identifiers: Don't allow invalid characters in RoomVersionId

crates/ruma-common/src/identifiers/room_version_id.rs

@@ -368,4 +368,17 @@ mod tests {
             RoomVersionId::try_from("io.ruma.1").expect("Failed to create RoomVersionId.")
         );
     }
+
+    #[test]
+    fn custom_room_id_invalid_character() {
+        assert!(serde_json::from_str::<RoomVersionId>(r#""io_ruma_1""#).is_err());
+        assert!(serde_json::from_str::<RoomVersionId>(r#""=""#).is_err());
+        assert!(serde_json::from_str::<RoomVersionId>(r#""/""#).is_err());
+        assert!(serde_json::from_str::<RoomVersionId>(r#"".""#).is_ok());
+        assert!(serde_json::from_str::<RoomVersionId>(r#""-""#).is_ok());
+        assert_eq!(
+            RoomVersionId::try_from("io_ruma_1").unwrap_err(),
+            IdParseError::InvalidCharacters
+        );
+    }
 }

crates/ruma-identifiers-validation/src/room_version_id.rs

@@ -8,6 +8,8 @@ pub fn validate(s: &str) -> Result<(), Error> {
         Err(Error::Empty)
     } else if s.chars().count() > MAX_CODE_POINTS {
         Err(Error::MaximumLengthExceeded)
+    } else if !s.chars().all(|c| c.is_alphanumeric() || ".-".contains(c)) {
+        Err(Error::InvalidCharacters)
     } else {
         Ok(())
     }