Use asym key to sign webhooks

cmd/server/flags.go

@@ -169,12 +169,6 @@ var flags = []cli.Flag{
 		Name:    "config-service-endpoint",
 		Usage:   "url used for calling configuration service endpoint",
 	},
-	&cli.StringFlag{
-		EnvVars:  []string{"WOODPECKER_CONFIG_SERVICE_SECRET"},
-		Name:     "config-service-secret",
-		Usage:    "secret to sign requests send to configuration service",
-		FilePath: os.Getenv("WOODPECKER_CONFIG_SERVICE_SECRET_FILE"),
-	},
 	&cli.StringFlag{
 		EnvVars: []string{"WOODPECKER_DATABASE_DRIVER"},
 		Name:    "driver",

cmd/server/server.go

@@ -42,7 +42,7 @@ import (
 	woodpeckerGrpcServer "github.com/woodpecker-ci/woodpecker/server/grpc"
 	"github.com/woodpecker-ci/woodpecker/server/logging"
 	"github.com/woodpecker-ci/woodpecker/server/model"
-	"github.com/woodpecker-ci/woodpecker/server/plugins/configuration"
+	"github.com/woodpecker-ci/woodpecker/server/plugins/config"
 	"github.com/woodpecker-ci/woodpecker/server/pubsub"
 	"github.com/woodpecker-ci/woodpecker/server/remote"
 	"github.com/woodpecker-ci/woodpecker/server/router"
@@ -267,13 +267,10 @@ func setupEvilGlobals(c *cli.Context, v store.Store, r remote.Remote) {
 	server.Config.Services.Secrets = setupSecretService(c, v)
 	server.Config.Services.Environ = setupEnvironService(c, v)
 
+	server.Config.Services.SignaturePrivateKey, server.Config.Services.SignaturePublicKey = setupSignatureKeys(v)
+
 	if endpoint := c.String("config-service-endpoint"); endpoint != "" {
-		secret := c.String("config-service-secret")
-		if secret == "" {
-			log.Error().Msg("could not configure configuration service, missing secret")
-		} else {
-			server.Config.Services.ConfigService = configuration.NewAPI(endpoint, secret)
-		}
+		server.Config.Services.ConfigService = config.NewHTTP(endpoint, server.Config.Services.SignaturePrivateKey)
 	}
 
 	// authentication

cmd/server/setup.go

@@ -16,6 +16,10 @@ package main
 
 import (
 	"context"
+	"crypto"
+	"crypto/ed25519"
+	"crypto/rand"
+	"encoding/hex"
 	"fmt"
 	"net/url"
 	"os"
@@ -352,3 +356,35 @@ func setupMetrics(g *errgroup.Group, _store store.Store) {
 		}
 	})
 }
+
+// generate or load key pair to sign webhooks requests (i.e. used for extensions)
+func setupSignatureKeys(_store store.Store) (crypto.PrivateKey, crypto.PublicKey) {
+	privKeyID := "signature-private-key"
+
+	privKey, err := _store.ServerConfigGet(privKeyID)
+	if err != nil && err == datastore.RecordNotExist {
+		_, privKey, err := ed25519.GenerateKey(rand.Reader)
+		if err != nil {
+			log.Fatal().Err(err).Msgf("Failed to generate private key")
+			return nil, nil
+		}
+		err = _store.ServerConfigSet(privKeyID, hex.EncodeToString(privKey))
+		if err != nil {
+			log.Fatal().Err(err).Msgf("Failed to generate private key")
+			return nil, nil
+		}
+		log.Info().Msg("Created private key")
+		return privKey, privKey.Public()
+	} else if err != nil {
+		log.Fatal().Err(err).Msgf("Failed to load private key")
+		return nil, nil
+	} else {
+		privKeyStr, err := hex.DecodeString(privKey)
+		if err != nil {
+			log.Fatal().Err(err).Msgf("Failed to decode private key")
+			return nil, nil
+		}
+		privKey := ed25519.PrivateKey(privKeyStr)
+		return privKey, privKey.Public()
+	}
+}

docs/docs/30-administration/10-server-config.md

@@ -356,16 +356,6 @@ Example: `WOODPECKER_LIMIT_CPU_SET=1,2`
 
 Specify a configuration service endpoint, see [Configuration Extension](/docs/administration/external-configuration-api)
 
-### `WOODPECKER_CONFIG_SERVICE_SECRET`
-> Default: ``
-
-Specify a signing secret for the configuration service endpoint, see [Configuration Extension](/docs/administration/external-configuration-api)
-
-### `WOODPECKER_CONFIG_SERVICE_SECRET_FILE`
-> Default: ``
-
-Read the value for `WOODPECKER_CONFIG_SERVICE_SECRET` from the specified filepath
-
 ---
 
 ### `WOODPECKER_GITHUB_...`

docs/docs/30-administration/100-external-configuration-api.md

@@ -3,7 +3,7 @@
 To provide additional management and preprocessing capabilities for pipeline configurations Woodpecker supports an HTTP api which can be enabled to call an external config service.
 Before the run or restart of any pipeline Woodpecker will make a POST request to an external HTTP api sending the current repository, build information and all current config files retrieved from the repository. The external api can then send back new pipeline configurations that will be used immediately or respond with `HTTP 204` to tell the system to use the existing configuration.
 
-Every request sent by Woodpecker is signed using a http-signature using the provided secret from `WOODPECKER_CONFIG_SERVICE_SECRET`. This way the external api can verify the authenticity request from the Woodpecker instance.
+Every request sent by Woodpecker is signed using a [http-signature](https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures) by a private key (ed25519) generated on the first start of the Woodpecker server. You can get the public key for the verification of the http-signature from `http(s)://your-woodpecker-server/api/signature/public-key`.
 
 A simplistic example configuration service can be found here: [https://github.com/woodpecker-ci/example-config-service](https://github.com/woodpecker-ci/example-config-service)
 
@@ -13,8 +13,6 @@ A simplistic example configuration service can be found here: [https://github.co
 # Server
 # ...
 WOODPECKER_CONFIG_SERVICE_ENDPOINT=https://example.com/ciconfig
-WOODPECKER_CONFIG_SERVICE_SECRET=mysecretsigningkey
-
 ```
 
 ### Example request made by Woodpecker

docs/docs/91-migrations.md

@@ -4,6 +4,7 @@ Some versions need some changes to the server configuration or the pipeline conf
 
 ## 1.0.0
 
+- The signature used to verify extensions calls (like those used for the [config-extension](/docs/administration/external-configuration-api)) done by the Woodpecker server switched from using a shared-secret HMac to an ed25519 key-pair. Read more about it at the [config-extensions](/docs/administration/external-configuration-api) documentation.
 - Refactored support of old agent filter labels and expression. Learn how to use the new [filter](/docs/usage/pipeline-syntax#labels).
 - Renamed step environment variable `CI_SYSTEM_ARCH` to `CI_SYSTEM_PLATFORM`. Same applies for the cli exec variable.
 

go.mod

@@ -4,7 +4,6 @@ go 1.16
 
 require (
 	code.gitea.io/sdk/gitea v0.15.1-0.20220501190934-319a978c6c71
-	github.com/99designs/httpsignatures-go v0.0.0-20170731043157-88528bf4ca7e
 	github.com/Microsoft/go-winio v0.5.1 // indirect
 	github.com/bmatcuk/doublestar/v4 v4.0.2
 	github.com/containerd/containerd v1.5.9 // indirect
@@ -19,6 +18,7 @@ require (
 	github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568
 	github.com/franela/goblin v0.0.0-20211003143422-0a4f594942bf
 	github.com/gin-gonic/gin v1.7.7
+	github.com/go-fed/httpsig v1.1.0
 	github.com/go-playground/validator/v10 v10.10.1 // indirect
 	github.com/go-sql-driver/mysql v1.6.0
 	github.com/goccy/go-json v0.9.7 // indirect

go.sum

@@ -60,8 +60,6 @@ dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7
 gitea.com/xorm/sqlfiddle v0.0.0-20180821085327-62ce714f951a h1:lSA0F4e9A2NcQSqGqTOXqu2aRi/XEQxDCBwM8yJtE6s=
 gitea.com/xorm/sqlfiddle v0.0.0-20180821085327-62ce714f951a/go.mod h1:EXuID2Zs0pAQhH8yz+DNjUbjppKQzKFAn28TMYPB6IU=
 gitee.com/travelliu/dm v1.8.11192/go.mod h1:DHTzyhCrM843x9VdKVbZ+GKXGRbKM2sJ4LxihRxShkE=
-github.com/99designs/httpsignatures-go v0.0.0-20170731043157-88528bf4ca7e h1:rl2Aq4ZODqTDkeSqQBy+fzpZPamacO1Srp8zq7jf2Sc=
-github.com/99designs/httpsignatures-go v0.0.0-20170731043157-88528bf4ca7e/go.mod h1:Xa6lInWHNQnuWoF0YPSsx+INFA9qk7/7pTjwb3PInkY=
 github.com/Antonboom/errname v0.1.5 h1:IM+A/gz0pDhKmlt5KSNTVAvfLMb+65RxavBXpRtCUEg=
 github.com/Antonboom/errname v0.1.5/go.mod h1:DugbBstvPFQbv/5uLcRRzfrNqKE9tVdVCqWCLp6Cifo=
 github.com/Antonboom/nilnil v0.1.0 h1:DLDavmg0a6G/F4Lt9t7Enrbgb3Oph6LnDE6YVsmTt74=
@@ -450,6 +448,8 @@ github.com/gin-gonic/gin v1.7.7 h1:3DoBmSbJbZAWqXJC3SLjAPfutPJJRN1U5pALB7EeTTs=
 github.com/gin-gonic/gin v1.7.7/go.mod h1:axIBovoeJpVj8S3BwE0uPMTeReE4+AfFtqpqaZ1qq1U=
 github.com/go-critic/go-critic v0.6.2 h1:L5SDut1N4ZfsWZY0sH4DCrsHLHnhuuWak2wa165t9gs=
 github.com/go-critic/go-critic v0.6.2/go.mod h1:td1s27kfmLpe5G/DPjlnFI7o1UCzePptwU7Az0V5iCM=
+github.com/go-fed/httpsig v1.1.0 h1:9M+hb0jkEICD8/cAiNqEB66R87tTINszBRTjwjQzWcI=
+github.com/go-fed/httpsig v1.1.0/go.mod h1:RCMrTZvN1bJYtofsG4rd5NaO5obxQ5xBkdiS7xsT7bM=
 github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20200222043503-6f7a984d4dc4/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=

server/api/build.go

@@ -482,7 +482,7 @@ func PostBuild(c *gin.Context) {
 			currentFileMeta[i] = &remote.FileMeta{Name: cfg.Name, Data: cfg.Data}
 		}
 
-		newConfig, useOld, err := server.Config.Services.ConfigService.FetchExternalConfig(c, repo, build, currentFileMeta)
+		newConfig, useOld, err := server.Config.Services.ConfigService.FetchConfig(c, repo, build, currentFileMeta)
 		if err != nil {
 			msg := fmt.Sprintf("On fetching external build config: %s", err)
 			c.String(http.StatusBadRequest, msg)

server/api/signature_public_key.go

@@ -0,0 +1,41 @@
+// Copyright 2021 Woodpecker Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package api
+
+import (
+	"crypto/x509"
+	"encoding/pem"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/rs/zerolog/log"
+	"github.com/woodpecker-ci/woodpecker/server"
+)
+
+func GetSignaturePublicKey(c *gin.Context) {
+	b, err := x509.MarshalPKIXPublicKey(server.Config.Services.SignaturePublicKey)
+	if err != nil {
+		log.Error().Err(err).Msg("can't marshal public key")
+		c.AbortWithStatus(http.StatusInternalServerError)
+		return
+	}
+
+	block := &pem.Block{
+		Type:  "PUBLIC KEY",
+		Bytes: b,
+	}
+
+	c.String(200, "%s", pem.EncodeToMemory(block))
+}

server/config.go

@@ -18,26 +18,29 @@
 package server
 
 import (
+	"crypto"
 	"time"
 
 	"github.com/woodpecker-ci/woodpecker/server/logging"
 	"github.com/woodpecker-ci/woodpecker/server/model"
-	"github.com/woodpecker-ci/woodpecker/server/plugins/configuration"
+	"github.com/woodpecker-ci/woodpecker/server/plugins/config"
 	"github.com/woodpecker-ci/woodpecker/server/pubsub"
 	"github.com/woodpecker-ci/woodpecker/server/queue"
 	"github.com/woodpecker-ci/woodpecker/server/remote"
 )
 
 var Config = struct {
 	Services struct {
-		Pubsub        pubsub.Publisher
-		Queue         queue.Queue
-		Logs          logging.Log
-		Secrets       model.SecretService
-		Registries    model.RegistryService
-		Environ       model.EnvironService
-		Remote        remote.Remote
-		ConfigService configuration.ConfigService
+		Pubsub              pubsub.Publisher
+		Queue               queue.Queue
+		Logs                logging.Log
+		Secrets             model.SecretService
+		Registries          model.RegistryService
+		Environ             model.EnvironService
+		Remote              remote.Remote
+		ConfigService       config.Extension
+		SignaturePrivateKey crypto.PrivateKey
+		SignaturePublicKey  crypto.PublicKey
 	}
 	Storage struct {
 		// Users  model.UserStore

server/model/server_config.go

@@ -0,0 +1,27 @@
+// Copyright 2022 Woodpecker Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+// ServerConfigStore persists key-value pairs for storing server configurations.
+type ServerConfigStore interface {
+	ServerConfigGet(key string) (string, error)
+	ServerConfigSet(key int64, value string) error
+}
+
+// ServerConfig represents a key-value pair for storing server configurations.
+type ServerConfig struct {
+	Key   string `json:"key"   xorm:"pk"`
+	Value string `json:"value" xorm:""`
+}

server/plugins/config/extension.go

@@ -0,0 +1,13 @@
+package config
+
+import (
+	"context"
+
+	"github.com/woodpecker-ci/woodpecker/server/model"
+	"github.com/woodpecker-ci/woodpecker/server/remote"
+)
+
+type Extension interface {
+	IsConfigured() bool
+	FetchConfig(ctx context.Context, repo *model.Repo, build *model.Build, currentFileMeta []*remote.FileMeta) (configData []*remote.FileMeta, useOld bool, err error)
+}

server/plugins/config/http.go

@@ -0,0 +1,66 @@
+package config
+
+import (
+	"context"
+	"crypto"
+	"fmt"
+
+	"github.com/woodpecker-ci/woodpecker/server/model"
+	"github.com/woodpecker-ci/woodpecker/server/plugins/utils"
+	"github.com/woodpecker-ci/woodpecker/server/remote"
+)
+
+type http struct {
+	endpoint   string
+	privateKey crypto.PrivateKey
+}
+
+// Same as remote.FileMeta but with json tags and string data
+type config struct {
+	Name string `json:"name"`
+	Data string `json:"data"`
+}
+
+type requestStructure struct {
+	Repo          *model.Repo  `json:"repo"`
+	Build         *model.Build `json:"build"`
+	Configuration []*config    `json:"configs"`
+}
+
+type responseStructure struct {
+	Configs []config `json:"configs"`
+}
+
+func NewHTTP(endpoint string, privateKey crypto.PrivateKey) Extension {
+	return &http{endpoint, privateKey}
+}
+
+func (cp *http) IsConfigured() bool {
+	return cp.endpoint != ""
+}
+
+func (cp *http) FetchConfig(ctx context.Context, repo *model.Repo, build *model.Build, currentFileMeta []*remote.FileMeta) (configData []*remote.FileMeta, useOld bool, err error) {
+	currentConfigs := make([]*config, len(currentFileMeta))
+	for i, pipe := range currentFileMeta {
+		currentConfigs[i] = &config{Name: pipe.Name, Data: string(pipe.Data)}
+	}
+
+	response := new(responseStructure)
+	body := requestStructure{Repo: repo, Build: build, Configuration: currentConfigs}
+	status, err := utils.Send(ctx, "POST", cp.endpoint, cp.privateKey, body, response)
+	if err != nil && status != 204 {
+		return nil, false, fmt.Errorf("Failed to fetch config via http (%d) %w", status, err)
+	}
+
+	var newFileMeta []*remote.FileMeta
+	if status != 200 {
+		newFileMeta = make([]*remote.FileMeta, 0)
+	} else {
+		newFileMeta = make([]*remote.FileMeta, len(response.Configs))
+		for i, pipe := range response.Configs {
+			newFileMeta[i] = &remote.FileMeta{Name: pipe.Name, Data: []byte(pipe.Data)}
+		}
+	}
+
+	return newFileMeta, status == 204, nil
+}