Decryption error on incoming credential

[Didr]

Steps to reproduce (all with wwWallet reference issuer):

1. Issue a PID
2. Issue a Bachelor Diploma
3. As you return to the wallet as the diploma is issued, the frontend breaks apart with the following error:

index-qm0yaUzi.js:79642 JWEDecryptionFailed: decryption operation failed
    at gcmDecrypt$1 (index-qm0yaUzi.js:21525:11)
    at async flattenedDecrypt$1 (index-qm0yaUzi.js:22529:19)
    at async compactDecrypt$1 (index-qm0yaUzi.js:22566:21)
    at async decryptPrivateData (index-qm0yaUzi.js:78280:14)
    at async openPrivateData (index-qm0yaUzi.js:78129:29)
    at async index-qm0yaUzi.js:79640:14
(anonymous) @ index-qm0yaUzi.js:79642Understand this error
index-qm0yaUzi.js:79643 Navigating to login-state to handle JWE decryption failure
index-qm0yaUzi.js:17763 Database initialized successfully
index-qm0yaUzi.js:111284 Database initialized
index-qm0yaUzi.js:79761 Uncaught (in promise) TypeError: object null is not iterable (cannot read property Symbol(Symbol.iterator))
    at index-qm0yaUzi.js:79761:32

4. Notice how the usage counter of the PID is now 0
5. Try issuing another bachelor diploma and notice how it succeeds

This is mostly a note to self right now. I'll add more info when I get the public instance running.

[leifj]

Analysis of Issue #16: Decryption Error on Incoming Credential

Root Cause Identified

The issue occurs in the wallet-frontend repo, specifically in src/api/index.ts in the syncPrivateData function (lines ~314-350).

Current problematic flow:

1. User is in the middle of credential issuance
2. syncPrivateData checks if server has newer private data (ETag comparison)
3. When server data differs (e.g., another device updated), instead of merging:
   • Code navigates to ?sync=fail
   • SyncPopup appears asking user to re-authenticate
   • User clicks Continue → loginWebauthn → finishUnlock (finally does merge)

Why This Is a Problem

• Interrupts credential issuance mid-flow - the OID4VCI state is lost
• User loses context and may need to restart the entire issuance process
• Poor UX for multi-device usage scenarios

The Solution Already Exists

The finishUnlock function in LocalStorageKeystore.ts (lines 334-347) already has proper merge logic:

if (privateData) { // keystore is already opened
    const [localPrivateData, localMainKey] = await assertKeystoreOpen();
    const [remoteContainer, remoteMainKey] = await keystore.openPrivateData(unlockSuccess.mainKey, unlockSuccess.privateData);
    const [localContainer] = await keystore.openPrivateData(localMainKey, localPrivateData);
    const mergedContainer = await mergeEventHistories(remoteContainer, localContainer);
    // ... updates state with merged data
}

Proposed Fix

1. Add a new method syncWithRemoteData(remotePrivateData) to LocalStorageKeystore that:

   • Uses the existing mainKey (keystore is already open) to decrypt remote data
   • Calls mergeEventHistories to merge remote + local
   • Updates state without requiring re-authentication

2. Modify syncPrivateData in api/index.ts to call this new method instead of navigating to ?sync=fail

Implementation is on branch fix/sync-merge-without-reauth in the wallet-frontend repo.

[leifj]

This issue is a frontend bug in the wallet-frontend repository, not in go-wallet-backend. The analysis in the previous comment correctly identifies the fix needed in wallet-frontend/src/api/index.ts.

Closing this issue here - the fix should be tracked in the wallet-frontend repository.

[leifj]

PR already exists upstream: wwWallet/wallet-frontend#1018

The PR has changes requested by @emlun that need to be addressed before merging.