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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;
}

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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.

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Re: First Time Untainting Data
by Abigail-II (Bishop) on Oct 10, 2003 at 17:10 UTC
    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 ($s =~ m{^([-\w \@(),./]+)$}) {

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    Abigail

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