drone/internal/api/middleware/encode/encode.go

105 lines
3.3 KiB
Go

// Copyright 2022 Harness Inc. All rights reserved.
// Use of this source code is governed by the Polyform Free Trial License
// that can be found in the LICENSE.md file for this repository.
package encode
import (
"net/http"
"strings"
"github.com/harness/gitness/internal/api/render"
"github.com/harness/gitness/internal/request"
"github.com/harness/gitness/types"
"github.com/rs/zerolog/hlog"
)
const (
EncodedPathSeparator = "%252F"
)
// GitPathBefore wraps an http.HandlerFunc in a layer that encodes a path coming
// as part of the GIT api (e.g. "space1/repo.git") before executing the provided http.HandlerFunc.
func GitPathBefore(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
_, err := pathTerminatedWithMarker(r, "", ".git", false)
if err != nil {
render.TranslatedUserError(w, err)
return
}
next.ServeHTTP(w, r)
})
}
// TerminatedPathBefore wraps an http.HandlerFunc in a layer that encodes a terminated path (e.g. "/space1/space2/+")
// before executing the provided http.HandlerFunc. The first prefix that matches the URL.Path will
// be used during encoding (prefix is ignored during encoding).
func TerminatedPathBefore(prefixes []string, next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
for _, p := range prefixes {
changed, err := pathTerminatedWithMarker(r, p, "/+", false)
if err != nil {
render.TranslatedUserError(w, err)
return
}
// first prefix that leads to success we can stop
if changed {
break
}
}
next.ServeHTTP(w, r)
})
}
// pathTerminatedWithMarker function encodes a path followed by a custom marker and returns a request with an
// updated URL.Path.
// A non-empty prefix can be provided to encode encode only after the prefix.
// It allows our Rest API to handle paths of the form "/spaces/space1/space2/+/authToken"
//
// Examples:
// Prefix: "" Path: "/space1/space2/+" => "/space1%2Fspace2"
// Prefix: "" Path: "/space1/space2.git" => "/space1%2Fspace2"
// Prefix: "/spaces" Path: "/spaces/space1/space2/+/authToken" => "/spaces/space1%2Fspace2/authToken".
func pathTerminatedWithMarker(r *http.Request, prefix string, marker string, keepMarker bool) (bool, error) {
// In case path doesn't start with prefix - nothing to encode
if len(r.URL.Path) < len(prefix) || r.URL.Path[0:len(prefix)] != prefix {
return false, nil
}
originalSubPath := r.URL.Path[len(prefix):]
path, _, found := strings.Cut(originalSubPath, marker)
// If we don't find a marker - nothing to encode
if !found {
return false, nil
}
// if marker was found - convert to escaped version (skip first character in case path starts with '/').
// Since replacePrefix unescapes the strings, we have to double escape.
escapedPath := path[0:1] + strings.ReplaceAll(path[1:], types.PathSeparator, EncodedPathSeparator)
if keepMarker {
escapedPath += marker
}
prefixWithPath := prefix + path + marker
prefixWithEscapedPath := prefix + escapedPath
hlog.FromRequest(r).Trace().Msgf(
"[Encode] prefix: '%s', marker: '%s', original: '%s', escaped: '%s'.\n",
prefix,
marker,
prefixWithPath,
prefixWithEscapedPath)
err := request.ReplacePrefix(r, prefixWithPath, prefixWithEscapedPath)
if err != nil {
return false, err
}
return true, nil
}