added new authentication mode optional-certificate

That mode allows having only specific group of users that are required
to present a certificate.

src/config.c

@@ -389,6 +389,8 @@ unsigned force_cert_auth;
 			config->auth_types |= AUTH_TYPE_PLAIN;
 		} else if (c_strcasecmp(auth[j], "certificate") == 0) {
 			config->auth_types |= AUTH_TYPE_CERTIFICATE;
+		} else if (c_strcasecmp(auth[j], "optional-certificate") == 0) {
+			config->auth_types |= AUTH_TYPE_CERTIFICATE_OPT;
 		} else {
 			fprintf(stderr, "Unknown auth method: %s\n", auth[j]);
 			exit(1);
@@ -652,7 +654,7 @@ static void check_cfg(struct cfg_st *config)
 	}
 
 	if (config->auth_types & AUTH_TYPE_CERTIFICATE) {
-		if (config->cisco_client_compat == 0)
+		if (config->cisco_client_compat == 0 && ((config->auth_types & AUTH_TYPE_CERTIFICATE_OPT) != AUTH_TYPE_CERTIFICATE_OPT))
 			config->cert_req = GNUTLS_CERT_REQUIRE;
 		else
 			config->cert_req = GNUTLS_CERT_REQUEST;

src/ipc.proto

@@ -4,6 +4,7 @@
  *   main                              worker
  *                      <------     AUTH_COOKIE_REQ
  * AUTH_REP(OK/FAILED)  ------>
+ *  +user config
  *
  */
 
@@ -17,7 +18,6 @@ enum AUTH_REP {
 message auth_cookie_request_msg
 {
 	required bytes cookie = 1;
-	required bool tls_auth_ok = 2 [default = false];
 }
 
 /* AUTH_REP */
@@ -127,7 +127,6 @@ message session_info_msg
 /* SEC_AUTH_INIT */
 message sec_auth_init_msg
 {
-	required bool user_present = 1;
 	required bool tls_auth_ok = 2 [default = false];
 	required string user_name = 3;
 	optional string group_name = 4; /* selected group name */
@@ -174,6 +173,7 @@ message cookie
 	required uint32 expiration = 6;
 	required uint32 ipv4_seed = 7;
 	required bytes sid = 8;
+	required bool tls_auth_ok = 9;
 }
 
 /*

src/main-auth.c

@@ -265,6 +265,12 @@ struct cookie_entry_st *old;
 			return -1;
 	}
 
+	if (proc->config.require_cert != 0 && cmsg->tls_auth_ok == 0) {
+		mslog(s, proc, LOG_ERR,
+		      "certificate is required for user '%s'", proc->username);
+		return -1;
+	}
+
 	if (cmsg->groupname)
 		snprintf(proc->groupname, sizeof(proc->groupname), "%s", cmsg->groupname);
 

src/ocserv-args.def

@@ -75,8 +75,10 @@ An example configuration file follows.
 
 # User authentication method. Could be set multiple times and in 
 # that case all should succeed. To enable multiple methods use
-# multiple auth directives. Available options: certificate, plain, pam. 
+# multiple auth directives. Available options: certificate, optional-certificate,
+# plain, pam. 
 #auth = "certificate"
+#auth = "optional-certificate"
 #auth = "pam"
 
 # The gid-min option is used by auto-select-group option, in order to
@@ -397,7 +399,7 @@ route = 192.168.5.0/255.255.255.0
 # or the groupname.
 # The options allowed in the configuration files are dns, nbns,
 #  ipv?-network, ipv4-netmask, ipv6-prefix, rx/tx-per-sec, iroute, route,
-#  net-priority, deny-roaming, no-udp, user-profile, and cgroup.
+#  net-priority, deny-roaming, no-udp, user-profile, require-cert, and cgroup.
 #
 # Note that the 'iroute' option allows to add routes on the server
 # based on a user or group. The syntax depends on the input accepted
@@ -413,6 +415,11 @@ route = 192.168.5.0/255.255.255.0
 #default-user-config = /etc/ocserv/defaults/user.conf
 #default-group-config = /etc/ocserv/defaults/group.conf
 
+# This option is only valid in a user/group configuration file. If the
+# auth mode is optional-certificate, it requires a certificate for this
+# particular user or group.
+#require-cert = true
+
 # The system command to use to setup a route. %{R} will be replaced with the
 # route/mask and %{D} with the (tun) device.
 #

src/sec-mod-auth.c

@@ -83,6 +83,7 @@ static int generate_cookie(sec_mod_st * sec, client_entry_st * entry)
 	msg.groupname = entry->groupname;
 	msg.hostname = entry->hostname;
 	msg.ip = entry->ip;
+	msg.tls_auth_ok = entry->tls_auth_ok;
 
 	/* Fixme: possibly we should allow for completely random seeds */
 	if (sec->config->predictable_ips != 0) {
@@ -200,14 +201,21 @@ static int check_user_group_status(sec_mod_st * sec, client_entry_st * e,
 				   unsigned cert_groups_size)
 {
 	unsigned found, i;
+	unsigned need_cert = 1;
+
 
 	if (sec->config->auth_types & AUTH_TYPE_CERTIFICATE) {
-		if (tls_auth_ok == 0) {
+		if ((sec->config->auth_types & AUTH_TYPE_CERTIFICATE_OPT) == AUTH_TYPE_CERTIFICATE_OPT) {
+			need_cert = 0;
+		}
+
+		if (tls_auth_ok == 0 && need_cert != 0) {
 			seclog(LOG_INFO, "user '%s' presented no certificate",
 			       e->username);
 			return -1;
 		}
 
+		e->tls_auth_ok = tls_auth_ok;
 		if (tls_auth_ok != 0) {
 			if (e->username[0] == 0 && sec->config->cert_user_oid != NULL) {
 				if (cert_user == NULL) {

src/sec-mod.h

@@ -46,6 +46,7 @@ typedef struct client_entry_st {
 	uint8_t sid[SID_SIZE];
 	void * auth_ctx; /* the context of authentication */
 	unsigned have_session; /* whether an auth session is initialized */
+	unsigned tls_auth_ok;
 
 	unsigned status; /* PS_AUTH_ */
 

src/sup-config/file.c

@@ -43,6 +43,7 @@ struct cfg_options {
 static struct cfg_options available_options[] = {
 	{ .name = "no-udp", .type = OPTION_BOOLEAN },
 	{ .name = "deny-roaming", .type = OPTION_BOOLEAN },
+	{ .name = "require-cert", .type = OPTION_BOOLEAN },
 	{ .name = "route", .type = OPTION_MULTI_LINE },
 	{ .name = "iroute", .type = OPTION_MULTI_LINE },
 	{ .name = "dns", .type = OPTION_MULTI_LINE },
@@ -172,6 +173,7 @@ struct group_cfg_st *sconfig = &proc->config;
 
 	READ_TF("no-udp", sconfig->no_udp, (global_config->udp_port!=0)?0:1);
 	READ_TF("deny-roaming", sconfig->deny_roaming, global_config->deny_roaming);
+	READ_TF("require-cert", sconfig->require_cert, 0);
 
 	READ_RAW_MULTI_LINE("route", sconfig->routes, sconfig->routes_size);
 	READ_RAW_MULTI_LINE("iroute", sconfig->iroutes, sconfig->iroutes_size);

src/vpn.h

@@ -73,8 +73,9 @@ extern int syslog_open;
 /* the first is generic, for the methods that require a username password */
 #define AUTH_TYPE_USERNAME_PASS (1<<0)
 #define AUTH_TYPE_PAM (1<<1 | AUTH_TYPE_USERNAME_PASS)
-#define AUTH_TYPE_CERTIFICATE (1<<2)
-#define AUTH_TYPE_PLAIN (1<<3 | AUTH_TYPE_USERNAME_PASS)
+#define AUTH_TYPE_PLAIN (1<<2 | AUTH_TYPE_USERNAME_PASS)
+#define AUTH_TYPE_CERTIFICATE (1<<3)
+#define AUTH_TYPE_CERTIFICATE_OPT (1<<4|AUTH_TYPE_CERTIFICATE)
 
 #define ERR_SUCCESS 0
 #define ERR_BAD_COMMAND -2
@@ -157,6 +158,7 @@ struct group_cfg_st {
 	unsigned deny_roaming; /* whether the user is allowed to re-use cookies from another IP */
 	unsigned net_priority;
 	unsigned no_udp; /* whether to disable UDP for this user */
+	unsigned require_cert; /* when optional certificate auth is selected require a certificate */
 };
 
 struct vpn_st {

src/worker-auth.c

@@ -805,19 +805,19 @@ int auth_cookie(worker_st * ws, void *cookie, size_t cookie_size)
 
 	if ((ws->config->auth_types & AUTH_TYPE_CERTIFICATE)
 	    && ws->config->cisco_client_compat == 0) {
-		if (ws->cert_auth_ok == 0) {
+		if (((ws->config->auth_types & AUTH_TYPE_CERTIFICATE_OPT) != AUTH_TYPE_CERTIFICATE_OPT && ws->cert_auth_ok == 0)) {
 			oclog(ws, LOG_INFO,
 			      "no certificate provided for cookie authentication");
 			return -1;
 		}
 
-		ret = get_cert_info(ws);
-		if (ret < 0) {
-			oclog(ws, LOG_INFO, "cannot obtain certificate info");
-			return -1;
+		if (ws->cert_auth_ok != 0) {
+			ret = get_cert_info(ws);
+			if (ret < 0) {
+				oclog(ws, LOG_INFO, "cannot obtain certificate info");
+				return -1;
+			}
 		}
-
-		msg.tls_auth_ok = 1;
 	}
 
 	msg.cookie.data = cookie;
@@ -1128,19 +1128,21 @@ int post_auth_handler(worker_st * ws, unsigned http_ver)
 		}
 
 		if (ws->config->auth_types & AUTH_TYPE_CERTIFICATE) {
-			if (ws->cert_auth_ok == 0) {
+			if ((ws->config->auth_types & AUTH_TYPE_CERTIFICATE_OPT) != AUTH_TYPE_CERTIFICATE_OPT && ws->cert_auth_ok == 0) {
 				reason = MSG_NO_CERT_ERROR;
 				oclog(ws, LOG_INFO,
 				      "no certificate provided for authentication");
 				goto auth_fail;
 			}
 
-			ret = get_cert_info(ws);
-			if (ret < 0) {
-				reason = MSG_CERT_READ_ERROR;
-				oclog(ws, LOG_ERR,
-				      "failed reading certificate info");
-				goto auth_fail;
+			if (ws->cert_auth_ok != 0) {
+				ret = get_cert_info(ws);
+				if (ret < 0) {
+					reason = MSG_CERT_READ_ERROR;
+					oclog(ws, LOG_ERR,
+					      "failed reading certificate info");
+					goto auth_fail;
+				}
 			}
 
 			if (def_group == 0 && ws->cert_groups_size > 0 && ws->groupname[0] == 0) {
@@ -1148,7 +1150,7 @@ int post_auth_handler(worker_st * ws, unsigned http_ver)
 				return get_auth_handler2(ws, http_ver, "Please select your group");
 			}
 
-			ireq.tls_auth_ok = 1;
+			ireq.tls_auth_ok = ws->cert_auth_ok;
 			ireq.cert_user_name = ws->cert_username;
 			ireq.cert_group_names = ws->cert_groups;
 			ireq.n_cert_group_names = ws->cert_groups_size;

src/worker.h

@@ -197,7 +197,6 @@ typedef struct worker_st {
 
 	/* the following are set only if authentication is complete */
 
-
 	char username[MAX_USERNAME_SIZE];
 	char groupname[MAX_GROUPNAME_SIZE];