Can't use vdc cryptfs?

[ervinshiznit]

I've rooted my phone and vdc cryptfs doesn't seem to work. What I'm trying to do is change the disk encryption password to be a nice long password which is NOT the screen unlock PIN (since clearly a long unlock password would be incredibly inconvenient). So I'm following the instructions found at nelenkov's blogspot (can't post links since I'm new here).

When I run the command vdc cryptfs in the terminal as the root user on my OnePlus 3T, I don't get any return code at all. I've also tried apps like Cryptfs Password to try to change the encryption password but they fail. However, when I run vdc cryptfs on my rooted HTC One m7 and Nexus 2013, I do get a return code of "500 0 Missing Argument"

It seems like this command is missing or something from OxygenOS. Does anybody know a workaround?

 

[Jo_Jo_2000]

Are you sure that your device is indeed encrypted?

 

[ervinshiznit]

Yes. Under the Security & Fingerprint menu in the settings, at the bottom it says Encrypted under Encrypt Phone. Furthermore, when booting into TWRP, it prompts me for the disk encryption password. If I don't enter it then data and system aren't mounted (and refuse to mount without the password).

 

[JoeF2]

I know this is an old thread, but the reason for this behavior is most likely that the phone uses file-based encryption. The password you are trying to change is for full-disk encryption, which doesn't exist.
For example, on my new OP 5T, logcat says:

D VoldCryptCmdListener: cryptfs getpw
E Cryptfs : cryptfs_get_password not valid for file encryption

When you set a pin to unlock, does it ask 'Require PIN to start device"? If not, you have file-based encryption.
Once file-based encryption is enabled, it is probably very hard to go back to full-disk encryption. The only way I can see is to reformat /data (and possibly /system), and start unencrypted. Then you could run disk encryption.