Re: Re: First Time Untainting Data

[svsingh]

in reply to Re: First Time Untainting Data
in thread First Time Untainting Data

Thanks for the tip. I rewrote the untaint subroutine as follows (borrowing from perlsec):

sub untaint {
   my $s = $_[0];
   if ($s =~ /^([\w \-\@\(\)\,\.\/]+)$/) {
      $s = $1;               # $data now untainted
    } else {
      die "Bad data in $s";  # log this somewhere
    }  
    return $s;
}

When I get home, I'll look into writing a separate untaint subroutine for each field, but is this more correct than the original?

Thanks again.

[Abigail-II]

This is at least a syntactical valid way of untainting the data, but I do not know whether it's semantically correct. That depends on how the data is used. And do yourself (and all readers of your code), don't backwack everything. Only use a backslash when it's really needed. Like this:

    if ($s =~ m{^([-\w \@(),./]+)$}) {

Abigail