feat: add Ethereum MPC keyring by matthiasgeihs · Pull Request #627 · MetaMask/accounts

matthiasgeihs · 2026-09-02T13:54:28Z

Do not merge yet: this PR still vendors MFA wallet packages as local .tgz files under packages/keyring-eth-mpc/. Replace those tarballs with published npm dependencies before merging.

Summary

Add @metamask/eth-mpc-keyring: a 2-party client/server MPC keyring with DKLS23 TSS, cloud backup sync, and vendored MFA wallet libs
Support create/import init, key-share rotate/check/sync, and signing (transactions, personal_sign, typed data, EIP-7702 authorizations)
Replaces the earlier WIP in feat: add MPC keyring #440 with a cleaned history rebased on main

Test plan

yarn workspace @metamask/eth-mpc-keyring test
yarn workspace @metamask/eth-mpc-keyring build
Smoke-check create/import and signing against a staging cloud/relayer if available

Made with Cursor

Introduce a 2-party client/server MPC keyring with DKLS23 TSS, cloud backup sync, and vendored MFA wallet libs. Co-authored-by: Cursor <cursoragent@cursor.com>

Co-authored-by: Cursor <cursoragent@cursor.com>

matthiasgeihs · 2026-09-02T13:54:45Z

Replaces #440 with a cleaned history rebased onto main.

socket-security · 2026-09-02T13:55:31Z

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
@metamask/mfa-wallet-util@0.0.0
@metamask/mfa-wallet-interface@0.0.0
@metamask/mfa-wallet-cl24-lib@0.0.0
@metamask/mfa-wallet-dkls23-lib@0.0.0	N/A	N/A	N/A	N/A	N/A
@metamask/mfa-wallet-e2ee@0.0.0
@metamask/mfa-wallet-network@0.0.0

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socket-security · 2026-09-02T13:55:33Z

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Copy-paste ignore lines for specific packages or a group of one kind with a note on what research you did to deem it safe.
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Action	Severity	Alert (click "▶" to expand/collapse)
Warn		Network access: npm `centrifuge` in module globalThis["fetch"] Module: globalThis["fetch"] Location: Package overview From: packages/keyring-eth-mpc/package.json → `npm/@metamask/mfa-wallet-network@0.0.0` → `npm/centrifuge@5.7.2` ℹ Read more on: This package \| This alert \| What is network access? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at `support@socket.dev`. Suggestion: Packages should remove all network access that is functionally unnecessary. Consumers should audit network access to ensure legitimate use. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment `@SocketSecurity ignore npm/centrifuge@5.7.2`. You can also ignore all packages with `@SocketSecurity ignore-all`. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.
Warn		Potential code anomaly (AI signal): npm `@protobufjs/codegen` is 72.0% likely to have a medium risk anomaly Notes: No direct malicious behavior (e.g., exfiltration, persistence, or credential theft) is evident in this module. However, it is inherently a dynamic code execution utility: it constructs JavaScript source from caller-influenced templates/body and scope, then executes it using the Function constructor. If any upstream input can influence templates or accumulated body, this module can enable code injection/RCE in the caller’s context. Treat as high-risk when used with untrusted data; otherwise it functions as a formatter/codegen helper. Confidence: 0.72 Severity: 0.52 From: packages/keyring-eth-mpc/package.json → `npm/@metamask/mfa-wallet-network@0.0.0` → `npm/@trezor/connect-web@9.6.1` → `npm/@protobufjs/codegen@2.0.5` ℹ Read more on: This package \| This alert \| What is an AI-detected potential code anomaly? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at `support@socket.dev`. Suggestion: An AI system found a low-risk anomaly in this package. It may still be fine to use, but you should check that it is safe before proceeding. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment `@SocketSecurity ignore npm/@protobufjs/codegen@2.0.5`. You can also ignore all packages with `@SocketSecurity ignore-all`. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.
Warn		Potential code anomaly (AI signal): npm `protobufjs` is 61.0% likely to have a medium risk anomaly Notes: The analyzed code segment is a standard RPC service wrapper (protobufjs style) with conventional input validation, encoding/decoding, event emission, and end handling. No malicious behavior is evident, and there are no observable security vulnerabilities beyond ordinary library-level error handling. It does not exhibit data exfiltration, backdoors, or other anti-security patterns. Confidence: 0.61 Severity: 0.55 From: packages/keyring-eth-mpc/package.json → `npm/@metamask/mfa-wallet-network@0.0.0` → `npm/protobufjs@7.6.6` ℹ Read more on: This package \| This alert \| What is an AI-detected potential code anomaly? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at `support@socket.dev`. Suggestion: An AI system found a low-risk anomaly in this package. It may still be fine to use, but you should check that it is safe before proceeding. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment `@SocketSecurity ignore npm/protobufjs@7.6.6`. You can also ignore all packages with `@SocketSecurity ignore-all`. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.

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Co-authored-by: Cursor <cursoragent@cursor.com>

Pass convertV so recovery id 27|28 becomes yParity or EIP-155 v. Co-authored-by: Cursor <cursoragent@cursor.com>

Co-authored-by: Cursor <cursoragent@cursor.com>

cursor

Risk: high. Not approved — this adds a new Ethereum MPC keyring with TSS signing, cloud backup, and vendored MFA libraries, which is above the low-risk approval threshold. Human review is needed.

_{Sent by Cursor Approval Agent: Pull Request Router}

Co-authored-by: Cursor <cursoragent@cursor.com>

Replace backupId with shareEpoch so create/rotate append and activate epochs only after backup readiness, matching the robust MPC architecture. Co-authored-by: Cursor <cursoragent@cursor.com>

Prevent mid-sign rotate/sync from being overwritten by stale Co-authored-by: Cursor <cursoragent@cursor.com> #applyKeyState snapshots from concurrent signing.

matthiasgeihs · 2026-09-03T12:17:59Z

Do not merge yet: this PR still vendors MFA wallet packages as local .tgz files under packages/keyring-eth-mpc/. It should not be merged until those tarballs are replaced with published npm dependencies.

cursor

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, have a team admin enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit e5a53ee. Configure here.}

Pass the create/rotate session nonce to storeKeyShareBackup so a delayed backup from an overwritten retry cannot attach to a newer share. Co-authored-by: Cursor <cursoragent@cursor.com>

## Summary - MPC cloud HTTP calls now send the profile token in an `Authorization: Bearer <token>` header instead of including `token` in JSON request bodies. - The shared `postJson` helper accepts the token as a separate argument and applies it consistently across all MPC backend requests. - Token-only endpoints (`getNetId`, `checkKeyShareBackupId`, `loadKeyShareBackup`) still use POST but now send an empty JSON body (`{}`). ## Test plan - [x] Run `packages/keyring-eth-mpc` unit tests (`cloud.test.ts`) - [x] Verify `getNetId` requests include the Bearer header and send `{}` as the body - [x] Verify sign and backup helpers include the Bearer header and omit `token` from the JSON payload - [ ] Confirm MPC backend accepts Bearer authentication for affected endpoints before merge   --- > [!NOTE] > **Medium Risk** > Auth moves from JSON to Bearer headers across all MPC cloud calls; clients and the backend must agree before deploy or requests will fail. > > **Overview** > MPC cloud HTTP clients no longer put the profile `token` in JSON bodies. **`postJson`** now takes the token separately and sets **`Authorization: Bearer <token>`** on every backend POST. > > Endpoints that previously sent only `{ token }` (**`getNetId`**, **`checkKeyShare`**, **`loadKeyShareBackup`**) now POST **`{}`** with auth in the header. Create/sign/rotate/backup/register calls keep their payloads but drop the **`token`** field. Unit tests in **`cloud.test.ts`** assert the header and that **`body.token`** is absent. > > The unreleased **CHANGELOG** entry is shortened to a single initial-release line (detailed feature bullets removed). > > <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit 400e5b1. Bugbot is set up for automated code reviews on this repo. Configure [here](https://www.cursor.com/dashboard/bugbot).</sup>  --------- Co-authored-by: Matthias Geihs <matthias.geihs@consensys.net>

## Summary - Add a shared `parseJsonResponse` helper in `packages/keyring-eth-mpc/src/cloud.ts` to centralize JSON parsing and non-OK error handling for cloud API responses. - Introduce `getJson` for Bearer-authenticated GET requests and refactor `postJson` to reuse `parseJsonResponse`. - Update `loadKeyShareBackup` to call `getJson` with GET instead of POST with an empty body.   --- > [!NOTE] > **Medium Risk** > Changes the HTTP method for loading encrypted key-share backups; behavior depends on the MPC backend accepting GET on that route. > > **Overview** > Refactors MPC cloud HTTP helpers and fixes how encrypted key-share backups are fetched. > > **`cloud.ts`** adds **`parseJsonResponse`** for shared non-OK handling and JSON/empty-body parsing, introduces **`getJson`** for Bearer-authenticated GETs, and routes **`postJson`** through the same parser (generic renamed to **`Result`**). **`loadKeyShareBackup`** now calls **`getJson`** on `/load-key-share-backup` instead of **`postJson`** with an empty body. > > **`cloud.test.ts`** asserts the backup load uses **GET** with **`Authorization: Bearer`** and no POST body. > > <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit 2690e54. Bugbot is set up for automated code reviews on this repo. Configure [here](https://www.cursor.com/dashboard/bugbot).</sup>  --------- Co-authored-by: Matthias Geihs <matthias.geihs@consensys.net> Co-authored-by: Cursor <cursoragent@cursor.com>

matthiasgeihs and others added 2 commits September 2, 2026 15:41

feat: add Ethereum MPC keyring package

5b1e954

Introduce a 2-party client/server MPC keyring with DKLS23 TSS, cloud backup sync, and vendored MFA wallet libs. Co-authored-by: Cursor <cursoragent@cursor.com>

feat: add EIP-7702 authorization signing to MPC keyring

1027e20

Co-authored-by: Cursor <cursoragent@cursor.com>

matthiasgeihs requested a review from a team as a code owner September 2, 2026 13:54

matthiasgeihs mentioned this pull request Sep 2, 2026

feat: add MPC keyring #440

Closed

cursor Bot requested review from ccharly and hmalik88 September 2, 2026 14:03

cursor Bot reviewed Sep 2, 2026

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Comment thread packages/keyring-eth-mpc/src/mpc-keyring.ts Outdated

Comment thread packages/keyring-eth-mpc/src/mpc-keyring.ts

Comment thread packages/keyring-eth-mpc/src/mpc-keyring.ts

Comment thread packages/keyring-eth-mpc/src/mpc-keyring.ts

matthiasgeihs and others added 4 commits September 2, 2026 16:12

fix: satisfy constraints and changelog checks for MPC keyring

86dfe55

Co-authored-by: Cursor <cursoragent@cursor.com>

fix: apply oxfmt to MPC keyring package files

952442e

Co-authored-by: Cursor <cursoragent@cursor.com>

fix: convert transaction signature v for ethereumjs typed txs

ae37af3

Pass convertV so recovery id 27|28 becomes yParity or EIP-155 v. Co-authored-by: Cursor <cursoragent@cursor.com>

fix: sort root package.json resolutions for oxfmt

faca5e6

Co-authored-by: Cursor <cursoragent@cursor.com>

cursor Bot reviewed Sep 2, 2026

View reviewed changes

matthiasgeihs and others added 2 commits September 2, 2026 16:48

fix: add static type on MPCKeyring for controller registration

68ca3ba

Co-authored-by: Cursor <cursoragent@cursor.com>

fix: dedupe yarn.lock after MPC MFA dependencies

870ccb5

Co-authored-by: Cursor <cursoragent@cursor.com>

matthiasgeihs marked this pull request as draft September 2, 2026 14:50

matthiasgeihs and others added 2 commits September 3, 2026 13:02

feat: use share epochs for MPC create, rotate, and sync

cb37f58

Replace backupId with shareEpoch so create/rotate append and activate epochs only after backup readiness, matching the robust MPC architecture. Co-authored-by: Cursor <cursoragent@cursor.com>

fix: serialize MPC sign, rotate, and sync on one op queue

e5a53ee

Prevent mid-sign rotate/sync from being overwritten by stale Co-authored-by: Cursor <cursoragent@cursor.com> #applyKeyState snapshots from concurrent signing.

matthiasgeihs marked this pull request as ready for review September 3, 2026 12:19

cursor Bot reviewed Sep 3, 2026

View reviewed changes

Comment thread packages/keyring-eth-mpc/src/mpc-keyring.ts

matthiasgeihs and others added 3 commits September 3, 2026 14:42

fix: bind MPC key-share backups to the DKG attempt nonce

f56ee36

Pass the create/rotate session nonce to storeKeyShareBackup so a delayed backup from an overwritten retry cannot attach to a newer share. Co-authored-by: Cursor <cursoragent@cursor.com>

ccharly added the DO-NOT-MERGE PRs related to this issue should not be merged label Sep 10, 2026

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feat: add Ethereum MPC keyring - #627

feat: add Ethereum MPC keyring#627
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