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points by boomlinde 2 days ago | 0 comments
> Check the GNU libc crypt() doco. It defines a whole family of 'impossible' values that signal errors, by dint of listing a load of magic characters that should never be in the encrypted string. Including asterisk.

No. https://man7.org/linux/man-pages/man3/crypt.3.html

My guess is that you are reading the libxcrypt crypt(3) manual: https://www.mankier.com/3/crypt

That's not GNU libc, but frequently deployed on Linux systems.

[–] JdeBP 2 days ago
Well caught. I was reading what man -s 3 crypt brought up, which mentions GNU and -lcrypt and only right at the very bottom says something else.

* https://manpages.debian.org/trixie/libcrypt-dev/crypt.3.en.h...

Although that's a fine distinction for the point being made, as it's still the manual page for the crypt() function that one gets on the operating system, which that other manual page is not.

[–] boomlinde 1 day ago
That naturally depends on the operating system and the crypt implementation they include.
[–] JdeBP 1 day ago
Not really. For Linux-based operatings systems, the GNU libc manual cryptography section is a shadow of its former self. It has no crypt() function to accompany it any more, and has not had since 2023.

* https://sourceware.org/git/?p=glibc.git;a=commit;h=e6e3c6668...

Notice that Debian didn't list your manual page, which doesn't accompany a crypt() function at all, since it isn't actually the GNU libc manual but a separate independent manual for Linux. The GNU libc manual nowadays acknowledges Michael Glad's work but no longer documents crypt(). It used to, and it used to explain some of the 'impossible' encrypted string values:

* https://sourceware.org/glibc/manual/2.38/html_node/Passphras...

You noticed that I'd not got the GNU libc manual. Neither had you. (-: