321bd56d93
This PR adds a func for verifying incoming webhooks from Gitea, as well as a middleware for easier addition to a router stack. Co-authored-by: jolheiser <john.olheiser@gmail.com> Reviewed-on: https://gitea.com/gitea/go-sdk/pulls/580 Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com> Reviewed-by: Gusted <williamzijl7@hotmail.com>
59 lines
1.6 KiB
Go
59 lines
1.6 KiB
Go
// Copyright 2022 The Gitea Authors. All rights reserved.
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// Use of this source code is governed by a MIT-style
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// license that can be found in the LICENSE file.
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package gitea
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import (
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"bytes"
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"crypto/hmac"
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"crypto/sha256"
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"encoding/hex"
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"io"
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"net/http"
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)
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// VerifyWebhookSignature verifies that a payload matches the X-Gitea-Signature based on a secret
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func VerifyWebhookSignature(secret, expected string, payload []byte) (bool, error) {
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hash := hmac.New(sha256.New, []byte(secret))
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if _, err := hash.Write(payload); err != nil {
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return false, err
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}
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expectedSum, err := hex.DecodeString(expected)
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if err != nil {
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return false, err
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}
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return hmac.Equal(hash.Sum(nil), expectedSum), nil
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}
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// VerifyWebhookSignatureMiddleware is a http.Handler for verifying X-Gitea-Signature on incoming webhooks
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func VerifyWebhookSignatureMiddleware(secret string) func(http.Handler) http.Handler {
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return func(next http.Handler) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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var b bytes.Buffer
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if _, err := io.Copy(&b, r.Body); err != nil {
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http.Error(w, err.Error(), http.StatusBadRequest)
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return
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}
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expected := r.Header.Get("X-Gitea-Signature")
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if expected == "" {
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http.Error(w, "no signature found", http.StatusBadRequest)
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return
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}
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ok, err := VerifyWebhookSignature(secret, expected, b.Bytes())
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if err != nil {
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http.Error(w, err.Error(), http.StatusUnauthorized)
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return
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}
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if !ok {
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http.Error(w, "invalid payload", http.StatusUnauthorized)
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return
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}
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r.Body = io.NopCloser(&b)
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next.ServeHTTP(w, r)
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})
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}
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}
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