1.9 KiB
MSC2540: Stricter event validation: JSON compliance
Background
There has been prior discussions about validating events more strictly. This MSC proposes fixing a small piece of this: JSON compliance.
The Canonical JSON specification requires that numbers that are serialized in JSON are integers in the range of [-2 ^ 53 + 1, 2 ^ 53 - 1], which matches the requirements of section 6 of RFC 7159. Note that it is not explicit, but all floats are invalid.
It is worth mentioning that there are common extensions to JSON which produce
invalid JSON according to the Matrix specification, some programming langauges
even support these by default. One common additional feature is handling
"special" float values: Infinity, -Infinity, and NaN.
Proposal
In a future room version, Matrix server implementations should strictly enforce the Canonical JSON specification for events.
The rationale for doing this in a future room version is to avoid a split brain room -- where some federated servers believe an event is valid and others reject it as invalid. Rooms will be able to opt into this behavior as part of a room version upgrade.
Potential issues
N/A
Alternatives
It could be argued that this MSC is unnecessary since it does not add any new requirements for handling of JSON data. Unfortunately starting to enforce these requirements in current rooms could cause federation to break as homeservers will disagree on whether events are valid.
Security considerations
N/A
Unstable prefix
A room versions of org.matrix.strict_canonicaljson until a future room version
is available. This room version will use
room version 5 as base and include the
above modifications.