header()[k] = v
}
w.Header().Set("Content-Length", fmt.Sprintf("%d", len(out.Data)))
w.WriteHeader(out.Code)
_, _ = w.Write(out.Data)
return nil
})
if err != nil {
_ = state.errorPage(w, r.Header.Get("X-Away-Id"), http.StatusInternalServerError, err, "")
return
}
})
c.Verify = func(key []byte, result string, r *http.Request) (ok bool, err error) {
err = state.Wasm.Instantiate(challengeName, func(ctx context.Context, mod api.Module) (err error) {
in := _interface.VerifyChallengeInput{
Key: key,
Parameters: p.Parameters,
Result: []byte(result),
}
out, err := wasm.VerifyChallengeCall(ctx, mod, in)
if err != nil {
return err
}
if out == _interface.VerifyChallengeOutputError {
return errors.New("error checking challenge")
}
ok = out == _interface.VerifyChallengeOutputOK
return nil
})
if err != nil {
return false, err
}
return ok, nil
}
}
state.Challenges[c.Id] = c
}
for _, rule := range p.Rules {
hasher := sha256.New()
hasher.Write([]byte(rule.Name))
hasher.Write([]byte{0})
if rule.Host != nil {
hasher.Write([]byte(*rule.Host))
}
hasher.Write([]byte{0})
hasher.Write(privateKeyFingerprint[:])
sum := hasher.Sum(nil)
for _, r := range p.Rules {
challenges := make([]challenge.Id, 0, len(rule.Challenges))
for _, challengeName := range rule.Challenges {
c, ok := state.GetChallengeByName(challengeName)
if !ok {
return nil, fmt.Errorf("challenge %s not found", challengeName)
}
challenges = append(challenges, c.Id)
}
r := RuleState{
Name: rule.Name,
Hash: hex.EncodeToString(sum[:8]),
Host: rule.Host,
Action: policy.RuleAction(strings.ToUpper(rule.Action)),
Challenges: challenges,
}
if (r.Action == policy.RuleActionCHALLENGE || r.Action == policy.RuleActionCHECK) && len(r.Challenges) == 0 {
return nil, fmt.Errorf("no challenges found in rule %s", rule.Name)
}
// allow nesting
var conditions []string
for _, cond := range rule.Conditions {
cond = conditionReplacer.Replace(cond)
conditions = append(conditions, cond)
}
ast, err := condition.FromStrings(state.RulesEnv, condition.OperatorOr, conditions...)
rule, err := NewRuleState(state, r, conditionReplacer, nil)
if err != nil {
return nil, fmt.Errorf("rules %s: error compiling conditions: %v", rule.Name, err)
return nil, fmt.Errorf("rule %s: %w", r.Name, err)
}
program, err := state.RulesEnv.Program(ast)
if err != nil {
return nil, fmt.Errorf("rules %s: error compiling program: %v", rule.Name, err)
}
r.Program = program
slog.Warn("loaded rule", "rule", r.Name, "hash", r.Hash, "action", rule.Action)
slog.Warn("loaded rule", "rule", rule.Name, "hash", rule.Hash, "action", rule.Action, "children", len(rule.Children))
state.Rules = append(state.Rules, r)
state.rules = append(state.rules, rule)
}
state.Mux = http.NewServeMux()
@@ -794,28 +172,5 @@ func NewState(p policy.Policy, settings StateSettings) (handler http.Handler, er
return nil, err
}
if state.DecayMap != nil {
go func() {
ticker := time.NewTicker(17 * time.Minute)
for {
select {
case <-ticker.C:
state.DecayMap.Decay()
case <-state.close:
return
}
}
}()
}
return state, nil
}
func (state *State) GetChallengeByName(name string) (challenge.Challenge, bool) {
for _, c := range state.Challenges {
if c.Name == name {
return c, true
}
}
return challenge.Challenge{}, false
}