3.1 Shadow Suite for Linux 的历史(暂不翻译)
3.2 History of the Shadow Suite for Linux
DO NOT USE THE PACKAGES IN THIS SECTION, THEY HAVE SECURITY PROBLEMS
The original Shadow Suite was written by John F. Haugh II.
There are several versions that have been used on Linux systems:
shadow-3.3.1 is the original.
shadow-3.3.1-2 is Linux specific patch made by Florian La Roche and contains some further enhancements.
shadow-mk was specifically packaged for Linux.
The shadow-mk package contains the shadow-3.3.1 package distributed by John F. Haugh II with the shadow-3.3.1-2 patch installed, a few fixes made by Mohan Kokal that make installation a lot easier, a patch by Joseph R.M. Zbiciak for login1.c (login.secure) that eliminates the -f, -h security holes in /bin/login, and some other miscellaneous patches.
The shadow.mk package was the previously recommended package, but should be replaced due to a security problem with the login program.
There are security problems with Shadow versions 3.3.1, 3.3.1-2, and shadow-mk involving the login program. This login bug involves not checking the length of a login name. This causes the buffer to overflow causing crashes or worse. It has been rumored that this buffer overflow can allow someone with an account on the system to use this bug and the shared libraries to gain root access. I won't discuss exactly how this is possible because there are a lot of Linux systems that are affected, but systems with these Shadow Suites installed, and most pre-ELF distributions without the Shadow Suite are vulnerable!
For more information on this and other Linux security issues, see the Linux Security home page (Shared Libraries and login Program Vulnerability)
3.3 如何取得 Shadow Suite？
目前建议 Shadow Suite 版本目前还是 BETA 测试版，然後，最近版本在生产环境是安全的且没有包含易受攻击的 签入(login) 程式。
该套件(package)使用惯例命名为：
shadow-YYMMDD.tar.gz
其中 YYMMDD 是Suite 的发行日期。
目前 BETA 测试版本是 Version 3.3.3 ，且由 Marek Michalkiewicz 维护。
还可以从该处得到： shadow-current.tar.gz.
下列网站也可以找到相关资讯：
ftp://ftp.icm.edu.pl/pub/Linux/shadow/shadow-current.tar.gz
ftp://iguana.hut.fi/pub/linux/shadow/shadow-current.tar.gz
ftp://ftp.cin.net/usr/ggallag/shadow/shadow-current.tar.gz
ftp://ftp.netural.com/pub/linux/shadow/shadow-current.tar.gz
你应该可以获得目前最新的版本。
你应该不要是用比 shadow-960129 更旧版本，因为它们有 签入 的安全问题。
於参考资料方面，我用 shadow-960129 档进行安装介绍。
如果你之前使用 shadow-mk ，你应该更信这个版本且重建编译。
3.4 Shadow Suite包含什麽？
Shadow Suite 包括对下列功能之替代程式：
su, login, passwd, newgrp, chfn, chsh, and id
该套件还包括新程式：
chage, newusers, dpasswd, gpasswd, useradd, userdel, usermod, groupadd, groupdel, groupmod, groups, pwck, grpck, lastlog, pwconv, and pwunconv
除此之外，函式库： libshadow.a 也包括需要存取使用者密码之写和编译程式。
程式之操作手册也包含在其中。
也有对签入程式的 configuration file ，它将被安装在 /etc/login.defs 档。
