feat(user-storage-controller): use deferred promises cache for KDF operations #6736

mathieuartu · 2025-09-26T15:38:38Z

Explanation

- Use deferred promises for encryption/decryption KDF operations ([#6736](https://github.com/MetaMask/core/pull/6736))
  - That will prevent duplicate KDF operations from being computed if one with the same options is already in progress.
  - For operations that already completed, we use the already existing cache.

This improves startup performance on mobile by ~70%; going from an average of ~6s to an average of ~2s for the time it takes to derive the key.

References

Fixes: https://consensyssoftware.atlassian.net/browse/MUL-1100

Checklist

I've updated the test suite for new or updated code as appropriate
I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
I've communicated my changes to consumers by updating changelogs for packages I've changed, highlighting breaking changes as necessary
I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes

Note

Deduplicates concurrent scrypt KDF operations via a bounded promise cache, adds concurrency/eviction tests, and updates changelog.

Encryption (src/shared/encryption):
- encryption.ts: Add deferred KDF promise cache to avoid duplicate scrypt derivations; cap size using MAX_KDF_PROMISE_CACHE_SIZE; add cache-key generation and #performKdfOperation helper; minor refactors to use salt consistently.
- constants.ts: Add MAX_KDF_PROMISE_CACHE_SIZE.
Tests:
- encryption.test.ts: Add concurrent encrypt/decrypt tests (same/different passwords), load tests, and cache size eviction test.
Changelog:
- Note use of deferred promises for KDF to prevent duplicate work.

^{Written by Cursor Bugbot for commit 3b179d1. This will update automatically on new commits. Configure here.}

…erations

packages/profile-sync-controller/src/shared/encryption/encryption.ts

fabiobozzo

LGTM 👏 Let's make KDF work as fast as 🚀 And one day we'll merge #6097 too hopefully, I remember that PR eheh

Tlees-MMI · 2025-09-26T19:22:23Z

@fabiobozzo lol we'll make sure to get it in the first RC after BIP-44!

gantunesr

Looks good, will approve after the comments are resolved

packages/profile-sync-controller/src/shared/encryption/encryption.test.ts

ccharly · 2025-09-29T09:04:21Z

packages/profile-sync-controller/src/sdk/user-storage.test.ts

 import { SHARED_SALT } from '../shared/encryption/constants';
 import { Env } from '../shared/env';
 import { USER_STORAGE_FEATURE_NAMES } from '../shared/storage-schema';
+import type { UserStorageGenericFeatureKey } from 'src/shared/storage-schema';


Shouldn't this be ../shared/storage-schema? I guess src/... probably works too

ccharly · 2025-09-29T09:05:43Z

packages/profile-sync-controller/src/shared/encryption/encryption.test.ts

+      const results = await Promise.all(promises);
+      expect(results).toHaveLength(numOperations);
+
+      // Verify a sampling of results can be decrypted (testing all 25 would be slow)


Nit:

Suggested change

// Verify a sampling of results can be decrypted (testing all 25 would be slow)

// Verify a sampling of results can be decrypted (testing 25 would be slow)

## Explanation Release for `@metamask/profile-sync-controller` & `@metamask/multichain-account-service`. ```md ## [25.1.0] ### Changed - Use deferred promises for encryption/decryption KDF operations ([#6736](#6736)) - That will prevent duplicate KDF operations from being computed if one with the same options is already in progress. - For operations that already completed, we use the already existing cache. - Bump `@metamask/utils` from `^11.8.0` to `^11.8.1` ([#6708](#6708)) - Bump `@metamask/keyring-api` from `^20.1.0` to `^21.0.0` ([#6560](#6560)) - Bump `@metamask/keyring-internal-api` from `^8.1.0` to `^9.0.0` ([#6560](#6560)) - Strip `srpSessionData.token.accessToken` from state logs ([#6553](#6553)) - We haven't started using the `includeInStateLogs` metadata yet in clients, so this will have no functional impact. This change brings this metadata into alignment with the hard-coded state log generation performed by clients.today. - Add dependency on `@metamask/utils` ([#6553](#6553)) - Bump `@metamask/base-controller` from `^8.3.0` to `^8.4.0` ([#6632](#6632)) ``` ## References  ## Checklist - [x] I've updated the test suite for new or updated code as appropriate - [x] I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate - [x] I've communicated my changes to consumers by [updating changelogs for packages I've changed](https://github.com/MetaMask/core/tree/main/docs/contributing.md#updating-changelogs), highlighting breaking changes as necessary - [ ] I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes  --- > [!NOTE] > Releases core 589.0.0, publishing @metamask/profile-sync-controller 25.1.0 and @metamask/multichain-account-service 1.3.0, and bumps dependent packages and changelogs. > > - **Release**: `@metamask/core-monorepo` to `589.0.0`. > - **Packages**: > - `@metamask/[email protected]` > - Use deferred promises for KDF operations; update deps and strip `srpSessionData.token.accessToken` from state logs. > - `@metamask/[email protected]` > - Add `{Btc, Trx}AccountProvider`; update compare links. > - **Deps Bumped**: > - Update references to `@metamask/profile-sync-controller` to `^25.1.0` in `account-tree-controller`, `notification-services-controller`, `subscription-controller`, and lockfile. > - Update references to `@metamask/multichain-account-service` to `^1.3.0` in `assets-controllers`, `account-tree-controller`, and lockfile. > - **Changelogs**: > - Add Unreleased note for `assets-controllers` reflecting `multichain-account-service` bump. > - Add `1.3.0` section and links in `multichain-account-service`. > - Add `25.1.0` section and links in `profile-sync-controller`. > > <sup>Written by [Cursor Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit 88351ca. This will update automatically on new commits. Configure [here](https://cursor.com/dashboard?tab=bugbot).</sup>  --------- Co-authored-by: Antonio Regadas <[email protected]>

feat(user-storage-controller): use deferred promises cache for KDF op…

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mathieuartu self-assigned this Sep 26, 2025

mathieuartu added the team-accounts label Sep 26, 2025

mathieuartu added 2 commits September 26, 2025 17:58

fix: restore old salt comparison code

3172e1e

Merge branch 'main' into feat/user-storage-encryption-kdf-deferred

3460e49

mathieuartu marked this pull request as ready for review September 26, 2025 16:01

mathieuartu requested review from a team as code owners September 26, 2025 16:01

fabiobozzo reviewed Sep 26, 2025

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fix: add cache size limit for kdf promises

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mathieuartu dismissed fabiobozzo’s stale review via 309edae September 29, 2025 07:32

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Merge branch 'main' into feat/user-storage-encryption-kdf-deferred

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fix: address PR comments

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fix: use max kdf cache size directly from constants

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ccharly reviewed Sep 29, 2025

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fix: revert unwanted change

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Merge branch 'main' into feat/user-storage-encryption-kdf-deferred

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mathieuartu merged commit 947355c into main Sep 29, 2025
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mathieuartu deleted the feat/user-storage-encryption-kdf-deferred branch September 29, 2025 09:44

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feat(user-storage-controller): use deferred promises cache for KDF operations #6736

feat(user-storage-controller): use deferred promises cache for KDF operations #6736

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mathieuartu commented Sep 26, 2025 •

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	// Verify a sampling of results can be decrypted (testing all 25 would be slow)
	// Verify a sampling of results can be decrypted (testing 25 would be slow)

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feat(user-storage-controller): use deferred promises cache for KDF operations #6736

feat(user-storage-controller): use deferred promises cache for KDF operations #6736

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mathieuartu commented Sep 26, 2025 •

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