Revamp furl to be more useful

- Allow skipping TLS checks with -k (for localhost dendrites)
- Allow self-hosting server keys (for ephemeral servers)

cmd/furl/main.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"bufio"
 	"bytes"
 	"context"
 	"crypto/ed25519"
@@ -9,99 +8,194 @@ import (
 	"encoding/pem"
 	"flag"
 	"fmt"
+	"net/http"
 	"net/url"
 	"os"
+	"strings"
+	"time"
 
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrix"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/gomatrixserverlib/fclient"
 	"github.com/matrix-org/gomatrixserverlib/spec"
 )
 
-var requestFrom = flag.String("from", "", "the server name that the request should originate from")
+var (
-var requestKey = flag.String("key", "matrix_key.pem", "the private key to use when signing the request")
+	flagSkipVerify bool   //  -k, --insecure           Allow insecure server connections
-var requestPost = flag.Bool("post", false, "send a POST request instead of GET (pipe input into stdin or type followed by Ctrl-D)")
+	flagMethod     string //  -X, --request <method>   Specify request method to use
+	flagData       string // -d, --data <data>        HTTP POST data
+
+	flagMatrixKey string
+	flagOrigin    string
+)
+
+func init() {
+	flag.BoolVar(&flagSkipVerify, "insecure", false, "Allow insecure server connections")
+	flag.BoolVar(&flagSkipVerify, "k", false, "Allow insecure server connections")
+
+	flag.StringVar(&flagMethod, "X", "GET", "Specify HTTP request method to use")
+	flag.StringVar(&flagMethod, "request", "GET", "Specify HTTP request method to use")
+
+	flag.StringVar(&flagData, "d", "", "HTTP JSON body data. If you start the data with the letter @, the rest should be a filename.")
+	flag.StringVar(&flagData, "data", "", "HTTP JSON body data. If you start the data with the letter @, the rest should be a filename.")
+
+	flag.StringVar(&flagMatrixKey, "M", "matrix_key.pem", "The private key to use when signing the request")
+	flag.StringVar(&flagMatrixKey, "key", "matrix_key.pem", "The private key to use when signing the request")
+
+	flag.StringVar(&flagOrigin, "O", "", "The server name that the request should originate from. The remote server will use this to request server keys. There MUST be a TLS listener at the .well-known address for this server name, i.e it needs to be pointing to a real homeserver. If blank, furl will self-host this on a random high numbered port, but only if the target is localhost. Use $PORT in request URLs/bodies to substitute the port number in.")
+	flag.StringVar(&flagOrigin, "origin", "", "The server name that the request should originate from. The remote server will use this to request server keys. There MUST be a TLS listener at the .well-known address for this server name, i.e it needs to be pointing to a real homeserver. If blank, furl will self-host this on a random high numbered port, but only if the target is localhost. Use $PORT in request URLs/bodies to substitute the port number in.")
+}
+
+type args struct {
+	SkipVerify  bool
+	Method      string
+	Data        []byte
+	MatrixKey   ed25519.PrivateKey
+	MatrixKeyID gomatrixserverlib.KeyID
+	Origin      spec.ServerName
+	SelfHostKey bool
+	TargetURL   *url.URL
+}
+
+func processArgs() (*args, error) {
+	if len(flag.Arg(0)) == 0 {
+		return nil, fmt.Errorf("furl [-k] [-X GET|PUT|POST|DELETE] [-d @filename|{\"inline\":\"json\"}] [-M matrix_key.pem] [-O localhost] https://federation-server.url/_matrix/.../")
+	}
+	targetURL, err := url.Parse(flag.Arg(0))
+	if err != nil {
+		return nil, fmt.Errorf("invalid url: %s", err)
+	}
+
+	// load .pem file
+	data, err := os.ReadFile(flagMatrixKey)
+	if err != nil {
+		return nil, err
+	}
+	keyBlock, _ := pem.Decode(data)
+	if keyBlock == nil {
+		return nil, fmt.Errorf("invalid pem file: %s", flagMatrixKey)
+	}
+	if keyBlock.Type != "MATRIX PRIVATE KEY" {
+		return nil, fmt.Errorf("pem file bad block type, want MATRIX PRIVATE KEY got %s", keyBlock.Type)
+	}
+	_, privateKey, err := ed25519.GenerateKey(bytes.NewReader(keyBlock.Bytes))
+	if err != nil {
+		return nil, err
+	}
+
+	var a args
+	a.MatrixKey = privateKey
+	a.MatrixKeyID = gomatrixserverlib.KeyID(keyBlock.Headers["Key-ID"])
+
+	a.SkipVerify = flagSkipVerify
+	a.Method = strings.ToUpper(flagMethod)
+	a.Origin = spec.ServerName(flagOrigin)
+	a.TargetURL = targetURL
+	a.SelfHostKey = a.Origin == "" && a.TargetURL.Hostname() == "localhost"
+
+	// load data
+	isFile := strings.HasPrefix(flagData, "@")
+	if isFile {
+		a.Data, err = os.ReadFile(flagData[1:])
+		if err != nil {
+			return nil, fmt.Errorf("failed to read file '%s': %s", flagData[1:], err)
+		}
+	} else if len(flagData) > 0 {
+		a.Data = []byte(flagData)
+	}
+
+	return &a, nil
+}
 
 func main() {
 	flag.Parse()
-
+	a, err := processArgs()
-	if requestFrom == nil || *requestFrom == "" {
+	if err != nil {
-		fmt.Println("expecting: furl -from origin.com [-key matrix_key.pem] https://path/to/url")
+		fmt.Println(err.Error())
-		fmt.Println("supported flags:")
 		flag.PrintDefaults()
 		os.Exit(1)
 	}
 
-	data, err := os.ReadFile(*requestKey)
+	if a.SelfHostKey {
+		fmt.Printf("Self-hosting key...")
+		apiURL, cancel := test.ListenAndServe(tt{}, http.DefaultServeMux, true)
+		defer cancel()
+		parsedURL, _ := url.Parse(apiURL)
+		a.Origin = spec.ServerName(parsedURL.Host)
+		fmt.Printf(" OK on %s\n", a.Origin)
+
+		// handle the request when it comes in
+		pubKey := a.MatrixKey.Public().(ed25519.PublicKey)
+		serverKey := gomatrixserverlib.ServerKeyFields{
+			ServerName:   a.Origin,
+			ValidUntilTS: spec.AsTimestamp(time.Now().Add(2 * time.Minute)),
+			VerifyKeys: map[gomatrixserverlib.KeyID]gomatrixserverlib.VerifyKey{
+				a.MatrixKeyID: {
+					Key: spec.Base64Bytes(pubKey),
+				},
+			},
+		}
+		serverKeyBytes, err := json.Marshal(serverKey)
 		if err != nil {
 			panic(err)
 		}
-
+		signedBytes, err := gomatrixserverlib.SignJSON(string(a.Origin), a.MatrixKeyID, a.MatrixKey, serverKeyBytes)
-	var privateKey ed25519.PrivateKey
+		if err != nil {
-	keyBlock, _ := pem.Decode(data)
+			panic(err)
-	if keyBlock == nil {
+		}
-		panic("keyBlock is nil")
+		resp := map[string]interface{}{
-	}
+			"server_keys": []json.RawMessage{signedBytes},
-	if keyBlock.Type == "MATRIX PRIVATE KEY" {
+		}
-		_, privateKey, err = ed25519.GenerateKey(bytes.NewReader(keyBlock.Bytes))
+		respBytes, err := json.Marshal(resp)
+		if err != nil {
+			panic(err)
+		}
+		fmt.Printf("Will return %s\n", string(respBytes))
+		http.HandleFunc("/_matrix/key/v2/query", func(w http.ResponseWriter, r *http.Request) {
+			if r.Method != "POST" {
+				w.WriteHeader(http.StatusMethodNotAllowed)
+				return
+			}
+			w.WriteHeader(http.StatusOK)
+			w.Write(respBytes)
+		})
+
+		// replace anything with $PORT
+		port := parsedURL.Port()
+		a.TargetURL, err = url.Parse(strings.ReplaceAll(a.TargetURL.String(), "$PORT", port))
 		if err != nil {
 			panic(err)
 		}
-	} else {
-		panic("unexpected key block")
 	}
 
-	serverName := spec.ServerName(*requestFrom)
 	client := fclient.NewFederationClient(
 		[]*fclient.SigningIdentity{
 			{
-				ServerName: serverName,
+				ServerName: a.Origin,
-				KeyID:      gomatrixserverlib.KeyID(keyBlock.Headers["Key-ID"]),
+				KeyID:      a.MatrixKeyID,
-				PrivateKey: privateKey,
+				PrivateKey: a.MatrixKey,
-			},
 			},
+		}, fclient.WithSkipVerify(a.SkipVerify),
 	)
 
-	u, err := url.Parse(flag.Arg(0))
-	if err != nil {
-		panic(err)
-	}
-
-	var bodyObj interface{}
-	var bodyBytes []byte
-	method := "GET"
-	if *requestPost {
-		method = "POST"
-		fmt.Println("Waiting for JSON input. Press Enter followed by Ctrl-D when done...")
-
-		scan := bufio.NewScanner(os.Stdin)
-		for scan.Scan() {
-			bytes := scan.Bytes()
-			bodyBytes = append(bodyBytes, bytes...)
-		}
-		fmt.Println("Done!")
-		if err = json.Unmarshal(bodyBytes, &bodyObj); err != nil {
-			panic(err)
-		}
-	}
-
 	req := fclient.NewFederationRequest(
-		method,
+		a.Method,
-		serverName,
+		a.Origin,
-		spec.ServerName(u.Host),
+		spec.ServerName(a.TargetURL.Host),
-		u.RequestURI(),
+		a.TargetURL.RequestURI(),
 	)
-
+	if a.Data != nil {
-	if *requestPost {
+		var jsonData interface{}
-		if err = req.SetContent(bodyObj); err != nil {
+		if err := json.Unmarshal(a.Data, &jsonData); err != nil {
-			panic(err)
+			fmt.Printf("Supplied data is not valid json: %s\n", err)
+			os.Exit(1)
+		}
+		if err = req.SetContent(jsonData); err != nil {
+			panic(err) // should be impossible as we just checked it was valid JSON
 		}
 	}
-
+	if err = req.Sign(a.Origin, a.MatrixKeyID, a.MatrixKey); err != nil {
-	if err = req.Sign(
-		spec.ServerName(*requestFrom),
-		gomatrixserverlib.KeyID(keyBlock.Headers["Key-ID"]),
-		privateKey,
-	); err != nil {
 		panic(err)
 	}
 
@@ -117,8 +211,16 @@ func main() {
 		&res,
 	)
 	if err != nil {
+		mxerr, ok := err.(gomatrix.HTTPError)
+		if ok {
+			fmt.Printf("Server returned HTTP %d\n", mxerr.Code)
+			fmt.Println(mxerr.Message)
+			fmt.Println(mxerr.WrappedError)
+		} else {
 			panic(err)
 		}
+		os.Exit(1)
+	}
 
 	j, err := json.MarshalIndent(res, "", "  ")
 	if err != nil {
@@ -127,3 +229,19 @@ func main() {
 
 	fmt.Println(string(j))
 }
+
+type tt struct{}
+
+func (t tt) Logf(format string, args ...any) {
+	fmt.Printf(format+"\n", args...)
+}
+func (t tt) Errorf(format string, args ...any) {
+	fmt.Printf(format+"\n", args...)
+}
+func (t tt) Fatalf(format string, args ...any) {
+	fmt.Printf(format+"\n", args...)
+	os.Exit(2)
+}
+func (t tt) TempDir() string {
+	return os.TempDir()
+}

test/http.go

@@ -49,9 +49,17 @@ func NewRequest(t *testing.T, method, path string, opts ...HTTPRequestOpt) *http
 	return req
 }
 
+// it's a testing.T but implementable for things which don't have one e.g furl
+type testInterface interface {
+	Logf(format string, args ...any)
+	Errorf(format string, args ...any)
+	Fatalf(format string, args ...any)
+	TempDir() string
+}
+
 // ListenAndServe will listen on a random high-numbered port and attach the given router.
 // Returns the base URL to send requests to. Call `cancel` to shutdown the server, which will block until it has closed.
-func ListenAndServe(t *testing.T, router http.Handler, withTLS bool) (apiURL string, cancel func()) {
+func ListenAndServe(t testInterface, router http.Handler, withTLS bool) (apiURL string, cancel func()) {
 	listener, err := net.Listen("tcp", "127.0.0.1:0")
 	if err != nil {
 		t.Fatalf("failed to listen: %s", err)