[SailfishDevel] Where did devel-su come from and what's its purpose?

[Mehdi El Gueddari]

Hi,

I'm been googling long and hard but haven't been able to find much
information about the 'devel-su' command, beyond the fact that it's the
command to use on Sailfish to switch to the root user. I also couldn't find
the source code for it anywhere.

If there is someone with more insider knowledge here, I'd love to hear
about where this command came from and how it differs from 'su'.

The first mentions of 'devel-su' I've been able to find were from 2011 in
relation to MeeGo. I couldn't find any information about why this command
was created for MeeGo though. It may have been related to MeeGo's security
platform Aegis (part of the Mobile Simplified Security Framework it seems)
but there's precious little information about Aegis or MSSF out there.

Back in the Meego days, 'devel-su' would let you switch to, quite
literally, a developer super user account, which had more privileges than a
normal user but wasn't quite root (or at least it seems that way from the
few user complaints I could find).

Sailfish is very different however. There's no Aegis there. The 'devel-su'
command lets you switch to the real root user and gives you full root
access to your device. In fact, once you're root, you can just reset the
root user password (which appears to not be set or be set to a random value
by default) and then just use the 'su' command normally instead of
'devel-su' (
https://together.jolla.com/question/30565/howto-using-su-instead-of-devel-su/
).

So why 'devel-su' then?

AFAICS, one difference between 'su' and 'devel-su' is that 'devel-su'
checks the password set in the device's Developer Mode settings instead of
using the normal root password. So you can disable root login via
'devel-su' or change the 'devel-su' password there.

Any insider info would be greatly appreciated :)

Mehdi
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