feat: encryption_disabled config option

Can be used with ROCKET_ENCRYPTION_DISABLED=true

src/database/globals.rs

@@ -10,6 +10,7 @@ pub struct Globals {
     reqwest_client: reqwest::Client,
     server_name: Box<ServerName>,
     registration_disabled: bool,
+    encryption_disabled: bool,
 }
 
 impl Globals {
@@ -33,6 +34,7 @@ impl Globals {
                 .try_into()
                 .map_err(|_| Error::BadConfig("Invalid server name found."))?,
             registration_disabled: config.get_bool("registration_disabled").unwrap_or(false),
+            encryption_disabled: config.get_bool("encryption_disabled").unwrap_or(false),
         })
     }
 
@@ -70,4 +72,8 @@ impl Globals {
     pub fn registration_disabled(&self) -> bool {
         self.registration_disabled
     }
+
+    pub fn encryption_disabled(&self) -> bool {
+        self.encryption_disabled
+    }
 }

src/database/rooms.rs

@@ -319,7 +319,12 @@ impl Rooms {
                 Some,
             );
 
+            // Is the event allowed?
             if !match event_type {
+                EventType::RoomEncryption => {
+                    // Don't allow encryption events when it's disabled
+                    !globals.encryption_disabled()
+                }
                 EventType::RoomMember => {
                     let target_user_id = UserId::try_from(&**state_key).map_err(|_| {
                         Error::BadRequest(