mirror of
https://github.com/scsibug/nostr-rs-relay.git
synced 2024-11-22 09:09:07 -05:00
80 lines
3.4 KiB
Markdown
80 lines
3.4 KiB
Markdown
# gRPC Extensions Design Document
|
|
|
|
The relay will be extensible through gRPC endpoints, definable in the
|
|
main configuration file. These will allow external programs to host
|
|
logic for deciding things such as, should this event be persisted,
|
|
should this connection be allowed, and should this subscription
|
|
request be registered. The primary goal is allow for relay operator
|
|
specific functionality that allows them to serve smaller communities
|
|
and reduce spam and abuse.
|
|
|
|
This will likely evolve substantially, the first goal is to get a
|
|
basic one-way service that lets an externalized program decide on
|
|
event persistence. This does not represent the final state of gRPC
|
|
extensibility in `nostr-rs-relay`.
|
|
|
|
## Considerations
|
|
|
|
Write event latency must not be significantly affected. However, the
|
|
primary reason we are implementing this is spam/abuse protection, so
|
|
we are willing to tolerate some increase in latency if that protects
|
|
us against outages!
|
|
|
|
The interface should provide enough information to make simple
|
|
decisions, without burdening the relay to do extra queries. The
|
|
decision endpoint will be mostly responsible for maintaining state and
|
|
gathering additional details.
|
|
|
|
## Design Overview
|
|
|
|
A gRPC server may be defined in the `config.toml` file. If it exists,
|
|
the relay will attempt to connect to it and send a message for each
|
|
`EVENT` command submitted by clients. If a successful response is
|
|
returned indicating the event is permitted, the relay continues
|
|
processing the event as normal. All existing whitelist, blacklist,
|
|
and `NIP-05` validation checks are still performed and MAY still
|
|
result in the event being rejected. If a successful response is
|
|
returned indicated the decision is anything other than permit, then
|
|
the relay MUST reject the event, and return a command result to the
|
|
user (using `NIP-20`) indicating the event was blocked (optionally
|
|
providing a message).
|
|
|
|
In the event there is an error in the gRPC interface, event processing
|
|
proceeds as if gRPC was disabled (fail open). This allows gRPC
|
|
servers to be deployed with minimal chance of causing a full relay
|
|
outage.
|
|
|
|
## Design Details
|
|
|
|
Currently one procedure call is supported, `EventAdmit`, in the
|
|
`Authorization` service. It accepts the following data in order to
|
|
support authorization decisions:
|
|
|
|
- The event itself
|
|
- The client IP that submitted the event
|
|
- The client's HTTP origin header, if one exists
|
|
- The client's HTTP user agent header, if one exists
|
|
- The public key of the client, if `NIP-42` authentication was
|
|
performed (not supported in the relay yet!)
|
|
- The `NIP-05` associated with the event's public key, if it is known
|
|
to the relay
|
|
|
|
A server providing authorization decisions will return the following:
|
|
|
|
- A decision to permit or deny the event
|
|
- An optional message that explains why the event was denied, to be
|
|
transmitted to the client
|
|
|
|
## Security Issues
|
|
|
|
There is little attempt to secure this interface, since it is intended
|
|
for use processes running on the same host. It is recommended to
|
|
ensure that the gRPC server providing the API is not exposed to the
|
|
public Internet. Authorization server implementations should have
|
|
their own security reviews performed.
|
|
|
|
A slow gRPC server could cause availability issues for event
|
|
processing, since this is performed on a single thread. Avoid any
|
|
expensive or long-running processes that could result from submitted
|
|
events, since any client can initiate a gRPC call to the service.
|