CGI error: "Invalid header value contains a newline not followed by whitespace"

groengoen has asked for the wisdom of the Perl Monks concerning the following question:

This is the same title as a previous question but the error occurs in different circumstances. I am a complete newby with CGI and PERL and was just looking to debug a CGI script.

######################################################################
+###############################################
# LOGOUT
######################################################################
+###############################################
sub logout
{
  my ($cgi) = @_;

  my $cookie1 = $cgi->cookie(-name => "login",
                        -value => "",
                        -expires => '-1d');

  my $cookie2 = $cgi->cookie(-name => 'password',
                        -value => "",
                        -expires => '-1d');

  my $cookie3 = $cgi->cookie(-name => 'id',
                        -value => "",
                        -expires => '-1d');

  my $cookie4 = $cgi->cookie(-name => 'CGISESSID',
                        -value => "",
                        -expires => '-1d');

  my $cookie = $cookie1."\nSet-Cookie: $cookie2"."\nSet-Cookie: $cooki
+e3\nSet-Cookie: $cookie4";

  print $cgi->redirect(-cookie => $cookie,
                       -uri    => "$PROTOCOL://$ENV{HTTP_HOST}$ENV{SCR
+IPT_NAME}"
                      );

  return;
}
[download]

This is to log out from the script and redirect to the previous screen.

Comment on CGI error: "Invalid header value contains a newline not followed by whitespace" Download Code

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Re: CGI error: "Invalid header value contains a newline not followed by whitespace" by Corion (Patriarch) on Oct 13, 2014 at 20:16 UTC
You build a header value that contains newlines, and these newlines are not immediately followed by whitespace. This is what CGI.pm complains about, as doing so is usually an error. Your code seems to try to abuse that function to set multiple cookies. Maybe you want to ask how to set multiple cookies using CGI.pm instead? Unsurprisingly, searching CGI for "multiple cookies" gives a ready result. Maybe you want to try that?	[reply]
Re: CGI error: "Invalid header value contains a newline not followed by whitespace" by GrandFather (Saint) on Oct 13, 2014 at 20:15 UTC
This is dabbling toward to edges of my expertise, but the error says "no new lines" and your $cookie assignment adds \n (new lines) to the string. Maybe relevant if you are interested in why this is a bad idea: [http://www.hpenterprisesecurity.com/vulncat/en/vulncat/cfml/header_manipulation_cookies.html]. Perl is the programming world's equivalent of English	[reply]
Re: CGI error: "Invalid header value contains a newline not followed by whitespace" by toolic (Bishop) on Oct 13, 2014 at 20:16 UTC
I am a complete newby with CGI and PERL and was just looking to debug a CGI script. Troubleshooting Perl CGI scripts	[reply]
Re: CGI error: "Invalid header value contains a newline not followed by whitespace" by ikegami (Patriarch) on Oct 14, 2014 at 06:49 UTC
`$cookie` does not contain a cookie or a reference to an array of cookies. It's garbage. `my $cookie = $cookie1."\nSet-Cookie: $cookie2"."\nSet-Cookie: $cookie3 +\nSet-Cookie: $cookie4";` [download] should be `my $cookie = [ $cookie1, $cookie2, $cookie3, $cookie4 ];` [download] Then we can clean up your code. `my @cookies; push @cookies, $cgi->cookie(-name => "login", -value => "", -expir +es => '-1d'); push @cookies, $cgi->cookie(-name => 'password', -value => "", -expir +es => '-1d'); push @cookies, $cgi->cookie(-name => 'id', -value => "", -expir +es => '-1d'); push @cookies, $cgi->cookie(-name => 'CGISESSID', -value => "", -expir +es => '-1d'); print $cgi->redirect( -cookie => \@cookies, -uri => $cgi->url(), );` [download] or even `my @cookies = map { $cgi->cookie(-name => $_ -value => "", -expires => + '-1d') } qw( login password id CGISESSID ); print $cgi->redirect( -cookie => \@cookies, -uri => $cgi->url(), );` [download]	[reply] [d/l] [select]
Re^2: CGI error: "Invalid header value contains a newline not followed by whitespace" by groengoen (Initiate) on Oct 14, 2014 at 08:39 UTC
Thanks very much for the very concise code. I used the last bit of code and it eliminated the error. However I actually wanted the logout to redirect to the calling url for the whole cgi. I am actually returned to the page with the logout tab(where I logged out). Any idea about that?	[reply]
Re^3: CGI error: "Invalid header value contains a newline not followed by whitespace" by ikegami (Patriarch) on Oct 14, 2014 at 14:24 UTC
Because you're passing the url of the page the user requested when you mean to redirect to the login page. Maybe `$cgi->url(-base => 1) . '/login.html'`?	[reply] [d/l]
Re^4: CGI error: "Invalid header value contains a newline not followed by whitespace" by groengoen (Initiate) on Oct 14, 2014 at 16:29 UTC