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scripts are almost all working. lcuserdel still has some problems, and lcuseradd
doesn't get the permissions quite right yet.

    1: #!/usr/bin/perl
    2: #
    3: # lcpasswd
    4: #
    5: # Scott Harrison
    6: # SH: October 27, 2000
    7: # SH: October 28, 2000
    8: # SH: October 29, 2000
    9: 
   10: use strict;
   11: 
   12: # This script is a setuid script that should
   13: # be run by user 'www'.  This script allows
   14: # for synchronous entry of passwords into
   15: # both the /etc/passwd and the /etc/smbpasswd
   16: # files.
   17: 
   18: # This script works under the same process control mechanism
   19: # as lcuseradd and lcpasswd, to make sure that only one of these
   20: # processes is running at any one time on the system.
   21: 
   22: # Standard input usage
   23: # First line is USERNAME
   24: # Second line is CURRENT PASSWORD
   25: # Third line is NEW PASSWORD
   26: 
   27: # Valid passwords must consist of the
   28: # ascii characters within the inclusive
   29: # range of 0x20 (32) to 0x7E (126).
   30: # These characters are:
   31: # SPACE and
   32: # !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNO
   33: # PQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~
   34: 
   35: # Valid user names must consist of ascii
   36: # characters that are alphabetical characters
   37: # (A-Z,a-z), numeric (0-9), or the underscore
   38: # mark (_). (Essentially, the perl regex \w).
   39: 
   40: # Command-line arguments
   41: # Yes, but be very careful here (don't pass shell commands)
   42: # and this is only supported to allow perl-system calls.
   43: 
   44: # Usage within code
   45: # Note: NEVER run as system("/home/httpd/perl/lcpasswd NAME OLDPWD NEWPWD")
   46: #
   47: # $exitcode=system("/home/httpd/perl/lcpasswd","NAME","OLDPWD","NEWPWD")/256;
   48: # print "uh-oh" if $exitcode;
   49: 
   50: # These are the exit codes.
   51: # ( (0,"ok"),
   52: #   (1,"User ID mismatch.  This program must be run as user 'www'"),
   53: #   (2,"Error. This program needs 3 command-line arguments (username, old password, new password)."),
   54: #   (3,"Error. Three lines need to be entered into standard input."),
   55: #   (4,"Error. Too many other simultaneous password change requests being made."),
   56: #   (5,"Error. User $username does not exist."),
   57: #   (6,"Error. Invalid entry of current password."),
   58: #   (7,"Error. Root was not successfully enabled."),
   59: #   (8,"Error. Cannot open /etc/passwd."),
   60: #   (9,"Error. The user name specified has invalid characters."),
   61: #   (10,"Error. A password entry had an invalid character.") )
   62: 
   63: # Security
   64: $ENV{'PATH'}='/bin:/usr/bin'; # Nullify path information except for what smbpasswd needs
   65: $ENV{'BASH_ENV'}=''; # Nullify shell environment information.
   66: 
   67: # Do not print error messages if there are command-line arguments
   68: my $noprint=0;
   69: if (@ARGV) {
   70:     $noprint=1;
   71: }
   72: 
   73: # Read in /etc/passwd, and make sure this process is running from user=www
   74: open (IN, '</etc/passwd');
   75: my @lines=<IN>;
   76: close IN;
   77: my $wwwid;
   78: for my $l (@lines) {
   79:     chop $l;
   80:     my @F=split(/\:/,$l);
   81:     if ($F[0] eq 'www') {$wwwid=$F[2];}
   82: }
   83: if ($wwwid!=$<) {
   84:     print("User ID mismatch.  This program must be run as user 'www'\n") unless $noprint;
   85:     exit 1;
   86: }
   87: &disable_root_capability;
   88: 
   89: # Handle case of another lcpasswd process
   90: unless (&try_to_lock('/tmp/lock_lcpasswd')) {
   91:     print "Error. Too many other simultaneous password change requests being made.\n" unless $noprint;
   92:     exit 4;
   93: }
   94: 
   95: # Gather input.  Should only be 3 values.
   96: my @input;
   97: if (@ARGV==3) {
   98:     @input=@ARGV;
   99: }
  100: elsif (@ARGV) {
  101:     print("Error. This program needs 3 command-line arguments (username, old password, new password).\n") unless $noprint;
  102:     unlink('/tmp/lock_lcpasswd');
  103:     exit 2;
  104: }
  105: else {
  106:     @input=<>;
  107:     if (@input!=3) {
  108: 	print("Error. Three lines need to be entered into standard input.\n") unless $noprint;
  109: 	unlink('/tmp/lock_lcpasswd');
  110: 	exit 3;
  111:     }
  112:     map {chop} @input;
  113: }
  114: 
  115: my ($username,$oldpwd,$newpwd)=@input;
  116: $username=~/^(\w+)$/;
  117: my $safeusername=$1;
  118: if ($username ne $safeusername) {
  119:     print "Error. The user name specified has invalid characters.\n";
  120:     unlink('/tmp/lock_lcpasswd');
  121:     exit 9;
  122: }
  123: my $pbad=0;
  124: map {if (($_<32)&&($_>126)){$pbad=1;}} (split(//,$oldpwd));
  125: map {if (($_<32)&&($_>126)){$pbad=1;}} (split(//,$newpwd));
  126: if ($pbad) {
  127:     print "Error. A password entry had an invalid character.\n";
  128:     unlink('/tmp/lock_lcpasswd');
  129:     exit 10;
  130: }
  131: 
  132: # Grab the line corresponding to username
  133: my ($userid,$useroldcryptpwd);
  134: my @F; my @U;
  135: for my $l (@lines) {
  136:     @F=split(/\:/,$l);
  137:     if ($F[0] eq $username) {($userid,$useroldcryptpwd)=($F[2],$F[1]); @U=@F;}
  138: }
  139: 
  140: # Verify existence of user
  141: if (!defined($userid)) {
  142:     print "Error. User $username does not exist.\n" unless $noprint;
  143:     unlink('/tmp/lock_lcpasswd');
  144:     exit 5;
  145: }
  146: 
  147: # Verify password entry
  148: if (crypt($oldpwd,$useroldcryptpwd) ne $useroldcryptpwd) {
  149:     print "Error. Invalid entry of current password.\n" unless $noprint;
  150:     unlink('/tmp/lock_lcpasswd');
  151:     exit 6;
  152: }
  153: 
  154: # Construct new password entry (random salt)
  155: my $newcryptpwd=crypt($newpwd,(join '', ('.', '/', 0..9, 'A'..'Z', 'a'..'z')[rand 64, rand 64]));
  156: $U[1]=$newcryptpwd;
  157: my $userline=join(':',@U);
  158: my $rootid=&enable_root_capability;
  159: if ($rootid!=0) {
  160:     print "Error.  Root was not successfully enabled.\n" unless $noprint;
  161:     unlink('/tmp/lock_lcpasswd');
  162:     exit 7;
  163: }
  164: open PASSWORDFILE, '>/etc/passwd' or (print("Error.  Cannot open /etc/passwd.\n") && unlink('/tmp/lock_lcpasswd') && exit(8));
  165: for my $l (@lines) {
  166:     @F=split(/\:/,$l);
  167:     if ($F[0] eq $username) {print PASSWORDFILE "$userline\n";}
  168:     else {print PASSWORDFILE "$l\n";}
  169: }
  170: close PASSWORDFILE;
  171: 
  172: ($>,$<)=(0,0); # fool smbpasswd here to think this is not a setuid environment
  173: unless (-e '/etc/smbpasswd') {
  174:     open (OUT,'>/etc/smbpasswd'); close OUT;
  175: }
  176: my $smbexist=0;
  177: open (IN, '</etc/smbpasswd');
  178: my @lines=<IN>;
  179: close IN;
  180: for my $l (@lines) {
  181:     chop $l;
  182:     my @F=split(/\:/,$l);
  183:     if ($F[0] eq $username) {$smbexist=1;}
  184: }
  185: unless ($smbexist) {
  186:     open(OUT,'>>/etc/smbpasswd');
  187:     print OUT join(':',($safeusername,$userid,'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX','','/home/'.$safeusername,'/bin/bash')) . "\n";
  188:     close OUT;
  189: }
  190: open(OUT,"|/usr/bin/smbpasswd -s $safeusername>/dev/null");
  191: print OUT $newpwd; print OUT "\n";
  192: print OUT $newpwd; print OUT "\n";
  193: close OUT;
  194: $<=$wwwid; # unfool the program
  195: &disable_root_capability;
  196: unlink('/tmp/lock_lcpasswd');
  197: exit 0;
  198: 
  199: # ----------------------------------------------------------- have setuid script run as root
  200: sub enable_root_capability {
  201:     if ($wwwid==$>) {
  202: 	($<,$>)=($>,$<);
  203: 	($(,$))=($),$();
  204:     }
  205:     else {
  206: 	# root capability is already enabled
  207:     }
  208:     return $>;
  209: }
  210: 
  211: # ----------------------------------------------------------- have setuid script run as www
  212: sub disable_root_capability {
  213:     if ($wwwid==$<) {
  214: 	($<,$>)=($>,$<);
  215: 	($(,$))=($),$();
  216:     }
  217:     else {
  218: 	# root capability is already disabled
  219:     }
  220: }
  221: 
  222: # ----------------------------------- make sure that another lcpasswd process isn't running
  223: sub try_to_lock {
  224:     my ($lockfile)=@_;
  225:     my $currentpid;
  226:     my $lastpid;
  227:     # Do not manipulate lock file as root
  228:     if ($>==0) {
  229: 	return 0;
  230:     }
  231:     # Try to generate lock file.
  232:     # Wait 3 seconds.  If same process id is in
  233:     # lock file, then assume lock file is stale, and
  234:     # go ahead.  If process id's fluctuate, try
  235:     # for a maximum of 10 times.
  236:     for (0..10) {
  237: 	if (-e $lockfile) {
  238: 	    open(LOCK,"<$lockfile");
  239: 	    $currentpid=<LOCK>;
  240: 	    close LOCK;
  241: 	    if ($currentpid==$lastpid) {
  242: 		last;
  243: 	    }
  244: 	    sleep 3;
  245: 	    $lastpid=$currentpid;
  246: 	}
  247: 	else {
  248: 	    last;
  249: 	}
  250: 	if ($_==10) {
  251: 	    return 0;
  252: 	}
  253:     }
  254:     open(LOCK,">$lockfile");
  255:     print LOCK $$;
  256:     close LOCK;
  257:     return 1;
  258: }