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Diff for /loncom/Attic/lcuseradd between versions 1.6 and 1.28

version 1.6, 2000/10/29 22:52:30 version 1.28, 2004/08/06 10:29:37
Line 1 Line 1
 #!/usr/bin/perl  #!/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  
 #  #
 # Scott Harrison  # $Id$
 # October 27, 2000  ###
   
   ###############################################################################
   ##                                                                           ##
   ## 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;  use strict;
   
   # ------------------------------------------------------- Description of script
   #
 # 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  
 # /etc/passwd and /etc/groups.  
 # Passwords are set with lcpasswd.  # Passwords are set with lcpasswd.
 # www becomes a member of this user group.  # www becomes a member of this user group.
   
 # Standard input usage  # -------------- Invoking script (standard input versus command-line arguments)
   #                Otherwise sensitive information will be available to ps-ers for
   #                a small but exploitable time window.
   #
   # Standard input (STDIN) usage
 # First line is USERNAME  # First line is USERNAME
 # Second line is PASSWORD  # Second line is PASSWORD
 # Third line is PASSWORD  # Third line is PASSWORD
   # Fouth line is the name of a file to which an error code will be written.
   #            If the fourth line is omitted, no error file will be written.
   #            In either case, the program Exits with the code as its Exit status.
   #            The error file will just be a single line containing an
   #            error code.
   #            
   #  
   #
 # Command-line arguments [USERNAME] [PASSWORD] [PASSWORD]  # 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.
   #
   # Valid passwords must consist of the
   # ascii characters within the inclusive
   # range of 0x20 (32) to 0x7E (126).
   # These characters are:
   # 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).
   
   # ---------------------------------- Example usage inside another piece of code
 # Usage within code  # Usage within code
 #  #
 # $exitcode=system("/home/httpd/perl/lcuseradd","NAME","PASSWORD1","PASSWORD2")/256;  # $Exitcode=
 # print "uh-oh" if $exitcode;  #      system("/home/httpd/perl/lcuseradd","NAME","PASSWORD1","PASSWORD2")/256;
   # print "uh-oh" if $Exitcode;
 # These are the exit codes.  
   # ---------------------------------------------------- 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)."),
   # (3,"Error. Three lines should be entered into standard input."),
   # (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 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\"."),
   # (13,"Error. Password mismatch."),
   # (14, "Error filename is invalid")
   
   # ------------------------------------------------------------- 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
   delete @ENV{qw(IFS CDPATH ENV BASH_ENV)}; # nullify potential taints
   
   # Do not print error messages.
   my $noprint=1;
   
   #  Error file:
   
   my $error_file; # This is either the error file name or undef.
   
   print "In lcuseradd\n" unless $noprint;
   
 # Do not print error messages if there are command-line arguments  # ----------------------------- Make sure this process is running from user=www
 my $noprint=0;  my $wwwid=getpwnam('www');
 if (@ARGV) {  &disable_root_capability;
     $noprint=1;  if ($wwwid!=$>) {
 }      print("User ID mismatch.  This program must be run as user 'www'\n")
    unless $noprint;
 # Read in /etc/passwd, and make sure this process is running from user=www      &Exit(1);
 open (IN, "</etc/passwd");  
 my @lines=<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;  
     exit 1;  
 }  }
   
   # ----------------------------------- Start running script with www permissions
 &disable_root_capability;  &disable_root_capability;
   
 # Handle case of another lcpasswd process  # --------------------------- Handle case of another lcpasswd process (locking)
 unless (&try_to_lock("/tmp/lock_lcpasswd")) {  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 ".
     exit 4;   "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;  my @input;
 if (@ARGV==3) {  if (@ARGV>=3) {
     @input=@ARGV;      @input=@ARGV;
 }  } elsif (@ARGV) {
 elsif (@ARGV) {      print("Error. This program needs at least 3 command-line arguments (username, ".
     print("Error. This program needs 3 command-line arguments (username, password 1, password 2).\n") unless $noprint;    "password 1, password 2 [errorfile]).\n") unless $noprint;
     unlink('/tmp/lock_lcpasswd');      unlink('/tmp/lock_lcpasswd');
     exit 2;      &Exit(2);
 }  } else {
 else {  
     @input=<>;      @input=<>;
     if (@input!=3) {      if (@input < 3) {
  print("Error. Three lines should be entered into standard input.\n") unless $noprint;   print("Error. At least three lines should be entered into standard input.\n")
       unless $noprint;
  unlink('/tmp/lock_lcpasswd');   unlink('/tmp/lock_lcpasswd');
  exit 3;   &Exit(3);
     }      }
     map {chop} @input;      foreach (@input) {chomp;}
 }  }
   
 my ($username,$password1,$password2)=@input;  my ($username,$password1,$password2, $error_file)=@input;
   print "Username = ".$username."\n" unless $noprint;
 $username=~/^(\w+)$/;  $username=~/^(\w+)$/;
   print "Username after substitution - ".$username unless $noprint;
 my $safeusername=$1;  my $safeusername=$1;
   print "Safe username = $safeusername \n" unless $noprint;
   
   if (($username ne $safeusername) or ($safeusername!~/^[A-Za-z]/)) {
       print "Error. The user name specified $username $safeusername  has invalid characters.\n"
    unless $noprint;
       unlink('/tmp/lock_lcpasswd');
       &Exit(9);
   }
   my $pbad=0;
   foreach (split(//,$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" unless $noprint;
       unlink('/tmp/lock_lcpasswd');
       &Exit(10);
   }
   
   #
   #   Safe the filename.  For our case, it must only have alpha, numeric, period
   #   and path sparators..
   #
   
   print "Error file is $error_file \n" unless $noprint;
   
   if($error_file) {
       if($error_file =~ /^([(\w)(\d)\.\/]+)$/) {
    print "Error file matched pattern $error_file : $1\n" unless $noprint;
    my $safe_error_file = $1; # Untainted I think.
    print "Error file after transform $safe_error_file\n"
       unless $noprint;
    if($error_file == $safe_error_file) {
       $error_file = $safe_error_file; # untainted error_file.
    } else {
       $error_file ="";
       print "Invalid error filename\n" unless $noprint;
       Exit(14);
    }
   
       } else {
    $error_file="";
    print "Invalid error filename\n" unless $noprint;
    Exit(14);
       }
   }
   
   
   # -- 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.
   
 if ($password1 ne $password2) {  if ($password1 ne $password2) {
     print "Error. Password mismatch.\n" unless $noprint;      print "Error. Password mismatch.\n" unless $noprint;
     unlink('/tmp/lock_lcpasswd');      unlink('/tmp/lock_lcpasswd');
     exit 7;      &Exit(13);
 }  }
   print "enabling root\n" unless $noprint;
   # ---------------------------------- Start running script with root permissions
 &enable_root_capability;  &enable_root_capability;
   
 # Add user entry to /etc/passwd and /etc/groups in such  # ------------------- Add user and make www a member of the user-specific group
 # a way that www is a member of the user-specific group  # -- Add user
   
 if (system('/usr/sbin/useradd','-c','LON-CAPA user',$safeusername)) {  print "adding user: $safeusername \n" unless $noprint;
     print "Error.  Something went wrong with the addition of user \"$safeusername\".\n" unless $noprint;  my $status = system('/usr/sbin/useradd','-c','LON-CAPA user',$safeusername);
   if ($status) {
       print "Error.  Something went wrong with the addition of user ".
     "\"$safeusername\".\n" unless $noprint;
       print "Final status of useradd = $status";
     unlink('/tmp/lock_lcpasswd');      unlink('/tmp/lock_lcpasswd');
     exit 5;      &Exit(12);
 }  }
 if (system('/usr/sbin/usermod','-G',$safeusername,'www')) {  print "Done adding user\n" unless $noprint;
     print "Error. Could not make www a member of the group \"$safeusername\".\n" unless $noprint;  # Make www a member of that user group.
   my $groups=`/usr/bin/groups www` or &Exit(6);
   # untaint
   my ($safegroups)=($groups=~/([\s\w]+)/);
   $groups=$safegroups;
   chomp $groups; $groups=~s/^\S+\s+\:\s+//;
   my @grouplist=split(/\s+/,$groups);
   my @ugrouplist=grep {!/www|$safeusername/} @grouplist;
   my $gl=join(',',(@ugrouplist,$safeusername));
   print "Putting user in its own group\n" unless $noprint;
   if (system('/usr/sbin/usermod','-G',$gl,'www')) {
       print "Error. Could not make www a member of the group ".
     "\"$safeusername\".\n" unless $noprint;
     unlink('/tmp/lock_lcpasswd');      unlink('/tmp/lock_lcpasswd');
     exit 6;      &Exit(6);
 }  }
   
 # Set password with lcpasswd-style algorithm (which creates smbpasswd entry).  # ---------------------------------------------------------------- Set password
 # I cannot place a direct shell call to lcpasswd since I have to allow  # Set password with lcpasswd (which creates smbpasswd entry).
 # for crazy characters in the password, and the setuid environment of perl  
 # requires me to make everything safe.  
   
   unlink('/tmp/lock_lcpasswd');
   &disable_root_capability;
   ($>,$<)=($wwwid,$wwwid);
   print "Opening lcpasswd pipeline\n" unless $noprint;
   open OUT,"|/home/httpd/perl/lcpasswd";
   print OUT $safeusername;
   print OUT "\n";
   print OUT $password1;
   print OUT "\n";
   print OUT $password1;
   print OUT "\n";
   close OUT;
   if ($?) {
       print "abnormal Exit from close lcpasswd\n" unless $noprint;
       &Exit(8);
   }
   ($>,$<)=($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
   
 # ----------------------------------------------------------- have setuid script run as root   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/$safeusername/public_html/index.html";
   print OUT<<END;
   <html>
   <head>
   <title>$safeusername</title>
   </head>
   <body>
   <h1>Construction Space</h1>
   <h3>$safeusername</h3>
   </body>
   </html>
   END
   close OUT;
   
   print "lcuseradd ownership\n" unless $noprint;
   system('/bin/chown','-R',"$safeusername:$safeusername","/home/$safeusername");
   # ---------------------------------------------------- Gracefull Apache Restart
   if (-e '/var/run/httpd.pid') {
       print "lcuseradd Apache restart\n" unless $noprint;
       open(PID,'/var/run/httpd.pid');
       my $pid=<PID>;
       close(PID);
       my ($safepid)=($pid=~s/(\D+)//g);
       if ($pid) {
    system('kill','-USR1',"$safepid");
       }
   }
   # -------------------------------------------------------- Exit script
   print "lcuseradd Exiting\n" unless $noprint;
   &disable_root_capability;
   &Exit(0);
   
   # ---------------------------------------------- Have setuid script run as root
 sub enable_root_capability {  sub enable_root_capability {
     if ($wwwid==$>) {      if ($wwwid==$>) {
  ($<,$>)=($>,$<);   ($<,$>)=($>,0);
  ($(,$))=($),$();   ($(,$))=($),0);
     }      } else {
     else {  
  # root capability is already enabled   # root capability is already enabled
     }      }
     return $>;      return $>;
 }  }
   
 # ----------------------------------------------------------- have setuid script run as www  # ----------------------------------------------- Have setuid script run as www
 sub disable_root_capability {  sub disable_root_capability {
     if ($wwwid==$<) {      if ($wwwid==$<) {
  ($<,$>)=($>,$<);   ($<,$>)=($>,$<);
  ($(,$))=($),$();   ($(,$))=($),$();
     }      } else {
     else {  
  # root capability is already disabled   # root capability is already disabled
     }      }
 }  }
   
 # ----------------------------------- make sure that another lcpasswd process isn't running  # ----------------------- Make sure that another lcpasswd process isn't running
 sub try_to_lock {  sub try_to_lock {
     my ($lockfile)=@_;      my ($lockfile)=@_;
     my $currentpid;      my $currentpid;
Line 163  sub try_to_lock { Line 371  sub try_to_lock {
     }      }
     sleep 3;      sleep 3;
     $lastpid=$currentpid;      $lastpid=$currentpid;
  }   } else {
  else {  
     last;      last;
  }   }
  if ($_==10) {   if ($_==10) {
Line 176  sub try_to_lock { Line 383  sub try_to_lock {
     close LOCK;      close LOCK;
     return 1;      return 1;
 }  }
   #-------------------------- Exit...
   #
   #   Write the file if the error_file is defined.  Regardless
   #   Exit with the status code.
   #
   sub Exit {
       my ($code) = @_; # Status code.
   
       print "Exiting with status $code error file is $error_file\n" unless $noprint;
       if($error_file) {
    open(FH, ">$error_file");
    print FH  "$code\n";
    close(FH);
       }
       exit $code;
   }
   
   =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
Removed from v.1.6  
changed lines
  Added in v.1.28

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