From c4d46d20aa352156e58a78b8b49d7473b9835289 Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Sun, 20 Feb 2022 01:16:26 +0100
Subject: [PATCH] Add the galene-link utility.

---
 galene-link/galene-link.go | 115 +++++++++++++++++++++++++++++++++++++
 token/token.go             |   4 +-
 token/token_test.go        |  12 ++--
 3 files changed, 123 insertions(+), 8 deletions(-)
 create mode 100644 galene-link/galene-link.go

diff --git a/galene-link/galene-link.go b/galene-link/galene-link.go
new file mode 100644
index 0000000..7de5b3b
--- /dev/null
+++ b/galene-link/galene-link.go
@@ -0,0 +1,115 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net/url"
+	"path"
+	"time"
+
+	"github.com/golang-jwt/jwt/v4"
+
+	"github.com/jech/galene/group"
+	"github.com/jech/galene/token"
+)
+
+func main() {
+	var username, kid, server string
+	var valid int
+	var tokenOnly bool
+	flag.StringVar(&group.Directory, "groups", "./groups/",
+		"group description `directory`")
+	flag.StringVar(&username, "user", "", "username")
+	flag.StringVar(&kid, "kid", "", "`id` of key to use")
+	flag.IntVar(&valid, "valid", 86400, "`seconds` validity")
+	flag.StringVar(&server, "server", "https://galene.org:8443",
+		"server `url`")
+	flag.BoolVar(&tokenOnly, "token", false, "generate token only")
+	flag.Parse()
+
+	if flag.NArg() != 1 {
+		log.Fatal("One argument (the group URL) required")
+	}
+	groupname := flag.Arg(0)
+
+	desc, err := group.GetDescription(groupname)
+	if err != nil {
+		log.Fatal("Get group description: ", err)
+	}
+
+	serverURL, err := url.Parse(server)
+	if err != nil {
+		log.Fatal("Couldn't parse server URL")
+	}
+	pth := path.Join(path.Join(serverURL.Path, "group"), groupname) + "/"
+	groupURL := &url.URL{
+		Scheme: serverURL.Scheme,
+		Host:   serverURL.Host,
+		Path:   pth,
+	}
+
+	keys := desc.AuthKeys
+	var key map[string]interface{}
+	for _, k := range keys {
+		kid2, _ := k["kid"].(string)
+		if kid == "" || kid == kid2 {
+			key = k
+			break
+		}
+	}
+
+	if key == nil {
+		log.Fatal("Couldn't find key")
+	}
+
+	alg, ok := key["alg"].(string)
+	var method jwt.SigningMethod
+	if ok {
+		method = jwt.GetSigningMethod(alg)
+	}
+	if method == nil {
+		log.Fatal("Couldn't determine key signing method")
+	}
+
+	kstring, err := token.ParseKey(key)
+	if err != nil {
+		log.Fatal("Couldn't parse key")
+	}
+
+	now := time.Now()
+	end := now.Add(time.Second * time.Duration(valid))
+	token := jwt.NewWithClaims(
+		method,
+		&jwt.MapClaims{
+			"sub":         username,
+			"aud":         groupURL.String(),
+			"exp":         &jwt.NumericDate{end},
+			"nbf":         &jwt.NumericDate{now},
+			"iat":         &jwt.NumericDate{now},
+			"permissions": []string{"present"},
+		},
+	)
+
+	s, err := token.SignedString(kstring)
+	if err != nil {
+		log.Fatal("Couldn't sign token: ", err)
+	}
+
+	if tokenOnly {
+		fmt.Println(s)
+	} else {
+		query := url.Values{}
+		if username != "" {
+			query.Add("username", username)
+		}
+		query.Add("token", s)
+		outURL := &url.URL{
+			Scheme:   groupURL.Scheme,
+			Host:     groupURL.Host,
+			Path:     groupURL.Path,
+			RawQuery: query.Encode(),
+		}
+		fmt.Println(outURL.String())
+	}
+}
diff --git a/token/token.go b/token/token.go
index 068c58b..cd04876 100644
--- a/token/token.go
+++ b/token/token.go
@@ -24,7 +24,7 @@ func parseBase64(k string, d map[string]interface{}) ([]byte, error) {
 	return vv, nil
 }
 
-func parseKey(key map[string]interface{}) (interface{}, error) {
+func ParseKey(key map[string]interface{}) (interface{}, error) {
 	kty, ok := key["kty"].(string)
 	if !ok {
 		return nil, errors.New("kty not found")
@@ -99,7 +99,7 @@ func getKey(header map[string]interface{}, keys []map[string]interface{}) (inter
 		kid2, _ := k["kid"].(string)
 		alg2, _ := k["alg"].(string)
 		if (kid == "" || kid == kid2) && alg == alg2 {
-			return parseKey(k)
+			return ParseKey(k)
 		}
 	}
 	return nil, errors.New("key not found")
diff --git a/token/token_test.go b/token/token_test.go
index 358f2a7..f0c2e4b 100644
--- a/token/token_test.go
+++ b/token/token_test.go
@@ -21,13 +21,13 @@ func TestHS256(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Unmarshal: %v", err)
 	}
-	k, err := parseKey(j)
+	k, err := ParseKey(j)
 	if err != nil {
-		t.Fatalf("parseKey: %v", err)
+		t.Fatalf("ParseKey: %v", err)
 	}
 	kk, ok := k.([]byte)
 	if !ok || len(kk) != 32 {
-		t.Errorf("parseKey: got %v", kk)
+		t.Errorf("ParseKey: got %v", kk)
 	}
 }
 
@@ -44,13 +44,13 @@ func TestES256(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Unmarshal: %v", err)
 	}
-	k, err := parseKey(j)
+	k, err := ParseKey(j)
 	if err != nil {
-		t.Fatalf("parseKey: %v", err)
+		t.Fatalf("ParseKey: %v", err)
 	}
 	kk, ok := k.(*ecdsa.PublicKey)
 	if !ok || kk.Params().Name != "P-256" {
-		t.Errorf("parseKey: got %v", kk)
+		t.Errorf("ParseKey: got %v", kk)
 	}
 	if !kk.IsOnCurve(kk.X, kk.Y) {
 		t.Errorf("point is not on curve")