[pmg-devel] [PATCH pmg-api 4/6] api: openid login similar to PVE

[Markus Frank <m.frank@proxmox.com>]

Signed-off-by: Markus Frank <m.frank@proxmox.com>
---
 src/Makefile                  |   1 +
 src/PMG/API2/AccessControl.pm |   7 +
 src/PMG/API2/OpenId.pm        | 243 ++++++++++++++++++++++++++++++++++
 src/PMG/HTTPServer.pm         |   2 +
 4 files changed, 253 insertions(+)
 create mode 100644 src/PMG/API2/OpenId.pm

diff --git a/src/Makefile b/src/Makefile
index 92662b5..6ebf54b 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -150,6 +150,7 @@ LIBSOURCES =				\
 	PMG/API2/Quarantine.pm		\
 	PMG/API2/AccessControl.pm	\
 	PMG/API2/Authdomains.pm		\
+	PMG/API2/OpenId.pm		\
 	PMG/API2/TFA.pm			\
 	PMG/API2/TFAConfig.pm		\
 	PMG/API2/ObjectGroupHelpers.pm	\
diff --git a/src/PMG/API2/AccessControl.pm b/src/PMG/API2/AccessControl.pm
index c720f59..6272a9f 100644
--- a/src/PMG/API2/AccessControl.pm
+++ b/src/PMG/API2/AccessControl.pm
@@ -13,6 +13,7 @@ use PMG::Utils;
 use PMG::UserConfig;
 use PMG::AccessControl;
 use PMG::API2::Authdomains;
+use PMG::API2::OpenId;
 use PMG::API2::Users;
 use PMG::API2::TFA;
 use PMG::TFAConfig;
@@ -36,6 +37,11 @@ __PACKAGE__->register_method ({
     path => 'domains',
 });
 
+__PACKAGE__->register_method ({
+    subclass => "PMG::API2::OpenId",
+    path => 'openid',
+});
+
 __PACKAGE__->register_method ({
     name => 'index',
     path => '',
@@ -64,6 +70,7 @@ __PACKAGE__->register_method ({
 	my $res = [
 	    { subdir => 'ticket' },
 	    { subdir => 'domains' },
+	    { subdir => 'openid' },
 	    { subdir => 'password' },
 	    { subdir => 'users' },
 	];
diff --git a/src/PMG/API2/OpenId.pm b/src/PMG/API2/OpenId.pm
new file mode 100644
index 0000000..52349a7
--- /dev/null
+++ b/src/PMG/API2/OpenId.pm
@@ -0,0 +1,243 @@
+package PMG::API2::OpenId;
+
+use strict;
+use warnings;
+
+use PVE::Tools qw(extract_param lock_file);
+use PMG::RS::OpenId;
+
+use PVE::Exception qw(raise raise_perm_exc raise_param_exc);
+use PVE::SafeSyslog;
+use PVE::INotify;
+use PVE::JSONSchema qw(get_standard_option);
+
+use PMG::AccessControl;
+use PMG::RESTEnvironment;
+use PVE::RESTHandler;
+
+use base qw(PVE::RESTHandler);
+
+my $openid_state_path = "/var/lib/pmg";
+
+my $lookup_openid_auth = sub {
+    my ($realm, $redirect_url) = @_;
+
+    my $cfg = PVE::INotify::read_file('realms.cfg');
+    my $ids = $cfg->{ids};
+
+    die "authentication domain '$realm' does not exist\n" if !$ids->{$realm};
+
+    my $config = $ids->{$realm};
+    die "wrong realm type ($config->{type} != openid)\n" if $config->{type} ne "openid";
+
+    my $openid_config = {
+	issuer_url => $config->{'issuer-url'},
+	client_id => $config->{'client-id'},
+	client_key => $config->{'client-key'},
+    };
+    $openid_config->{prompt} = $config->{'prompt'} if defined($config->{'prompt'});
+
+    my $scopes = $config->{'scopes'} // 'email profile';
+    $openid_config->{scopes} = [ PVE::Tools::split_list($scopes) ];
+
+    if (defined(my $acr = $config->{'acr-values'})) {
+	$openid_config->{acr_values} = [ PVE::Tools::split_list($acr) ];
+    }
+
+    my $openid = PMG::RS::OpenId->discover($openid_config, $redirect_url);
+    return ($config, $openid);
+};
+
+__PACKAGE__->register_method ({
+    name => 'index',
+    path => '',
+    method => 'GET',
+    description => "Directory index.",
+    permissions => {
+	user => 'all',
+    },
+    parameters => {
+	additionalProperties => 0,
+	properties => {},
+    },
+    returns => {
+	type => 'array',
+	items => {
+	    type => "object",
+	    properties => {
+		subdir => { type => 'string' },
+	    },
+	},
+	links => [ { rel => 'child', href => "{subdir}" } ],
+    },
+    code => sub {
+	my ($param) = @_;
+
+	return [
+	    { subdir => 'auth-url' },
+	    { subdir => 'login' },
+	];
+    }});
+
+__PACKAGE__->register_method ({
+    name => 'auth_url',
+    path => 'auth-url',
+    method => 'POST',
+    protected => 1,
+    description => "Get the OpenId Authorization Url for the specified realm.",
+    parameters => {
+	additionalProperties => 0,
+	properties => {
+	    realm => {
+		description => "Authentication domain ID",
+		type => 'string',
+		pattern => qr/[A-Za-z][A-Za-z0-9\.\-_]+/,
+		maxLength => 32,
+	    },
+	    'redirect-url' => {
+		description => "Redirection Url. The client should set this to the used server url (location.origin).",
+		type => 'string',
+		maxLength => 255,
+	    },
+	},
+    },
+    returns => {
+	type => "string",
+	description => "Redirection URL.",
+    },
+    permissions => { user => 'world' },
+    code => sub {
+	my ($param) = @_;
+
+	my $realm = extract_param($param, 'realm');
+	my $redirect_url = extract_param($param, 'redirect-url');
+
+	my ($config, $openid) = $lookup_openid_auth->($realm, $redirect_url);
+	my $url = $openid->authorize_url($openid_state_path , $realm);
+
+	return $url;
+    }});
+
+__PACKAGE__->register_method ({
+    name => 'login',
+    path => 'login',
+    method => 'POST',
+    protected => 1,
+    description => " Verify OpenID authorization code and create a ticket.",
+    parameters => {
+	additionalProperties => 0,
+	properties => {
+	    'state' => {
+		description => "OpenId state.",
+		type => 'string',
+		maxLength => 1024,
+            },
+	    code => {
+		description => "OpenId authorization code.",
+		type => 'string',
+		maxLength => 4096,
+            },
+	    'redirect-url' => {
+		description => "Redirection Url. The client should set this to the used server url (location.origin).",
+		type => 'string',
+		maxLength => 255,
+	    },
+	},
+    },
+    returns => {
+	properties => {
+	    role => { type => 'string', optional => 1},
+	    username => { type => 'string' },
+	    ticket => { type => 'string' },
+	    CSRFPreventionToken => { type => 'string' },
+	},
+    },
+    permissions => { user => 'world' },
+    code => sub {
+	my ($param) = @_;
+
+	my $rpcenv = PMG::RESTEnvironment->get();
+
+	my $res;
+	eval {
+	    my ($realm, $private_auth_state) = PMG::RS::OpenId::verify_public_auth_state(
+		$openid_state_path, $param->{'state'});
+
+	    my $redirect_url = extract_param($param, 'redirect-url');
+
+	    my ($config, $openid) = $lookup_openid_auth->($realm, $redirect_url);
+
+	    my $info = $openid->verify_authorization_code($param->{code}, $private_auth_state);
+	    my $subject = $info->{'sub'};
+
+	    my $unique_name;
+
+	    my $user_attr = $config->{'username-claim'} // 'sub';
+	    if (defined($info->{$user_attr})) {
+		$unique_name = $info->{$user_attr};
+	    } elsif ($user_attr eq 'subject') { # stay compat with old versions
+		$unique_name = $subject;
+	    } elsif ($user_attr eq 'username') { # stay compat with old versions
+		my $username = $info->{'preferred_username'};
+		die "missing claim 'preferred_username'\n" if !defined($username);
+		$unique_name =  $username;
+	    } else {
+		# neither the attr nor fallback are defined in info..
+		die "missing configured claim '$user_attr' in returned info object\n";
+	    }
+
+	    my $username = "${unique_name}\@${realm}";
+	    # first, check if $username respects our naming conventions
+	    PMG::Utils::verify_username($username);
+	    if ($config->{'autocreate'} && !$rpcenv->check_user_exist($username, 1)) {
+		my $code = sub {
+		    my $usercfg = PMG::UserConfig->new();
+
+		    my $entry = { enable => 1 };
+		    if (defined(my $email = $info->{'email'})) {
+			$entry->{email} = $email;
+		    }
+		    if (defined(my $given_name = $info->{'given_name'})) {
+			$entry->{firstname} = $given_name;
+		    }
+		    if (defined(my $family_name = $info->{'family_name'})) {
+			$entry->{lastname} = $family_name;
+		    }
+		    $entry->{role} //= 'audit';
+		    $entry->{userid} = $username;
+		    $entry->{username} = $unique_name;
+		    $entry->{realm} = $realm;
+
+		    die "User '$username' already exists\n"
+			if $usercfg->{$username};
+
+		    $usercfg->{$username} = $entry;
+
+		    $usercfg->write();
+		};
+		PMG::UserConfig::lock_config($code, "autocreate openid user failed");
+	    }
+	    my $role = $rpcenv->check_user_enabled($username);
+
+	    my $ticket = PMG::Ticket::assemble_ticket($username);
+	    my $csrftoken = PMG::Ticket::assemble_csrf_prevention_token($username);
+
+	    $res = {
+		ticket => $ticket,
+		username => $username,
+		CSRFPreventionToken => $csrftoken,
+		role => $role,
+	    };
+
+	};
+	if (my $err = $@) {
+	    my $clientip = $rpcenv->get_client_ip() || '';
+	    syslog('err', "openid authentication failure; rhost=$clientip msg=$err");
+	    # do not return any info to prevent user enumeration attacks
+	    die PVE::Exception->new("authentication failure $err\n", code => 401);
+	}
+
+	syslog('info', 'root@pam', "successful openid auth for user '$res->{username}'");
+
+	return $res;
+    }});
diff --git a/src/PMG/HTTPServer.pm b/src/PMG/HTTPServer.pm
index b6c50d9..f043142 100644
--- a/src/PMG/HTTPServer.pm
+++ b/src/PMG/HTTPServer.pm
@@ -58,6 +58,8 @@ sub auth_handler {
 
     # explicitly allow some calls without auth
     if (($rel_uri eq '/access/domains' && $method eq 'GET') ||
+	($rel_uri eq '/access/openid/login' &&  $method eq 'POST') ||
+	($rel_uri eq '/access/openid/auth-url' &&  $method eq 'POST') ||
 	($rel_uri eq '/quarantine/sendlink' && ($method eq 'GET' || $method eq 'POST')) ||
 	($rel_uri eq '/access/ticket' && ($method eq 'GET' || $method eq 'POST'))) {
 	$require_auth = 0;
-- 
2.39.2