forgejo/services/webhook/matrix.go
zeripath bbffcc3aec
Multiple Escaping Improvements (#17551)
There are multiple places where Gitea does not properly escape URLs that it is building and there are multiple places where it builds urls when there is already a simpler function available to use this.
    
This is an extensive PR attempting to fix these issues.

1. The first commit in this PR looks through all href, src and links in the Gitea codebase and has attempted to catch all the places where there is potentially incomplete escaping.
2. Whilst doing this we will prefer to use functions that create URLs over recreating them by hand.
3. All uses of strings should be directly escaped - even if they are not currently expected to contain escaping characters. The main benefit to doing this will be that we can consider relaxing the constraints on user names and reponames in future. 
4. The next commit looks at escaping in the wiki and re-considers the urls that are used there. Using the improved escaping here wiki files containing '/'. (This implementation will currently still place all of the wiki files the root directory of the repo but this would not be difficult to change.)
5. The title generation in feeds is now properly escaped.
6. EscapePound is no longer needed - urls should be PathEscaped / QueryEscaped as necessary but then re-escaped with Escape when creating html with locales Signed-off-by: Andrew Thornton <art27@cantab.net>

Signed-off-by: Andrew Thornton <art27@cantab.net>
2021-11-16 18:18:25 +00:00

309 lines
10 KiB
Go

// Copyright 2020 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package webhook
import (
"crypto/sha1"
"errors"
"fmt"
"html"
"net/http"
"net/url"
"regexp"
"strings"
webhook_model "code.gitea.io/gitea/models/webhook"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/json"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/setting"
api "code.gitea.io/gitea/modules/structs"
"code.gitea.io/gitea/modules/util"
)
const matrixPayloadSizeLimit = 1024 * 64
// MatrixMeta contains the Matrix metadata
type MatrixMeta struct {
HomeserverURL string `json:"homeserver_url"`
Room string `json:"room_id"`
AccessToken string `json:"access_token"`
MessageType int `json:"message_type"`
}
var messageTypeText = map[int]string{
1: "m.notice",
2: "m.text",
}
// GetMatrixHook returns Matrix metadata
func GetMatrixHook(w *webhook_model.Webhook) *MatrixMeta {
s := &MatrixMeta{}
if err := json.Unmarshal([]byte(w.Meta), s); err != nil {
log.Error("webhook.GetMatrixHook(%d): %v", w.ID, err)
}
return s
}
// MatrixPayloadUnsafe contains the (unsafe) payload for a Matrix room
type MatrixPayloadUnsafe struct {
MatrixPayloadSafe
AccessToken string `json:"access_token"`
}
var (
_ PayloadConvertor = &MatrixPayloadUnsafe{}
)
// safePayload "converts" a unsafe payload to a safe payload
func (m *MatrixPayloadUnsafe) safePayload() *MatrixPayloadSafe {
return &MatrixPayloadSafe{
Body: m.Body,
MsgType: m.MsgType,
Format: m.Format,
FormattedBody: m.FormattedBody,
Commits: m.Commits,
}
}
// MatrixPayloadSafe contains (safe) payload for a Matrix room
type MatrixPayloadSafe struct {
Body string `json:"body"`
MsgType string `json:"msgtype"`
Format string `json:"format"`
FormattedBody string `json:"formatted_body"`
Commits []*api.PayloadCommit `json:"io.gitea.commits,omitempty"`
}
// JSONPayload Marshals the MatrixPayloadUnsafe to json
func (m *MatrixPayloadUnsafe) JSONPayload() ([]byte, error) {
data, err := json.MarshalIndent(m, "", " ")
if err != nil {
return []byte{}, err
}
return data, nil
}
// MatrixLinkFormatter creates a link compatible with Matrix
func MatrixLinkFormatter(url string, text string) string {
return fmt.Sprintf(`<a href="%s">%s</a>`, html.EscapeString(url), html.EscapeString(text))
}
// MatrixLinkToRef Matrix-formatter link to a repo ref
func MatrixLinkToRef(repoURL, ref string) string {
refName := git.RefEndName(ref)
switch {
case strings.HasPrefix(ref, git.BranchPrefix):
return MatrixLinkFormatter(repoURL+"/src/branch/"+util.PathEscapeSegments(refName), refName)
case strings.HasPrefix(ref, git.TagPrefix):
return MatrixLinkFormatter(repoURL+"/src/tag/"+util.PathEscapeSegments(refName), refName)
default:
return MatrixLinkFormatter(repoURL+"/src/commit/"+util.PathEscapeSegments(refName), refName)
}
}
// Create implements PayloadConvertor Create method
func (m *MatrixPayloadUnsafe) Create(p *api.CreatePayload) (api.Payloader, error) {
repoLink := MatrixLinkFormatter(p.Repo.HTMLURL, p.Repo.FullName)
refLink := MatrixLinkToRef(p.Repo.HTMLURL, p.Ref)
text := fmt.Sprintf("[%s:%s] %s created by %s", repoLink, refLink, p.RefType, p.Sender.UserName)
return getMatrixPayloadUnsafe(text, nil, m.AccessToken, m.MsgType), nil
}
// Delete composes Matrix payload for delete a branch or tag.
func (m *MatrixPayloadUnsafe) Delete(p *api.DeletePayload) (api.Payloader, error) {
refName := git.RefEndName(p.Ref)
repoLink := MatrixLinkFormatter(p.Repo.HTMLURL, p.Repo.FullName)
text := fmt.Sprintf("[%s:%s] %s deleted by %s", repoLink, refName, p.RefType, p.Sender.UserName)
return getMatrixPayloadUnsafe(text, nil, m.AccessToken, m.MsgType), nil
}
// Fork composes Matrix payload for forked by a repository.
func (m *MatrixPayloadUnsafe) Fork(p *api.ForkPayload) (api.Payloader, error) {
baseLink := MatrixLinkFormatter(p.Forkee.HTMLURL, p.Forkee.FullName)
forkLink := MatrixLinkFormatter(p.Repo.HTMLURL, p.Repo.FullName)
text := fmt.Sprintf("%s is forked to %s", baseLink, forkLink)
return getMatrixPayloadUnsafe(text, nil, m.AccessToken, m.MsgType), nil
}
// Issue implements PayloadConvertor Issue method
func (m *MatrixPayloadUnsafe) Issue(p *api.IssuePayload) (api.Payloader, error) {
text, _, _, _ := getIssuesPayloadInfo(p, MatrixLinkFormatter, true)
return getMatrixPayloadUnsafe(text, nil, m.AccessToken, m.MsgType), nil
}
// IssueComment implements PayloadConvertor IssueComment method
func (m *MatrixPayloadUnsafe) IssueComment(p *api.IssueCommentPayload) (api.Payloader, error) {
text, _, _ := getIssueCommentPayloadInfo(p, MatrixLinkFormatter, true)
return getMatrixPayloadUnsafe(text, nil, m.AccessToken, m.MsgType), nil
}
// Release implements PayloadConvertor Release method
func (m *MatrixPayloadUnsafe) Release(p *api.ReleasePayload) (api.Payloader, error) {
text, _ := getReleasePayloadInfo(p, MatrixLinkFormatter, true)
return getMatrixPayloadUnsafe(text, nil, m.AccessToken, m.MsgType), nil
}
// Push implements PayloadConvertor Push method
func (m *MatrixPayloadUnsafe) Push(p *api.PushPayload) (api.Payloader, error) {
var commitDesc string
if len(p.Commits) == 1 {
commitDesc = "1 commit"
} else {
commitDesc = fmt.Sprintf("%d commits", len(p.Commits))
}
repoLink := MatrixLinkFormatter(p.Repo.HTMLURL, p.Repo.FullName)
branchLink := MatrixLinkToRef(p.Repo.HTMLURL, p.Ref)
text := fmt.Sprintf("[%s] %s pushed %s to %s:<br>", repoLink, p.Pusher.UserName, commitDesc, branchLink)
// for each commit, generate a new line text
for i, commit := range p.Commits {
text += fmt.Sprintf("%s: %s - %s", MatrixLinkFormatter(commit.URL, commit.ID[:7]), commit.Message, commit.Author.Name)
// add linebreak to each commit but the last
if i < len(p.Commits)-1 {
text += "<br>"
}
}
return getMatrixPayloadUnsafe(text, p.Commits, m.AccessToken, m.MsgType), nil
}
// PullRequest implements PayloadConvertor PullRequest method
func (m *MatrixPayloadUnsafe) PullRequest(p *api.PullRequestPayload) (api.Payloader, error) {
text, _, _, _ := getPullRequestPayloadInfo(p, MatrixLinkFormatter, true)
return getMatrixPayloadUnsafe(text, nil, m.AccessToken, m.MsgType), nil
}
// Review implements PayloadConvertor Review method
func (m *MatrixPayloadUnsafe) Review(p *api.PullRequestPayload, event webhook_model.HookEventType) (api.Payloader, error) {
senderLink := MatrixLinkFormatter(setting.AppURL+url.PathEscape(p.Sender.UserName), p.Sender.UserName)
title := fmt.Sprintf("#%d %s", p.Index, p.PullRequest.Title)
titleLink := fmt.Sprintf("%s/pulls/%d", p.Repository.HTMLURL, p.Index)
repoLink := MatrixLinkFormatter(p.Repository.HTMLURL, p.Repository.FullName)
var text string
switch p.Action {
case api.HookIssueReviewed:
action, err := parseHookPullRequestEventType(event)
if err != nil {
return nil, err
}
text = fmt.Sprintf("[%s] Pull request review %s: [%s](%s) by %s", repoLink, action, title, titleLink, senderLink)
}
return getMatrixPayloadUnsafe(text, nil, m.AccessToken, m.MsgType), nil
}
// Repository implements PayloadConvertor Repository method
func (m *MatrixPayloadUnsafe) Repository(p *api.RepositoryPayload) (api.Payloader, error) {
senderLink := MatrixLinkFormatter(setting.AppURL+p.Sender.UserName, p.Sender.UserName)
repoLink := MatrixLinkFormatter(p.Repository.HTMLURL, p.Repository.FullName)
var text string
switch p.Action {
case api.HookRepoCreated:
text = fmt.Sprintf("[%s] Repository created by %s", repoLink, senderLink)
case api.HookRepoDeleted:
text = fmt.Sprintf("[%s] Repository deleted by %s", repoLink, senderLink)
}
return getMatrixPayloadUnsafe(text, nil, m.AccessToken, m.MsgType), nil
}
// GetMatrixPayload converts a Matrix webhook into a MatrixPayloadUnsafe
func GetMatrixPayload(p api.Payloader, event webhook_model.HookEventType, meta string) (api.Payloader, error) {
s := new(MatrixPayloadUnsafe)
matrix := &MatrixMeta{}
if err := json.Unmarshal([]byte(meta), &matrix); err != nil {
return s, errors.New("GetMatrixPayload meta json:" + err.Error())
}
s.AccessToken = matrix.AccessToken
s.MsgType = messageTypeText[matrix.MessageType]
return convertPayloader(s, p, event)
}
func getMatrixPayloadUnsafe(text string, commits []*api.PayloadCommit, accessToken, msgType string) *MatrixPayloadUnsafe {
p := MatrixPayloadUnsafe{}
p.AccessToken = accessToken
p.FormattedBody = text
p.Body = getMessageBody(text)
p.Format = "org.matrix.custom.html"
p.MsgType = msgType
p.Commits = commits
return &p
}
var urlRegex = regexp.MustCompile(`<a [^>]*?href="([^">]*?)">(.*?)</a>`)
func getMessageBody(htmlText string) string {
htmlText = urlRegex.ReplaceAllString(htmlText, "[$2]($1)")
htmlText = strings.ReplaceAll(htmlText, "<br>", "\n")
return htmlText
}
// getMatrixHookRequest creates a new request which contains an Authorization header.
// The access_token is removed from t.PayloadContent
func getMatrixHookRequest(w *webhook_model.Webhook, t *webhook_model.HookTask) (*http.Request, error) {
payloadunsafe := MatrixPayloadUnsafe{}
if err := json.Unmarshal([]byte(t.PayloadContent), &payloadunsafe); err != nil {
log.Error("Matrix Hook delivery failed: %v", err)
return nil, err
}
payloadsafe := payloadunsafe.safePayload()
var payload []byte
var err error
if payload, err = json.MarshalIndent(payloadsafe, "", " "); err != nil {
return nil, err
}
if len(payload) >= matrixPayloadSizeLimit {
return nil, fmt.Errorf("getMatrixHookRequest: payload size %d > %d", len(payload), matrixPayloadSizeLimit)
}
t.PayloadContent = string(payload)
txnID, err := getMatrixTxnID(payload)
if err != nil {
return nil, fmt.Errorf("getMatrixHookRequest: unable to hash payload: %+v", err)
}
url := fmt.Sprintf("%s/%s", w.URL, url.PathEscape(txnID))
req, err := http.NewRequest(w.HTTPMethod, url, strings.NewReader(string(payload)))
if err != nil {
return nil, err
}
req.Header.Set("Content-Type", "application/json")
req.Header.Add("Authorization", "Bearer "+payloadunsafe.AccessToken)
return req, nil
}
// getMatrixTxnID creates a txnID based on the payload to ensure idempotency
func getMatrixTxnID(payload []byte) (string, error) {
h := sha1.New()
_, err := h.Write(payload)
if err != nil {
return "", err
}
return fmt.Sprintf("%x", h.Sum(nil)), nil
}