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The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: This allows a server to indicate a temporary problem on the server and allows the server to indicate how to proceed (i.e. move to the next server, retry the same server, wait a certain time, ...) This adds options_utils.c/h to be able to unit test the new function. Content analysis details: (0.3 points, 6.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.2 HEADER_FROM_DIFFERENT_DOMAINS From and EnvelopeFrom 2nd level mail domains are different 0.0 SPF_NONE SPF: sender does not publish an SPF Record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [URIs: makefile.am] X-Headers-End: 1oYVli-008CcZ-Ov Subject: [Openvpn-devel] [PATCH v4] Implement AUTH_FAIL, TEMP message support X-BeenThere: openvpn-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: openvpn-devel-bounces@lists.sourceforge.net X-getmail-retrieved-from-mailbox: Inbox This allows a server to indicate a temporary problem on the server and allows the server to indicate how to proceed (i.e. move to the next server, retry the same server, wait a certain time,...) This adds options_utils.c/h to be able to unit test the new function. Patch v2: Improve documentation, format man page better, comment that protocol-flags is not a user usable option. Patch v3: cleanup parse_auth_failed_temp to use a simple const string instead of a buffer Patch v4: move message + strlen(TEMP) to caller Signed-off-by: Arne Schwabe --- doc/man-sections/script-options.rst | 36 ++++++++++ src/openvpn/Makefile.am | 1 + src/openvpn/init.c | 9 ++- src/openvpn/openvpn.vcxproj | 2 + src/openvpn/options.h | 9 ++- src/openvpn/options_util.c | 102 +++++++++++++++++++++++++++ src/openvpn/options_util.h | 33 +++++++++ src/openvpn/push.c | 33 +++++---- src/openvpn/ssl.c | 13 ++-- src/openvpn/ssl.h | 3 + tests/unit_tests/openvpn/Makefile.am | 1 + tests/unit_tests/openvpn/test_misc.c | 40 +++++++++++ 12 files changed, 264 insertions(+), 18 deletions(-) create mode 100644 src/openvpn/options_util.c create mode 100644 src/openvpn/options_util.h diff --git a/doc/man-sections/script-options.rst b/doc/man-sections/script-options.rst index 61c89b0ad..2a2e70fca 100644 --- a/doc/man-sections/script-options.rst +++ b/doc/man-sections/script-options.rst @@ -102,6 +102,42 @@ SCRIPT HOOKS the authentication, a :code:`1` or :code:`0` must be written to the file specified by the :code:`auth_control_file`. + If the file specified by :code:`auth_failed_reason` exists and has non-empty + content, the content of this file will be used as AUTH_FAILED message. To + avoid race conditions, this file should be written before + :code:`auth_control_file`. + + This auth fail reason can be something simple like "User has been permanently + disabled" but there are also some special auth failed messages. + + The ``TEMP`` message indicates that the authentication + temporarily failed and that the client should continue to retry to connect. + The server can optionally give a user readable message and hint the client a + behavior how to proceed. The keywords of the ``AUTH_FAILED,TEMP`` message + are comma separated keys/values and provide a hint to the client how to + proceed. Currently defined keywords are: + + ``backoff`` :code:`s` + instructs the client to wait at least :code:`s` seconds before the next + connection attempt. If the client already uses a higher delay for + reconnection attempt, the delay will not be shortened. + + ``advance addr`` + Instructs the client to reconnect to the next (IP) address of the + current server. + + ``advance remote`` + Instructs the client to skip the remaining IP addresses of the current + server and instead connect to the next server specified in the + configuration file. + + ``advance no`` + Instructs the client to retry connecting to the same server again. + + For example, the message ``TEMP[backoff 42,advance no]: No free IP addresses`` + indicates that the VPN connection can currently not succeed and instructs + the client to retry in 42 seconds again. + When deferred authentication is in use, the script can also request pending authentication by writing to the file specified by the :code:`auth_pending_file`. The first line must be the timeout in diff --git a/src/openvpn/Makefile.am b/src/openvpn/Makefile.am index 71648ef18..79a3f9574 100644 --- a/src/openvpn/Makefile.am +++ b/src/openvpn/Makefile.am @@ -101,6 +101,7 @@ openvpn_SOURCES = \ pkcs11_mbedtls.c \ openvpn.c openvpn.h \ options.c options.h \ + options_util.c options_util.h \ otime.c otime.h \ packet_id.c packet_id.h \ perf.c perf.h \ diff --git a/src/openvpn/init.c b/src/openvpn/init.c index c40e975ed..d0ae7ac7d 100644 --- a/src/openvpn/init.c +++ b/src/openvpn/init.c @@ -484,13 +484,15 @@ next_connection_entry(struct context *c) /* Check if there is another resolved address to try for * the current connection */ if (c->c1.link_socket_addr.current_remote - && c->c1.link_socket_addr.current_remote->ai_next) + && c->c1.link_socket_addr.current_remote->ai_next + && !c->options.advance_next_remote) { c->c1.link_socket_addr.current_remote = c->c1.link_socket_addr.current_remote->ai_next; } else { + c->options.advance_next_remote = false; /* FIXME (schwabe) fix the persist-remote-ip option for real, * this is broken probably ever since connection lists and multiple * remote existed @@ -2513,6 +2515,11 @@ socket_restart_pause(struct context *c) /* sec is less than 2^16; we can left shift it by up to 15 bits without overflow */ sec = max_int(sec, 1) << min_int(backoff, 15); } + if (c->options.server_backoff_time) + { + sec = max_int(sec, c->options.server_backoff_time); + c->options.server_backoff_time = 0; + } if (sec > c->options.ce.connect_retry_seconds_max) { diff --git a/src/openvpn/openvpn.vcxproj b/src/openvpn/openvpn.vcxproj index a45fb993f..9b5e416fa 100644 --- a/src/openvpn/openvpn.vcxproj +++ b/src/openvpn/openvpn.vcxproj @@ -308,6 +308,7 @@ + @@ -400,6 +401,7 @@ + diff --git a/src/openvpn/options.h b/src/openvpn/options.h index f4549edba..c0c0417ef 100644 --- a/src/openvpn/options.h +++ b/src/openvpn/options.h @@ -272,10 +272,17 @@ struct options struct connection_list *connection_list; struct remote_list *remote_list; - /* Do not advanced the connection or remote addr list*/ + /* Do not advance the connection or remote addr list*/ bool no_advance; + /* Advance directly to the next remote, skipping remaining addresses of the + * current remote */ + bool advance_next_remote; /* Counts the number of unsuccessful connection attempts */ unsigned int unsuccessful_attempts; + /* the server can suggest a backoff time to the client, it + * will still be capped by the max timeout between connections + * (300s by default) */ + int server_backoff_time; #if ENABLE_MANAGEMENT struct http_proxy_options *http_proxy_override; diff --git a/src/openvpn/options_util.c b/src/openvpn/options_util.c new file mode 100644 index 000000000..72c8bda4d --- /dev/null +++ b/src/openvpn/options_util.c @@ -0,0 +1,102 @@ +/* + * OpenVPN -- An application to securely tunnel IP networks + * over a single TCP/UDP port, with support for SSL/TLS-based + * session authentication and key exchange, + * packet encryption, packet authentication, and + * packet compression. + * + * Copyright (C) 2002-2022 OpenVPN Inc + * Copyright (C) 2010-2021 Fox Crypto B.V. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#elif defined(_MSC_VER) +#include "config-msvc.h" +#endif + +#include "syshead.h" + +#include "options_util.h" + +const char * +parse_auth_failed_temp(struct options *o, const char *reason) +{ + struct gc_arena gc = gc_new(); + + const char *message = reason; + char *m = string_alloc(reason, &gc); + + /* Check if the message uses the TEMP[flags]: message format*/ + char *endofflags = strstr(m, "]"); + + /* Temporary failure from the server */ + if (m[0] == '[' && endofflags) + { + message = strstr(reason, "]") + 1; + /* null terminate the substring to only looks for flags between [ and ] */ + *endofflags = '\x00'; + const char *token = strtok(m, "[,"); + while (token) + { + if (!strncmp(token, "backoff ", strlen("backoff "))) + { + if (sscanf(token, "backoff %d", &o->server_backoff_time) != 1) + { + msg(D_PUSH, "invalid AUTH_FAIL,TEMP flag: %s", token); + o->server_backoff_time = 0; + } + } + else if (!strncmp(token, "advance ", strlen("advance "))) + { + token += strlen("advance "); + if (!strcmp(token, "no")) + { + o->no_advance = true; + } + else if (!strcmp(token, "remote")) + { + o->advance_next_remote = true; + o->no_advance = false; + } + else if (!strcmp(token, "addr")) + { + /* Go on to the next remote */ + o->no_advance = false; + } + } + else + { + msg(D_PUSH_ERRORS, "WARNING: unknown AUTH_FAIL,TEMP flag: %s", token); + } + token = strtok(NULL, "[,"); + } + } + + /* Look for the message in the original buffer to safely be + * able to return it */ + if (!message || message[0] != ':') + { + message = ""; + } + else + { + /* Skip the : at the beginning */ + message += 1; + } + gc_free(&gc); + return message; +} diff --git a/src/openvpn/options_util.h b/src/openvpn/options_util.h new file mode 100644 index 000000000..17d62047b --- /dev/null +++ b/src/openvpn/options_util.h @@ -0,0 +1,33 @@ +/* + * OpenVPN -- An application to securely tunnel IP networks + * over a single TCP/UDP port, with support for SSL/TLS-based + * session authentication and key exchange, + * packet encryption, packet authentication, and + * packet compression. + * + * Copyright (C) 2002-2022 OpenVPN Inc + * Copyright (C) 2010-2021 Fox Crypto B.V. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef OPTIONS_UTIL_H_ +#define OPTIONS_UTIL_H_ + +#include "options.h" + +const char * +parse_auth_failed_temp(struct options *o, const char *reason); + +#endif diff --git a/src/openvpn/push.c b/src/openvpn/push.c index 47a799282..9f47b5d5a 100644 --- a/src/openvpn/push.c +++ b/src/openvpn/push.c @@ -38,6 +38,7 @@ #include "memdbg.h" #include "ssl_util.h" +#include "options_util.h" static char push_reply_cmd[] = "PUSH_REPLY"; @@ -58,15 +59,34 @@ receive_auth_failed(struct context *c, const struct buffer *buffer) return; } + struct buffer buf = *buffer; + + /* If the AUTH_FAIL message ends with a , it is an extended message that + * contains further flags */ + bool authfail_extended = buf_string_compare_advance(&buf, "AUTH_FAILED,"); + + const char *reason = NULL; + if (authfail_extended && BLEN(&buf)) + { + reason = BSTR(&buf); + } + + if (authfail_extended && buf_string_match_head_str(&buf, "TEMP")) + { + parse_auth_failed_temp(&c->options, reason + strlen("TEMP")); + c->sig->signal_received = SIGUSR1; + c->sig->signal_text = "auth-temp-failure (server temporary reject)"; + } /* Before checking how to react on AUTH_FAILED, first check if the * failed auth might be the result of an expired auth-token. * Note that a server restart will trigger a generic AUTH_FAILED * instead an AUTH_FAILED,SESSION so handle all AUTH_FAILED message * identical for this scenario */ - if (ssl_clean_auth_token()) + else if (ssl_clean_auth_token()) { c->sig->signal_received = SIGUSR1; /* SOFT-SIGUSR1 -- Auth failure error */ c->sig->signal_text = "auth-failure (auth-token)"; + c->options.no_advance = true; } else { @@ -89,19 +109,8 @@ receive_auth_failed(struct context *c, const struct buffer *buffer) c->sig->signal_text = "auth-failure"; } #ifdef ENABLE_MANAGEMENT - struct buffer buf = *buffer; - - /* If the AUTH_FAIL message ends with a , it is an extended message that - * contains further flags */ - bool authfail_extended = buf_string_compare_advance(&buf, "AUTH_FAILED,"); - if (management) { - const char *reason = NULL; - if (authfail_extended && BLEN(&buf)) - { - reason = BSTR(&buf); - } management_auth_failure(management, UP_TYPE_AUTH, reason); } /* diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c index d3f7a0203..672cd9c84 100644 --- a/src/openvpn/ssl.c +++ b/src/openvpn/ssl.c @@ -1972,14 +1972,19 @@ push_peer_info(struct buffer *buf, struct tls_session *session) /* support for exit notify via control channel */ iv_proto |= IV_PROTO_CC_EXIT_NOTIFY; - /* support for receiving push_reply before sending - * push request, also signal that the client wants - * to get push-reply messages without without requiring a round - * trip for a push request message*/ if (session->opt->pull) { + /* support for receiving push_reply before sending + * push request, also signal that the client wants + * to get push-reply messages without requiring a round + * trip for a push request message*/ iv_proto |= IV_PROTO_REQUEST_PUSH; + + /* Support keywords in the AUTH_PENDING control message */ iv_proto |= IV_PROTO_AUTH_PENDING_KW; + + /* support for AUTH_FAIL,TEMP control message */ + iv_proto |= IV_PROTO_AUTH_FAIL_TEMP; } /* support for Negotiable Crypto Parameters */ diff --git a/src/openvpn/ssl.h b/src/openvpn/ssl.h index 12ffd44d7..8ca4c4aa8 100644 --- a/src/openvpn/ssl.h +++ b/src/openvpn/ssl.h @@ -100,6 +100,9 @@ * This also includes support for the protocol-flags pushed option */ #define IV_PROTO_CC_EXIT_NOTIFY (1<<7) +/** Support for AUTH_FAIL,TEMP messages */ +#define IV_PROTO_AUTH_FAIL_TEMP (1<<8) + /* Default field in X509 to be username */ #define X509_USERNAME_FIELD_DEFAULT "CN" diff --git a/tests/unit_tests/openvpn/Makefile.am b/tests/unit_tests/openvpn/Makefile.am index 63b53a6ac..65cf9549c 100644 --- a/tests/unit_tests/openvpn/Makefile.am +++ b/tests/unit_tests/openvpn/Makefile.am @@ -176,5 +176,6 @@ misc_testdriver_LDFLAGS = @TEST_LDFLAGS@ misc_testdriver_SOURCES = test_misc.c mock_msg.c \ mock_get_random.c \ $(openvpn_srcdir)/buffer.c \ + $(openvpn_srcdir)/options_util.c \ $(openvpn_srcdir)/ssl_util.c \ $(openvpn_srcdir)/platform.c diff --git a/tests/unit_tests/openvpn/test_misc.c b/tests/unit_tests/openvpn/test_misc.c index 636fc45d6..90c9a1214 100644 --- a/tests/unit_tests/openvpn/test_misc.c +++ b/tests/unit_tests/openvpn/test_misc.c @@ -37,6 +37,7 @@ #include #include "ssl_util.h" +#include "options_util.h" static void test_compat_lzo_string(void **state) @@ -72,8 +73,47 @@ test_compat_lzo_string(void **state) gc_free(&gc); } +static void +test_auth_fail_temp_no_flags(void **state) +{ + struct options o; + + const char *teststr = "TEMP:There are no flags here [really not]"; + + const char *msg = parse_auth_failed_temp(&o, teststr + strlen("TEMP")); + assert_string_equal(msg, "There are no flags here [really not]"); +} + +static void +test_auth_fail_temp_flags(void **state) +{ + struct options o; + + const char *teststr = "[backoff 42,advance no]"; + + const char *msg = parse_auth_failed_temp(&o, teststr); + assert_string_equal(msg, ""); + assert_int_equal(o.server_backoff_time, 42); + assert_int_equal(o.no_advance, true); +} + +static void +test_auth_fail_temp_flags_msg(void **state) +{ + struct options o; + + const char *teststr = "[advance remote,backoff 77]:go round and round"; + + const char *msg = parse_auth_failed_temp(&o, teststr); + assert_string_equal(msg, "go round and round"); + assert_int_equal(o.server_backoff_time, 77); +} + const struct CMUnitTest misc_tests[] = { cmocka_unit_test(test_compat_lzo_string), + cmocka_unit_test(test_auth_fail_temp_no_flags), + cmocka_unit_test(test_auth_fail_temp_flags), + cmocka_unit_test(test_auth_fail_temp_flags_msg), }; int