mirror of
https://github.com/logos-messaging/specs.git
synced 2026-01-02 14:13:06 +00:00
173 lines
9.6 KiB
Markdown
173 lines
9.6 KiB
Markdown
---
|
|
title: WAKU2-ENR
|
|
name: Waku v2 usage of ENR
|
|
tags: [waku/core-protocol]
|
|
editor: Franck Royer <franck@status.im>
|
|
contributors:
|
|
---
|
|
|
|
## Abstract
|
|
|
|
This specification describes the usage of the ENR (Ethereum Node Records)
|
|
format for [10/WAKU2](https://github.com/vacp2p/rfc-index/blob/main/waku/standards/core/10/waku2.md) purposes.
|
|
The ENR format is defined in [EIP-778](https://eips.ethereum.org/EIPS/eip-778) [[3]](#references).
|
|
|
|
This specification is an extension of EIP-778, ENR used in Waku MUST adhere to both EIP-778 and 31/WAKU2-ENR.
|
|
|
|
## Motivation
|
|
|
|
EIP-1459 with the usage of ENR has been implemented [[1]](#references) [[2]](#references) as a discovery protocol for Waku.
|
|
|
|
EIP-778 specifies a number of pre-defined keys.
|
|
However, the usage of these keys alone does not allow for certain transport capabilities to be encoded,
|
|
such as Websocket.
|
|
Currently, Waku nodes running in a browser only support websocket transport protocol.
|
|
Hence, new ENR keys need to be defined to allow for the encoding of transport protocol other than raw TCP.
|
|
|
|
### Usage of Multiaddr Format Rationale
|
|
|
|
One solution would be to define new keys such as `ws` to encode the websocket port of a node.
|
|
However, we expect new transport protocols to be added overtime such as quic.
|
|
Hence, this would only provide a short term solution until another specification would need to be added.
|
|
|
|
Moreover, secure websocket involves SSL certificates.
|
|
SSL certificates are only valid for a given domain and ip, so an ENR containing the following information:
|
|
|
|
- secure websocket port
|
|
- ipv4 fqdn
|
|
- ipv4 address
|
|
- ipv6 address
|
|
|
|
Would carry some ambiguity: Is the certificate securing the websocket port valid for the ipv4 fqdn?
|
|
the ipv4 address?
|
|
the ipv6 address?
|
|
|
|
The [10/WAKU2](https://github.com/vacp2p/rfc-index/blob/main/waku/standards/core/10/waku2.md) protocol family is built on the [libp2p](https://github.com/libp2p/specs) protocol stack.
|
|
Hence, it uses [multiaddr](https://github.com/multiformats/multiaddr) to format network addresses.
|
|
|
|
Directly storing one or several multiaddresses in the ENR would fix the issues listed above:
|
|
|
|
- multiaddr is self-describing and support addresses for any network protocol:
|
|
No new specification would be needed to support encoding other transport protocols in an ENR.
|
|
- multiaddr contains both the host and port information, allowing the ambiguity previously described to be resolved.
|
|
|
|
## Wire Format
|
|
|
|
### `multiaddrs` ENR key
|
|
|
|
We define a `multiaddrs` key.
|
|
|
|
- The value MUST be a list of binary encoded multiaddr prefixed by their size.
|
|
- The size of the multiaddr MUST be encoded in a Big Endian unsigned 16-bit integer.
|
|
- The size of the multiaddr MUST be encoded in 2 bytes.
|
|
- The `secp256k1` value MUST be present on the record;
|
|
`secp256k1` is defined in [EIP-778](https://eips.ethereum.org/EIPS/eip-778) and contains the compressed secp256k1 public key.
|
|
- The node's peer id SHOULD be deduced from the `secp256k1` value.
|
|
- The multiaddresses SHOULD NOT contain a peer id except for circuit relay addresses
|
|
- For raw TCP & UDP connections details, [EIP-778](https://eips.ethereum.org/EIPS/eip-778) pre-defined keys SHOULD be used;
|
|
The keys `tcp`, `udp`, `ip` (and `tcp6`, `udp6`, `ip6` for IPv6) are enough to convey all necessary information;
|
|
- To save space, `multiaddrs` key SHOULD only be used for connection details that cannot be represented using the [EIP-778](https://eips.ethereum.org/EIPS/eip-778) pre-defined keys.
|
|
- The 300 bytes size limit as defined by [EIP-778](https://eips.ethereum.org/EIPS/eip-778) still applies;
|
|
In practice, it is possible to encode 3 multiaddresses in ENR, more or less could be encoded depending on the size of each multiaddress.
|
|
|
|
### Usage
|
|
|
|
#### Many connection types
|
|
|
|
Alice is a Waku node operator, she runs a node that supports inbound connection for the following protocols:
|
|
|
|
- TCP 10101 on `1.2.3.4`
|
|
- UDP 20202 on `1.2.3.4`
|
|
- TCP 30303 on `1234:5600:101:1::142`
|
|
- UDP 40404 on `1234:5600:101:1::142`
|
|
- Secure Websocket on `wss://example.com:443/`
|
|
- QUIC on `quic://quic.example.com:443/`
|
|
- A circuit relay address `/ip4/1.2.3.4/tcp/55555/p2p/QmRelay/p2p-circuit/p2p/QmAlice`
|
|
|
|
Alice SHOULD structure the ENR for her node as follows:
|
|
|
|
| key | value |
|
|
| ------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
|
| `tcp` | `10101` |
|
|
| `udp` | `20202` |
|
|
| `tcp6` | `30303` |
|
|
| `udp6` | `40404` |
|
|
| `ip` | `1.2.3.4` |
|
|
| `ip6` | `1234:5600:101:1::142` |
|
|
| `secp256k1` | Alice's compressed secp256k1 public key, 33 bytes |
|
|
| `multiaddrs` | <code>len1 | /dns4/example.com/tcp/443/wss | len2 | /dns4/quic.examle.com/tcp/443/quic | len3 | /ip4/1.2.3.4/tcp/55555/p2p/QmRelay </code> |
|
|
|
|
Where `multiaddrs`:
|
|
|
|
- `|` is the concatenation operator,
|
|
- `len1` is the length of `/dns4/example.com/tcp/443/wss` byte representation,
|
|
- `len2` is the length of `/dns4/quic.examle.com/tcp/443/quic` byte representation.
|
|
- `len3` is the length of `/ip4/1.2.3.4/tcp/55555/p2p/QmRelay` byte representation. Notice that the `/p2p-circuit` component is not stored, but, since circuit relay addresses are the only one containing a `p2p` component, it's safe to assume that any address containing this component is a circuit relay address. Decoding this type of multiaddresses would require appending the `/p2p-circuit` component.
|
|
|
|
#### Raw TCP only
|
|
|
|
Bob is a node operator that runs a node that supports inbound connection for the following protocols:
|
|
|
|
- TCP 10101 on `1.2.3.4`
|
|
|
|
Bob SHOULD structure the ENR for his node as follows:
|
|
|
|
| key | value |
|
|
| ----------- | ----------------------------------------------- |
|
|
| `tcp` | `10101` |
|
|
| `ip` | `1.2.3.4` |
|
|
| `secp256k1` | Bob's compressed secp256k1 public key, 33 bytes |
|
|
|
|
As Bob's node's connection details can be represented with EIP-778's pre-defined keys only,
|
|
it is not needed to use the `multiaddrs` key.
|
|
|
|
### Limitations
|
|
|
|
Supported key type is `secp256k1` only.
|
|
|
|
Support for other elliptic curve cryptography such as `ed25519` MAY be used.
|
|
|
|
### `waku2` ENR key
|
|
|
|
We define a `waku2` field key:
|
|
|
|
- The value MUST be an 8-bit flag field,
|
|
where bits set to `1` indicate `true` and bits set to `0` indicate `false` for the relevant flags.
|
|
- The flag values already defined are set out below,
|
|
with `bit 7` the most significant bit and `bit 0` the least significant bit.
|
|
|
|
| bit 7 | bit 6 | bit 5 | bit 4 | bit 3 | bit 2 | bit 1 | bit 0 |
|
|
| ------- | ------- | ------- | ------- | ----------- | -------- | ------- | ------- |
|
|
| `undef` | `undef` | `undef` | `sync` | `lightpush` | `filter` | `store` | `relay` |
|
|
|
|
- In the scheme above, the flags `sync`, `lightpush`, `filter`, `store` and `relay` correlates with support for protocols with the same name.
|
|
If a protocol is not supported, the corresponding field MUST be set to `false`.
|
|
Indicating positive support for any specific protocol is OPTIONAL,
|
|
though it MAY be required by the relevant application or discovery process.
|
|
- Flags marked as `undef` is not yet defined.
|
|
These SHOULD be set to `false` by default.
|
|
|
|
### Usage
|
|
|
|
- A Waku node MAY choose to populate the `waku2` field for enhanced discovery capabilities,
|
|
such as indicating supported protocols.
|
|
Such a node MAY indicate support for any specific protocol by setting the corresponding flag to `true`.
|
|
- Waku nodes that want to participate in [Node Discovery Protocol v5](https://github.com/vacp2p/rfc-index/blob/main/waku/standards/core/33/discv5.md) [[4]](#references), however,
|
|
MUST implement the `waku2` key with at least one flag set to `true`.
|
|
- Waku nodes that discovered other participants using Discovery v5,
|
|
MUST filter out participant records that do not implement this field or do not have at least one flag set to `true`.
|
|
- In addition, such nodes MAY choose to filter participants on specific flags (such as supported protocols),
|
|
or further interpret the `waku2` field as required by the application.
|
|
|
|
## Copyright
|
|
|
|
Copyright and related rights waived via [CC0](https://creativecommons.org/publicdomain/zero/1.0/).
|
|
|
|
## References
|
|
|
|
- [1](https://github.com/vacp2p/rfc-index/blob/main/waku/standards/core/10/waku2.md)
|
|
- [2](https://github.com/status-im/nim-waku/pull/690)
|
|
- [3](https://github.com/vacp2p/rfc/issues/462#issuecomment-943869940)
|
|
- [4](https://eips.ethereum.org/EIPS/eip-778)
|
|
- [5](https://github.com/ethereum/devp2p/blob/master/discv5/discv5.md)
|