@@ -409,7 +409,8 @@ which mode OpenVPN is configured as.
* :code:`OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY` plug-in hooks returns
success/failure via :code:`auth_control_file` when using deferred auth
- method
+ method and pending authentification via :code:`pending_auth_file`.
+
* :code:`OPENVPN_PLUGIN_ENABLE_PF` plugin hook to pass filtering rules
via ``pf_file``
@@ -567,6 +567,14 @@ OPENVPN_PLUGIN_DEF openvpn_plugin_handle_t OPENVPN_PLUGIN_FUNC(openvpn_plugin_op
* auth_control_file/client_connect_deferred_file
* in the environmental variable list (envp).
*
+ * Additionally the auth_pending_file can be written, which causes the openvpn
+ * server to send a pending auth request to the client. See doc/management.txt
+ * for more details on this authentication mechanism. The format of the
+ * auth_pending_file is
+ * line 1: timeout in seconds
+ * line 2: Pending auth method the client needs to support (e.g. openurl)
+ * line 3: EXTRA (e.g. OPEN_URL:http://www.example.com)
+ *
* In addition the OPENVPN_PLUGIN_CLIENT_CONNECT_DEFER and
* OPENVPN_PLUGIN_CLIENT_CONNECT_DEFER_V2 are called when OpenVPN tries to
* get the deferred result. For a V2 call implementing this function is
@@ -993,7 +993,7 @@ key_state_free(struct key_state *ks, bool clear)
packet_id_free(&ks->crypto_options.packet_id);
#ifdef PLUGIN_DEF_AUTH
- key_state_rm_auth_control_file(ks);
+ key_state_rm_auth_control_files(ks);
#endif
if (clear)
@@ -215,6 +215,7 @@ struct key_state
unsigned int auth_control_status;
time_t acf_last_mod;
char *auth_control_file;
+ char *auth_pending_file;
};
/** Control channel wrapping (--tls-auth/--tls-crypt) context */
@@ -865,13 +865,129 @@ man_def_auth_test(const struct key_state *ks)
}
#endif /* ifdef ENABLE_MANAGEMENT */
+/**
+ * Removes auth_pending file from the file system
+ * and key_state structure
+ */
+static void
+key_state_rm_auth_pending_file(struct key_state *ks)
+{
+ if (ks && ks->auth_pending_file)
+ {
+ platform_unlink(ks->auth_pending_file);
+ free(ks->auth_pending_file);
+ ks->auth_pending_file = NULL;
+ }
+}
-/*
- * auth_control_file functions
+/**
+ * Check peer_info if the client supports the requested pending auth method
+ */
+static bool
+check_auth_pending_method(const char *peer_info, const char *method)
+{
+ struct gc_arena gc = gc_new();
+
+ char *iv_sso = extract_var_peer_info(peer_info, "IV_SSO=", &gc);
+ if (!iv_sso)
+ {
+ gc_free(&gc);
+ return false;
+ }
+
+ const char *client_method = strtok(iv_sso, ",");
+ bool supported = false;
+
+ while (client_method)
+ {
+ if (0 == strcmp(client_method, method))
+ {
+ supported = true;
+ break;
+ }
+ client_method = strtok(NULL, ":");
+ }
+
+ gc_free(&gc);
+ return supported;
+}
+
+/**
+ * Checks if the deferred state should also send auth pending
+ * request to the client. Also removes the auth_pending control file
+ *
+ * @returns true if file was either processed sucessfully or did not
+ * exist at all
+ * @returns false The file had an invlaid format or another error occured
*/
+static bool
+key_state_check_auth_pending_file(struct key_state *ks,
+ struct tls_multi *multi)
+{
+ bool ret = true;
+ if (ks && ks->auth_pending_file)
+ {
+ struct buffer_list *lines = buffer_list_file(ks->auth_pending_file,
+ 1024);
+ if (lines && lines->head)
+ {
+ /* Must have at least three lines. further lines are ignored for
+ * forward compatibility */
+ if (!lines->head || !lines->head->next || !lines->head->next->next)
+ {
+ msg(M_WARN, "auth pending control file is not at least "
+ "three lines long.");
+ buffer_list_free(lines);
+ return false;
+ }
+ struct buffer *timeout_buf = &lines->head->buf;
+ struct buffer *iv_buf = &lines->head->next->buf;
+ struct buffer *extra_buf = &lines->head->next->next->buf;
+
+ /* Remove newline chars at the end of the lines */
+ buf_chomp(timeout_buf);
+ buf_chomp(iv_buf);
+ buf_chomp(extra_buf);
+
+ long timeout = strtol(BSTR(timeout_buf), NULL, 10);
+ if (timeout == 0)
+ {
+ msg(M_WARN, "could not parse auth pending file timeout");
+ buffer_list_free(lines);
+ return false;
+ }
+
+ const char* pending_method = BSTR(iv_buf);
+ if (!check_auth_pending_method(multi->peer_info, pending_method))
+ {
+ char buf[128];
+ openvpn_snprintf(buf, sizeof(buf),
+ "Authentication failed, required pending auth "
+ "method '%s' not supported", pending_method);
+ auth_set_client_reason(multi, buf);
+ msg(M_INFO, "Client does not supported auth pending method "
+ "'%s'", pending_method);
+ ret = false;
+ }
+ else
+ {
+ send_auth_pending_messages(multi, BSTR(extra_buf), timeout);
+ }
+ }
+
+ buffer_list_free(lines);
+ }
+ key_state_rm_auth_pending_file(ks);
+ return ret;
+}
+
+/**
+ * Removes auth_pending and auth_control files from file system
+ * and key_state structure
+ */
void
-key_state_rm_auth_control_file(struct key_state *ks)
+key_state_rm_auth_control_files(struct key_state *ks)
{
if (ks && ks->auth_control_file)
{
@@ -879,23 +995,34 @@ key_state_rm_auth_control_file(struct key_state *ks)
free(ks->auth_control_file);
ks->auth_control_file = NULL;
}
+ key_state_rm_auth_pending_file(ks);
}
+/**
+ * Generates and creates the control files used for deferred authentification
+ * in the temporary directory.
+ *
+ * @return true if file creation was successful
+ */
static bool
-key_state_gen_auth_control_file(struct key_state *ks, const struct tls_options *opt)
+key_state_gen_auth_control_files(struct key_state *ks, const struct tls_options *opt)
{
struct gc_arena gc = gc_new();
- key_state_rm_auth_control_file(ks);
+ key_state_rm_auth_control_files(ks);
const char *acf = platform_create_temp_file(opt->tmp_dir, "acf", &gc);
- if (acf)
+ const char *apf = platform_create_temp_file(opt->tmp_dir, "apf", &gc);
+
+ if (acf && apf)
{
ks->auth_control_file = string_alloc(acf, NULL);
+ ks->auth_pending_file = string_alloc(apf, NULL);
setenv_str(opt->es, "auth_control_file", ks->auth_control_file);
+ setenv_str(opt->es, "auth_pending_file", ks->auth_pending_file);
}
gc_free(&gc);
- return acf;
+ return (acf && apf);
}
static unsigned int
@@ -1140,7 +1267,7 @@ verify_user_pass_plugin(struct tls_session *session, struct tls_multi *multi,
setenv_str(session->opt->es, "password", up->password);
/* generate filename for deferred auth control file */
- if (!key_state_gen_auth_control_file(ks, session->opt))
+ if (!key_state_gen_auth_control_files(ks, session->opt))
{
msg(D_TLS_ERRORS, "TLS Auth Error (%s): "
"could not create deferred auth control file", __func__);
@@ -1150,10 +1277,20 @@ verify_user_pass_plugin(struct tls_session *session, struct tls_multi *multi,
/* call command */
retval = plugin_call(session->opt->plugins, OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY, NULL, NULL, session->opt->es);
- /* purge auth control filename (and file itself) for non-deferred returns */
- if (retval != OPENVPN_PLUGIN_FUNC_DEFERRED)
+ if (retval == OPENVPN_PLUGIN_FUNC_DEFERRED)
+ {
+ /* Check if we the plugin has written the pending auth control
+ * file and send the pending auth to the client */
+ if(!key_state_check_auth_pending_file(ks, multi))
+ {
+ retval = OPENVPN_PLUGIN_FUNC_ERROR;
+ key_state_rm_auth_control_files(ks);
+ }
+ }
+ else
{
- key_state_rm_auth_control_file(ks);
+ /* purge auth control filename (and file itself) for non-deferred returns */
+ key_state_rm_auth_control_files(ks);
}
setenv_del(session->opt->es, "password");
@@ -1224,7 +1361,7 @@ set_verify_user_pass_env(struct user_pass *up, struct tls_multi *multi,
}
}
-/*
+/**
* Main username/password verification entry point
*
* Will set session->ks[KS_PRIMARY].authenticated according to
@@ -117,7 +117,7 @@ tls_authentication_status(struct tls_multi *multi, const int latency);
*
* @param ks The key state the remove the file for
*/
-void key_state_rm_auth_control_file(struct key_state *ks);
+void key_state_rm_auth_control_files(struct key_state *ks);
/**
* Frees the given set of certificate hashes.
Patch v2: removed change that slipped into this patch and belongs into the next Signed-off-by: Arne Schwabe <arne@rfc2549.org> --- doc/man-sections/generic-options.rst | 3 +- include/openvpn-plugin.h.in | 8 ++ src/openvpn/ssl.c | 2 +- src/openvpn/ssl_common.h | 1 + src/openvpn/ssl_verify.c | 161 +++++++++++++++++++++++++-- src/openvpn/ssl_verify.h | 2 +- 6 files changed, 162 insertions(+), 15 deletions(-)