[REFACTOR] webhook.Handler interface

services/webhook/default.go

@@ -0,0 +1,136 @@
+// Copyright 2024  The Forgejo Authors c/o Codeberg e.V.. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package webhook
+
+import (
+	"context"
+	"crypto/hmac"
+	"crypto/sha1"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+
+	webhook_model "code.gitea.io/gitea/models/webhook"
+	"code.gitea.io/gitea/modules/log"
+	webhook_module "code.gitea.io/gitea/modules/webhook"
+)
+
+var _ Handler = defaultHandler{}
+
+type defaultHandler struct {
+	forgejo bool
+}
+
+func (dh defaultHandler) Type() webhook_module.HookType {
+	if dh.forgejo {
+		return webhook_module.FORGEJO
+	}
+	return webhook_module.GITEA
+}
+
+func (defaultHandler) Metadata(*webhook_model.Webhook) any { return nil }
+
+func (defaultHandler) NewRequest(ctx context.Context, w *webhook_model.Webhook, t *webhook_model.HookTask) (req *http.Request, body []byte, err error) {
+	switch w.HTTPMethod {
+	case "":
+		log.Info("HTTP Method for %s webhook %s [ID: %d] is not set, defaulting to POST", w.Type, w.URL, w.ID)
+		fallthrough
+	case http.MethodPost:
+		switch w.ContentType {
+		case webhook_model.ContentTypeJSON:
+			req, err = http.NewRequest("POST", w.URL, strings.NewReader(t.PayloadContent))
+			if err != nil {
+				return nil, nil, err
+			}
+
+			req.Header.Set("Content-Type", "application/json")
+		case webhook_model.ContentTypeForm:
+			forms := url.Values{
+				"payload": []string{t.PayloadContent},
+			}
+
+			req, err = http.NewRequest("POST", w.URL, strings.NewReader(forms.Encode()))
+			if err != nil {
+				return nil, nil, err
+			}
+
+			req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+		default:
+			return nil, nil, fmt.Errorf("invalid content type: %v", w.ContentType)
+		}
+	case http.MethodGet:
+		u, err := url.Parse(w.URL)
+		if err != nil {
+			return nil, nil, fmt.Errorf("invalid URL: %w", err)
+		}
+		vals := u.Query()
+		vals["payload"] = []string{t.PayloadContent}
+		u.RawQuery = vals.Encode()
+		req, err = http.NewRequest("GET", u.String(), nil)
+		if err != nil {
+			return nil, nil, err
+		}
+	case http.MethodPut:
+		switch w.Type {
+		case webhook_module.MATRIX: // used when t.Version == 1
+			txnID, err := getMatrixTxnID([]byte(t.PayloadContent))
+			if err != nil {
+				return nil, nil, err
+			}
+			url := fmt.Sprintf("%s/%s", w.URL, url.PathEscape(txnID))
+			req, err = http.NewRequest("PUT", url, strings.NewReader(t.PayloadContent))
+			if err != nil {
+				return nil, nil, err
+			}
+		default:
+			return nil, nil, fmt.Errorf("invalid http method: %v", w.HTTPMethod)
+		}
+	default:
+		return nil, nil, fmt.Errorf("invalid http method: %v", w.HTTPMethod)
+	}
+
+	body = []byte(t.PayloadContent)
+	return req, body, addDefaultHeaders(req, []byte(w.Secret), t, body)
+}
+
+func addDefaultHeaders(req *http.Request, secret []byte, t *webhook_model.HookTask, payloadContent []byte) error {
+	var signatureSHA1 string
+	var signatureSHA256 string
+	if len(secret) > 0 {
+		sig1 := hmac.New(sha1.New, secret)
+		sig256 := hmac.New(sha256.New, secret)
+		_, err := io.MultiWriter(sig1, sig256).Write(payloadContent)
+		if err != nil {
+			// this error should never happen, since the hashes are writing to []byte and always return a nil error.
+			return fmt.Errorf("prepareWebhooks.sigWrite: %w", err)
+		}
+		signatureSHA1 = hex.EncodeToString(sig1.Sum(nil))
+		signatureSHA256 = hex.EncodeToString(sig256.Sum(nil))
+	}
+
+	event := t.EventType.Event()
+	eventType := string(t.EventType)
+	req.Header.Add("X-Forgejo-Delivery", t.UUID)
+	req.Header.Add("X-Forgejo-Event", event)
+	req.Header.Add("X-Forgejo-Event-Type", eventType)
+	req.Header.Add("X-Forgejo-Signature", signatureSHA256)
+	req.Header.Add("X-Gitea-Delivery", t.UUID)
+	req.Header.Add("X-Gitea-Event", event)
+	req.Header.Add("X-Gitea-Event-Type", eventType)
+	req.Header.Add("X-Gitea-Signature", signatureSHA256)
+	req.Header.Add("X-Gogs-Delivery", t.UUID)
+	req.Header.Add("X-Gogs-Event", event)
+	req.Header.Add("X-Gogs-Event-Type", eventType)
+	req.Header.Add("X-Gogs-Signature", signatureSHA256)
+	req.Header.Add("X-Hub-Signature", "sha1="+signatureSHA1)
+	req.Header.Add("X-Hub-Signature-256", "sha256="+signatureSHA256)
+	req.Header["X-GitHub-Delivery"] = []string{t.UUID}
+	req.Header["X-GitHub-Event"] = []string{event}
+	req.Header["X-GitHub-Event-Type"] = []string{eventType}
+	return nil
+}