iOS AutoFill shows "no matching entries" when vault has more than ~100 items
AutoFill stops working on iOS once the vault grows beyond roughly 100 items. With a smaller vault it works as expected.
Environment
Device: iPhone 16 Pro
App: PearPass Mobile v2.1.0
iOS version: 27.0.1
Steps to reproduce
Have a vault with ~160 items (the main vault).
Open any app or website with a login form and tap the password field.
Trigger the AutoFill / Passwords suggestion and choose PearPass.
Actual behavior The AutoFill UI immediately reports that no matching entries were found and suggests nothing, even though matching entries exist in the vault.
Expected behavior Matching entries are suggested and can be used to fill credentials.
Additional observations
I created a second vault and deleted entries until it had 97 items. AutoFill worked correctly with that vault.
The main vault has ~160 items and AutoFill fails every time.
The exact threshold is unknown, but the failure appears somewhere around 100 items.
The in-app experience (opening the vault, viewing entries) works normally. Only the AutoFill extension is affected.
Possible cause (hypothesis) iOS limits the memory available to AutoFill extensions, and exceeding it can cause the extension to be killed or to fail silently. The KeePass documentation describes a similar limitation: https://keepass.info/help/base/security.html (section "Argon2 on iOS"). It notes that if an app uses a lot of RAM (e.g. a large Argon2 memory parameter), AutoFill may not work, and recommends lower memory values (64 MB or less, depending on the app and database size) with more iterations.
It's possible that PearPass hits a similar memory limit in the AutoFill extension, either due to the KDF parameters or because the whole vault is decrypted/loaded into memory, so that the limit is reached as the number of entries grows.
Questions / suggestions
Is there a known memory limit or entry-count limit for the AutoFill extension? Could the extension load and decrypt entries lazily or filter by domain before decrypting everything? Could the extension log or surface an error instead of silently reporting "no matching entries"?
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Comments1
Dotpwnpewpew
Oct 2
iOS AutoFill shows "no matching entries" when vault has more than ~100 items
AutoFill stops working on iOS once the vault grows beyond roughly 100 items. With a smaller vault it works as expected.
Environment
Device: iPhone 16 Pro
App: PearPass Mobile v2.1.0
iOS version: 27.0.1
Steps to reproduce
Have a vault with ~160 items (the main vault).
Open any app or website with a login form and tap the password field.
Trigger the AutoFill / Passwords suggestion and choose PearPass.
Actual behavior The AutoFill UI immediately reports that no matching entries were found and suggests nothing, even though matching entries exist in the vault.
Expected behavior Matching entries are suggested and can be used to fill credentials.
Additional observations
I created a second vault and deleted entries until it had 97 items. AutoFill worked correctly with that vault.
The main vault has ~160 items and AutoFill fails every time.
The exact threshold is unknown, but the failure appears somewhere around 100 items.
The in-app experience (opening the vault, viewing entries) works normally. Only the AutoFill extension is affected.
Possible cause (hypothesis) iOS limits the memory available to AutoFill extensions, and exceeding it can cause the extension to be killed or to fail silently. The KeePass documentation describes a similar limitation: https://keepass.info/help/base/security.html (section "Argon2 on iOS"). It notes that if an app uses a lot of RAM (e.g. a large Argon2 memory parameter), AutoFill may not work, and recommends lower memory values (64 MB or less, depending on the app and database size) with more iterations.
It's possible that PearPass hits a similar memory limit in the AutoFill extension, either due to the KDF parameters or because the whole vault is decrypted/loaded into memory, so that the limit is reached as the number of entries grows.
Questions / suggestions
Is there a known memory limit or entry-count limit for the AutoFill extension? Could the extension load and decrypt entries lazily or filter by domain before decrypting everything? Could the extension log or surface an error instead of silently reporting "no matching entries"?