--- loncom/Attic/lcuseradd 2000/10/30 03:37:51 1.14 +++ loncom/Attic/lcuseradd 2002/05/03 03:43:54 1.21 @@ -1,26 +1,69 @@ #!/usr/bin/perl + +# The Learning Online Network with CAPA +# +# lcuseradd - LON-CAPA setuid script to coordinate all actions +# with adding a user with filesystem privileges (e.g. author) # -# lcuseradd +# YEAR=2000 +# 10/27,10/29,10/30 Scott Harrison +# YEAR=2001 +# 10/21,11/13,11/15 Scott Harrison +# YEAR=2002 +# May 19, 2002 Ron Fox +# - Removed creation of the pulic_html directory. This directory +# can now be added in two ways: +# o The user can add it themselves if they want some local web +# space which may or may not contain construction items. +# o LonCapa will add it if/when the user is granted an Author +# role. # -# Scott Harrison -# SH: October 27, 2000 -# SH: October 29, 2000 +# $Id: lcuseradd,v 1.21 2002/05/03 03:43:54 foxr Exp $ +### + +############################################################################### +## ## +## ORGANIZATION OF THIS PERL SCRIPT ## +## ## +## 1. Description of script ## +## 2. Invoking script (standard input) ## +## 3. Example usage inside another piece of code ## +## 4. Description of functions ## +## 5. Exit codes ## +## 6. Initializations ## +## 7. Make sure this process is running from user=www ## +## 8. Start running script with www permissions ## +## 9. Handle case of another lcpasswd process (locking) ## +## 10. Error-check input, need 3 values (user name, password 1, password 2) ## +## 11. Start running script with root permissions ## +## 12. Add user and make www a member of the user-specific group ## +## 13. Set password ## +## 14. Make final modifications to the user directory ## +## 15. Exit script (unlock) ## +## ## +############################################################################### use strict; +# ------------------------------------------------------- Description of script +# # This script is a setuid script that should -# be run by user 'www'. It creates a /home/USERNAME directory -# as well as a /home/USERNAME/public_html directory. -# It adds user entries to -# /etc/passwd and /etc/groups. +# be run by user 'www'. It creates a /home/USERNAME directory. +# It adds a user to the unix system. # Passwords are set with lcpasswd. # www becomes a member of this user group. -# Standard input usage +# -------------- Invoking script (standard input versus command-line arguments) +# +# Standard input (STDIN) usage # First line is USERNAME # Second line is PASSWORD # Third line is PASSWORD - +# +# Command-line arguments [USERNAME] [PASSWORD] [PASSWORD] +# Yes, but be very careful here (don't pass shell commands) +# and this is only supported to allow perl-system calls. +# # Valid passwords must consist of the # ascii characters within the inclusive # range of 0x20 (32) to 0x7E (126). @@ -28,242 +71,214 @@ use strict; # SPACE and # !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNO # PQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ - +# # Valid user names must consist of ascii # characters that are alphabetical characters # (A-Z,a-z), numeric (0-9), or the underscore # mark (_). (Essentially, the perl regex \w). +# User names must begin with an alphabetical character +# (A-Z,a-z). -# Command-line arguments [USERNAME] [PASSWORD] [PASSWORD] -# Yes, but be very careful here (don't pass shell commands) -# and this is only supported to allow perl-system calls. - +# ---------------------------------- Example usage inside another piece of code # Usage within code # -# $exitcode=system("/home/httpd/perl/lcuseradd","NAME","PASSWORD1","PASSWORD2")/256; +# $exitcode= +# system("/home/httpd/perl/lcuseradd","NAME","PASSWORD1","PASSWORD2")/256; # print "uh-oh" if $exitcode; +# ---------------------------------------------------- Description of functions +# enable_root_capability() : have setuid script run as root +# disable_root_capability() : have setuid script run as www +# try_to_lock() : make sure that another lcpasswd process isn't running + +# ------------------------------------------------------------------ Exit codes # These are the exit codes. # ( (0,"ok"), # (1,"User ID mismatch. This program must be run as user 'www'"), -# (2,"Error. This program needs 3 command-line arguments (username, password 1, password 2)."), +# (2,"Error. This program needs 3 command-line arguments (username, ". +# "password 1, password 2)."), # (3,"Error. Three lines should be entered into standard input."), -# (4,"Error. Too many other simultaneous password change requests being made."), +# (4,"Error. Too many other simultaneous password change requests being ". +# "made."), # (5,"Error. User $username does not exist."), # (6,"Error. Could not make www a member of the group \"$safeusername\"."), # (7,"Error. Root was not successfully enabled.), -# (8,"Error. Cannot open /etc/passwd."), +# (8,"Error. Cannot set password."), # (9,"Error. The user name specified has invalid characters."), # (10,"Error. A password entry had an invalid character."), # (11,"Error. User already exists.), -# (12,"Error. Something went wrong with the addition of user \"$safeusername\"."), +# (12,"Error. Something went wrong with the addition of user ". +# "\"$safeusername\"."), # (13,"Error. Password mismatch."), +# ------------------------------------------------------------- Initializations # Security -$ENV{'PATH'}=""; # Nullify path information. -$ENV{'BASH_ENV'}=""; # Nullify shell environment information. +$ENV{'PATH'}='/bin/:/usr/bin:/usr/local/sbin:/home/httpd/perl'; # Nullify path + # information +delete @ENV{qw(IFS CDPATH ENV BASH_ENV)}; # nullify potential taints -# Do not print error messages if there are command-line arguments -my $noprint=0; -if (@ARGV) { - $noprint=1; -} - -# Read in /etc/passwd, and make sure this process is running from user=www -open (IN, "; -close IN; -my $wwwid; -for my $l (@lines) { - chop $l; - my @F=split(/\:/,$l); - if ($F[0] eq 'www') {$wwwid=$F[2];} -} -if ($wwwid!=$<) { - print("User ID mismatch. This program must be run as user 'www'\n") unless $noprint; +# Do not print error messages. +my $noprint=1; + +# ----------------------------- Make sure this process is running from user=www +my $wwwid=getpwnam('www'); +&disable_root_capability; +if ($wwwid!=$>) { + print("User ID mismatch. This program must be run as user 'www'\n") + unless $noprint; exit 1; } + +# ----------------------------------- Start running script with www permissions &disable_root_capability; -# Handle case of another lcpasswd process +# --------------------------- Handle case of another lcpasswd process (locking) unless (&try_to_lock("/tmp/lock_lcpasswd")) { - print "Error. Too many other simultaneous password change requests being made.\n" unless $noprint; + print "Error. Too many other simultaneous password change requests being ". + "made.\n" unless $noprint; exit 4; } -# Gather input. Should be 3 values (user name, password 1, password 2). +# ------- Error-check input, need 3 values (user name, password 1, password 2). my @input; if (@ARGV==3) { @input=@ARGV; } elsif (@ARGV) { - print("Error. This program needs 3 command-line arguments (username, password 1, password 2).\n") unless $noprint; + print("Error. This program needs 3 command-line arguments (username, ". + "password 1, password 2).\n") unless $noprint; unlink('/tmp/lock_lcpasswd'); exit 2; } else { @input=<>; if (@input!=3) { - print("Error. Three lines should be entered into standard input.\n") unless $noprint; + print("Error. Three lines should be entered into standard input.\n") + unless $noprint; unlink('/tmp/lock_lcpasswd'); exit 3; } - map {chop} @input; + foreach (@input) {chomp;} } my ($username,$password1,$password2)=@input; $username=~/^(\w+)$/; my $safeusername=$1; -if ($username ne $safeusername) { - print "Error. The user name specified has invalid characters.\n"; +if (($username ne $safeusername) or ($safeusername!~/^[A-Za-z]/)) { + print "Error. The user name specified has invalid characters.\n" + unless $noprint; unlink('/tmp/lock_lcpasswd'); exit 9; } my $pbad=0; -map {if ((ord($_)<32)||(ord($_)>126)){$pbad=1;}} (split(//,$password1)); -map {if ((ord($_)<32)||(ord($_)>126)){$pbad=1;}} (split(//,$password2)); +foreach (split(//,$password1)) {if ((ord($_)<32)||(ord($_)>126)){$pbad=1;}} +foreach (split(//,$password2)) {if ((ord($_)<32)||(ord($_)>126)){$pbad=1;}} if ($pbad) { print "Error. A password entry had an invalid character.\n"; unlink('/tmp/lock_lcpasswd'); exit 10; } -# Only add user if we can create a brand new home directory (/home/username). +# -- Only add user if we can create a brand new home directory (/home/username) if (-e "/home/$safeusername") { print "Error. User already exists.\n" unless $noprint; unlink('/tmp/lock_lcpasswd'); exit 11; } -# Only add user if the two password arguments match. +# -- Only add user if the two password arguments match. if ($password1 ne $password2) { print "Error. Password mismatch.\n" unless $noprint; unlink('/tmp/lock_lcpasswd'); exit 13; } +# ---------------------------------- Start running script with root permissions &enable_root_capability; -# Add user entry to /etc/passwd and /etc/groups in such -# a way that www is a member of the user-specific group - +# ------------------- Add user and make www a member of the user-specific group +# -- Add user if (system('/usr/sbin/useradd','-c','LON-CAPA user',$safeusername)) { - print "Error. Something went wrong with the addition of user \"$safeusername\".\n" unless $noprint; + print "Error. Something went wrong with the addition of user ". + "\"$safeusername\".\n" unless $noprint; unlink('/tmp/lock_lcpasswd'); exit 12; } # Make www a member of that user group. -if (system('/usr/sbin/usermod','-G',$safeusername,'www')) { - print "Error. Could not make www a member of the group \"$safeusername\".\n" unless $noprint; +my $groups=`/usr/bin/groups www` or exit(6); +chomp $groups; $groups=~s/^\S+\s+\:\s+//; +my @grouplist=split(/\s+/,$groups); +my @ugrouplist=grep {!/www|$safeusername/} @grouplist; +my $gl=join(',',(@ugrouplist,$safeusername)); +if (system('/usr/sbin/usermod','-G',$gl,'www')) { + print "Error. Could not make www a member of the group ". + "\"$safeusername\".\n" unless $noprint; unlink('/tmp/lock_lcpasswd'); exit 6; } -# Set password with lcpasswd-style algorithm (which creates smbpasswd entry). -# I cannot place a direct shell call to lcpasswd since I have to allow -# for crazy characters in the password, and the setuid environment of perl -# requires me to make everything safe. - -# Grab the line corresponding to username -open (IN, "; -close IN; -my ($userid,$useroldcryptpwd); -my @F; my @U; -for my $l (@lines) { - chop $l; - @F=split(/\:/,$l); - if ($F[0] eq $username) {($userid,$useroldcryptpwd)=($F[2],$F[1]); @U=@F;} -} - -# Verify existence of user -if (!defined($userid)) { - print "Error. User $username does not exist.\n" unless $noprint; - unlink('/tmp/lock_lcpasswd'); - exit 5; -} +# ---------------------------------------------------------------- Set password +# Set password with lcpasswd (which creates smbpasswd entry). -# Construct new password entry (random salt) -my $newcryptpwd=crypt($password1,(join '', ('.', '/', 0..9, 'A'..'Z', 'a'..'z')[rand 64, rand 64])); -$U[1]=$newcryptpwd; -my $userline=join(':',@U); -my $rootid=&enable_root_capability; -if ($rootid!=0) { - print "Error. Root was not successfully enabled.\n" unless $noprint; - unlink('/tmp/lock_lcpasswd'); - exit 7; -} -open PASSWORDFILE, '>/etc/passwd' or (print("Error. Cannot open /etc/passwd.\n") && unlink('/tmp/lock_lcpasswd') && exit(8)); -for my $l (@lines) { - @F=split(/\:/,$l); - if ($F[0] eq $username) {print PASSWORDFILE "$userline\n";} - else {print PASSWORDFILE "$l\n";} -} -close PASSWORDFILE; - -($>,$<)=(0,0); # fool smbpasswd here to think this is not a setuid environment -unless (-e '/etc/smbpasswd') { - open (OUT,'>/etc/smbpasswd'); close OUT; -} -my $smbexist=0; -open (IN, '; -close IN; -for my $l (@lines) { - chop $l; - my @F=split(/\:/,$l); - if ($F[0] eq $username) {$smbexist=1;} -} -unless ($smbexist) { - open(OUT,'>>/etc/smbpasswd'); - print OUT join(':',($safeusername,$userid,'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX','','/home/'.$safeusername,'/bin/bash')) . "\n"; - close OUT; -} -open(OUT,"|/usr/bin/smbpasswd -s $safeusername>/dev/null"); -print OUT $password1; print OUT "\n"; -print OUT $password1; print OUT "\n"; +unlink('/tmp/lock_lcpasswd'); +&disable_root_capability; +($>,$<)=($wwwid,$wwwid); +open OUT,"|/home/httpd/perl/lcpasswd"; +print OUT $safeusername; +print OUT "\n"; +print OUT $password1; +print OUT "\n"; +print OUT $password1; +print OUT "\n"; close OUT; -$<=$wwwid; # unfool the program +if ($?) { + exit 8; +} +($>,$<)=($wwwid,0); +&enable_root_capability; + +# -- Don't add public_html... that can be added either by the user +# or by lchtmldir when the user is granted an authorship role. -# Make final modifications to the user directory. -# Add a public_html file with a stand-in index.html file. +# ------------------------------ Make final modifications to the user directory +# -- Add a public_html file with a stand-in index.html file -system('/bin/chmod','-R','0660',"/home/$safeusername"); -system('/bin/chmod','0770',"/home/$safeusername"); -mkdir "/home/$safeusername/public_html",0770; + system('/bin/chmod','-R','0660',"/home/$safeusername"); +system('/bin/chmod','0710',"/home/$safeusername"); +mkdir "/home/$safeusername/public_html",0755; +system('/bin/chmod','02770',"/home/$safeusername/public_html"); open OUT,">/home/$safeusername/public_html/index.html"; print OUT< - -$safeusername - - -

$safeusername

-

+ + +$safeusername + + +

$safeusername

+

Learning Online Network -

-

+

+

This area provides for: -

- - - +

+ + + END close OUT; + system('/bin/chown','-R',"$safeusername:$safeusername","/home/$safeusername"); -system('/bin/chmod','-R','0660',"/home/$safeusername"); -system('/bin/chmod','0770',"/home/$safeusername"); -system('/bin/chmod','0770',"/home/$safeusername/public_html"); + +# -------------------------------------------------------- Exit script &disable_root_capability; -unlink('/tmp/lock_lcpasswd'); exit 0; -# ----------------------------------------------------------- have setuid script run as root +# ---------------------------------------------- Have setuid script run as root sub enable_root_capability { if ($wwwid==$>) { ($<,$>)=($>,$<); @@ -275,7 +290,7 @@ sub enable_root_capability { return $>; } -# ----------------------------------------------------------- have setuid script run as www +# ----------------------------------------------- Have setuid script run as www sub disable_root_capability { if ($wwwid==$<) { ($<,$>)=($>,$<); @@ -286,7 +301,7 @@ sub disable_root_capability { } } -# ----------------------------------- make sure that another lcpasswd process isn't running +# ----------------------- Make sure that another lcpasswd process isn't running sub try_to_lock { my ($lockfile)=@_; my $currentpid; @@ -323,3 +338,32 @@ sub try_to_lock { close LOCK; return 1; } + +=head1 NAME + +lcuseradd - LON-CAPA setuid script to coordinate all actions + with adding a user with filesystem privileges (e.g. author) + +=head1 DESCRIPTION + +lcuseradd - LON-CAPA setuid script to coordinate all actions + with adding a user with filesystem privileges (e.g. author) + +=head1 README + +lcuseradd - LON-CAPA setuid script to coordinate all actions + with adding a user with filesystem privileges (e.g. author) + +=head1 PREREQUISITES + +=head1 COREQUISITES + +=pod OSNAMES + +linux + +=pod SCRIPT CATEGORIES + +LONCAPA/Administrative + +=cut