gitsources: create secret and webhook secret

Use the webhook secret on webhook creation and check it and webhook receive

internal/gitsources/agolagit/agolagit.go

@@ -28,7 +28,6 @@ import (
 
 	"github.com/pkg/errors"
 	gitsource "github.com/sorintlab/agola/internal/gitsources"
-	"github.com/sorintlab/agola/internal/services/types"
 )
 
 var jsonContent = http.Header{"content-type": []string{"application/json"}}
@@ -166,10 +165,6 @@ func (c *Client) CreateCommitStatus(repopath, commitSHA string, status gitsource
 	return nil
 }
 
-func (c *Client) ParseWebhook(r *http.Request) (*types.WebhookData, error) {
-	return parseWebhook(r)
-}
-
 func (c *Client) ListUserRepos() ([]*gitsource.RepoInfo, error) {
 	return nil, nil
 }

internal/gitsources/agolagit/parse.go

@@ -18,6 +18,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net/http"
 	"path"
 	"strconv"
@@ -40,31 +41,25 @@ const (
 	prActionSync = "synchronized"
 )
 
-func parseWebhook(r *http.Request) (*types.WebhookData, error) {
+func (c *Client) ParseWebhook(r *http.Request, secret string) (*types.WebhookData, error) {
+	data, err := ioutil.ReadAll(io.LimitReader(r.Body, 10*1024*1024))
+	if err != nil {
+		return nil, err
+	}
+
 	switch r.Header.Get(hookEvent) {
 	case hookPush:
-		return parsePushHook(r.Body)
+		return parsePushHook(data)
 	case hookPullRequest:
-		return parsePullRequestHook(r.Body)
+		return parsePullRequestHook(data)
 	default:
 		return nil, errors.Errorf("unknown webhook event type: %q", r.Header.Get(hookEvent))
 	}
 }
 
-func parsePush(r io.Reader) (*pushHook, error) {
+func parsePushHook(data []byte) (*types.WebhookData, error) {
 	push := new(pushHook)
-	err := json.NewDecoder(r).Decode(push)
+	err := json.Unmarshal(data, push)
-	return push, err
-}
-
-func parsePullRequest(r io.Reader) (*pullRequestHook, error) {
-	pr := new(pullRequestHook)
-	err := json.NewDecoder(r).Decode(pr)
-	return pr, err
-}
-
-func parsePushHook(payload io.Reader) (*types.WebhookData, error) {
-	push, err := parsePush(payload)
 	if err != nil {
 		return nil, err
 	}
@@ -72,8 +67,9 @@ func parsePushHook(payload io.Reader) (*types.WebhookData, error) {
 	return webhookDataFromPush(push)
 }
 
-func parsePullRequestHook(payload io.Reader) (*types.WebhookData, error) {
+func parsePullRequestHook(data []byte) (*types.WebhookData, error) {
-	prhook, err := parsePullRequest(payload)
+	prhook := new(pullRequestHook)
+	err := json.Unmarshal(data, prhook)
 	if err != nil {
 		return nil, err
 	}

internal/gitsources/gitea/parse.go

@@ -15,9 +15,13 @@
 package gitea
 
 import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net/http"
 	"path"
 	"strconv"
@@ -30,6 +34,7 @@ import (
 
 const (
 	hookEvent       = "X-Gitea-Event"
+	signatureHeader = "X-Gitea-Signature"
 
 	hookPush        = "push"
 	hookPullRequest = "pull_request"
@@ -40,31 +45,40 @@ const (
 	prActionSync = "synchronized"
 )
 
-func (c *Client) ParseWebhook(r *http.Request) (*types.WebhookData, error) {
+func (c *Client) ParseWebhook(r *http.Request, secret string) (*types.WebhookData, error) {
+	data, err := ioutil.ReadAll(io.LimitReader(r.Body, 10*1024*1024))
+	if err != nil {
+		return nil, err
+	}
+
+	// verify signature
+	if secret != "" {
+		signature := r.Header.Get(signatureHeader)
+		ds, err := hex.DecodeString(signature)
+		if err != nil {
+			return nil, errors.Errorf("wrong webhook signature")
+		}
+		h := hmac.New(sha256.New, []byte(secret))
+		h.Write(data)
+		cs := h.Sum(nil)
+		if !hmac.Equal(cs, ds) {
+			return nil, errors.Errorf("wrong webhook signature")
+		}
+	}
+
 	switch r.Header.Get(hookEvent) {
 	case hookPush:
-		return parsePushHook(r.Body)
+		return parsePushHook(data)
 	case hookPullRequest:
-		return parsePullRequestHook(r.Body)
+		return parsePullRequestHook(data)
 	default:
 		return nil, errors.Errorf("unknown webhook event type: %q", r.Header.Get(hookEvent))
 	}
 }
 
-func parsePush(r io.Reader) (*pushHook, error) {
+func parsePushHook(data []byte) (*types.WebhookData, error) {
 	push := new(pushHook)
-	err := json.NewDecoder(r).Decode(push)
+	err := json.Unmarshal(data, push)
-	return push, err
-}
-
-func parsePullRequest(r io.Reader) (*pullRequestHook, error) {
-	pr := new(pullRequestHook)
-	err := json.NewDecoder(r).Decode(pr)
-	return pr, err
-}
-
-func parsePushHook(payload io.Reader) (*types.WebhookData, error) {
-	push, err := parsePush(payload)
 	if err != nil {
 		return nil, err
 	}
@@ -72,8 +86,9 @@ func parsePushHook(payload io.Reader) (*types.WebhookData, error) {
 	return webhookDataFromPush(push)
 }
 
-func parsePullRequestHook(payload io.Reader) (*types.WebhookData, error) {
+func parsePullRequestHook(data []byte) (*types.WebhookData, error) {
-	prhook, err := parsePullRequest(payload)
+	prhook := new(pullRequestHook)
+	err := json.Unmarshal(data, prhook)
 	if err != nil {
 		return nil, err
 	}

internal/gitsources/gitlab/gitlab.go

@@ -219,6 +219,7 @@ func (c *Client) CreateRepoWebhook(repopath, url, secret string) error {
 		PushEvents:          gitlab.Bool(true),
 		TagPushEvents:       gitlab.Bool(true),
 		MergeRequestsEvents: gitlab.Bool(true),
+		Token:               gitlab.String(secret),
 	}
 	_, _, err := c.client.Projects.AddProjectHook(repopath, opts)
 

internal/gitsources/gitlab/parse.go

@@ -18,6 +18,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net/http"
 	"strconv"
 	"strings"
@@ -29,6 +30,7 @@ import (
 
 const (
 	hookEvent   = "X-Gitlab-Event"
+	tokenHeader = "X-Gitlab-Token"
 
 	hookPush        = "Push Hook"
 	hookTagPush     = "Tag Push Hook"
@@ -40,33 +42,36 @@ const (
 	prActionSync = "synchronized"
 )
 
-func (c *Client) ParseWebhook(r *http.Request) (*types.WebhookData, error) {
+func (c *Client) ParseWebhook(r *http.Request, secret string) (*types.WebhookData, error) {
+	data, err := ioutil.ReadAll(io.LimitReader(r.Body, 10*1024*1024))
+	if err != nil {
+		return nil, err
+	}
+
+	// verify token (gitlab doesn't sign the payload but just returns the provided
+	// secret)
+	if secret != "" {
+		token := r.Header.Get(tokenHeader)
+		if token != secret {
+			return nil, errors.Errorf("wrong webhook token")
+		}
+	}
+
 	switch r.Header.Get(hookEvent) {
 	case hookPush:
-		return parsePushHook(r.Body)
+		return parsePushHook(data)
 	case hookTagPush:
-		return parsePushHook(r.Body)
+		return parsePushHook(data)
 	case hookPullRequest:
-		return parsePullRequestHook(r.Body)
+		return parsePullRequestHook(data)
 	default:
 		return nil, errors.Errorf("unknown webhook event type: %q", r.Header.Get(hookEvent))
 	}
 }
 
-func parsePush(r io.Reader) (*pushHook, error) {
+func parsePushHook(data []byte) (*types.WebhookData, error) {
 	push := new(pushHook)
-	err := json.NewDecoder(r).Decode(push)
+	err := json.Unmarshal(data, push)
-	return push, err
-}
-
-func parsePullRequest(r io.Reader) (*pullRequestHook, error) {
-	pr := new(pullRequestHook)
-	err := json.NewDecoder(r).Decode(pr)
-	return pr, err
-}
-
-func parsePushHook(payload io.Reader) (*types.WebhookData, error) {
-	push, err := parsePush(payload)
 	if err != nil {
 		return nil, err
 	}
@@ -79,20 +84,15 @@ func parsePushHook(payload io.Reader) (*types.WebhookData, error) {
 	return webhookDataFromPush(push)
 }
 
-func parsePullRequestHook(payload io.Reader) (*types.WebhookData, error) {
+func parsePullRequestHook(data []byte) (*types.WebhookData, error) {
-	prhook, err := parsePullRequest(payload)
+	prhook := new(pullRequestHook)
+	err := json.Unmarshal(data, prhook)
 	if err != nil {
 		return nil, err
 	}
 
-	//	// skip non open pull requests
+	// TODO(sgotti) skip non open pull requests
-	//	if prhook.PullRequest.State != prStateOpen {
+	// TODO(sgotti) only accept actions that have new commits
-	//		return nil, nil
-	//	}
-	//	// only accept actions that have new commits
-	//	if prhook.Action != prActionOpen && prhook.Action != prActionSync {
-	//		return nil, nil
-	//	}
 
 	return webhookDataFromPullRequest(prhook), nil
 }

internal/gitsources/gitsource.go

@@ -37,7 +37,7 @@ type GitSource interface {
 	UpdateDeployKey(repopath, title, pubKey string, readonly bool) error
 	DeleteRepoWebhook(repopath, url string) error
 	CreateRepoWebhook(repopath, url, secret string) error
-	ParseWebhook(r *http.Request) (*types.WebhookData, error)
+	ParseWebhook(r *http.Request, secret string) (*types.WebhookData, error)
 	CreateCommitStatus(repopath, commitSHA string, status CommitStatus, targetURL, description, context string) error
 	ListUserRepos() ([]*RepoInfo, error)
 }

internal/services/configstore/action/project.go

@@ -133,7 +133,9 @@ func (h *ActionHandler) CreateProject(ctx context.Context, project *types.Projec
 
 	project.ID = uuid.NewV4().String()
 	project.Parent.Type = types.ConfigTypeProjectGroup
+	// generate the Secret and the WebhookSecret
 	project.Secret = util.EncodeSha1Hex(uuid.NewV4().String())
+	project.WebhookSecret = util.EncodeSha1Hex(uuid.NewV4().String())
 
 	pcj, err := json.Marshal(project)
 	if err != nil {

internal/services/gateway/action/project.go

@@ -194,7 +194,7 @@ func (h *ActionHandler) SetupProject(ctx context.Context, rs *types.RemoteSource
 		return errors.Wrapf(err, "failed to delete repository webhook")
 	}
 	h.log.Infof("creating webhook to url: %s", webhookURL)
-	if err := gitsource.CreateRepoWebhook(project.RepositoryPath, webhookURL.String(), ""); err != nil {
+	if err := gitsource.CreateRepoWebhook(project.RepositoryPath, webhookURL.String(), project.WebhookSecret); err != nil {
 		return errors.Wrapf(err, "failed to create repository webhook")
 	}
 

internal/services/gateway/webhook.go

@@ -155,7 +155,7 @@ func (h *webhooksHandler) handleWebhook(r *http.Request) (int, string, error) {
 			skipSSHHostKeyCheck = project.SkipSSHHostKeyCheck
 		}
 		runType = types.RunTypeProject
-		webhookData, err = gitSource.ParseWebhook(r)
+		webhookData, err = gitSource.ParseWebhook(r, project.WebhookSecret)
 		if err != nil {
 			return http.StatusBadRequest, "", errors.Wrapf(err, "failed to parse webhook")
 		}
@@ -213,7 +213,7 @@ func (h *webhooksHandler) handleWebhook(r *http.Request) (int, string, error) {
 	} else {
 		gitSource = agolagit.New(h.apiExposedURL + "/repos")
 		var err error
-		webhookData, err = gitSource.ParseWebhook(r)
+		webhookData, err = gitSource.ParseWebhook(r, "")
 		if err != nil {
 			return http.StatusBadRequest, "", errors.Wrapf(err, "failed to parse webhook")
 		}

internal/services/types/types.go

@@ -73,7 +73,8 @@ type User struct {
 
 	Name string `json:"name,omitempty"`
 
-	// A secret string that could be used for signing or other purposes
+	// Secret is a secret that could be used for signing or other purposes. It
+	// should never be directly exposed to external services
 	Secret string `json:"secret,omitempty"`
 
 	LinkedAccounts map[string]*LinkedAccount `json:"linked_accounts,omitempty"`
@@ -236,7 +237,8 @@ type Project struct {
 	ID   string `json:"id,omitempty"`
 	Name string `json:"name,omitempty"`
 
-	// A secret string that could be used for signing or other purposes
+	// Secret is a secret that could be used for signing or other purposes. It
+	// should never be directly exposed to external services
 	Secret string `json:"secret,omitempty"`
 
 	Parent Parent `json:"parent,omitempty"`
@@ -263,6 +265,10 @@ type Project struct {
 	SSHPrivateKey string `json:"ssh_private_key,omitempty"` // PEM Encoded private key
 
 	SkipSSHHostKeyCheck bool `json:"skip_ssh_host_key_check,omitempty"`
+
+	// Webhooksecret is the secret passed to git sources that support a
+	// secret/token for signing or verifying the webhook payload
+	WebhookSecret string `json:"webhook_secret,omitempty"`
 }
 
 type SecretType string