Prevent all courier HTTP requests from accessing local networks

attachments.go

@@ -93,7 +93,7 @@ func FetchAndStoreAttachment(ctx context.Context, b Backend, channel Channel, at
 		return nil, errors.Wrap(err, "unable to create attachment request")
 	}
 
-	trace, err := httpx.DoTrace(utils.GetHTTPClient(), attRequest, nil, nil, maxAttBodyReadBytes)
+	trace, err := httpx.DoTrace(b.HttpClient(true), attRequest, nil, b.HttpAccess(), maxAttBodyReadBytes)
 	if trace != nil {
 		clog.HTTP(trace)
 

backend.go

@@ -3,9 +3,11 @@ package courier
 import (
 	"context"
 	"fmt"
+	"net/http"
 	"strings"
 
 	"github.com/gomodule/redigo/redis"
+	"github.com/nyaruka/gocommon/httpx"
 	"github.com/nyaruka/gocommon/urns"
 )
 
@@ -88,6 +90,10 @@ type Backend interface {
 	// ResolveMedia resolves an outgoing attachment URL to a media object
 	ResolveMedia(context.Context, string) (Media, error)
 
+	// HttpClient returns an HTTP client for making external requests
+	HttpClient(bool) *http.Client
+	HttpAccess() *httpx.AccessConfig
+
 	// Health returns a string describing any health problems the backend has, or empty string if all is well
 	Health() string
 

backends/rapidpro/backend.go

@@ -3,10 +3,12 @@
 import (
 	"bytes"
 	"context"
+	"crypto/tls"
 	"database/sql"
 	"encoding/json"
 	"fmt"
 	"log/slog"
+	"net/http"
 	"net/url"
 	"path"
 	"path/filepath"
@@ -23,6 +25,7 @@
 	"github.com/nyaruka/courier/queue"
 	"github.com/nyaruka/gocommon/analytics"
 	"github.com/nyaruka/gocommon/dbutil"
+	"github.com/nyaruka/gocommon/httpx"
 	"github.com/nyaruka/gocommon/jsonx"
 	"github.com/nyaruka/gocommon/storage"
 	"github.com/nyaruka/gocommon/syncx"
@@ -66,6 +69,10 @@
 	stopChan  chan bool
 	waitGroup *sync.WaitGroup
 
+	httpClient         *http.Client
+	httpClientInsecure *http.Client
+	httpAccess         *httpx.AccessConfig
+
 	mediaCache   *redisx.IntervalHash
 	mediaMutexes syncx.HashMutex
 
@@ -85,9 +92,26 @@
 
 // NewBackend creates a new RapidPro backend
 func newBackend(cfg *courier.Config) courier.Backend {
+	transport := http.DefaultTransport.(*http.Transport).Clone()
+	transport.MaxIdleConns = 64
+	transport.MaxIdleConnsPerHost = 8
+	transport.IdleConnTimeout = 15 * time.Second
+
+	insecureTransport := http.DefaultTransport.(*http.Transport).Clone()
+	insecureTransport.MaxIdleConns = 64
+	insecureTransport.MaxIdleConnsPerHost = 8
+	insecureTransport.IdleConnTimeout = 15 * time.Second
+	insecureTransport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
+
+	disallowedIPs, disallowedNets, _ := cfg.ParseDisallowedNetworks()
+
 	return &backend{
 		config: cfg,
 
+		httpClient:         &http.Client{Transport: transport, Timeout: 30 * time.Second},
+		httpClientInsecure: &http.Client{Transport: insecureTransport, Timeout: 30 * time.Second},
+		httpAccess:         httpx.NewAccessConfig(10*time.Second, disallowedIPs, disallowedNets),
+
 		stopChan:  make(chan bool),
 		waitGroup: &sync.WaitGroup{},
 
@@ -720,6 +744,17 @@
 	return media, nil
 }
 
+func (b *backend) HttpClient(secure bool) *http.Client {
+	if secure {
+		return b.httpClient
+	}
+	return b.httpClientInsecure
+}
+
+func (b *backend) HttpAccess() *httpx.AccessConfig {
+	return b.httpAccess
+}
+
 // Health returns the health of this backend as a string, returning "" if all is well
 func (b *backend) Health() string {
 	// test redis

config.go

@@ -1,7 +1,15 @@
 package courier
 
 import (
+	"encoding/csv"
+	"io"
+	"net"
+	"strings"
+
+	"github.com/nyaruka/courier/utils"
 	"github.com/nyaruka/ezconf"
+	"github.com/nyaruka/gocommon/httpx"
+	"github.com/pkg/errors"
 )
 
 // Config is our top level configuration object
@@ -30,15 +38,16 @@
 	FacebookWebhookSecret        string `help:"the secret for Facebook webhook URL verification"`
 	WhatsappAdminSystemUserToken string `help:"the token of the admin system user for WhatsApp"`
 
-	MediaDomain     string `help:"the domain on which we'll try to resolve outgoing media URLs"`
-	MaxWorkers      int    `help:"the maximum number of go routines that will be used for sending (set to 0 to disable sending)"`
-	LibratoUsername string `help:"the username that will be used to authenticate to Librato"`
-	LibratoToken    string `help:"the token that will be used to authenticate to Librato"`
-	StatusUsername  string `help:"the username that is needed to authenticate against the /status endpoint"`
-	StatusPassword  string `help:"the password that is needed to authenticate against the /status endpoint"`
-	AuthToken       string `help:"the authentication token need to access non-channel endpoints"`
-	LogLevel        string `help:"the logging level courier should use"`
-	Version         string `help:"the version that will be used in request and response headers"`
+	DisallowedNetworks string `help:"comma separated list of IP addresses and networks which we disallow fetching attachments from"`
+	MediaDomain        string `help:"the domain on which we'll try to resolve outgoing media URLs"`
+	MaxWorkers         int    `help:"the maximum number of go routines that will be used for sending (set to 0 to disable sending)"`
+	LibratoUsername    string `help:"the username that will be used to authenticate to Librato"`
+	LibratoToken       string `help:"the token that will be used to authenticate to Librato"`
+	StatusUsername     string `help:"the username that is needed to authenticate against the /status endpoint"`
+	StatusPassword     string `help:"the password that is needed to authenticate against the /status endpoint"`
+	AuthToken          string `help:"the authentication token need to access non-channel endpoints"`
+	LogLevel           string `help:"the logging level courier should use"`
+	Version            string `help:"the version that will be used in request and response headers"`
 
 	// IncludeChannels is the list of channels to enable, empty means include all
 	IncludeChannels []string
@@ -73,9 +82,10 @@
 		FacebookWebhookSecret:        "missing_facebook_webhook_secret",
 		WhatsappAdminSystemUserToken: "missing_whatsapp_admin_system_user_token",
 
-		MaxWorkers: 32,
-		LogLevel:   "error",
-		Version:    "Dev",
+		DisallowedNetworks: `127.0.0.1,::1,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16,169.254.0.0/16,fe80::/10`,
+		MaxWorkers:         32,
+		LogLevel:           "error",
+		Version:            "Dev",
 	}
 }
 
@@ -91,3 +101,25 @@
 	loader.MustLoad()
 	return config
 }
+
+// Validate validates the config
+func (c *Config) Validate() error {
+	if err := utils.Validate(c); err != nil {
+		return err
+	}
+
+	if _, _, err := c.ParseDisallowedNetworks(); err != nil {
+		return errors.Wrap(err, "unable to parse 'DisallowedNetworks'")
+	}
+	return nil
+}
+
+// ParseDisallowedNetworks parses the list of IPs and IP networks (written in CIDR notation)
+func (c *Config) ParseDisallowedNetworks() ([]net.IP, []*net.IPNet, error) {
+	addrs, err := csv.NewReader(strings.NewReader(c.DisallowedNetworks)).Read()
+	if err != nil && err != io.EOF {
+		return nil, nil, err
+	}
+
+	return httpx.ParseNetworks(addrs...)
+}

go.mod

@@ -15,7 +15,7 @@ require (
 	github.com/jmoiron/sqlx v1.3.5
 	github.com/lib/pq v1.10.9
 	github.com/nyaruka/ezconf v0.2.1
-	github.com/nyaruka/gocommon v1.42.1
+	github.com/nyaruka/gocommon v1.42.2
 	github.com/nyaruka/null/v3 v3.0.0
 	github.com/nyaruka/redisx v0.5.0
 	github.com/patrickmn/go-cache v2.1.0+incompatible

go.sum

@@ -69,8 +69,8 @@ github.com/naoina/toml v0.1.1 h1:PT/lllxVVN0gzzSqSlHEmP8MJB4MY2U7STGxiouV4X8=
 github.com/naoina/toml v0.1.1/go.mod h1:NBIhNtsFMo3G2szEBne+bO4gS192HuIYRqfvOWb4i1E=
 github.com/nyaruka/ezconf v0.2.1 h1:TDXWoqjqYya1uhou1mAJZg7rgFYL98EB0Tb3+BWtUh0=
 github.com/nyaruka/ezconf v0.2.1/go.mod h1:ey182kYkw2MIi4XiWe1FR/mzI33WCmTWuceDYYxgnQw=
-github.com/nyaruka/gocommon v1.42.1 h1:BIS+RpgG06Vl4nzrPLxuFFVF+KTP7PZ+V1xJE1ksLBo=
-github.com/nyaruka/gocommon v1.42.1/go.mod h1:JuphjZr/q+GYycaXSQ1WmXzJdbqkbm0iMBlqxxVcF8M=
+github.com/nyaruka/gocommon v1.42.2 h1:VGJ/h7WNmCyQ6wNYClJfFkXkU7ZZn+Aiz9xoKJHVRH4=
+github.com/nyaruka/gocommon v1.42.2/go.mod h1:JuphjZr/q+GYycaXSQ1WmXzJdbqkbm0iMBlqxxVcF8M=
 github.com/nyaruka/librato v1.1.1 h1:0nTYtJLl3Sn7lX3CuHsLf+nXy1k/tGV0OjVxLy3Et4s=
 github.com/nyaruka/librato v1.1.1/go.mod h1:fme1Fu1PT2qvkaBZyw8WW+SrnFe2qeeCWpvqmAaKAKE=
 github.com/nyaruka/null/v2 v2.0.3 h1:rdmMRQyVzrOF3Jff/gpU/7BDR9mQX0lcLl4yImsA3kw=

handlers/africastalking/handler.go

@@ -150,7 +150,7 @@ func (h *handler) Send(ctx context.Context, msg courier.MsgOut, clog *courier.Ch
 	req.Header.Set("Accept", "application/json")
 	req.Header.Set("apikey", apiKey)
 
-	resp, respBody, err := handlers.RequestHTTP(req, clog)
+	resp, respBody, err := h.RequestHTTP(req, clog)
 	if err != nil || resp.StatusCode/100 != 2 {
 		return status, nil
 	}

handlers/arabiacell/handler.go

@@ -96,7 +96,7 @@ func (h *handler) Send(ctx context.Context, msg courier.MsgOut, clog *courier.Ch
 		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 		req.Header.Set("Accept", "application/xml")
 
-		resp, respBody, err := handlers.RequestHTTP(req, clog)
+		resp, respBody, err := h.RequestHTTP(req, clog)
 		if err != nil || resp.StatusCode/100 != 2 {
 			return status, nil
 		}

handlers/bandwidth/handler.go

@@ -227,7 +227,7 @@ func (h *handler) Send(ctx context.Context, msg courier.MsgOut, clog *courier.Ch
 		req.Header.Set("Accept", "application/json")
 		req.SetBasicAuth(username, password)
 
-		resp, respBody, _ := handlers.RequestHTTP(req, clog)
+		resp, respBody, _ := h.RequestHTTP(req, clog)
 
 		response := &mtResponse{}
 		err = json.Unmarshal(respBody, response)

handlers/base.go

@@ -2,10 +2,12 @@
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 
 	"github.com/go-chi/chi"
 	"github.com/nyaruka/courier"
+	"github.com/nyaruka/gocommon/httpx"
 )
 
 var defaultRedactConfigKeys = []string{courier.ConfigAuthToken, courier.ConfigAPIKey, courier.ConfigSecret, courier.ConfigPassword, courier.ConfigSendAuthorization}
@@ -98,6 +100,36 @@
 	return h.backend.GetChannel(ctx, h.ChannelType(), uuid)
 }
 
+// RequestHTTP does the given request, logging the trace, and returns the response
+func (h *BaseHandler) RequestHTTP(req *http.Request, clog *courier.ChannelLog) (*http.Response, []byte, error) {
+	return h.RequestHTTPWithClient(h.backend.HttpClient(true), req, clog)
+}
+
+// RequestHTTP does the given request, logging the trace, and returns the response
+func (h *BaseHandler) RequestHTTPInsecure(req *http.Request, clog *courier.ChannelLog) (*http.Response, []byte, error) {
+	return h.RequestHTTPWithClient(h.backend.HttpClient(false), req, clog)
+}
+
+// RequestHTTP does the given request using the given client, logging the trace, and returns the response
+func (h *BaseHandler) RequestHTTPWithClient(client *http.Client, req *http.Request, clog *courier.ChannelLog) (*http.Response, []byte, error) {
+	var resp *http.Response
+	var body []byte
+
+	req.Header.Set("User-Agent", fmt.Sprintf("Courier/%s", h.server.Config().Version))
+
+	trace, err := httpx.DoTrace(client, req, nil, h.backend.HttpAccess(), 0)
+	if trace != nil {
+		clog.HTTP(trace)
+		resp = trace.Response
+		body = trace.ResponseBody
+	}
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return resp, body, nil
+}
+
 // WriteStatusSuccessResponse writes a success response for the statuses
 func (h *BaseHandler) WriteStatusSuccessResponse(ctx context.Context, w http.ResponseWriter, statuses []courier.StatusUpdate) error {
 	return courier.WriteStatusSuccess(w, statuses)

handlers/http_test.go → handlers/base_test.go

@@ -12,7 +12,7 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestDoHTTPRequest(t *testing.T) {
+func TestRequestHTTP(t *testing.T) {
 	httpx.SetRequestor(httpx.NewMockRequestor(map[string][]*httpx.MockResponse{
 		"https://api.messages.com/send.json": {
 			httpx.NewMockResponse(200, nil, []byte(`{"status":"success"}`)),
@@ -26,8 +26,14 @@ func TestDoHTTPRequest(t *testing.T) {
 	mm := mb.NewOutgoingMsg(mc, 123, urns.URN("tel:+1234"), "Hello World", false, nil, "", "", courier.MsgOriginChat, nil)
 	clog := courier.NewChannelLogForSend(mm, nil)
 
+	config := courier.NewConfig()
+	server := test.NewMockServer(config, mb)
+
+	h := handlers.NewBaseHandler("NX", "Test")
+	h.SetServer(server)
+
 	req, _ := http.NewRequest("POST", "https://api.messages.com/send.json", nil)
-	resp, respBody, err := handlers.RequestHTTP(req, clog)
+	resp, respBody, err := h.RequestHTTP(req, clog)
 	assert.NoError(t, err)
 	assert.Equal(t, 200, resp.StatusCode)
 	assert.Equal(t, []byte(`{"status":"success"}`), respBody)
@@ -38,7 +44,7 @@ func TestDoHTTPRequest(t *testing.T) {
 	assert.Equal(t, "https://api.messages.com/send.json", hlog1.URL)
 
 	req, _ = http.NewRequest("POST", "https://api.messages.com/send.json", nil)
-	resp, _, err = handlers.RequestHTTP(req, clog)
+	resp, _, err = h.RequestHTTP(req, clog)
 	assert.NoError(t, err)
 	assert.Equal(t, 400, resp.StatusCode)
 	assert.Len(t, clog.HTTPLogs(), 2)

handlers/bongolive/handler.go

@@ -165,7 +165,7 @@ func (h *handler) Send(ctx context.Context, msg courier.MsgOut, clog *courier.Ch
 		}
 		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 
-		resp, respBody, err := handlers.RequestHTTPInsecure(req, clog)
+		resp, respBody, err := h.RequestHTTPInsecure(req, clog)
 		if err != nil || resp.StatusCode/100 != 2 {
 			return status, nil
 		}

handlers/burstsms/handler.go

@@ -84,7 +84,7 @@ func (h *handler) Send(ctx context.Context, msg courier.MsgOut, clog *courier.Ch
 		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 		req.Header.Set("Accept", "application/json")
 
-		resp, respBody, err := handlers.RequestHTTP(req, clog)
+		resp, respBody, err := h.RequestHTTP(req, clog)
 		if err != nil || resp.StatusCode/100 != 2 {
 			return status, nil
 		}

handlers/clickatell/handler.go

@@ -180,7 +180,7 @@ func (h *handler) Send(ctx context.Context, msg courier.MsgOut, clog *courier.Ch
 		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 		req.Header.Set("Accept", "application/json")
 
-		resp, respBody, err := handlers.RequestHTTP(req, clog)
+		resp, respBody, err := h.RequestHTTP(req, clog)
 		if err != nil || resp.StatusCode/100 != 2 {
 			return status, nil
 		}

handlers/clickmobile/handler.go

@@ -156,7 +156,7 @@ func (h *handler) Send(ctx context.Context, msg courier.MsgOut, clog *courier.Ch
 		req.Header.Set("Content-Type", "application/json")
 		req.Header.Set("Accept", "application/json")
 
-		resp, respBody, err := handlers.RequestHTTP(req, clog)
+		resp, respBody, err := h.RequestHTTP(req, clog)
 		if err != nil || resp.StatusCode/100 != 2 {
 			return status, nil
 		}

handlers/clicksend/handler.go

@@ -93,7 +93,7 @@ func (h *handler) Send(ctx context.Context, msg courier.MsgOut, clog *courier.Ch
 		req.Header.Set("Accept", "application/json")
 		req.SetBasicAuth(username, password)
 
-		resp, respBody, err := handlers.RequestHTTP(req, clog)
+		resp, respBody, err := h.RequestHTTP(req, clog)
 		if err != nil || resp.StatusCode/100 != 2 {
 			return status, nil
 		}

handlers/dart/handler.go

@@ -186,7 +186,7 @@ func (h *handler) Send(ctx context.Context, msg courier.MsgOut, clog *courier.Ch
 
 		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 
-		resp, respBody, err := handlers.RequestHTTP(req, clog)
+		resp, respBody, err := h.RequestHTTP(req, clog)
 		if err != nil || resp.StatusCode/100 != 2 {
 			return status, nil
 		}