path: root/perl-install/authentication.pm

package authentication; # $Id$
use common;

my $lib = arch() =~ /x86_64/ ? 'lib64' : 'lib';

sub kinds { 
    my $no_para = @_ == 0;
    my ($do_pkgs) = @_;
    my $allow_SmartCard = $no_para || $do_pkgs->is_available('castella-pam');
    my $allow_AD = 1;
    (
	'local', 
	'LDAP',
	'NIS', 
	if_($allow_SmartCard, 'SmartCard'), 
	'winbind', 
	if_($allow_AD, 'AD', 'SMBKRB'),
    );
}

sub kind2name {
    my ($kind) = @_;
    # Keep the following strings in sync with kind2description ones!!!
    ${{ local => N("Local file"), 
    LDAP => N("LDAP"), 
    NIS => N("NIS"),
    SmartCard => N("Smart Card"),
    winbind => N("Windows Domain"), 
    AD => N("Active Directory with SFU"),
    SMBKRB => N("Active Directory with Winbind") }}{$kind};
}

my %kind2pam_kind = (
    local     => [],
    SmartCard => ['castella'],
    LDAP      => ['ldap'], 
    NIS       => [],
    AD        => ['krb5'],
    winbind   => ['winbind'], 
    SMBKRB    => ['winbind'],
);

my %kind2nsswitch = (
    local     => [],
    SmartCard => [],
    LDAP      => ['ldap'], 
    NIS       => ['nis'],
    AD        => ['ldap'],
    winbind   => ['winbind'], 
    SMBKRB    => ['winbind'],
);

my %kind2packages = (
    local     => [],
    SmartCard => [ 'castella-pam' ],
    LDAP      => [ 'openldap-clients', 'nss_ldap', 'pam_ldap', 'autofs' ],
    AD        => [ 'nss_ldap', 'pam_krb5', $lib . 'sasl2-plug-gssapi' ],
    NIS       => [ 'ypbind', 'autofs' ],
    winbind   => [ 'samba-winbind' ],
    SMBKRB    => [ 'samba-winbind', 'pam_krb5', 'samba-server', 'samba-client' ],
);


sub kind2description {
    my (@kinds) = @_;
    my %kind2description = (
	local     => [ N("Local file:"), N("Use information stored in local files for all authentication"), ],
	LDAP      => [ N("LDAP:"), N("Tells your computer to use LDAP for some or all authentication. LDAP consolidates certain types of information within your organization."), ],
	NIS       => [ N("NIS:"), N("Allows you to run a group of computers in the same Network Information Service domain with a common password and group file."), ],
	winbind   => [ N("Windows Domain:"), N("Winbind allows the system to retrieve information and authenticate users in a Windows domain."), ],
	AD        => [ N("Active Directory with SFU:"), N("With Kerberos and Ldap for authentication in Active Directory Server "), ],
	SMBKRB    => [ N("Active Directory with Winbind:"), N("Winbind allows the system to authenticate users in a Windows Active Directory Server.")  ],
    );
    join('', map { $_ ? qq($_->[0]\n$_->[1]\n\n) : '' } map { $kind2description{$_} } @kinds);
}
sub to_kind {
    my ($authentication) = @_;
    (find { exists $authentication->{$_} } kinds()) || 'local';
}

sub domain_to_ldap_domain {
    my ($domain) = @_;
    join(',', map { "dc=$_" } split /\./, $domain);
}

sub ask_parameters {
    my ($in, $net, $authentication, $kind) = @_;

    #- keep only this authentication kind
    foreach (kinds()) {
	delete $authentication->{$_} if $_ ne $kind;
    }

    if ($kind eq 'LDAP') {
	$authentication->{LDAPDOMAIN} ||= domain_to_ldap_domain($net->{resolv}{DOMAINNAME});
	$in->ask_from('',
		     N("Authentication LDAP"),
		     [ { label => N("LDAP Base dn"), val => \$authentication->{LDAPDOMAIN} },
		       { label => N("LDAP Server"), val => \$authentication->{LDAP_server} },
		     ]) or return;
    } elsif ($kind eq 'AD') {
	
	$authentication->{AD_domain} ||= $net->{resolv}{DOMAINNAME};
	$authentication->{AD_users_db} ||= 'cn=users,' . domain_to_ldap_domain($authentication->{AD_domain});

	$in->do_pkgs->ensure_are_installed([ 'perl-Net-DNS' ], 1) or return;

	my @srvs = query_srv_names($authentication->{AD_domain});
	$authentication->{AD_server} ||= $srvs[0] if @srvs;

	my %sub_kinds = (
	    simple => N("simple"), 
	    tls => N("TLS"),
	    ssl => N("SSL"),
	    kerberos => N("security layout (SASL/Kerberos)"),
	);

	my $AD_user = $authentication->{AD_user} =~ /(.*)\@\Q$authentication->{AD_domain}\E$/ ? $1 : $authentication->{AD_user};
	my $anonymous = $AD_user;

	$in->ask_from('',
		     N("Authentication Active Directory"),
		     [ { label => N("Domain"), val => \$authentication->{AD_domain} },
		     #{ label => N("Server"), val => \$authentication->{AD_server} },
		       { label => N("Server"), type => 'combo', val => \$authentication->{AD_server}, list => \@srvs , not_edit => 0 },
		       { label => N("LDAP users database"), val => \$authentication->{AD_users_db} },
		       { label => N("Use Anonymous BIND "), val => \$anonymous, type => 'bool' },
		       { label => N("LDAP user allowed to browse the Active Directory"), val => \$AD_user, disabled => sub { $anonymous } },
		       { label => N("Password for user"), val => \$authentication->{AD_password}, hidden => 1, disabled => sub { $anonymous } },
		       #{ label => N("Encryption"), val => \$authentication->{sub_kind}, list => [ map { $_->[0] } group_by2(@sub_kinds) ], format => sub { $sub_kinds{$_[0]} } },
		     ]) or return;
	$authentication->{AD_user} = !$AD_user || $authentication->{sub_kind} eq 'anonymous' ? '' : 
	                             $AD_user =~ /@/ ? $AD_user : "$AD_user\@$authentication->{AD_domain}";
	$authentication->{AD_password} = '' if !$authentication->{AD_user};


    } elsif ($kind eq 'NIS') { 
	$authentication->{NIS_server} ||= 'broadcast';
	$net->{network}{NISDOMAIN} ||= $net->{resolv}{DOMAINNAME};
	$in->ask_from('',
		     N("Authentication NIS"),
		     [ { label => N("NIS Domain"), val => \$net->{network}{NISDOMAIN} },
		       { label => N("NIS Server"), val => \$authentication->{NIS_server}, list => ["broadcast"], not_edit => 0 },
		     ]) or return;
    } elsif ($kind eq 'winbind' || $kind eq 'SMBKRB') {
	#- maybe we should browse the network like diskdrake --smb and get the 'doze server names in a list 
	#- but networking is not setup yet necessarily
	$in->ask_warn('', N("For this to work for a W2K PDC, you will probably need to have the admin run: C:\\>net localgroup \"Pre-Windows 2000 Compatible Access\" everyone /add and reboot the server.
You will also need the username/password of a Domain Admin to join the machine to the Windows(TM) domain.
If networking is not yet enabled, Drakx will attempt to join the domain after the network setup step.
Should this setup fail for some reason and domain authentication is not working, run 'smbpasswd -j DOMAIN -U USER%%PASSWORD' using your Windows(tm) Domain, and Admin Username/Password, after system boot.
The command 'wbinfo -t' will test whether your authentication secrets are good."))
	  if $kind eq 'winbind';

	$authentication->{AD_domain} ||= $net->{resolv}{DOMAINNAME} if $kind eq 'SMBKRB';
	 $authentication->{AD_users_idmap} ||= 'ou=idmap,' . domain_to_ldap_domain($authentication->{AD_domain}) if $kind eq 'SMBKRB';
	$authentication->{WINDOMAIN} ||= $net->{resolv}{DOMAINNAME};

	$in->ask_from('',
		      $kind eq 'SMBKRB' ? N("Authentication Active Directory") : N("Authentication Windows Domain"),
		        [ if_($kind eq 'SMBKRB', 
			  { label => N("Active Directory Realm "), val => \$authentication->{AD_domain} }
			     ),
			  { label => N("Windows Domain"), val => \$authentication->{WINDOMAIN} },
			  { label => N("Domain Admin User Name"), val => \$authentication->{winuser} },
			  { label => N("Domain Admin Password"), val => \$authentication->{winpass}, hidden => 1 },
			  #{ label => N("Use Idmap for store UID/SID "), val => \$anonymous, type => 'bool' },
			  #{ label => N("Default Idmap "), val => \$authentication->{AD_users_idmap}, disabled => sub { $anonymous } },
			]) or return;
    }
    $authentication->{$kind} ||= 1;
    1;
}

sub ask_root_password_and_authentication {
    my ($in, $net, $superuser, $authentication, $_meta_class, $security) = @_;

    my $kind = to_kind($authentication);
    my @kinds = kinds($in->do_pkgs);

    $in->ask_from_({
	 title => N("Authentication"), 
	 messages => N("Set administrator (root) password"),
	 icon => 'banner-pw',
	 advanced_label => N("Authentication method"),
	 advanced_messages => kind2description(@kinds),
	 interactive_help_id => "setRootPassword",
	 cancel => ($security <= 2 ? 
		    #-PO: keep this short or else the buttons will not fit in the window
		    N("No password") : ''),
	 focus_first => 1,
	 callbacks => { 
	     complete => sub {
		 check_given_password($in, $superuser, 2 * $security) or return 1,0;
		 return 0;
        } } }, [
{ label => N("Password"), val => \$superuser->{password},  hidden => 1 },
{ label => N("Password (again)"), val => \$superuser->{password2}, hidden => 1 },
{ label => N("Authentication"), val => \$kind, type => 'list', list => \@kinds, format => \&kind2name, advanced => 1 },
        ]) or delete $superuser->{password};

    ask_parameters($in, $net, $authentication, $kind) or goto &ask_root_password_and_authentication;
}

sub check_given_password {
    my ($in, $u, $min_length) = @_;
    if ($u->{password} ne $u->{password2}) {
	$in->ask_warn('', [ N("The passwords do not match"), N("Please try again") ]);
	0;
    } elsif (length $u->{password} < $min_length) {
	$in->ask_warn('', N("This password is too short (it must be at least %d characters long)", $min_length));
	0;
    } else {
	1;
    }
}

sub get() {
    my $system_auth = cat_("/etc/pam.d/system-auth");
    my $authentication = { 
	md5 => $system_auth =~ /md5/, shadow => $system_auth =~ /shadow/, 
    };

    my @pam_kinds = get_pam_authentication_kinds();
    if (my $kind = find { intersection(\@pam_kinds, $kind2pam_kind{$_}) } keys %kind2pam_kind) {
	$authentication->{$kind} = '';
    } else {
	#- we can't use pam to detect NIS
	if (my $yp_conf = read_yp_conf()) {
	    $authentication->{NIS} = 1;
	    map_each { $authentication->{"NIS_$::a"} = $::b } %$yp_conf;
	}
    }
    $authentication;
}

sub install_needed_packages {
    my ($do_pkgs, $kind) = @_;
    if (my $pkgs = $kind2packages{$kind}) {
	#- automatic during install
	$do_pkgs->ensure_are_installed($pkgs, $::isInstall) or return;
    } else {
	log::l("ERROR: $kind not listed in kind2packages");
    }
    1;
}

sub set {
    my ($in, $net, $authentication, $o_when_network_is_up) = @_;

    install_needed_packages($in->do_pkgs, to_kind($authentication)) or return;
    set_raw($net, $authentication, $o_when_network_is_up);
}

sub set_raw {
    my ($net, $authentication, $o_when_network_is_up) = @_;

    my $when_network_is_up = $o_when_network_is_up || sub { my ($f) = @_; $f->() };

    enable_shadow() if $authentication->{shadow};    

    my $kind = to_kind($authentication);

    log::l("authentication::set $kind");

    my $pam_modules = $kind2pam_kind{$kind} or log::l("kind2pam_kind does not know $kind");
    $pam_modules ||= [];
    sshd_config_UsePAM(@$pam_modules > 0);
    set_pam_authentication(@$pam_modules);

    my $nsswitch = $kind2nsswitch{$kind} or log::l("kind2nsswitch does not know $kind");
    $nsswitch ||= [];
    set_nsswitch_priority(@$nsswitch);

    if ($kind eq 'local') {
    } elsif ($kind eq 'SmartCard') {
    } elsif ($kind eq 'LDAP') {
	my $domain = $authentication->{LDAPDOMAIN} || do {
	    my $s = run_program::rooted_get_stdout($::prefix, 'ldapsearch', '-x', '-h', $authentication->{LDAP_server}, '-b', '', '-s', 'base', '+');
	    first($s =~ /namingContexts: (.+)/);
	} or log::l("no ldap domain found on server $authentication->{LDAP_server}"), return;

	update_ldap_conf(
			 host => $authentication->{LDAP_server},
			 base => $domain,
			 nss_base_shadow => $domain . "?sub",
			 nss_base_passwd => $domain . "?sub",
			 nss_base_group => $domain . "?sub",
			);
    } elsif ($kind eq 'AD') {
	my $port = "389";
	
	my $ssl = { 
		   anonymous => 'off', 
		   simple => 'off', 
		   tls => 'start_tls',
		   ssl => 'on',
		   kerberos => 'off',
		  }->{$authentication->{sub_kind}};

	if ($ssl eq 'on') {
		$port = '636';
	}
	
	
	
	update_ldap_conf(
			 host => $authentication->{AD_server},
			 base => domain_to_ldap_domain($authentication->{AD_domain}),
			 nss_base_shadow => "$authentication->{AD_users_db}?sub",
			 nss_base_passwd => "$authentication->{AD_users_db}?sub",
			 nss_base_group => "$authentication->{AD_users_db}?sub",

			 ssl => $ssl,
			 sasl_mech => $authentication->{sub_kind} eq 'kerberos' ? 'GSSAPI' : '',
			 port => $port,

			 binddn => $authentication->{AD_user},
			 bindpw => $authentication->{AD_password},

			 (map_each { "nss_map_objectclass_$::a" => $::b }
			  posixAccount => 'User',
			  shadowAccount => 'User',
			  posixGroup => 'Group',
			 ),


			 scope => 'sub',
			 pam_login_attribute => 'sAMAccountName',
			 pam_filter => 'objectclass=User',
			 pam_password => 'ad',

			 
			 (map_each { "nss_map_attribute_$::a" => $::b }
			  uid => 'sAMAccountName',
			  uidNumber => 'msSFU30UidNumber',
			  gidNumber => 'msSFU30GidNumber',
			  cn => 'sAMAccountName',
			  uniqueMember => 'member',
			  userPassword => 'msSFU30Password',
			  homeDirectory => 'msSFU30HomeDirectory',
			  loginShell => 'msSFU30LoginShell',
			  gecos => 'name',
			 ),
			);

	configure_krb5_for_AD($authentication);

    } elsif ($kind eq 'NIS') {
	my $domain = $net->{network}{NISDOMAIN};
	my $NIS_server = $authentication->{NIS_server};
	$domain || $NIS_server ne "broadcast" or die N("Can not use broadcast with no NIS domain");
	my $t = $domain ? 
	  ($NIS_server eq 'broadcast' ? 
	     "domain $domain broadcast" : 
	     "domain $domain server $NIS_server") :
	     "server $NIS_server";

	substInFile {
	    if (/^#/) {
		$_ = '' if /^#\Q[PREVIOUS]/;
	    } else {
		$_ = "#[PREVIOUS] $_";
	    }
	    $_ .= "$t\n" if eof;
	} "$::prefix/etc/yp.conf";

	#- no need to modify system-auth for nis

	$when_network_is_up->(sub {
	    run_program::rooted($::prefix, 'nisdomainname', $domain);
	    run_program::rooted($::prefix, 'service', 'ypbind', 'restart');
	});
#    } elsif ($kind eq 'winbind' || $kind eq 'AD' && $authentication->{subkind} eq 'winbind') {

    } elsif ($kind eq 'winbind') {

	my $domain = uc $authentication->{WINDOMAIN};
	
	require fs::remote::smb;
	fs::remote::smb::write_smb_conf($domain);
	run_program::rooted($::prefix, "chkconfig", "--level", "35", "winbind", "on");
	mkdir_p("$::prefix/home/$domain");
	run_program::rooted($::prefix, 'service', 'smb', 'restart');
	run_program::rooted($::prefix, 'service', 'winbind', 'restart');
	
	#- defer running smbpassword until the network is up

	$when_network_is_up->(sub {
	    run_program::raw({ root => $::prefix, sensitive_arguments => 1 },
			     'net', 'join', $domain, '-U', $authentication->{winuser} . '%' . $authentication->{winpass});
	});
    } elsif ($kind eq 'SMBKRB') {
	 $authentication->{AD_server} ||= 'ads.' . $authentication->{AD_domain};
	my $domain = uc $authentication->{WINDOMAIN};
	my $realm = $authentication->{AD_domain};

	configure_krb5_for_AD($authentication);
		
	require fs::remote::smb;
	fs::remote::smb::write_smb_ads_conf($domain,$realm);
	run_program::rooted($::prefix, "chkconfig", "--level", "35", "winbind", "on");
	mkdir_p("$::prefix/home/$domain");
	run_program::rooted($::prefix, 'net', 'time', 'set', '-S', $authentication->{AD_server});
	run_program::rooted($::prefix, 'service', 'smb', 'restart');
	run_program::rooted($::prefix, 'service', 'winbind', 'restart');
	
	$when_network_is_up->(sub {
	    run_program::raw({ root => $::prefix, sensitive_arguments => 1 }, 
			     'net', 'ads', 'join', '-U', $authentication->{winuser} . '%' . $authentication->{winpass});
	});
    }
    1;
}


sub pam_modules() {
    'pam_ldap', 'pam_castella', 'pam_winbind', 'pam_krb5', 'pam_mkhomedir';
}
sub pam_module_from_path { 
    $_[0] && $_[0] =~ m|(/lib/security/)?(pam_.*)\.so| && $2;
}
sub pam_module_to_path { 
    "$_[0].so";
}
sub pam_format_line {
    my ($type, $control, $module, @para) = @_;
    sprintf("%-11s %-13s %s\n", $type, $control, join(' ', pam_module_to_path($module), @para));
}

sub get_raw_pam_authentication() {
    my %before_deny;
    foreach (cat_("$::prefix/etc/pam.d/system-auth")) {
	my ($type, $control, $module, @para) = split;
	if ($module = pam_module_from_path($module)) {
	    $before_deny{$type}{$module} = \@para if $control eq 'sufficient' && member($module, pam_modules());
	}
    }
    \%before_deny;
}

sub get_pam_authentication_kinds() {
    my $before_deny = get_raw_pam_authentication();
    map { s/pam_//; $_ } keys %{$before_deny->{auth}};
}

sub set_pam_authentication {
    my (@authentication_kinds) = @_;
    
    my %special = (
	auth => [ difference2(\@authentication_kinds,, [ 'mount' ]) ],
	account => [ difference2(\@authentication_kinds, [ 'castella', 'mount' ]) ],
	password => [ intersection(\@authentication_kinds, [ 'ldap', 'krb5' ]) ],
    );
    my %before_first = (
	auth => member('mount', @authentication_kinds) ? pam_format_line('auth', 'required', 'pam_mount') : '',
	session => 
	  intersection(\@authentication_kinds, [ 'winbind', 'krb5', 'ldap' ]) 
	    ? pam_format_line('session', 'optional', 'pam_mkhomedir', 'skel=/etc/skel/', 'umask=0022') :
	  member('castella', @authentication_kinds)
	    ? pam_format_line('session', 'optional', 'pam_castella') : '',
    );
    my %after_deny = (
	session =>
          member('krb5', @authentication_kinds)
            ? pam_format_line('session', 'optional', 'pam_krb5') :
          member('mount', @authentication_kinds)
            ? pam_format_line('session', 'optional', 'pam_mount') : '',
    );

    substInFile {
	my ($type, $control, $module, @para) = split;
	if ($module = pam_module_from_path($module)) {
	    if (member($module, pam_modules())) {
		#- first removing previous config
		$_ = '';
	    }
	    if ($module eq 'pam_unix' && $special{$type}) {
		my @para_for_last = 
		    member($type, 'auth', 'account') ? qw(use_first_pass) : @{[]};
		@para = difference2(\@para, \@para_for_last);

		my ($before_noask, $ask) = partition { $_ eq 'castella' } @{$special{$type}};
		my ($before, $after) = partition { $_ eq 'krb5' } @$ask;

		if (!@$ask) {
		    @para_for_last = grep { $_ ne 'use_first_pass' } @para_for_last;
		}

		my @l = ((map { [ "pam_$_" ] } @$before_noask, @$before),
			 [ 'pam_unix', @para ],
			 (map { [ "pam_$_" ] } @$after),
			 );
		push @{$l[-1]}, @para_for_last;
		$_ = join('', map { pam_format_line($type, 'sufficient', @$_) } @l);

		if ($control eq 'required') {
		    #- ensure a pam_deny line is there
		    ($control, $module, @para) = ('required', 'pam_deny');
		    $_ .= pam_format_line($type, $control, $module);
		}
	    }
	    if (my $s = delete $before_first{$type}) {
		$_ = $s . $_;
	    }
	    if ($control eq 'required' && member($module, 'pam_deny', 'pam_unix')) {
		if (my $s = delete $after_deny{$type}) {
		    $_ .= $s;
		}
	    }
	}
    } "$::prefix/etc/pam.d/system-auth";
}

sub set_nsswitch_priority {
    my (@kinds) = @_;
    my @known = qw(nis ldap winbind);
    substInFile {
	if (my ($database, $l) = /^(\s*(?:passwd|shadow|group|automount):\s*)(.*)/) {
	    my @l = difference2([ split(' ', $l) ], \@known);
	    $_ = $database . join(' ', uniq('files', @kinds, @l)) . "\n";
	}	
    } "$::prefix/etc/nsswitch.conf";
}

sub read_yp_conf() {
    my $yp_conf = cat_("$::prefix/etc/yp.conf");
    
    if ($yp_conf =~ /^domain\s+(\S+)\s+(\S+)\s*(.*)/m) {
	{ domain => $1, server => $2 eq 'broadcast' ? 'broadcast' : $3 };
    } elsif ($yp_conf =~ /^server\s+(.*)/m) {
	{ server => $1 };
    } else {
	undef;
    }    
}

my $special_ldap_cmds = join('|', 'nss_map_attribute', 'nss_map_objectclass');
sub _after_read_ldap_line {
    my ($s) = @_;
    $s =~ s/\b($special_ldap_cmds)\s*/$1 . '_'/e;
    $s;
}
sub _pre_write_ldap_line {
    my ($s) = @_;
    $s =~ s/\b($special_ldap_cmds)_/$1 . ' '/e;
    $s;
}

sub read_ldap_conf() {
    my %conf = map { 
	s/^\s*#.*//; 
	if_(_after_read_ldap_line($_) =~ /(\S+)\s+(.*)/, $1 => $2);
    } cat_("$::prefix/etc/ldap.conf");
    \%conf;
}

sub update_ldap_conf {    
    my (%conf) = @_;

    substInFile {
	my ($cmd) = _after_read_ldap_line($_) =~ /^\s*#?\s*(\w+)\s/;
	if ($cmd && exists $conf{$cmd}) {
	    my $val = $conf{$cmd};
	    $conf{$cmd} = '';
	    $_ = $val ? _pre_write_ldap_line("$cmd $val\n") : /^\s*#/ ? $_ : "#$_";
        }
	if (eof) {
	    foreach my $cmd (keys %conf) {
		my $val = $conf{$cmd} or next;
		$_ .= _pre_write_ldap_line("$cmd $val\n");
	    }
	}
    } "$::prefix/etc/ldap.conf";
}

sub configure_krb5_for_AD {
    my ($authentication) = @_;

    my $uc_domain = uc $authentication->{AD_domain};
    my $krb5_conf_file = "$::prefix/etc/krb5.conf";

    krb5_conf_update($krb5_conf_file,
		     libdefaults => (
				     default_realm => $uc_domain,
				     dns_lookup_realm => $authentication->{AD_server} ? 'false' : 'true',
				     dns_lookup_kdc => $authentication->{AD_server} ? 'false' : 'true',
				     default_tgs_enctypes => undef, 
				     default_tkt_enctypes => undef,
				     permitted_enctypes => undef,
				    ));

    my @sections = (
		    realms => <<EOF,
 $uc_domain = {
  kdc = $authentication->{AD_server}:88
  admin_server = $authentication->{AD_server}:749
  default_domain = $authentication->{AD_domain}
 }
EOF
		    domain_realm => <<EOF,
 .$authentication->{AD_domain} = $uc_domain
EOF
		    kdc => <<'EOF',
 profile = /etc/kerberos/krb5kdc/kdc.conf
EOF
		    pam => <<'EOF',
 debug = false
 ticket_lifetime = 36000
 renew_lifetime = 36000
 forwardable = true
 krb4_convert = false
EOF
		    login => <<'EOF',
 krb4_convert = false
 krb4_get_tickets = false
EOF
		       );
    foreach (group_by2(@sections)) {
	my ($section, $txt) = @$_;
	krb5_conf_overwrite_category($krb5_conf_file, $section => $authentication->{AD_server} ? $txt : '');
    }
}

sub krb5_conf_overwrite_category {
    my ($file, $category, $new_val) = @_;

    my $done;
    substInFile {
	if (my $i = /^\s*\[\Q$category\E\]/i ... /^\[/) {
	    if ($new_val) {
		if ($i == 1) {
		    $_ .= $new_val;
		    $done = 1;
		} elsif ($i =~ /E/) {
		    $_ = "\n$_";
		} else {
		    $_ = '';
		}
	    } else {
		$_ = '' if $i !~ /E/;
	    }
	}
	#- if category has not been found above.
	if (eof && $new_val && !$done) {
	    $_ .= "\n[$category]\n$new_val";
	}
    } $file;
}

#- same as update_gnomekderc(), but allow spaces around "="
sub krb5_conf_update {
    my ($file, $category, %subst_) = @_;

    my %subst = map { lc($_) => [ $_, $subst_{$_} ] } keys %subst_;

    my $s;
    foreach (MDK::Common::File::cat_($file), "[NOCATEGORY]\n") {
	if (my $i = /^\s*\[\Q$category\E\]/i ... /^\[/) {
	    if ($i =~ /E/) { #- for last line of category
		chomp $s; $s .= "\n";
		$s .= " $_->[0] = $_->[1]\n" foreach grep { defined($_->[1]) } values %subst;
		%subst = ();
	    } elsif (/^\s*([^=]*?)\s*=/) {
		if (my $e = delete $subst{lc($1)}) {
		    $_ = defined($e->[1]) ? " $1 = $e->[1]\n" : '';
		}
	      }
	}
	$s .= $_ if !/^\Q[NOCATEGORY]/;
    }

    #- if category has not been found above.
    if (keys %subst) {
	chomp $s;
	$s .= "\n[$category]\n";
	$s .= " $_->[0] = $_->[1]\n" foreach grep { defined($_->[1]) } values %subst;
    }

    MDK::Common::File::output($file, $s);

}

sub sshd_config_UsePAM {
    my ($UsePAM) = @_;
    my $sshd = "$::prefix/etc/ssh/sshd_config";
    -e $sshd or return;

    my $val = "UsePAM " . bool2yesno($UsePAM);
    substInFile {
	$val = '' if s/^#?UsePAM.*/$val/;
	$_ .= "$val\n" if eof && $val;
    } $sshd;
}

sub query_srv_names {
    my ($domain) = @_;

    eval { require Net::DNS; 1 } or return;
    my $res = Net::DNS::Resolver->new;
    my $query = $res->query("_ldap._tcp.$domain", 'srv') or return;
    map { $_->target } $query->answer;
}

sub enable_shadow() {
    run_program::rooted($::prefix, "pwconv")  or log::l("pwconv failed");
    run_program::rooted($::prefix, "grpconv") or log::l("grpconv failed");
}

sub salt {
    my ($nb) = @_;
    require devices;
    open(my $F, devices::make("random")) or die "missing random";
    my $s; read $F, $s, $nb;
    $s = pack("b8" x $nb, unpack "b6" x $nb, $s);
    $s =~ tr|\0-\x3f|0-9a-zA-Z./|;
    $s;
}

sub user_crypted_passwd {
    my ($u, $isMD5) = @_;
    if ($u->{password}) {
	crypt($u->{password}, $isMD5 ? '$1$' . salt(8) : salt(2));
    } else {
	$u->{pw} || '';
    }
}

sub set_root_passwd {
    my ($superuser, $authentication) = @_;
    $superuser->{name} = 'root';
    write_passwd_user($superuser, $authentication->{md5});    
    delete $superuser->{name};
}

sub write_passwd_user {
    my ($u, $isMD5) = @_;

    $u->{pw} = user_crypted_passwd($u, $isMD5);      
    $u->{shell} ||= '/bin/bash';

    substInFile {
	my $l = unpack_passwd($_);
	if ($l->{name} eq $u->{name}) {
	    add2hash_($u, $l);
	    $_ = pack_passwd($u);
	    $u = {};
	}
	if (eof && $u->{name}) {
	    $_ .= pack_passwd($u);
	}
    } "$::prefix/etc/passwd";
}

my @etc_pass_fields = qw(name pw uid gid realname home shell);
sub unpack_passwd {
    my ($l) = @_;
    my %l; @l{@etc_pass_fields} = split ':', chomp_($l);
    \%l;
}
sub pack_passwd {
    my ($l) = @_;
    join(':', @$l{@etc_pass_fields}) . "\n";
}

1;