Linux Shadow Password HOWTO.pdf

Linux Shadow Password HOWTO Table of Contents Linux Shadow Password HOWTO1 Michael H. Jackson, mhjack@1 1.Introduction1 2.Why shadow your passwd file?1 3.Getting the Shadow Suite1 4.Compiling the programs2 5.Installing2 6.Other programs you may need to upgrade or patch2 7.Putting the Shadow Suite to use2 8.Adding shadow support to a C program2 9.Frequently Asked Questions3 10.Copyright Message3 11.Miscellaneous and Acknowledgments3 1.Introduction3 1.1 Changes from the previous release3 1.2 New versions of this document4 1.3 Feedback4 2.Why shadow your passwd file?4 2.1 Why you might NOT want to shadow your passwd file7 2.2 Format of the /etc/passwd file7 2.3 Format of the shadow file8 2.4 Review of crypt(3)9 3.Getting the Shadow Suite10 3.1 History of the Shadow Suite for Linux10 3.2 Where to get the Shadow Suite11 3.3 What is included with the Shadow Suite12 4.Compiling the programs12 4.1 Unpacking the archive12 4.2 Configuring with the config.h file12 4.3 Making backup copies of your original programs14 4.4 Running make14 5.Installing14 5.1 Have a boot disk handy in case you break anything14 5.2 Removing duplicate man pages15 5.3 Running make install15 5.4 Running pwconv16 5.5 Renaming npasswd and nshadow16 6.Other programs you may need to upgrade or patch17 6.1 Slackware adduser program17 6.2 The wu_ftpd Server18 6.3 Standard ftpd20 6.4 pop3d (Post Office Protocol 3)20 6.5 xlock20 6.6 xdm21 6.7 sudo22 6.9 pppd (Point?to?Point Protocol Server)22 7.Putting the Shadow Suite to use23 Linux Shadow Password HOWTO i Table of Contents 7.1 Adding, Modifying, and deleting users23 useradd23 usermod26 userdel27 7.2 The passwd command and passwd aging27 7.3 The login.defs file28 7.4 Group passwords28 7.5 Consistency checking programs30 pwck30 grpck30 7.6 Dial?up passwords31 8.Adding shadow support to a C program31 8.1 Header files32 8.2 libshadow.a library32 8.3 Shadow Structure32 8.4 Shadow Functions33 8.5 Example33 9.Frequently Asked Questions37 10.Copyright Message38 1