mirror of
https://github.com/go-gitea/gitea
synced 2024-11-14 22:24:24 +00:00
263 lines
9.3 KiB
Go
Vendored
263 lines
9.3 KiB
Go
Vendored
// Copyright 2016 The go-github AUTHORS. All rights reserved.
|
|
//
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// This file provides functions for validating payloads from GitHub Webhooks.
|
|
// GitHub API docs: https://developer.github.com/webhooks/securing/#validating-payloads-from-github
|
|
|
|
package github
|
|
|
|
import (
|
|
"crypto/hmac"
|
|
"crypto/sha1"
|
|
"crypto/sha256"
|
|
"crypto/sha512"
|
|
"encoding/hex"
|
|
"encoding/json"
|
|
"errors"
|
|
"fmt"
|
|
"hash"
|
|
"io/ioutil"
|
|
"net/http"
|
|
"net/url"
|
|
"strings"
|
|
)
|
|
|
|
const (
|
|
// sha1Prefix is the prefix used by GitHub before the HMAC hexdigest.
|
|
sha1Prefix = "sha1"
|
|
// sha256Prefix and sha512Prefix are provided for future compatibility.
|
|
sha256Prefix = "sha256"
|
|
sha512Prefix = "sha512"
|
|
// signatureHeader is the GitHub header key used to pass the HMAC hexdigest.
|
|
signatureHeader = "X-Hub-Signature"
|
|
// eventTypeHeader is the GitHub header key used to pass the event type.
|
|
eventTypeHeader = "X-Github-Event"
|
|
// deliveryIDHeader is the GitHub header key used to pass the unique ID for the webhook event.
|
|
deliveryIDHeader = "X-Github-Delivery"
|
|
)
|
|
|
|
var (
|
|
// eventTypeMapping maps webhooks types to their corresponding go-github struct types.
|
|
eventTypeMapping = map[string]string{
|
|
"check_run": "CheckRunEvent",
|
|
"check_suite": "CheckSuiteEvent",
|
|
"commit_comment": "CommitCommentEvent",
|
|
"create": "CreateEvent",
|
|
"delete": "DeleteEvent",
|
|
"deploy_key": "DeployKeyEvent",
|
|
"deployment": "DeploymentEvent",
|
|
"deployment_status": "DeploymentStatusEvent",
|
|
"fork": "ForkEvent",
|
|
"github_app_authorization": "GitHubAppAuthorizationEvent",
|
|
"gollum": "GollumEvent",
|
|
"installation": "InstallationEvent",
|
|
"installation_repositories": "InstallationRepositoriesEvent",
|
|
"issue_comment": "IssueCommentEvent",
|
|
"issues": "IssuesEvent",
|
|
"label": "LabelEvent",
|
|
"marketplace_purchase": "MarketplacePurchaseEvent",
|
|
"member": "MemberEvent",
|
|
"membership": "MembershipEvent",
|
|
"meta": "MetaEvent",
|
|
"milestone": "MilestoneEvent",
|
|
"organization": "OrganizationEvent",
|
|
"org_block": "OrgBlockEvent",
|
|
"package": "PackageEvent",
|
|
"page_build": "PageBuildEvent",
|
|
"ping": "PingEvent",
|
|
"project": "ProjectEvent",
|
|
"project_card": "ProjectCardEvent",
|
|
"project_column": "ProjectColumnEvent",
|
|
"public": "PublicEvent",
|
|
"pull_request_review": "PullRequestReviewEvent",
|
|
"pull_request_review_comment": "PullRequestReviewCommentEvent",
|
|
"pull_request": "PullRequestEvent",
|
|
"push": "PushEvent",
|
|
"repository": "RepositoryEvent",
|
|
"repository_dispatch": "RepositoryDispatchEvent",
|
|
"repository_vulnerability_alert": "RepositoryVulnerabilityAlertEvent",
|
|
"release": "ReleaseEvent",
|
|
"star": "StarEvent",
|
|
"status": "StatusEvent",
|
|
"team": "TeamEvent",
|
|
"team_add": "TeamAddEvent",
|
|
"user": "UserEvent",
|
|
"watch": "WatchEvent",
|
|
}
|
|
)
|
|
|
|
// genMAC generates the HMAC signature for a message provided the secret key
|
|
// and hashFunc.
|
|
func genMAC(message, key []byte, hashFunc func() hash.Hash) []byte {
|
|
mac := hmac.New(hashFunc, key)
|
|
mac.Write(message)
|
|
return mac.Sum(nil)
|
|
}
|
|
|
|
// checkMAC reports whether messageMAC is a valid HMAC tag for message.
|
|
func checkMAC(message, messageMAC, key []byte, hashFunc func() hash.Hash) bool {
|
|
expectedMAC := genMAC(message, key, hashFunc)
|
|
return hmac.Equal(messageMAC, expectedMAC)
|
|
}
|
|
|
|
// messageMAC returns the hex-decoded HMAC tag from the signature and its
|
|
// corresponding hash function.
|
|
func messageMAC(signature string) ([]byte, func() hash.Hash, error) {
|
|
if signature == "" {
|
|
return nil, nil, errors.New("missing signature")
|
|
}
|
|
sigParts := strings.SplitN(signature, "=", 2)
|
|
if len(sigParts) != 2 {
|
|
return nil, nil, fmt.Errorf("error parsing signature %q", signature)
|
|
}
|
|
|
|
var hashFunc func() hash.Hash
|
|
switch sigParts[0] {
|
|
case sha1Prefix:
|
|
hashFunc = sha1.New
|
|
case sha256Prefix:
|
|
hashFunc = sha256.New
|
|
case sha512Prefix:
|
|
hashFunc = sha512.New
|
|
default:
|
|
return nil, nil, fmt.Errorf("unknown hash type prefix: %q", sigParts[0])
|
|
}
|
|
|
|
buf, err := hex.DecodeString(sigParts[1])
|
|
if err != nil {
|
|
return nil, nil, fmt.Errorf("error decoding signature %q: %v", signature, err)
|
|
}
|
|
return buf, hashFunc, nil
|
|
}
|
|
|
|
// ValidatePayload validates an incoming GitHub Webhook event request
|
|
// and returns the (JSON) payload.
|
|
// The Content-Type header of the payload can be "application/json" or "application/x-www-form-urlencoded".
|
|
// If the Content-Type is neither then an error is returned.
|
|
// secretToken is the GitHub Webhook secret token.
|
|
// If your webhook does not contain a secret token, you can pass nil or an empty slice.
|
|
// This is intended for local development purposes only and all webhooks should ideally set up a secret token.
|
|
//
|
|
// Example usage:
|
|
//
|
|
// func (s *GitHubEventMonitor) ServeHTTP(w http.ResponseWriter, r *http.Request) {
|
|
// payload, err := github.ValidatePayload(r, s.webhookSecretKey)
|
|
// if err != nil { ... }
|
|
// // Process payload...
|
|
// }
|
|
//
|
|
func ValidatePayload(r *http.Request, secretToken []byte) (payload []byte, err error) {
|
|
var body []byte // Raw body that GitHub uses to calculate the signature.
|
|
|
|
switch ct := r.Header.Get("Content-Type"); ct {
|
|
case "application/json":
|
|
var err error
|
|
if body, err = ioutil.ReadAll(r.Body); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// If the content type is application/json,
|
|
// the JSON payload is just the original body.
|
|
payload = body
|
|
|
|
case "application/x-www-form-urlencoded":
|
|
// payloadFormParam is the name of the form parameter that the JSON payload
|
|
// will be in if a webhook has its content type set to application/x-www-form-urlencoded.
|
|
const payloadFormParam = "payload"
|
|
|
|
var err error
|
|
if body, err = ioutil.ReadAll(r.Body); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// If the content type is application/x-www-form-urlencoded,
|
|
// the JSON payload will be under the "payload" form param.
|
|
form, err := url.ParseQuery(string(body))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
payload = []byte(form.Get(payloadFormParam))
|
|
|
|
default:
|
|
return nil, fmt.Errorf("Webhook request has unsupported Content-Type %q", ct)
|
|
}
|
|
|
|
// Only validate the signature if a secret token exists. This is intended for
|
|
// local development only and all webhooks should ideally set up a secret token.
|
|
if len(secretToken) > 0 {
|
|
sig := r.Header.Get(signatureHeader)
|
|
if err := ValidateSignature(sig, body, secretToken); err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
return payload, nil
|
|
}
|
|
|
|
// ValidateSignature validates the signature for the given payload.
|
|
// signature is the GitHub hash signature delivered in the X-Hub-Signature header.
|
|
// payload is the JSON payload sent by GitHub Webhooks.
|
|
// secretToken is the GitHub Webhook secret token.
|
|
//
|
|
// GitHub API docs: https://developer.github.com/webhooks/securing/#validating-payloads-from-github
|
|
func ValidateSignature(signature string, payload, secretToken []byte) error {
|
|
messageMAC, hashFunc, err := messageMAC(signature)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if !checkMAC(payload, messageMAC, secretToken, hashFunc) {
|
|
return errors.New("payload signature check failed")
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// WebHookType returns the event type of webhook request r.
|
|
//
|
|
// GitHub API docs: https://developer.github.com/v3/repos/hooks/#webhook-headers
|
|
func WebHookType(r *http.Request) string {
|
|
return r.Header.Get(eventTypeHeader)
|
|
}
|
|
|
|
// DeliveryID returns the unique delivery ID of webhook request r.
|
|
//
|
|
// GitHub API docs: https://developer.github.com/v3/repos/hooks/#webhook-headers
|
|
func DeliveryID(r *http.Request) string {
|
|
return r.Header.Get(deliveryIDHeader)
|
|
}
|
|
|
|
// ParseWebHook parses the event payload. For recognized event types, a
|
|
// value of the corresponding struct type will be returned (as returned
|
|
// by Event.ParsePayload()). An error will be returned for unrecognized event
|
|
// types.
|
|
//
|
|
// Example usage:
|
|
//
|
|
// func (s *GitHubEventMonitor) ServeHTTP(w http.ResponseWriter, r *http.Request) {
|
|
// payload, err := github.ValidatePayload(r, s.webhookSecretKey)
|
|
// if err != nil { ... }
|
|
// event, err := github.ParseWebHook(github.WebHookType(r), payload)
|
|
// if err != nil { ... }
|
|
// switch event := event.(type) {
|
|
// case *github.CommitCommentEvent:
|
|
// processCommitCommentEvent(event)
|
|
// case *github.CreateEvent:
|
|
// processCreateEvent(event)
|
|
// ...
|
|
// }
|
|
// }
|
|
//
|
|
func ParseWebHook(messageType string, payload []byte) (interface{}, error) {
|
|
eventType, ok := eventTypeMapping[messageType]
|
|
if !ok {
|
|
return nil, fmt.Errorf("unknown X-Github-Event in message: %v", messageType)
|
|
}
|
|
|
|
event := Event{
|
|
Type: &eventType,
|
|
RawPayload: (*json.RawMessage)(&payload),
|
|
}
|
|
return event.ParsePayload()
|
|
}
|