Bug#376670: Patch for reseed: postinst failure when no HTTP proxy and ICMP is filtered

[José Parrella]

tags 376670 +patch
thank you

The following patch should solve the failure in the postinst action in
ICMP filtered environments, while preventing the further execution of
the program if no random seed could be retrieved:

50,13d12
< use Net::Ping;
50,54d48
< # see if we've got net access
< my $p = new Net::Ping('icmp');
< die("no net access\n") unless $p->ping($ping_host);
< $p->close();
<
58a53
> die("no net access\n") unless $response->{_rc} eq "200";

I'm attaching a patched reseed program. Please comment on this patch and
apply it as soon as you can if it's good for you.

Jose

-- 
José M. Parrella -> Debian Sid, k2.6.16.20
Escuela de Ingenieria Electrica
Universidad Central de Venezuela -> ucvlug.info

#!/usr/bin/perl

# reseed - re-seed the random number generator using a number
# acquired from random.org, the Internet random numbers source
# Generally this script is intended to be run as part of the
# boot process, and must be run with root permissions
# $Id: reseed,v 1.1 1999/11/01 12:30:43 dobsons Exp $

use strict;

use LWP::UserAgent;
use URI::URL;

autoflush STDOUT 1;
print "Re-seeding random number generator from net...";

my $proxies = "/etc/sysconfig/proxies";
my $random_device = "/dev/urandom";
my $bytes = 512;
my $random_host = "www.random.org";
my $random_url =
"http://$random_host/cgi-bin/randnum?num=$bytes&min=0&max=255&col=1";;
my $ping_host = $random_host;

# set up web access from local sysconfig
my $ua = new LWP::UserAgent;
my ($lower, $url);
if(-f $proxies)
  {
    # We expect $proxies to contain a file of shell variable definitions
    # for proxies for different protocols - in particular a variable
    # HTTP_PROXY for the local web proxy. Otherwise we assume a direct
    # Internet connection
    open(PROXY, "<$proxies") || die("can't open $proxies\n");
    while(<PROXY>)
      {
        if(/(\w+)_PROXY \s* = \s* \"([^\"]*)\"/ix)
          {
            $lower = $1;   $url = $2;
            $lower =~ tr/A-Z/a-z/;
            $ua->proxy([$lower], $url);
            if($url =~ m#\w+://([^/:]+)#)
               { $ping_host = $1; }
          }
      }
    close(PROXY);
  }

# hit random number source for a seed
my ($request, $response, @bytes);
$request = new HTTP::Request("GET", $random_url);
$response = $ua->request($request);
die("no net access\n") unless $response->{_rc} eq "200";

# generate a byte stream from the numbers
@bytes = split /\n/, $response->content();
map { chr($_) } @bytes;

# write the byte stream into the random number generator
open(RANDOM, "| dd of=$random_device bs=$bytes count=1 2>/dev/null") ||
die("can't write to $random_device\n");
print RANDOM (join "", @bytes);
close(RANDOM);

print "done\n";
exit 0;