private ipv6 address identified as public

[marcus-pousette]

• Version:
  1.8.1

• Subsystem:
  dialer, defaultAddressSort

Severity:

Low

Description:

Address

const address = '/ip6/::ffff:7f00:1/tcp/52498/p2p/12D3KooWFp4Uq323R3rF1ukZouXhmai37TejRJwMmsRg9fMM2jjY/p2p-circuit/p2p/12D3KooWPv7ef6tF1PjK1vFzjxW11rpcxp2rHjowtSLU4Xt2CNWP'

evaluates

import { isPrivate } from './multiaddr/is-private.js';

isPrivate(address) 

is false, but expected true?

This makes the default address sorter to prefer this address over other addresses

This one

/ip4/127.0.0.1/tcp/52493/ws/p2p/12D3KooWFp4Uq323R3rF1ukZouXhmai37TejRJwMmsRg9fMM2jjY/p2p-circuit/p2p/12D3KooWPv7ef6tF1PjK1vFzjxW11rpcxp2rHjowtSLU4Xt2CNWP

evaluates to as private correctly

[achingbrain]

Reading RFC4291, the address ::ffff:7f00:1 is an IPv4-Mapped IPv6 Address.

So the ::ffff part marks it as this type of address and the final 32 bits are an IPv4 address.

Add the omitted zeroes and split the octets, and 7f00:1 becomes 7f.00.00.01, which in base 10 is 127.0.0.1.

I think we need to add an extra check in isPrivateIp for this type of address, then convert the final 32 bits to an IPv4 address and test that like the others.

Would you like to open a PR?

[marcus-pousette]

already did :)