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Hostnames and usernames to reserve

ldpreload.com

1–10 of 25 posts

Re: Hostnames and usernames to reserve

#5
post #2

The article looks great and makes many good points, but I'll pick on one: why disallow upper case letters from usernames?

Email addresses and domain names are case-ignoring so you should never allow usernames that differ only in case. Allowing only lower case is an easy way to do this.

Re: Hostnames and usernames to reserve

#6
post #5
post #2

The article looks great and makes many good points, but I'll pick on one: why disallow upper case letters from usernames?

Email addresses and domain names are case-ignoring so you should never allow usernames that differ only in case. Allowing only lower case is an easy way to do this.

The username part of an email address can actually be case sensitive, and this has been known to cause problems with some systems (e.g. https://airmail.tenderapp.com/help/discussions/287/113-case-...).

Re: Hostnames and usernames to reserve

#7
When github used to host "pages" under github.com I remember registering "blog.github.com" (and reporting obviously). If you take the social-engineering into account the list should be made long: login, support, status, help, ...

Just to say, the list could be made much longer (eg: login)

Re: Hostnames and usernames to reserve

#9
Thanks, this was very informative.

I wonder how the pull requests for the public suffix domains are being checked. Can somebody use it as an attack surface by adding the victim's domain in that list and effectively blocking their website from setting cookies?

Re: Hostnames and usernames to reserve

#10
post #5

Earlier quoted context omitted.

Email addresses and domain names are case-ignoring so you should never allow usernames that differ only in case. Allowing only lower case is an easy way to do this.

The username part of an email address can actually be case sensitive, and this has been known to cause problems with some systems (e.g. https://airmail.tenderapp.com/help/discussions/287/113-case-... ).

Yes, and its a pain in the butt error to track down. I was helping a friend with an old postfix / cyrus server with some custom software and case sensitivity was the final cause of bad mail delivery. Gotta love the combo of a bad config and an old mainframe app sending in all uppercase.
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