This patch makes curl utilize a gateway for ipfs:// addresses. It prefers a local one but can also use public gateways. It makes no effort to verify that the final product's cryptographic hash corresponds to the one in the address.

This lack of verification is expected with HTTP, but not with IPFS. curl should verify that the resultant output conforms with the IPFS address or else just have users input the gateway/ipfs HTTP address as you always could.

curl can operate in a pipe mode and that adds additional complexity in respect to verification.

IPFS gateways can serve you in a manner that allows continuous(?) verification: <https://docs.ipfs.tech/reference/http/gateway/#trusted-vs-tr...>

This would in theory allow curl to block the pipe until it is able to confirm that a piece that arrived is verified or abort a tampered-with file early. This would take quite a bit of work to implement however - since it seems like there is no maintained IPFS implementation in C: <https://docs.ipfs.tech/concepts/ipfs-implementations>