Files
go-away/lib/challenge/preload-link/preload-link.go

129 lines
3.1 KiB
Go

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 * 2,
}
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
}