add LDAP Wrapper code

This will be used for PMG and PVE LDAP Authentication & Sync.
The code is largely copied/inspired by the already existing LDAP code in
PVEs AccessControl and PMGs LDAPCache

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/Makefile

@@ -20,6 +20,7 @@ LIB_SOURCES = \
 	Exception.pm \
 	INotify.pm \
 	JSONSchema.pm \
+	LDAP.pm \
 	Network.pm \
 	OTP.pm \
 	PTY.pm \

src/PVE/LDAP.pm

@@ -0,0 +1,254 @@
+package PVE::LDAP;
+
+use strict;
+use warnings;
+
+use Net::IP;
+use Net::LDAP;
+use Net::LDAP::Control::Paged;
+use Net::LDAP::Constant qw(LDAP_CONTROL_PAGED);
+
+sub ldap_connect {
+    my ($servers, $scheme, $port, $opts) = @_;
+
+    my $start_tls = 0;
+
+    if ($scheme eq 'ldap+starttls') {
+	$scheme = 'ldap';
+	$start_tls = 1;
+    }
+
+    my %ldap_opts = (
+	scheme => $scheme,
+	port => $port,
+	timeout => 10,
+	onerror => 'die',
+    );
+
+    my $hosts = [];
+    for my $host (@$servers) {
+	if (Net::IP::ip_is_ipv6($host)) {
+	    push @$hosts, "[$host]";
+	} else {
+	    push @$hosts, $host;
+	}
+    }
+
+    for my $opt (qw(clientcert clientkey capath cafile sslversion verify)) {
+	$ldap_opts{$opt} = $opts->{$opt} if $opts->{$opt};
+    }
+
+    my $ldap = Net::LDAP->new($hosts, %ldap_opts) || die $@;
+
+    if ($start_tls) {
+	$ldap->start_tls(%$opts);
+    }
+
+    return $ldap;
+}
+
+sub ldap_bind {
+    my ($ldap, $dn, $pw) = @_;
+
+    my $res;
+    if (defined($dn) && defined($pw)) {
+	$res = $ldap->bind($dn, password => $pw);
+    } else { # anonymous bind
+	$res = $ldap->bind();
+    }
+
+    my $code = $res->code;
+    my $err = $res->error;
+
+    die "ldap bind failed: $err\n" if $code;
+}
+
+sub get_user_dn {
+    my ($ldap, $name, $attr, $base_dn) = @_;
+
+    # search for dn
+    my $result = $ldap->search(
+	base    => $base_dn // "",
+	scope   => "sub",
+	filter  => "$attr=$name",
+	attrs   => ['dn']
+    );
+    return undef if !$result->entries;
+    my @entries = $result->entries;
+    return $entries[0]->dn;
+}
+
+sub auth_user_dn {
+    my ($ldap, $dn, $pw, $noerr) = @_;
+    my $res = $ldap->bind($dn, password => $pw);
+
+    my $code = $res->code;
+    my $err = $res->error;
+
+    if ($code) {
+	return undef if $noerr;
+	die $err;
+    }
+
+    return 1;
+}
+
+sub query_users {
+    my ($ldap, $filter, $attributes, $base_dn) = @_;
+
+    # build filter from given filter and attribute list
+    my $tmp = "(|";
+    foreach my $att (@$attributes) {
+	$tmp .= "($att=*)";
+    }
+    $tmp .= ")";
+
+    if ($filter) {
+	$filter = "($filter)" if $filter !~ m/^\(.*\)$/;
+	$filter = "(&${filter}${tmp})"
+    } else {
+	$filter = $tmp;
+    }
+
+    my $page = Net::LDAP::Control::Paged->new(size => 900);
+
+    my @args = (
+	base     => $base_dn // "",
+	scope    => "subtree",
+	filter   => $filter,
+	control  => [ $page ],
+	attrs    => [ @$attributes, 'memberOf'],
+    );
+
+    my $cookie;
+    my $err;
+    my $users = [];
+
+    while(1) {
+
+	my $mesg = $ldap->search(@args);
+
+	# stop on error
+	if ($mesg->code)  {
+	    $err = "ldap user search error: " . $mesg->error;
+	    last;
+	}
+
+	#foreach my $entry ($mesg->entries) { $entry->dump; }
+	foreach my $entry ($mesg->entries) {
+	    my $user = {
+		dn => $entry->dn,
+		attributes => {},
+		groups => [$entry->get_value('memberOf')],
+	    };
+
+	    foreach my $attr (@$attributes) {
+		my $vals = [$entry->get_value($attr)];
+		if (scalar(@$vals)) {
+		    $user->{attributes}->{$attr} = $vals;
+		}
+	    }
+
+	    push @$users, $user;
+	}
+
+	# Get cookie from paged control
+	my ($resp) = $mesg->control(LDAP_CONTROL_PAGED) or last;
+	$cookie = $resp->cookie;
+
+	last if (!defined($cookie) || !length($cookie));
+
+	# Set cookie in paged control
+	$page->cookie($cookie);
+    }
+
+    if (defined($cookie) && length($cookie)) {
+	# We had an abnormal exit, so let the server know we do not want any more
+	$page->cookie($cookie);
+	$page->size(0);
+	$ldap->search(@args);
+	$err = "LDAP user query unsuccessful" if !$err;
+    }
+
+    die $err if $err;
+
+    return $users;
+}
+
+sub query_groups {
+    my ($ldap, $base_dn, $classes, $filter) = @_;
+
+    my $tmp = "(|";
+    for my $class (@$classes) {
+	$tmp .= "(objectclass=$class)";
+    }
+    $tmp .= ")";
+
+    if ($filter) {
+	$filter = "($filter)" if $filter !~ m/^\(.*\)$/;
+	$filter = "(&${filter}${tmp})"
+    } else {
+	$filter = $tmp;
+    }
+
+    my $page = Net::LDAP::Control::Paged->new(size => 100);
+
+    my @args = (
+	base     => $base_dn,
+	scope    => "subtree",
+	filter   => $filter,
+	control  => [ $page ],
+	attrs    => [ 'member', 'uniqueMember' ],
+    );
+
+    my $cookie;
+    my $err;
+    my $groups = [];
+
+    while(1) {
+
+	my $mesg = $ldap->search(@args);
+
+	# stop on error
+	if ($mesg->code)  {
+	    $err = "ldap group search error: " . $mesg->error;
+	    last;
+	}
+
+	foreach my $entry ( $mesg->entries ) {
+	    my $group = {
+		dn => $entry->dn,
+		members => []
+	    };
+	    my $members = [$entry->get_value('member')];
+	    if (!scalar(@$members)) {
+		$members = [$entry->get_value('uniqueMember')];
+	    }
+	    $group->{members} = $members;
+	    push @$groups, $group;
+	}
+
+	# Get cookie from paged control
+	my ($resp) = $mesg->control(LDAP_CONTROL_PAGED) or last;
+	$cookie = $resp->cookie;
+
+	last if (!defined($cookie) || !length($cookie));
+
+	# Set cookie in paged control
+	$page->cookie($cookie);
+    }
+
+    if ($cookie) {
+	# We had an abnormal exit, so let the server know we do not want any more
+	$page->cookie($cookie);
+	$page->size(0);
+	$ldap->search(@args);
+	$err = "LDAP group query unsuccessful" if !$err;
+    }
+
+    die $err if $err;
+
+    return $groups;
+}
+
+1;