useradd suggests --badname when it won't help (username too long)

[orlitzky]

$ useradd --badname -d "/home/2022.txindependencehealthplan.com" -m "2022.txindependencehealthplan.com"
useradd: invalid user name '2022.txindependencehealthplan.com': use --badname to ignore

[hallyn]

The length check (< 32 characters) is still enforced. If you drop 3 chars from the username, does it then proceed?

[orlitzky]

Yes, but that's the wrong username :)

[orlitzky]

Oh. I was thinking this was a regression from when --badnames had an "s" on it, but looking back at my notes, the --badnames was used only to allow the username to begin with a "2". The length was still a problem that I had to hack around in /etc/passwd, /etc/group, and /etc/shadow last year.

For something constructive... I suppose useradd shouldn't tell me to use --badname if it won't help?

[hallyn]

Oh. I was thinking this was a regression from when --badnames had an "s" on it, but looking back at my notes, the --badnames was used only to allow the username to begin with a "2". The length was still a problem that I had to hack around in /etc/passwd, /etc/group, and /etc/shadow last year.

For something constructive... I suppose useradd shouldn't tell me to use --badname if it won't help?

Indeed, that's an unfortunate mis-direction.

[orlitzky]

I'm not sure if I changed something or if you changed something, but I noticed today that...

# useradd awsdlkfjawklegfhjskdjhfgsjkidfhgjksdkasdjhflasjdhgkjsdhfgklshdfkghdf

apparently works fine:

# tail -n1 /etc/passwd
awsdlkfjawklegfhjskdjhfgsjkidfhgjksdkasdjhflasjdhgkjsdhfgklshdfkghdf:x:1001:1001::/home/awsdlkfjawklegfhjskdjhfgsjkidfhgjksdkasdjhflasjdhgkjsdhfgklshdfkghdf:/bin/bash

(this is with shadow-4.14.2 on Gentoo). If the length limit is gone, then this issue is resolved.

[ikerexxe]

The username length limit has been moved to 256 to align with the kernel limit.

[orlitzky]

Thanks, I see it now in lib/chkname.c. Should https://github.com/shadow-maint/shadow/blob/master/man/useradd.8.xml#L730 be updated?

While you have to try a lot harder (at least on linux), I guess this suggestion is still misleading:

seradd: invalid user name 'wdfhaslkdghaskldhjklsadhgkljshdfkljghsdklfhgjksdhfgjklhsdlfkghskldfhgkljsdhfgklhsdklfghklsdfhgklshdfklghsdklfhgklshdfklghsdklfhgklsdhfgklhsdeklfjghsdklfhgklsdhfgkljhsdklfjghskldfhgksdhfgklhsdlkfghsdklfhglksdhfgklhsdfghoerhowthpqw39oejdgfneongfweuprhgwu9efnjgvpfuioehgnwerujghnweuiognweurgnwpeorngwernhwpernhpwernvpenwrpgnweprnhwwegnwonvcweiorngoe': use --badname to ignore

[ikerexxe]

Opened #986 to update it