[Leechael]

Problem

An external JS/TS verifier (Node, Electron main, Bun) needs to check a dstack 0.6.x TDX CVM's OS locally, with no hosted service. It already verifies the DCAP quote and replays RTMR3. What it cannot do itself is dstack's lite OS check: vm_config.tdx_measurement against os_image_hash, regenerate the three RTMR0 ACPI digests from vm_config (they depend on QEMU version/settings, vCPU, memory, NICs, verity volumes, GPU/NUMA layout), recompute MRTD/RTMR0-2, and compare with the quote.

dstack-verifier does that check today, but it does not build for wasm32 (tokio, reqwest, tempfile, tar, getrandom). A static table or allowlist does not scale.

Fix

Extract the lite check out of the verifier's &self method into a pure function in dstack-mr, and have dstack-verifier call it. No duplicated logic.

Why dstack-mr rather than a new crate. This is the same split as dstack_mr::sev::verify_sev_launch: measurement math lives in dstack-mr, the service only supplies already-verified MRs. expected_rtmr0_acpi_hashes and tdx_measurements_from_measurement_document already live here. The function adds a cc-eventlog dependency to parse named RTMR0 ACPI DATA events; that crate already builds for wasm32. A new glue crate would only wrap ~100 lines.

Public API:

pub fn verify_tdx_lite_os(
    verified_mrs: &TdxMeasurements,
    event_log: &[TdxEvent],
    vm_config: &VmConfig,
) -> Result<TdxLiteOsCheck>

It does not judge os_image_hash approval, DCAP, or RTMR3.

On top of that function:

• dstack-verifier-wasm: wasm32 cdylib, JSON in/out, zero imports, no wasm-bindgen.
• @phala/dstack-verifier-wasm: ESM, Node >=20.19, wasm bytes embedded in the JS module, synchronous lazy instantiation, .d.ts. Never throws: a trap is caught, the instance recreated, { ok: false } returned. Published as 0.1.0-beta.0 (see Published below).

On an MR mismatch, dstack-verifier's HTTP details.acpi_tables_verified is now false (previously true after the ACPI compare and before the MR compare). is_valid is unchanged (still false). JS osImageHash is non-null only when ok is true.

JS contract (osImageHash only when ok; no acpiTablesVerified):

verifyTdxLiteOs(input: {
  mrtd: string; rtmr0: string; rtmr1: string; rtmr2: string;
  eventLog: string; vmConfig: string;
}): { ok: boolean; osImageHash: string | null; reason: string | null }

MRs are hex (any case). eventLog and vmConfig are the GetQuote strings verbatim.

Verification

• cargo test -p dstack-mr tdx_lite: public tdx-lite-getquote.json fixture accepted; memory_size, pci_hole64_size, hotplug_off, num_nics, cpu_count, qemu_version, an ACPI digest, and RTMR2 tampers rejected.
• cargo test -p dstack-verifier tdx_lite and verifies_real: existing lite fixtures still pass, no image download.
• cargo clippy -p dstack-mr -p dstack-verifier -p dstack-verifier-wasm and --target wasm32-unknown-unknown for the wasm crate.
• Built with the repo toolchain (1.92, wasm32-unknown-unknown), opt-level=z, LTO, panic=abort: 466832 bytes raw, 174830 gzip. WebAssembly.Module.imports is empty.
• JS tests on Node 20.10, Node 24.15, Bun 1.4.4: accept + tamper cases.
• Same check against two real dstack 0.6.1 CVMs on two hosts: QEMU 8.2.2 hotplug on; QEMU 10.1.0 hotplug off, 8 TiB PCI hole. Both accepted; the tampers above rejected with the failing table/register named. ~6 ms first call, ~1 ms after.

Runtime coverage is in .github/workflows/verifier-wasm.yml:

• Node 20.19.0, 22.x, 24.x and Bun 1.x on every relevant run.
• Electron 31.x and current stable (ELECTRON_RUN_AS_NODE plus a real main-process app), and Chromium/Firefox/WebKit via Playwright (page main thread and a module worker), when the PR has label verifier-wasm-runtimes, on workflow_dispatch (runtimes, default true), and on pushes to next / release tags.

Not verified locally: Electron itself, browsers (those run in CI when the label is set).

qemu-user cannot run the x86_64 rustc 1.92.0 (SIGSEGV even with RUST_MIN_STACK=16MiB); wasm verification is linux/amd64 native or an x86_64 VM, not emulated amd64 on arm64.

Published

@phala/dstack-verifier-wasm@0.1.0-beta.0 was published by hand from commit 7f466e2f4cdd0094e47c1dff264cd13ef3839114, using the verifier-wasm-bytes artifact of run 42871855257. Decoded wasm sha256 f25a714e3d7e8febcf0bbfe1629e4801ef273f81034a675750bb98b6e9175c71; wasm-bytes.js sha256 515018bc79a5609533a41685aea665a12902905a31b632ceb491a2bbb3a7b1b1. Manual publish, no provenance. The next release must be 0.1.0-beta.1 or later. Do not push tag verifier-wasm-v0.1.0-beta.0: the release workflow would try to publish a version that already exists.

Releasing

The package exists on npm. A maintainer configures trusted publishing on npmjs.com for @phala/dstack-verifier-wasm:

• Publisher: GitHub Actions
• Organization or user: Dstack-TEE
• Repository: dstack
• Workflow filename: verifier-wasm-release.yml
• Environment: leave empty (the workflow does not use a GitHub Environment)

Optionally disallow token publishing on that package afterwards. Then: merge, bump sdk/verifier-wasm/package.json to a version that is not already on npm (0.1.0-beta.1 or later), push tag verifier-wasm-v<version>.