--- loncom/lcpasswd	2000/10/28 19:22:19	1.6
+++ loncom/lcpasswd	2000/10/29 23:14:16	1.8
@@ -23,6 +23,19 @@ use strict;
 # Second line is CURRENT PASSWORD
 # Third line is NEW PASSWORD
 
+# 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).
+
 # Command-line arguments
 # Yes, but be very careful here (don't pass shell commands)
 # and this is only supported to allow perl-system calls.
@@ -35,13 +48,13 @@ use strict;
 
 # These are the exit codes.
 # ( (0,"ok"),
-#   (1,"User ID mismatch.  This program must be run as user 'www'),
+#   (1,"User ID mismatch.  This program must be run as user 'www'"),
 #   (2,"Error. This program does not accept command-line arguments."),
 #   (3,"Error. Three lines need to 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. Invalid entry of current password."),
-#   (7,"Error.  Root was not successfully enabled.") )
+#   (7,"Error.  Root was not successfully enabled."),
 #   (8,"Error.  Cannot open /etc/passwd.") )
 
 # Security
@@ -97,6 +110,14 @@ else {
 }
 
 my ($username,$oldpwd,$newpwd)=@input;
+$username=~/^(\w+)$/;
+my $safeusername=$1;
+if ($username ne $safeusername) {
+    print "Error. The user name specified has invalid characters.\n";
+    unlink('/tmp/lock_lcpasswd');
+    exit 9;
+}
+
 
 # Grab the line corresponding to username
 my ($userid,$useroldcryptpwd);
@@ -137,8 +158,7 @@ for my $l (@lines) {
     else {print PASSWORDFILE "$l\n";}
 }
 close PASSWORDFILE;
-$username=~/^(\w+)$/;
-my $safeusername=$1;
+
 ($>,$<)=(0,0); # fool smbpasswd here to think this is not a setuid environment
 unless (-e '/etc/smbpasswd') {
     open (OUT,'>/etc/smbpasswd'); close OUT;