Add Filecoin custom multihashes?

[jimpick]

Filecoin defines some new multihash codes here:

https://github.com/filecoin-project/go-fil-commcid/blob/05624bdb669c908632a93b826c25e9b579237d65/commcid.go#L20

Should the master list of multihash codes include there?

I tried plugging a PieceCID bafk4chzaammouedlmmvekovrg4ema7lvuj5fzfqdrcycg5vfnrioxxjmo4ta into https://cid.ipfs.io/ and it complained "multihash unknown function code: 0xfc1".

https://cid.ipfs.io/#bafk4chzaammouedlmmvekovrg4ema7lvuj5fzfqdrcycg5vfnrioxxjmo4ta

Also, the ipfs cid tool can't identify the CIDs:

$ ipfs cid format bafk4chzaammouedlmmvekovrg4ema7lvuj5fzfqdrcycg5vfnrioxxjmo4ta -f "%b CIDv%V %h"
base32 CIDv1 hash?4033

[ribasushi]

@jimpick thank you for surfacing this, it actually got lost in my set of notes 🙀 after @rvagg alerted me to it last week
TLDR is this:

• The way go-cid and friends work makes "placeholders" really awkward
  => 0xfc{{X}} was chosen to work around that knowing that these are not the final values
• The final values were settled after a very long back and forth, and are now: feat(multicodecs): add filecoin multicodecs multicodec#161 (comment)

sha2-256-trunc254-padded: 0x1012
poseidon-bls12_381-a2-fc1: 0xb401
poseidon-bls12_381-a2-fc1-sc: 0xb402
fil-commitment-unsealed: 0xf101
fil-commitment-sealed: 0xf102

My understanding is that the plan was to smply fix https://github.com/filecoin-project/go-fil-commcid/blob/master/commcid.go#L18-L24 since these bytes are not anywhere on-chain.

Can you confirm?

[jimpick]

I believe the PieceCIDs are on chain as they are part of the deal proposal.

[ribasushi]

@jimpick I gathered more feedback/history on this, and apparantley the plan was to change the IDs on-chain before mainnet. I opened a PR to start things moving in this direction: filecoin-project/go-fil-commcid#2 (comment)

We will close this ( #129 ) issue once the other PR takes off.

[ribasushi]

@jimpick the new CIDs are now included in https://github.com/filecoin-project/lotus/tree/next
The cid explorer should display the new commX cids correctly on next chain reset

/cc @mikeal @rvagg

[lidel]

Hey folks, where can I find sample CIDs produced by Filecoin?
Want to make sure our GUIs work fine when someone pastes them.
(ok to just paste a sample here in comment)

[ribasushi]

@lidel good catch, it doesn't work 🙀

Not sure where to open an issue for https://cid.ipfs.io/ : just c/p the below testcases where they belong.

baga6ea4seaqggjjfh7whhdoxvhrix6jbcgobmdyhajcimfn33iedcp3kr23gruq ( raw bytes )
baga6ea4seaqidbk23bub2dmg2hur4aawpe44wzuu2lccflgsbcqaokjzjb7wtgi ( raw bytes )
bagboea4b5abcax5zbow3g7cyeg3nsvjguqnjkbdibnhhzc3whinr2sousvoijbrb ( raw bytes )
bagboea4b5abcb245dcsepbaelwd7hrt46itun2mvv5nckntzkg5kf73m2ry4ja7r ( raw bytes )

[vmx]

The source for https://cid.ipfs.io/ is at https://github.com/multiformats/cid-utils-website.

[lidel]

Done:

updated TXT _dnslink.cid.ipfs.io to dnslink=/ipfs/bafybeifuvxkoxxjrjv47qvog26a4iwglmeq4fnnmqxrikc4g4u2ob7jzre

When DNSLink update is applied,

• https://cid.ipfs.io/#bagboea4b5abcb245dcsepbaelwd7hrt46itun2mvv5nckntzkg5kf73m2ry4ja7r

should work the same as

• https://bafybeifuvxkoxxjrjv47qvog26a4iwglmeq4fnnmqxrikc4g4u2ob7jzre.ipfs.dweb.link/#bagboea4b5abcb245dcsepbaelwd7hrt46itun2mvv5nckntzkg5kf73m2ry4ja7r

For IPLD Explorer support see ipld/explore.ipld.io#64