Alejandro ColomarandIker Pedrosa
6adaa40135
There's been a very long and interesting discussion in linux-man@ and libc-alpha@, where we've discussed all the string-copying functions, their pros and cons, when should each be used and avoided, etc. Paul Eggert pointed out an important problem of strlcpy(3): it is vulnerable to DoS attacks if an attacker controls the length of the source string. And even if it doesn't control it, the function is dead slow (because its API forces it to calculate strlen(src)). We've agreed that the general solution for a truncating string-copying function is to write a wrapper over strnlen(3)+memcpy(3), which is limited to strnlen(src, sizeof(dst)). This is not vulnerable to DoS, and is very fast for all buffer sizes. string_copying(7) has been updated to reflect this, and provides a reference implementation for this wrapper function. This strtcpy(3) (t for truncation) wrapper happens to have the same API that our strlcpy_() function had, so replace it with the better implementation. We don't need to update callers nor tests, since the API is the same. A future commit will rename STRLCPY() to STRTCPY(), and replace remaining calls to strlcpy(3) by calls to this strtcpy(3). Link: <https://lore.kernel.org/linux-man/ZU4SDh-Se5gjPny5@debian/T/#mfb5a3fdeb35487dec6f8d9e3d8548bd0d92c4975/> Signed-off-by: Alejandro Colomar <alx@kernel.org>
shadow-utils
Introduction
The shadow-utils package includes the necessary programs for converting UNIX password files to the shadow password format, plus programs for managing user and group accounts. The pwconv command converts passwords to the shadow password format. The pwunconv command unconverts shadow passwords and generates a passwd file (a standard UNIX password file). The pwck command checks the integrity of password and shadow files. The lastlog command prints out the last login times for all users. The useradd, userdel, and usermod commands are used for managing user accounts. The groupadd, groupdel, and groupmod commands are used for managing group accounts.
Sites
Code
The main development branch is at https://github.com/shadow-maint/shadow.git
See STABLE.md for a list of supported stable branches.
Contacts
There are several ways to contact us:
- the general discussion mailing list
- the #shadow IRC channel on libera.chat:
- irc://irc.libera.chat/shadow
Mailing archives
- the general discussion mailing list archive
- the commit mailing list archive, only used for historical purposes
Contributions
Contributions are welcome. Follow the guidelines before posting any patches.
Authors and maintainers
Authors and maintainers are listed in AUTHORS.md.