Error "Encountered an error reading input data" when decrypting files created by gpg4win

[gator2000]

Expected Behavior

I first reported this issue as a comment on issue #1687. @dschuermann suggested I opened a separate issue.
The issue is as follows:
I encrypt a file on Windows, using gpg4win. I've tried both with text files and binary files, and I see the same behavior: when I decrypt with OpenKeychain on Android, the decryption phase works fine, and ends with "Unknown filename (touch to open)". But when I touch to go ahead, I get an Android popup saying "Decrypt with OpenKeychain" popup. This seems to invoke OpenKeychain on the decrypted file, and that fails with an error "Encountered an error reading input data".
I'm attaching 4 screenshots. Two of them are the popups, and the other two are the logs from the two invocations to OpenKeychaing (the original and the nested one)
drive-download-20170429T142514Z-001.zip

Current Behavior

The decryption of any file encrypted with gpg4win, results in a nested invocation of OpenKeychain from within OpenKeychain. The top level invocation succeeds, but the nested one fails with "Encountered an error reading input data". As a result I can't see or save the decrypted file.

Possible Solution

It seems to me that after proceeding from "Unknown filename (touch to open)", OpenKeychain is calling some Android action that triggers the nested invocation. Maybe it's trying to save the file using ".asc" or ".pgp" extension?

Steps to Reproduce (for bugs)

Hopefully the attached screenshots help. Let me know if I can provide anything else.
If you provide a key, I could encrypt a file for you using gpg4win, so that you can reproduce.

Context

I'm simply trying to keep encrypted files in Google drive that I can decrypt on my phone.

Your Environment

• Android Version:
  6.0.1
• OpenKeychain Version:
  4.3
• From Google Play or F-Droid?:
  Google Play

[Valodim]

Thanks for the report. My first intuition is that the file has no metadata whatsoever, so openkeychain doesn't know what to do with it.

Please encrypt a file for 0xdeadfa11, and send to look@my.amazin.horse

[gator2000]

I that your github user?
I tried getting they key using:
wget https://github.com/0xDEADFA11.keys

but get an empty file.
Guessing I'm missing something obvious

[Valodim]

That's my pgp key id :)

[gator2000]

I had not been using key servers so far. Now I have :)
OK, so I've imported your key and encrypted a few files using my key and yours. For most text files, the decryption using OpenKeychain works fine. It fails for any binary file. And it also fails for some text files.
I guess there are some heuristics to determine when a file is text, which do not work for some files.
I'm attaching two files, Good.txt.asc and Bad.docx.asc. The former decrypts fine, the seconds one fails.

If your intuition is about the problem being the lack of metadata is right, couldn't the behavior be such that in the absence of metadata, decrypted files be saved using generated names. for example, Unknown1, Unknown2, etc. After all, OpenKeychain does manage to decrypt the files. It's only the nested invocation that fails after OpenKeychain decides the file is not text.
Thanks for looking into the issue.

files.zip

[gator2000]

Oops, I closed the issue by mistake. Reopening.

[msfjarvis]

This was reported on APS last week and the root cause seems to be incompatibility between OpenKeychain and GnuPG 2.3.x. Both users who downgraded from GnuPG 2.3.x to GnuPG 2.2.x reported they no longer faced decryption failure.

[detwiler]

This Keybase issue seems related, and following the steps in this comment fixed both Keybase and OpenKeychain for me.

[lduktus]

This Keybase issue seems related, and following the steps in this comment fixed both Keybase and OpenKeychain for me.

Not sure if it is related to this bug, but I had the same error message with Password Store. I tried the fix in the mentioned comment, but it didn't work in my case.
I am using GPG 2.3.3. OpenKeyChain is Version 5.7.5 on Android 11. I didn't try to downgrade GPG.

[SebastianErfort]

I found following the answers here fixed the problems for me. Using GnuPG 2.3.4 I had to re-encrypt my .gpg files with the option --no-throw-keyids, then OpenKeychain was able to read them. Of course this is only a work-around and it would be nice to see a fix.

[rahilarious]

This Keybase issue seems related, and following the steps in this comment fixed both Keybase and OpenKeychain for me.

Thank you for this. it seems after running command gpg --list-packets on both openable-by-okc and non-openable-by-okc files, I came to conclusion that :aead encrypted packet is the problem. AEAD doesn't work with OKC

[Discere8]

I too have observed that Key Pairs created on gpg4win do not work on OpenKeyChain and Key Pairs created on OpenKeyChain do not work on gpg4win.

I understand that in order to be secure there has to be a Robust process to key creation, export, import, encryption, and decryption; however, I am relatively computer literate and I have found this attempt at cross platform file sharing, (Windows to Android and Android to Windows) to be extremely frustratingly difficult. The average Windows and Android user would not even try this again after the problem is fixed. If software developers hope to see their products used by more than a small cadre of coders, there has to be a more streamlined method for sharing keys between pc and smartphone.

Please fix this issue as soon as practicable.

Many thanks.

[qknight]

I think I've hit the same issue but with using 'Android Password Store' which is using OKC.

• Secrets created on windows can't be decrypted with 'Password Store'
• However, secrets created with the 'Password Store' can be opened on windows.

So what can I do now?

gpg windows

PS C:\Users\joschie\Desktop\Projects> gpg --version
gpg (GnuPG) 2.4.3
libgcrypt 1.10.2
Copyright (C) 2023 g10 Code GmbH
License GNU GPL-3.0-or-later <https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: C:\Users\joschie\AppData\Roaming\gnupg
Unterstützte Verfahren:
Öff. Schlüssel: RSA, ELG, DSA, ECDH, ECDSA, EDDSA
Verschlü.: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
           CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Komprimierung: nicht komprimiert, ZIP, ZLIB, BZIP2

openkeychain android

Versiohn 5.8.2 (58902)