#! /usr/bin/perl -w
#
# This package doesn't depend on perl, so make sure that everything done in
# this script can be done with perl-base.  In particular, using any Perl
# modules other than the Debconf modules and the basic pragmata probably isn't
# valid.  (Some Perl modules do ship with perl-base, but there is no guarantee
# that set won't change.)

use strict;
use Debconf::Client::ConfModule ':all';

my $fix_etypes = 0;

if ($ARGV[0] eq 'configure' || $ARGV[0] eq 'reconfigure') {
    version('2.0') or die "Failed to start debconf\n";
    set ('krb5-config/read_conf', 'true');
    my $defrealm = get ('krb5-config/default_realm');

    # We should not manage krb5.conf if it is a symlink.  If people would
    # rather us manage if a symlink but writable please open a bug.
    exit(0) if -l "/etc/krb5.conf";
    unless (-f "/etc/krb5.conf" ) {
        system ('cp', '/usr/share/kerberos-configs/krb5.conf.template',
                '/etc/krb5.conf') == 0
            or die "Unable to create /etc/krb5.conf: $!\n";
    }
    if ($ARGV[1]) {
        my $version = $ARGV[1];
        system ('dpkg', '--compare-versions', $version, 'lt', '1.6');
        if ($? == 0) {
            $fix_etypes = 1;
        }
    }
    open(CONF, "/etc/krb5.conf") or die "Unable to open krb5.conf: $!\n";
    open (OUT, ">/etc/krb5.conf.dpkg-new")
        or die "Unable too open temporary config: $!";

    # The following loop allows any settings read from debconf to be placed
    # into krb5.conf file.  These settings should have been seeded from the
    # config script so we should not lose user changes.  We also look to see
    # if the default realm is mentioned in the realms section to know if we
    # need to add it later.
    my $defrealm_in_conf = 0;
    my $changed_defrealm = 0;
    while (<CONF>) {
        if (/^\s*\[libdefaults\]/i ... /^\s*\[(?!libdefaults)/i) {
            next if /^\s*[\#;]/;
            if ($defrealm && /\bdefault_realm\s*=\s*(\S+)/) {
                if ($1 ne $defrealm) {
                    $changed_defrealm = 1;
                    s/default_realm(\s*)=(.*)$/default_realm$1= $defrealm/i;
                }
            }
            if ($fix_etypes) {
                s/^\s*default_tgs_enctypes = des3-hmac-sha1 des-cbc-crc des-cbc-md5/\#$&/;
                s/^\s*default_tkt_enctypes = des3-hmac-sha1 des-cbc-crc des-cbc-md5/\#$&/;
                s/^\s*permitted_enctypes = des3-hmac-sha1 des-cbc-crc des-cbc-md5/\#$&/;
            }
        }
        if (/^\s*\[realms\]/i ... /^\s*\[(?!realms)/i) {
            if (/^\s*$defrealm\s*=\s*\{/) {
                $defrealm_in_conf = 1;
            }
        }
    } continue {
        print OUT;
    }
    close OUT or die "Unable to close output: $!,";
    rename ("/etc/krb5.conf.dpkg-new", "/etc/krb5.conf")
        or die "Unable to rename file: $!, stopped";
    my $add_servers = get ("krb5-config/add_servers");
  realm_config: {
        if (($add_servers eq "true") and !$defrealm_in_conf) {
            my $servers = get ('krb5-config/kerberos_servers');
            reset ('krb5-config/kerberos_servers');
            last realm_config unless $servers;
            my @servers = split (' ', $servers);
            my $admin = get ('krb5-config/admin_server');
            reset ('krb5-config/admin_server');
            local $/; # scoped for realm config section
            open (CONF, "/etc/krb5.conf")
                or die "Unable to open krb5.conf: $!, stopped";
            $_ = <CONF>;
            my $text = "\t$defrealm = {\n";
            map { $text .= "\t\tkdc = $_\n" } @servers;
            $text .= "\t\tadmin_server = $admin\n" if $admin;
	    $text .=  "\t}";
            s/\[realms\]/[realms]\n$text/;
            open (OUT, ">/etc/krb5.conf.dpkg-new")
                or die "Unable to open output: $!, stopped";
            print OUT $_;
            close OUT or die "Unable to close output: $!, stopped";
            rename ("/etc/krb5.conf.dpkg-new", "/etc/krb5.conf")
                or die "Unable to rename config file into place: $!, stopped";
        }
    }
}


# Run any additional debhelper commands.
open(CMD, "| sh")
    or die "Unable to run debhelper commands: $!\n";
print CMD "set -e\nset -- " . join (" ", @ARGV) . "\n";
print CMD <<'eof';

eof
close CMD;
exit $?>>8;