getString fails on reload after calling delete with encyptionKey set in config

[morganick]

Steps to reproduce:

• Set the encryptionKey in the config for your MMKV store
• Set a single key in the store
• Reload application to see the value you set pulling from the store with getString
• Remove the key from the store
• Set the single key in the store
• Reload the app with the developer menu
• 💥 Value is undefined
• Close the application
• Open application
• Value appears back on the screen

Conditions to reproduce:

• encryptionKey set in config
• Item being stored is over 253 characters long
• Only one item is stored in MMKV

Minimum Reproducible Example (MRE)

There are instructions in the README for installation:

https://github.com/morganick/mmkv-encryption-app-mre

I've documented permutations in the code that you can make that make it work again:

• https://github.com/morganick/mmkv-encryption-app-mre/blob/main/App.tsx#L14
• https://github.com/morganick/mmkv-encryption-app-mre/blob/main/App.tsx#L21

Video

This happens on both iOS and Android.

iOS 17.4 - iPhone 15 Pro
MMKV_encrypted_single_key_store_delete_reload_bug.mov

Logs

If you use the create-expo-app cli, you'll get MMKV logging in the metro output as follow:

[MMKVEncryptionTestApp] [I] <MMKV_IO.cpp:84::loadFromFile> loading [session] with 0 actual size, file size 16384, InterProcess 0, meta info version:0
[MMKVEncryptionTestApp] [I] <MMKV_IO.cpp:133::loadFromFile> loaded [session] with 0 key-values
[MMKVEncryptionTestApp] [I] <MMKV_IO.cpp:516::writeActualSize> [session] increase sequence to 1, crc 727578001, actualSize 4
iOS Bundled 37ms (node_modules/expo/AppEntry.js)
iOS Bundled 35ms (node_modules/expo/AppEntry.js)
[MMKVEncryptionTestApp] Installing global.mmkvCreateNewInstance...
[MMKVEncryptionTestApp] [W] <libMMKV.mm:76::+[MMKV initializeMMKV:logLevel:handler:]> already called +initializeMMKV before, ignore this request
[MMKVEncryptionTestApp] Installed global.mmkvCreateNewInstance!
[MMKVEncryptionTestApp] [D] <libMMKV.mm:919::+[MMKV mmapKeyWithMMapID:rootPath:]> mmapKey: session
iOS Bundled 37ms (node_modules/expo/AppEntry.js)
iOS Bundled 31ms (node_modules/expo/AppEntry.js)
[MMKVEncryptionTestApp] Installing global.mmkvCreateNewInstance...
[MMKVEncryptionTestApp] [W] <libMMKV.mm:76::+[MMKV initializeMMKV:logLevel:handler:]> already called +initializeMMKV before, ignore this request
[MMKVEncryptionTestApp] Installed global.mmkvCreateNewInstance!
[MMKVEncryptionTestApp] [D] <libMMKV.mm:919::+[MMKV mmapKeyWithMMapID:rootPath:]> mmapKey: session
[MMKVEncryptionTestApp] [E] <MMKV_OSX.cpp:225::getObject> InvalidProtocolBuffer truncatedMessage
iOS Bundled 37ms (node_modules/expo/AppEntry.js)
iOS Bundled 29ms (node_modules/expo/AppEntry.js)
[MMKVEncryptionTestApp] Installing global.mmkvCreateNewInstance...
[MMKVEncryptionTestApp] [W] <libMMKV.mm:76::+[MMKV initializeMMKV:logLevel:handler:]> already called +initializeMMKV before, ignore this request
[MMKVEncryptionTestApp] Installed global.mmkvCreateNewInstance!
[MMKVEncryptionTestApp] [D] <libMMKV.mm:919::+[MMKV mmapKeyWithMMapID:rootPath:]> mmapKey: session
[MMKVEncryptionTestApp] [E] <MMKV_OSX.cpp:225::getObject> InvalidProtocolBuffer truncatedMessage
[MMKVEncryptionTestApp] [I] <MMKV_OSX.cpp:99::setIsInBackground> g_isInBackground:1
[MMKVEncryptionTestApp] [I] <libMMKV.mm:308::+[MMKV didEnterBackground]> isInBackground:1

[!NOTE]
The InvalidProtocolBuffer truncatedMessage shows up in the logs when this breaks.

Special thanks to @frankcalise for being a sounding board while I tracked this down and testing out the MRE.

[scblason]

I have a similar issue with version 2.12.2. Before I was using 2.9.0 and I don't have any issues (and we just updated MMKV, we didn't made any code changes).
But repro steps are similar to the ones mentioned above. The getString fails to get the valid data in an ecrypted store after applying a delete and set operation.
In our case:

• We refresh the app
• We read the store (getString OK)
• We delete the key from the store
• We set a new value for that same key
• We do a getString from that key FAILS

[scblason]

An update on this: I get the same error in 2.9.0. This started to happen when we updated to RN 0.73.x

[Akumzy]

Facing the same issue here

[mrousavy]

Two things:

1. Does this bug also happen when not using encryption?
2. Can you reproduce this in the current example app? This one uses new-arch, react-native-mmkv V3. Please test this.

[Romick2005]

1. It is not happen when not using encryption.

[mrousavy]

Okay gotcha - maybe a bug with encryption. Did you test if react-native-mmkv V3 fixes this issue? (requires new architeceture)

[scblason]

Okay gotcha - maybe a bug with encryption. Did you test if react-native-mmkv V3 fixes this issue? (requires new architeceture)

I tested with latest v3 version and I had the same issue, but I'm not working with the new architecture though

[morganick]

@mrousavy it happens only when encryption is turned on. I pulled in the code from my repro project into the example application, but haven't had a chance to put it through its paces yet. I'll try to get to that this afternoon and report back.

Thanks for your patience 🙇