A followup on this with a few options on how this could be implemented.

This is a bit trickier than we thought. Reason for that is that on the go-side the registered type PubKeyEd25519 is just a type alias type PubKeyEd25519 [PubKeyEd25519Size]byte.

type PubKeyMsg struct {
	PubKey crypto.PubKey // <- we only need PubKeyEd25519 for this PR!
}

The encoded bytes will have prefix bytes for the registered types privval.PubKeyMsg and the registered type crypto.PubKeyEd25519.

To achieve the same via prost we would ideally, be able to annotate a rust type alias. That isn't possible as derive only works on structs, enums and unions.

In signatory, the key is a struct without an explicit field:
https://github.com/tendermint/signatory/blob/aec83b4c6f18b63f598bc74336ca6ad414988fba/src/ed25519/public_key.rs#L10-L14
This looks like another candidate how we could handle this: annotate a similar struct with derive. Again, this doesn't work from scratch. This time the restrictions come from proc-marco2 on which prost is based on (implicit field "names" are numbers).

This leaves us with two options:

add an amino_name (or similar) attribute to fields (and not only structs as currently) to derive the prefix bytes from (and without the need to define another annotated struct).
add an attribute a la skip_fieldnum_and_type; as field tagged with this attribute would cause encoding the field contents of field (and not their field num and wire type as default in amino and mandatory in proto3). This could even be useful to encode raw bytes as in secret connection: https://github.com/tendermint/tendermint/blob/2aa2b63cadc42cca1071c36adfd2f2ce14e1aa8f/p2p/conn/secret_connection.go#L202-L220

Thoughts @zmanian? I'm leaning to option 2) as this would further ease implementing secret connection in Rust (skip over field number and type for a struct with just bytes leaves us with length prrefixed bytes as in the lines of code above).

In case 1) the annotated message would look like:

#[derive(Clone, PartialEq, Message)]
#[amino_name = "tendermint/socketpv/PubKeyMsg"]
pub struct PubKeyMsg {
    #[prost(message, tag = "1", amino_name = "tendermint/PubKeySecp256k1")]
    pub_key_ed25519: Option<Vec<u8>>,
}

In case 2) the annotated messages would look sth like:

#[derive(Clone, PartialEq, Message)]
#[amino_name = "tendermint/socketpv/PubKeyMsg"]
pub struct PubKeyMsg {
    #[prost(message, tag = "1")]
    pub_key_ed25519: Option<PubKeyEd25519>,
}

#[derive(Copy, Clone, PartialEq, Message)]
#[amino_name = "tendermint/PubKeyEd25519"]
pub struct PubKeyEd25519{
    #[prost(message, tag = "1", skip_fieldnum_and_type)]
    pub_key: Vec<u8>,
}

Add a PubKey Type to the types module #34

Description

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions