Failed to specify which Dex to parse in a multidex APK

[haeter525]

Hi there!

I currently use Rizin to analyze a multidex APK. I chose this sample (Password: infected) as my target and tried to get data from all its Dex files respectively with command ou. However, an error occurred.

Work environment

Questions	Answers
OS/arch/bits (mandatory)	Ubuntu 22.04
File format of the file you reverse (mandatory)	APK
Architecture/bits of the file (mandatory)	Dalvik
rizin -v full output, not truncated (mandatory)	rizin 0.4.0-git @ linux-x86-64 commit: d8ed585, build: 2022-05-04__02:27:18

Expected behavior

Successfully switch to the specified Dex by using command ou.

Actual behavior

An error occurred as follows.

$> rizin apk://c02bd4289acacf65d9cb70ce42d0ff27.apk 
WARNING: No calling convention defined for this file, analysis may be inaccurate.
 -- Thanks for using rizin!
[0x100966804]> ol
 3 - r-x 0x000dfd24 classes2.dex
 4 * r-x 0x0091fd3c classes.dex
 5 - r-x 0x00006eda vfile://0/reloc-targets
 6 - r-x 0x0000098e vfile://1/reloc-targets
[0x100966804]> ou 3
ERROR: Could not find any opened file with fd 3
[0x100966804]> 

Steps to reproduce the behavior

• Open this sample with Rizin. (Password: infected)
• Run the following commands.

ol
ou 3

[ret2libc]

cc @wargio

[wargio]

I think this is a misusage of rizin.
technically to open just one dex file, you need to call apk://app.apk//classes.dex (be sure to have a // after the extension).

[haeter525]

@wargio. Thanks for the reply!

I tried the path with both commit d8ed585 and the latest commit. But, they all gave the following error.
Have I missed something? Thanks.

$> rizin apk://c02bd4289acacf65d9cb70ce42d0ff27.apk//classes2.dex
WARNING: No calling convention defined for this file, analysis may be inaccurate.
ERROR: Cannot load bin file apk://c02bd4289acacf65d9cb70ce42d0ff27.apk//classes2.dex.
 -- Control the height of the terminal on serial consoles with e scr.height
[0x100046804]> 

[wargio]

that error is weird, why it loads the bin but throws an error?

[wargio]

I can confirm is not a real error, essentially tries to reopen the same file but fails, because it was already opened before.

[ret2libc]

I can confirm is not a real error, essentially tries to reopen the same file but fails, because it was already opened before.

Is it or is it not a real error? I see the message above, but also a PR that says to fix this issue.

[wargio]

no, is just missing a check. i will fix this.