AtHeartEngineer/specs
1
0
Fork 0
mirror of https://github.com/vacp2p/specs.git synced 2026-01-08 23:08:09 -05:00
Code Issues Packages Projects Releases Wiki Activity

clarify 42 byte rule

Browse Source
This commit is contained in:
Mike Goelzer
2018-10-12 12:28:51 +01:00
parent d8459bcade
commit e2dfbe2207
1 changed files with 14 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
peer-ids/peer-ids.md
View File

@@ -44,6 +44,20 @@ Here is the process by which we generate peer id's based on the public/private k
3. If the length of the serialized bytes <= 42, then we compute the "identity" multihash of the serialized bytes. In other words, no hashing is performed, but the [multihash format is still followed](https://github.com/multiformats/multihash) (byte plus varint plus serialized bytes). The idea here is that if the serialized byte array is short enough, we can fit it in a multihash proto without having to condense it using a hash function.
4. If the length is >42, then we hash it using it using the SHA256 multihash.
For more information, refer to this block in [libp2p/go-libp2p-peer/peer.go](https://github.com/libp2p/go-libp2p-peer/blob/master/peer.go):
```
// MaxInlineKeyLength is the maximum length a key can be for it to be inlined in
// the peer ID.
//
// * When `len(pubKey.Bytes()) <= MaxInlineKeyLength`, the peer ID is the
// identity multihash hash of the public key.
// * When `len(pubKey.Bytes()) > MaxInlineKeyLength`, the peer ID is the
// sha2-256 multihash of the public key.
const MaxInlineKeyLength = 42
```
## How Keys are Encoded and Messages Signed
Four key types are supported: