| 19 |
|
|
| 20 |
|
|
| 21 |
|
my ($query) = new CGI; |
| 22 |
– |
my ($doc) = ($query->param('doc') =~ /^\s*(.*?\.txt)\s*$/); |
| 23 |
– |
$doc = "../documentation/".$doc; |
| 22 |
|
|
| 23 |
+ |
# Note filenames may only have one dot in them, in the ".txt". |
| 24 |
+ |
# This prevents malicious users using "../" to view files. |
| 25 |
+ |
my ($doc) = ($query->param('doc') =~ /^\s*([^\.]*?\.txt)\s*$/); |
| 26 |
+ |
|
| 27 |
|
print "Content-type: text/html\n\n"; |
| 28 |
+ |
|
| 29 |
+ |
unless (defined $doc) { |
| 30 |
+ |
print "The link to this page was broken - it must specify a .txt file."; |
| 31 |
+ |
exit; |
| 32 |
+ |
} |
| 33 |
+ |
|
| 34 |
+ |
# Prevent hackers from supplying a malformed document string. |
| 35 |
+ |
# I.e. only allow normal characters, slashes and dots. |
| 36 |
+ |
unless ($doc =~ /^[a-zA-Z_\-0-9\.\/]+$/) { |
| 37 |
+ |
print "Go Away, you nasty hax0r!"; |
| 38 |
+ |
exit; |
| 39 |
+ |
} |
| 40 |
+ |
$doc = "../documentation/".$doc; |
| 41 |
|
|
| 42 |
|
print <<"END"; |
| 43 |
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> |
