From d16fc18f9cbe85e7ca2f6afdd8fa26e569856223 Mon Sep 17 00:00:00 2001
From: Larry Bordowitz <laurence.bordowitz@gmail.com>
Date: Wed, 13 Mar 2024 17:41:41 -0500
Subject: [PATCH] Add option for randomly-generated Stream Key

---
 main.go     |  2 +-
 readme.md   |  1 +
 settings.go | 28 ++++++++++++++++++++++++++--
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/main.go b/main.go
index 5f13167..662f2a6 100644
--- a/main.go
+++ b/main.go
@@ -34,7 +34,7 @@ func setupSettings(adminPass string, confFile string) error {
 	if err != nil {
 		return fmt.Errorf("unable to load settings: %w", err)
 	}
-	if len(settings.StreamKey) == 0 {
+	if !settings.NewStreamKey && len(settings.StreamKey) == 0 {
 		return fmt.Errorf("missing stream key is settings.json")
 	}
 
diff --git a/readme.md b/readme.md
index 617d874..b551ffd 100644
--- a/readme.md
+++ b/readme.md
@@ -182,6 +182,7 @@ MovieNight’s configuration is controlled by `settings.json`:
     - `LogLevel`: the log level, defaults to `debug`.
     - `MaxMessageCount`: the number of messages displayed in the chat window.
     - `NewPin`: if true, regenerates `RoomAccessPin` when the server starts.
+    - `NewStreamKey`: if true, uses a random `StreamKey` when the server starts. The command line option takes precedence, and will be used if it is set.
     - `PageTitle`: The base string used in the `<title>` element of the page.  When the stream title is set with `/playing`, it is appended; e.g., `Movie Night | The Man Who Killed Hitler and Then the Bigfoot`
     - `RegenAdminPass`: if true, regenerates `AdminPassword` when the server starts.
     - `RoomAccess`: the access policy of the chat room; this is managed by the application and should not be edited manually.
diff --git a/settings.go b/settings.go
index 5abeb52..d386f4a 100644
--- a/settings.go
+++ b/settings.go
@@ -21,8 +21,9 @@ var sstore *sessions.CookieStore
 
 type Settings struct {
 	// Non-Saved settings
-	filename   string
-	cmdLineKey string // stream key from the command line
+	filename     string
+	cmdLineKey   string // stream key from the command line
+	rndStreamKey string // random stream key; only used if NewStreamKey is set
 
 	// Saved settings
 	AdminPassword     string
@@ -33,6 +34,7 @@ type Settings struct {
 	LogLevel          common.LogLevel
 	MaxMessageCount   int
 	NewPin            bool   // Auto generate a new pin on start.  Overwrites RoomAccessPin if set.
+	NewStreamKey      bool   // Auto generate a new stream key on start. Used instead of StreamKey if set.
 	PageTitle         string // primary value for the page <title> element
 	RegenAdminPass    bool   // regenerate admin password on start?
 	RoomAccess        AccessMode
@@ -172,6 +174,11 @@ func LoadSettings(filename string) (*Settings, error) {
 		s.TitleLength = 50
 	}
 
+	// Set a random stream key
+	if s.NewStreamKey {
+		s.rndStreamKey = randStringRunes(20)
+	}
+
 	// Is this a good way to do this? Probably not...
 	if len(s.SessionKey) == 0 {
 		out := ""
@@ -294,6 +301,10 @@ func (s *Settings) GetStreamKey() string {
 	if len(s.cmdLineKey) > 0 {
 		return s.cmdLineKey
 	}
+	if s.NewStreamKey {
+		return s.rndStreamKey
+	}
+
 	return s.StreamKey
 }
 
@@ -311,3 +322,16 @@ func (s *Settings) generateNewPin() (string, error) {
 	}
 	return s.RoomAccessPin, nil
 }
+
+// Adapted from: https://stackoverflow.com/questions/22892120/how-to-generate-a-random-string-of-a-fixed-length-in-go/22892986#22892986
+var letterRunes = []rune("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+
+func randStringRunes(n int) string {
+	length := big.NewInt(int64(len(letterRunes)))
+	b := make([]rune, n)
+	for i := range b {
+		letter_idx, _ := rand.Int(rand.Reader, length)
+		b[i] = letterRunes[letter_idx.Int64()]
+	}
+	return string(b)
+}