version 1.1, 2000/10/27 23:42:33
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version 1.24, 2002/12/09 16:15:51
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#!/usr/bin/perl |
#!/usr/bin/perl |
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# The Learning Online Network with CAPA |
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# |
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# lcuseradd - LON-CAPA setuid script to coordinate all actions |
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# with adding a user with filesystem privileges (e.g. author) |
# |
# |
# lcuseradd |
# YEAR=2000 |
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# 10/27,10/29,10/30 Scott Harrison |
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# YEAR=2001 |
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# 10/21,11/13,11/15 Scott Harrison |
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# YEAR=2002 |
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# May 19, 2002 Ron Fox |
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# - Removed creation of the pulic_html directory. This directory |
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# can now be added in two ways: |
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# o The user can add it themselves if they want some local web |
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# space which may or may not contain construction items. |
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# o LonCapa will add it if/when the user is granted an Author |
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# role. |
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# Scott Harrison |
# $Id$ |
# October 27, 2000 |
### |
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############################################################################### |
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## ## |
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## ORGANIZATION OF THIS PERL SCRIPT ## |
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## ## |
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## 1. Description of script ## |
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## 2. Invoking script (standard input) ## |
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## 3. Example usage inside another piece of code ## |
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## 4. Description of functions ## |
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## 5. Exit codes ## |
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## 6. Initializations ## |
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## 7. Make sure this process is running from user=www ## |
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## 8. Start running script with www permissions ## |
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## 9. Handle case of another lcpasswd process (locking) ## |
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## 10. Error-check input, need 3 values (user name, password 1, password 2) ## |
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## 11. Start running script with root permissions ## |
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## 12. Add user and make www a member of the user-specific group ## |
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## 13. Set password ## |
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## 14. Make final modifications to the user directory ## |
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## 15. Exit script (unlock) ## |
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## ## |
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############################################################################### |
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use strict; |
use strict; |
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# ------------------------------------------------------- Description of script |
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# |
# This script is a setuid script that should |
# This script is a setuid script that should |
# be run by user 'www'. It creates a /home/USERNAME directory |
# be run by user 'www'. It creates a /home/USERNAME directory. |
# as well as a /home/USERNAME/public_html directory. |
# It adds a user to the unix system. |
# It adds user entries to |
# Passwords are set with lcpasswd. |
# /etc/passwd and /etc/groups. |
# www becomes a member of this user group. |
# Passwords are set with lcpasswd |
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# Standard input usage |
# -------------- Invoking script (standard input versus command-line arguments) |
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# |
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# Standard input (STDIN) usage |
# First line is USERNAME |
# First line is USERNAME |
# Second line is PASSWORD |
# Second line is PASSWORD |
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# Third line is PASSWORD |
# Command-line arguments [USERNAME] [PASSWORD] |
# |
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# Command-line arguments [USERNAME] [PASSWORD] [PASSWORD] |
# Yes, but be very careful here (don't pass shell commands) |
# Yes, but be very careful here (don't pass shell commands) |
# and this is only supported to allow perl-system calls. |
# and this is only supported to allow perl-system calls. |
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# |
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# Valid passwords must consist of the |
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# ascii characters within the inclusive |
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# range of 0x20 (32) to 0x7E (126). |
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# These characters are: |
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# SPACE and |
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# !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNO |
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# PQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ |
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# |
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# Valid user names must consist of ascii |
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# characters that are alphabetical characters |
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# (A-Z,a-z), numeric (0-9), or the underscore |
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# mark (_). (Essentially, the perl regex \w). |
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# User names must begin with an alphabetical character |
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# (A-Z,a-z). |
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# ---------------------------------- Example usage inside another piece of code |
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# Usage within code |
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# |
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# $exitcode= |
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# system("/home/httpd/perl/lcuseradd","NAME","PASSWORD1","PASSWORD2")/256; |
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# print "uh-oh" if $exitcode; |
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# ---------------------------------------------------- Description of functions |
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# enable_root_capability() : have setuid script run as root |
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# disable_root_capability() : have setuid script run as www |
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# try_to_lock() : make sure that another lcpasswd process isn't running |
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# ------------------------------------------------------------------ Exit codes |
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# These are the exit codes. |
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# ( (0,"ok"), |
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# (1,"User ID mismatch. This program must be run as user 'www'"), |
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# (2,"Error. This program needs 3 command-line arguments (username, ". |
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# "password 1, password 2)."), |
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# (3,"Error. Three lines should be entered into standard input."), |
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# (4,"Error. Too many other simultaneous password change requests being ". |
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# "made."), |
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# (5,"Error. User $username does not exist."), |
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# (6,"Error. Could not make www a member of the group \"$safeusername\"."), |
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# (7,"Error. Root was not successfully enabled.), |
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# (8,"Error. Cannot set password."), |
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# (9,"Error. The user name specified has invalid characters."), |
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# (10,"Error. A password entry had an invalid character."), |
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# (11,"Error. User already exists.), |
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# (12,"Error. Something went wrong with the addition of user ". |
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# "\"$safeusername\"."), |
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# (13,"Error. Password mismatch."), |
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# ------------------------------------------------------------- Initializations |
# Security |
# Security |
$ENV{'PATH'}=""; # Nullify path information. |
$ENV{'PATH'}='/bin/:/usr/bin:/usr/local/sbin:/home/httpd/perl'; # Nullify path |
$ENV{'BASH_ENV'}=""; # Nullify shell environment information. |
# information |
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delete @ENV{qw(IFS CDPATH ENV BASH_ENV)}; # nullify potential taints |
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# Do not print error messages. |
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my $noprint=1; |
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print "In lcuseradd\n" unless $noprint; |
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# ----------------------------- Make sure this process is running from user=www |
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my $wwwid=getpwnam('www'); |
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&disable_root_capability; |
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if ($wwwid!=$>) { |
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print("User ID mismatch. This program must be run as user 'www'\n") |
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unless $noprint; |
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exit 1; |
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} |
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# ----------------------------------- Start running script with www permissions |
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&disable_root_capability; |
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# --------------------------- Handle case of another lcpasswd process (locking) |
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unless (&try_to_lock("/tmp/lock_lcpasswd")) { |
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print "Error. Too many other simultaneous password change requests being ". |
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"made.\n" unless $noprint; |
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exit 4; |
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} |
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# ------- Error-check input, need 3 values (user name, password 1, password 2). |
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my @input; |
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if (@ARGV==3) { |
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@input=@ARGV; |
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} |
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elsif (@ARGV) { |
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print("Error. This program needs 3 command-line arguments (username, ". |
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"password 1, password 2).\n") unless $noprint; |
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unlink('/tmp/lock_lcpasswd'); |
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exit 2; |
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} |
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else { |
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@input=<>; |
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if (@input!=3) { |
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print("Error. Three lines should be entered into standard input.\n") |
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unless $noprint; |
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unlink('/tmp/lock_lcpasswd'); |
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exit 3; |
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} |
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foreach (@input) {chomp;} |
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} |
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my ($username,$password1,$password2)=@input; |
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print "Username = ".$username."\n" unless $noprint; |
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$username=~/^(\w+)$/; |
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print "Username after substitution - ".$username unless $noprint; |
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my $safeusername=$1; |
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print "Safe username = $safeusername \n" unless $noprint; |
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if (($username ne $safeusername) or ($safeusername!~/^[A-Za-z]/)) { |
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print "Error. The user name specified $username $safeusername has invalid characters.\n" |
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unless $noprint; |
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unlink('/tmp/lock_lcpasswd'); |
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exit 9; |
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} |
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my $pbad=0; |
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foreach (split(//,$password1)) {if ((ord($_)<32)||(ord($_)>126)){$pbad=1;}} |
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foreach (split(//,$password2)) {if ((ord($_)<32)||(ord($_)>126)){$pbad=1;}} |
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if ($pbad) { |
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print "Error. A password entry had an invalid character.\n"; |
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unlink('/tmp/lock_lcpasswd'); |
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exit 10; |
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} |
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# -- Only add user if we can create a brand new home directory (/home/username) |
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if (-e "/home/$safeusername") { |
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print "Error. User already exists.\n" unless $noprint; |
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unlink('/tmp/lock_lcpasswd'); |
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exit 11; |
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} |
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# -- Only add user if the two password arguments match. |
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if ($password1 ne $password2) { |
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print "Error. Password mismatch.\n" unless $noprint; |
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unlink('/tmp/lock_lcpasswd'); |
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exit 13; |
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} |
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print "enabling root\n" unless $noprint; |
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# ---------------------------------- Start running script with root permissions |
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&enable_root_capability; |
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# ------------------- Add user and make www a member of the user-specific group |
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# -- Add user |
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print "adding user: $safeusername \n" unless $noprint; |
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my $status = system('/usr/sbin/useradd','-c','LON-CAPA user',$safeusername); |
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if ($status) { |
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print "Error. Something went wrong with the addition of user ". |
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"\"$safeusername\".\n" unless $noprint; |
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print "Final status of useradd = $status"; |
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unlink('/tmp/lock_lcpasswd'); |
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exit 12; |
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} |
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print "Done adding user\n" unless $noprint; |
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# Make www a member of that user group. |
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my $groups=`/usr/bin/groups www` or exit(6); |
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chomp $groups; $groups=~s/^\S+\s+\:\s+//; |
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my @grouplist=split(/\s+/,$groups); |
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my @ugrouplist=grep {!/www|$safeusername/} @grouplist; |
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my $gl=join(',',(@ugrouplist,$safeusername)); |
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print "Putting user in its own group\n" unless $noprint; |
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if (system('/usr/sbin/usermod','-G',$gl,'www')) { |
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print "Error. Could not make www a member of the group ". |
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"\"$safeusername\".\n" unless $noprint; |
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unlink('/tmp/lock_lcpasswd'); |
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exit 6; |
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} |
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# ---------------------------------------------------------------- Set password |
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# Set password with lcpasswd (which creates smbpasswd entry). |
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unlink('/tmp/lock_lcpasswd'); |
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&disable_root_capability; |
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($>,$<)=($wwwid,$wwwid); |
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print "Opening lcpasswd pipeline\n" unless $noprint; |
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open OUT,"|/home/httpd/perl/lcpasswd"; |
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print OUT $safeusername; |
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print OUT "\n"; |
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print OUT $password1; |
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print OUT "\n"; |
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print OUT $password1; |
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print OUT "\n"; |
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close OUT; |
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if ($?) { |
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print "abnormal exit from close lcpasswd\n" unless $noprint; |
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exit 8; |
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} |
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($>,$<)=($wwwid,0); |
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&enable_root_capability; |
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# -- Don't add public_html... that can be added either by the user |
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# or by lchtmldir when the user is granted an authorship role. |
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# ------------------------------ Make final modifications to the user directory |
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# -- Add a public_html file with a stand-in index.html file |
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system('/bin/chmod','-R','0660',"/home/$safeusername"); |
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system('/bin/chmod','0710',"/home/$safeusername"); |
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mkdir "/home/$safeusername/public_html",0755; |
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system('/bin/chmod','02770',"/home/$safeusername/public_html"); |
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open OUT,">/home/$safeusername/public_html/index.html"; |
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print OUT<<END; |
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<html> |
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<head> |
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<title>$safeusername</title> |
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</head> |
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<body> |
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<h1>Construction Space</h1> |
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<h3>$safeusername</h3> |
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</body> |
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</html> |
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END |
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close OUT; |
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print "lcuseradd ownership\n" unless $noprint; |
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system('/bin/chown','-R',"$safeusername:$safeusername","/home/$safeusername"); |
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# ---------------------------------------------------- Gracefull Apache Restart |
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if (-e '/var/run/httpd.pid') { |
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print "lcuseradd Apache restart\n" unless $noprint; |
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open(PID,'/var/run/httpd.pid'); |
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my $pid=<PID>; |
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close(PID); |
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$pid=~s/\D+//g; |
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if ($pid) { |
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system('kill','-USR1',"$pid"); |
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} |
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} |
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# -------------------------------------------------------- Exit script |
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print "lcuseradd exiting\n" unless $noprint; |
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&disable_root_capability; |
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exit 0; |
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# ---------------------------------------------- Have setuid script run as root |
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sub enable_root_capability { |
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if ($wwwid==$>) { |
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($<,$>)=($>,0); |
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($(,$))=($),0); |
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} |
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else { |
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# root capability is already enabled |
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} |
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return $>; |
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} |
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# ----------------------------------------------- Have setuid script run as www |
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sub disable_root_capability { |
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if ($wwwid==$<) { |
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($<,$>)=($>,$<); |
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($(,$))=($),$(); |
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} |
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else { |
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# root capability is already disabled |
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} |
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} |
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# ----------------------- Make sure that another lcpasswd process isn't running |
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sub try_to_lock { |
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my ($lockfile)=@_; |
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my $currentpid; |
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my $lastpid; |
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# Do not manipulate lock file as root |
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if ($>==0) { |
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return 0; |
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} |
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# Try to generate lock file. |
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# Wait 3 seconds. If same process id is in |
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# lock file, then assume lock file is stale, and |
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# go ahead. If process id's fluctuate, try |
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# for a maximum of 10 times. |
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for (0..10) { |
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if (-e $lockfile) { |
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open(LOCK,"<$lockfile"); |
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$currentpid=<LOCK>; |
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close LOCK; |
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if ($currentpid==$lastpid) { |
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last; |
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} |
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sleep 3; |
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$lastpid=$currentpid; |
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} |
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else { |
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last; |
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} |
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if ($_==10) { |
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return 0; |
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} |
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} |
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open(LOCK,">$lockfile"); |
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print LOCK $$; |
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close LOCK; |
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return 1; |
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} |
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=head1 NAME |
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lcuseradd - LON-CAPA setuid script to coordinate all actions |
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with adding a user with filesystem privileges (e.g. author) |
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=head1 DESCRIPTION |
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lcuseradd - LON-CAPA setuid script to coordinate all actions |
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with adding a user with filesystem privileges (e.g. author) |
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=head1 README |
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lcuseradd - LON-CAPA setuid script to coordinate all actions |
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with adding a user with filesystem privileges (e.g. author) |
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=head1 PREREQUISITES |
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=head1 COREQUISITES |
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=pod OSNAMES |
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linux |
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=pod SCRIPT CATEGORIES |
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LONCAPA/Administrative |
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=cut |