Make signature verification customizable in the host module

[tomaka]

cc @xlc
After looking at #2952, I thought that the approach in this PR is a better idea.

As shown in the changes to runtime_host.rs and read_only_runtime_host.rs, you now have a new variant called SignatureVerification that allows you to overwrite the verification if you so desire.

As I was implemented this PR, I noticed that the implementation of ext_crypto_ecdsa_verify loads the message from the first parameter, which is actually the signature. Oops. This is fixed at the same time.

[mergify]

Automatically approving tomaka's pull requests. This auto-approval will be removed once more maintainers are active.

[github-actions]

twiggy diff report

Difference in .wasm size before and after this pull request.

---

 Delta Bytes │ Item
─────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────
      -46751 ┊ smoldot::executor::host::ReadyToRun::run_once::hf7ef020065c87327
      +43446 ┊ smoldot::executor::host::ReadyToRun::run_once::hb561411be6b6648f
       +6498 ┊ smoldot::executor::runtime_host::Inner::run::h00dbc1e8c496721a
       -6425 ┊ smoldot::executor::runtime_host::Inner::run::h9ce8afad44bbbc9e
       +3317 ┊ smoldot::chain::chain_information::build::ChainInformationBuild::from_call_in_progress::h78f133b288650e47
       -3279 ┊ smoldot::chain::chain_information::build::ChainInformationBuild::from_call_in_progress::hc1307e305a6a59b1
       -2433 ┊ smoldot::executor::runtime_host::PrefixKeys::inject_keys_ordered::h03ca3001a3b4e38c
       +2433 ┊ smoldot::executor::runtime_host::PrefixKeys::inject_keys_ordered::h6ae2f62989d2df62
       +2081 ┊ smoldot::executor::host::SignatureVerification::is_valid::h1841d24f16569000
       +1659 ┊ smoldot::executor::read_only_runtime_host::Inner::run::ha0ee4cf62bf56c74
       -1586 ┊ smoldot::executor::read_only_runtime_host::Inner::run::h024988323bc43ea8
       +1202 ┊ smoldot::transactions::validate::Query::from_step1::hc0cf20082d0389d4
       -1177 ┊ smoldot::transactions::validate::Query::from_step1::h343ecc865befbad8
       -1117 ┊ <smoldot::executor::host::Error as core::fmt::Debug>::fmt::h314eed3af6e93936
       +1117 ┊ <smoldot::executor::host::Error as core::fmt::Debug>::fmt::h7499c8a10287db1b
       +1045 ┊ smoldot::executor::runtime_host::StorageGet::inject_value::h13e5f5b9f7f9032d
       -1045 ┊ smoldot::executor::runtime_host::StorageGet::inject_value::ha90296e5300e1ef6
       +1038 ┊ smoldot::transactions::validate::Query::from_step2::h40737ba20899a5e1
       -1007 ┊ smoldot::transactions::validate::Query::from_step2::hb486cd8add5380b8
        -853 ┊ smoldot::executor::host::ExternalStorageGet::resume_vectored::h931bd0a461f3506e
       +3533 ┊ ... and 165 more.
       +2524 ┊ Σ [185 Total Rows]

[tomaka]

I also did ext_crypto_ecdsa_verify_prehashed_version_1, which I had forgotten about.

[xlc]

This is indeed better. Will try integrate this.

[xlc]

Because I am using RuntimeHostVm, so I will need a variant for it to be able to override the verification handling logic

smoldot/src/executor/runtime_host.rs

Line 160 in 6df249e

pub enum RuntimeHostVm {