%general-entities; ]> shadow &shadow-version;

&shadow-url;

Shadow If you would like to enforce the use of strong passwords, refer to for installing CrackLib prior to building Shadow. Then add --with-libcrack to the configure command below. Disable the installation of the groups program and its man pages, as Coreutils provides a better version. Also, prevent the installation of manual pages that were already installed in : sed -i 's/groups$(EXEEXT) //' src/Makefile.in find man -name Makefile.in -exec sed -i 's/groups\.1 / /' {} \; find man -name Makefile.in -exec sed -i 's/getspnam\.3 / /' {} \; find man -name Makefile.in -exec sed -i 's/passwd\.5 / /' {} \; Instead of using the default crypt method, use the more secure SHA-512 method of password encryption, which also allows passwords longer than 8 characters. It is also necessary to change the obsolete /var/spool/mail location for user mailboxes that Shadow uses by default to the /var/mail location used currently: sed -e 's:#ENCRYPT_METHOD DES:ENCRYPT_METHOD SHA512:' \ -e 's:/var/spool/mail:/var/mail:' \ -i etc/login.defs If you chose to build Shadow with Cracklib support, run the following: sed -i 's:DICTPATH.*:DICTPATH\t/lib/cracklib/pw_dict:' etc/login.defs Make a minor change to make the first group number generated by useradd 1000: sed -i 's/1000/999/' etc/useradd Prepare Shadow for compilation: touch /usr/bin/passwd ./configure --sysconfdir=/etc \ --with-group-name-max-length=32 touch /usr/bin/passwd The file /usr/bin/passwd needs to exist because its location is harcoded in some programs, and the default location if it does not exist is not right. --with-group-name-max-length=32 The maximum user name is 32 characters. Make the maximum group name the same. Compile the package: make This package does not come with a test suite. Install the package: make install Shadow configuring This package contains utilities to add, modify, and delete users and groups; set and change their passwords; and perform other administrative tasks. For a full explanation of what password shadowing means, see the doc/HOWTO file within the unpacked source tree. If using Shadow support, keep in mind that programs which need to verify passwords (display managers, FTP programs, pop3 daemons, etc.) must be Shadow-compliant. That is, they need to be able to work with shadowed passwords. To enable shadowed passwords, run the following command: pwconv To enable shadowed group passwords, run: grpconv Shadow's stock configuration for the useradd utility has a few caveats that need some explanation. First, the default action for the useradd utility is to create the user and a group of the same name as the user. By default the user ID (UID) and group ID (GID) numbers will begin with 1000. This means if you don't pass parameters to useradd, each user will be a member of a unique group on the system. If this behavior is undesirable, you'll need to pass the -g parameter to useradd. The default parameters are stored in the /etc/default/useradd file. You may need to modify two parameters in this file to suit your particular needs. GROUP=1000 This parameter sets the beginning of the group numbers used in the /etc/group file. You can modify it to anything you desire. Note that useradd will never reuse a UID or GID. If the number identified in this parameter is used, it will use the next available number after this. Note also that if you don't have a group 1000 on your system the first time you use useradd without the -g parameter, you'll get a message displayed on the terminal that says: useradd: unknown GID 1000. You may disregard this message and group number 1000 will be used. CREATE_MAIL_SPOOL=yes This parameter causes useradd to create a mailbox file for the newly created user. useradd will make the group ownership of this file to the mail group with 0660 permissions. If you would prefer that these mailbox files are not created by useradd, issue the following command: sed -i 's/yes/no/' /etc/default/useradd Choose a password for user root and set it by running: passwd root Installed programs Installed directory chage, chfn, chgpasswd, chpasswd, chsh, expiry, faillog, gpasswd, groupadd, groupdel, groupmems, groupmod, grpck, grpconv, grpunconv, lastlog, login, logoutd, newgidmap, newgrp, newuidmap, newusers, nologin, passwd, pwck, pwconv, pwunconv, sg (link to newgrp), su, useradd, userdel, usermod, vigr (link to vipw), and vipw /etc/default Short Descriptions chage Used to change the maximum number of days between obligatory password changes chage chfn Used to change a user's full name and other information chfn chgpasswd Used to update group passwords in batch mode chgpasswd chpasswd Used to update user passwords in batch mode chpasswd chsh Used to change a user's default login shell chsh expiry Checks and enforces the current password expiration policy expiry faillog Is used to examine the log of login failures, to set a maximum number of failures before an account is blocked, or to reset the failure count faillog gpasswd Is used to add and delete members and administrators to groups gpasswd groupadd Creates a group with the given name groupadd groupdel Deletes the group with the given name groupdel groupmems Allows a user to administer his/her own group membership list without the requirement of super user privileges. groupmems groupmod Is used to modify the given group's name or GID groupmod grpck Verifies the integrity of the group files /etc/group and /etc/gshadow grpck grpconv Creates or updates the shadow group file from the normal group file grpconv grpunconv Updates /etc/group from /etc/gshadow and then deletes the latter grpunconv lastlog Reports the most recent login of all users or of a given user lastlog login Is used by the system to let users sign on login logoutd Is a daemon used to enforce restrictions on log-on time and ports logoutd newgidmap Is used to set the gid mapping of a user namespace newgidmap newgrp Is used to change the current GID during a login session newgrp newuidmap Is used to set the uid mapping of a user namespace newuidmap newusers Is used to create or update an entire series of user accounts newusers nologin Displays a message that an account is not available; it is designed to be used as the default shell for accounts that have been disabled nologin passwd Is used to change the password for a user or group account passwd pwck Verifies the integrity of the password files /etc/passwd and /etc/shadow pwck pwconv Creates or updates the shadow password file from the normal password file pwconv pwunconv Updates /etc/passwd from /etc/shadow and then deletes the latter pwunconv sg Executes a given command while the user's GID is set to that of the given group sg su Runs a shell with substitute user and group IDs su useradd Creates a new user with the given name, or updates the default new-user information useradd userdel Deletes the given user account userdel usermod Is used to modify the given user's login name, User Identification (UID), shell, initial group, home directory, etc. usermod vigr Edits the /etc/group or /etc/gshadow files vigr vipw Edits the /etc/passwd or /etc/shadow files vipw