Arch Linux

Waan

Member

Registered: 2019-12-25

Posts: 30

[Solved] Long username

32 characters seems to be the max for setting new username on Arch Linux.
Example # useradd -m 12345678901234567890123456789012

Is it possible that picking username that long, would cause any problems?

Last edited by Waan (2020-01-10 01:26:48)

sabroad

Member

Registered: 2015-05-24

Posts: 242

Re: [Solved] Long username

Is it possible that picking username that long, would cause any problems?

Yes- some user sockets are stored in the homedir, and these have max filepath length of 108 characters.

Example issue Flatpak: socket path too long if username is longer than 17 characters.

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saint_abroad

Waan

Member

Registered: 2019-12-25

Posts: 30

Re: [Solved] Long username

Is it possible that picking username that long, would cause any problems?

Yes- some user sockets are stored in the homedir, and these have max filepath length of 108 characters.

Example issue Flatpak: socket path too long if username is longer than 17 characters.

Then i wonder, why it is possible to set 32 characters username on Arch?
Is it worth reinstall of the entire system because i have 32 character usernames? Or should i simply # userdel
Not that i care much about security, but still, does having a long username that exceeds the maximum characters opens security holes?
Sorry for my newbie question.

sabroad

Member

Registered: 2015-05-24

Posts: 242

Re: [Solved] Long username

i wonder, why it is possible to set 32 characters username on Arch?

It's only the useradd utility that has a 32-character limit. Linux itself supports usernames up to 256 characters.

Is it worth reinstall of the entire system because i have 32 character usernames?

No- and certainly not if the potential issues don't affect you (eg. you don't use Virt-Manager Flatpak).

Not that i care much about security, but still, does having a long username that exceeds the maximum characters opens security holes?

Vulnerabilities for long usernames will happen whether you have long usernames or not. No reason to be concerned (unless you're interested in fixing things).

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saint_abroad

WorMzy

Administrator

From: Scotland

Registered: 2010-06-16

Posts: 13,405

Website

Re: [Solved] Long username

You'll need to ask upstream(s) why username limits exist and/or have been arbitrarily added to certain utilities. They are not added or set by Arch.

Is it worth reinstall of the entire system because i have 32 character usernames?

No. Why do you think reinstalling is even worth considering?

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Waan

Member

Registered: 2019-12-25

Posts: 30

Re: [Solved] Long username

Like they said on Gentoo Forums: "You only install Gentoo once"
I actually can not think of a reason to reinstall.

CarbonChauvinist

Member

Registered: 2012-06-16

Posts: 413

Website

Re: [Solved] Long username

I actually can not think of a reason to reinstall.

I actually can not think of a reason to have a 32 character user name. Is this a purely academic exercise?

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"the wind-blown way, wanna win? don't play"

Waan

Member

Registered: 2019-12-25

Posts: 30

Re: [Solved] Long username

I actually can not think of a reason to have a 32 character user name. Is this a purely academic exercise?

No