diff options
Diffstat (limited to 'openvpn/src/openvpn/ssl.c')
| -rw-r--r-- | openvpn/src/openvpn/ssl.c | 3547 |
1 files changed, 0 insertions, 3547 deletions
diff --git a/openvpn/src/openvpn/ssl.c b/openvpn/src/openvpn/ssl.c deleted file mode 100644 index c61701a7..00000000 --- a/openvpn/src/openvpn/ssl.c +++ /dev/null @@ -1,3547 +0,0 @@ -/* - * 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) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net> - * Copyright (C) 2010 Fox Crypto B.V. <openvpn@fox-it.com> - * Copyright (C) 2008-2013 David Sommerseth <dazo@users.sourceforge.net> - * - * 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 (see the file COPYING included with this - * distribution); if not, write to the Free Software Foundation, Inc., - * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ - -/** - * @file Control Channel SSL/Data channel negotiation Module - */ - -/* - * The routines in this file deal with dynamically negotiating - * the data channel HMAC and cipher keys through a TLS session. - * - * Both the TLS session and the data channel are multiplexed - * over the same TCP/UDP port. - */ - -#ifdef HAVE_CONFIG_H -#include "config.h" -#elif defined(_MSC_VER) -#include "config-msvc.h" -#endif - -#include "syshead.h" - -#if defined(ENABLE_CRYPTO) && defined(ENABLE_SSL) - -#include "error.h" -#include "common.h" -#include "integer.h" -#include "socket.h" -#include "misc.h" -#include "fdmisc.h" -#include "interval.h" -#include "perf.h" -#include "status.h" -#include "gremlin.h" -#include "pkcs11.h" -#include "list.h" -#include "base64.h" -#include "route.h" - -#include "ssl.h" -#include "ssl_verify.h" -#include "ssl_backend.h" - -#include "memdbg.h" - -#ifndef ENABLE_OCC -static const char ssl_default_options_string[] = "V0 UNDEF"; -#endif - -static inline const char * -local_options_string (const struct tls_session *session) -{ -#ifdef ENABLE_OCC - return session->opt->local_options; -#else - return ssl_default_options_string; -#endif -} - -#ifdef MEASURE_TLS_HANDSHAKE_STATS - -static int tls_handshake_success; /* GLOBAL */ -static int tls_handshake_error; /* GLOBAL */ -static int tls_packets_generated; /* GLOBAL */ -static int tls_packets_sent; /* GLOBAL */ - -#define INCR_SENT ++tls_packets_sent -#define INCR_GENERATED ++tls_packets_generated -#define INCR_SUCCESS ++tls_handshake_success -#define INCR_ERROR ++tls_handshake_error - -void -show_tls_performance_stats(void) -{ - msg (D_TLS_DEBUG_LOW, "TLS Handshakes, success=%f%% (good=%d, bad=%d), retransmits=%f%%", - (double) tls_handshake_success / (tls_handshake_success + tls_handshake_error) * 100.0, - tls_handshake_success, tls_handshake_error, - (double) (tls_packets_sent - tls_packets_generated) / tls_packets_generated * 100.0); -} -#else - -#define INCR_SENT -#define INCR_GENERATED -#define INCR_SUCCESS -#define INCR_ERROR - -#endif - -/** - * SSL/TLS Cipher suite name translation table - */ -static const tls_cipher_name_pair tls_cipher_name_translation_table[] = { - {"ADH-SEED-SHA", "TLS-DH-anon-WITH-SEED-CBC-SHA"}, - {"AES128-GCM-SHA256", "TLS-RSA-WITH-AES-128-GCM-SHA256"}, - {"AES128-SHA256", "TLS-RSA-WITH-AES-128-CBC-SHA256"}, - {"AES128-SHA", "TLS-RSA-WITH-AES-128-CBC-SHA"}, - {"AES256-GCM-SHA384", "TLS-RSA-WITH-AES-256-GCM-SHA384"}, - {"AES256-SHA256", "TLS-RSA-WITH-AES-256-CBC-SHA256"}, - {"AES256-SHA", "TLS-RSA-WITH-AES-256-CBC-SHA"}, - {"CAMELLIA128-SHA256", "TLS-RSA-WITH-CAMELLIA-128-CBC-SHA256"}, - {"CAMELLIA128-SHA", "TLS-RSA-WITH-CAMELLIA-128-CBC-SHA"}, - {"CAMELLIA256-SHA256", "TLS-RSA-WITH-CAMELLIA-256-CBC-SHA256"}, - {"CAMELLIA256-SHA", "TLS-RSA-WITH-CAMELLIA-256-CBC-SHA"}, - {"DES-CBC3-SHA", "TLS-RSA-WITH-3DES-EDE-CBC-SHA"}, - {"DES-CBC-SHA", "TLS-RSA-WITH-DES-CBC-SHA"}, - {"DH-DSS-SEED-SHA", "TLS-DH-DSS-WITH-SEED-CBC-SHA"}, - {"DHE-DSS-AES128-GCM-SHA256", "TLS-DHE-DSS-WITH-AES-128-GCM-SHA256"}, - {"DHE-DSS-AES128-SHA256", "TLS-DHE-DSS-WITH-AES-128-CBC-SHA256"}, - {"DHE-DSS-AES128-SHA", "TLS-DHE-DSS-WITH-AES-128-CBC-SHA"}, - {"DHE-DSS-AES256-GCM-SHA384", "TLS-DHE-DSS-WITH-AES-256-GCM-SHA384"}, - {"DHE-DSS-AES256-SHA256", "TLS-DHE-DSS-WITH-AES-256-CBC-SHA256"}, - {"DHE-DSS-AES256-SHA", "TLS-DHE-DSS-WITH-AES-256-CBC-SHA"}, - {"DHE-DSS-CAMELLIA128-SHA256", "TLS-DHE-DSS-WITH-CAMELLIA-128-CBC-SHA256"}, - {"DHE-DSS-CAMELLIA128-SHA", "TLS-DHE-DSS-WITH-CAMELLIA-128-CBC-SHA"}, - {"DHE-DSS-CAMELLIA256-SHA256", "TLS-DHE-DSS-WITH-CAMELLIA-256-CBC-SHA256"}, - {"DHE-DSS-CAMELLIA256-SHA", "TLS-DHE-DSS-WITH-CAMELLIA-256-CBC-SHA"}, - {"DHE-DSS-SEED-SHA", "TLS-DHE-DSS-WITH-SEED-CBC-SHA"}, - {"DHE-RSA-AES128-GCM-SHA256", "TLS-DHE-RSA-WITH-AES-128-GCM-SHA256"}, - {"DHE-RSA-AES128-SHA256", "TLS-DHE-RSA-WITH-AES-128-CBC-SHA256"}, - {"DHE-RSA-AES128-SHA", "TLS-DHE-RSA-WITH-AES-128-CBC-SHA"}, - {"DHE-RSA-AES256-GCM-SHA384", "TLS-DHE-RSA-WITH-AES-256-GCM-SHA384"}, - {"DHE-RSA-AES256-SHA256", "TLS-DHE-RSA-WITH-AES-256-CBC-SHA256"}, - {"DHE-RSA-AES256-SHA", "TLS-DHE-RSA-WITH-AES-256-CBC-SHA"}, - {"DHE-RSA-CAMELLIA128-SHA256", "TLS-DHE-RSA-WITH-CAMELLIA-128-CBC-SHA256"}, - {"DHE-RSA-CAMELLIA128-SHA", "TLS-DHE-RSA-WITH-CAMELLIA-128-CBC-SHA"}, - {"DHE-RSA-CAMELLIA256-SHA256", "TLS-DHE-RSA-WITH-CAMELLIA-256-CBC-SHA256"}, - {"DHE-RSA-CAMELLIA256-SHA", "TLS-DHE-RSA-WITH-CAMELLIA-256-CBC-SHA"}, - {"DHE-RSA-SEED-SHA", "TLS-DHE-RSA-WITH-SEED-CBC-SHA"}, - {"DH-RSA-SEED-SHA", "TLS-DH-RSA-WITH-SEED-CBC-SHA"}, - {"ECDH-ECDSA-AES128-GCM-SHA256", "TLS-ECDH-ECDSA-WITH-AES-128-GCM-SHA256"}, - {"ECDH-ECDSA-AES128-SHA256", "TLS-ECDH-ECDSA-WITH-AES-128-CBC-SHA256"}, - {"ECDH-ECDSA-AES128-SHA", "TLS-ECDH-ECDSA-WITH-AES-128-CBC-SHA"}, - {"ECDH-ECDSA-AES256-GCM-SHA384", "TLS-ECDH-ECDSA-WITH-AES-256-GCM-SHA384"}, - {"ECDH-ECDSA-AES256-SHA256", "TLS-ECDH-ECDSA-WITH-AES-256-CBC-SHA256"}, - {"ECDH-ECDSA-AES256-SHA384", "TLS-ECDH-ECDSA-WITH-AES-256-CBC-SHA384"}, - {"ECDH-ECDSA-AES256-SHA", "TLS-ECDH-ECDSA-WITH-AES-256-CBC-SHA"}, - {"ECDH-ECDSA-CAMELLIA128-SHA256", "TLS-ECDH-ECDSA-WITH-CAMELLIA-128-CBC-SHA256"}, - {"ECDH-ECDSA-CAMELLIA128-SHA", "TLS-ECDH-ECDSA-WITH-CAMELLIA-128-CBC-SHA"}, - {"ECDH-ECDSA-CAMELLIA256-SHA256", "TLS-ECDH-ECDSA-WITH-CAMELLIA-256-CBC-SHA256"}, - {"ECDH-ECDSA-CAMELLIA256-SHA", "TLS-ECDH-ECDSA-WITH-CAMELLIA-256-CBC-SHA"}, - {"ECDH-ECDSA-DES-CBC3-SHA", "TLS-ECDH-ECDSA-WITH-3DES-EDE-CBC-SHA"}, - {"ECDH-ECDSA-DES-CBC-SHA", "TLS-ECDH-ECDSA-WITH-DES-CBC-SHA"}, - {"ECDH-ECDSA-RC4-SHA", "TLS-ECDH-ECDSA-WITH-RC4-128-SHA"}, - {"ECDHE-ECDSA-AES128-GCM-SHA256", "TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256"}, - {"ECDHE-ECDSA-AES128-SHA256", "TLS-ECDHE-ECDSA-WITH-AES-128-CBC-SHA256"}, - {"ECDHE-ECDSA-AES128-SHA384", "TLS-ECDHE-ECDSA-WITH-AES-128-CBC-SHA384"}, - {"ECDHE-ECDSA-AES128-SHA", "TLS-ECDHE-ECDSA-WITH-AES-128-CBC-SHA"}, - {"ECDHE-ECDSA-AES256-GCM-SHA384", "TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384"}, - {"ECDHE-ECDSA-AES256-SHA256", "TLS-ECDHE-ECDSA-WITH-AES-256-CBC-SHA256"}, - {"ECDHE-ECDSA-AES256-SHA384", "TLS-ECDHE-ECDSA-WITH-AES-256-CBC-SHA384"}, - {"ECDHE-ECDSA-AES256-SHA", "TLS-ECDHE-ECDSA-WITH-AES-256-CBC-SHA"}, - {"ECDHE-ECDSA-CAMELLIA128-SHA256", "TLS-ECDHE-ECDSA-WITH-CAMELLIA-128-CBC-SHA256"}, - {"ECDHE-ECDSA-CAMELLIA128-SHA", "TLS-ECDHE-ECDSA-WITH-CAMELLIA-128-CBC-SHA"}, - {"ECDHE-ECDSA-CAMELLIA256-SHA256", "TLS-ECDHE-ECDSA-WITH-CAMELLIA-256-CBC-SHA256"}, - {"ECDHE-ECDSA-CAMELLIA256-SHA", "TLS-ECDHE-ECDSA-WITH-CAMELLIA-256-CBC-SHA"}, - {"ECDHE-ECDSA-DES-CBC3-SHA", "TLS-ECDHE-ECDSA-WITH-3DES-EDE-CBC-SHA"}, - {"ECDHE-ECDSA-DES-CBC-SHA", "TLS-ECDHE-ECDSA-WITH-DES-CBC-SHA"}, - {"ECDHE-ECDSA-RC4-SHA", "TLS-ECDHE-ECDSA-WITH-RC4-128-SHA"}, - {"ECDHE-RSA-AES128-GCM-SHA256", "TLS-ECDHE-RSA-WITH-AES-128-GCM-SHA256"}, - {"ECDHE-RSA-AES128-SHA256", "TLS-ECDHE-RSA-WITH-AES-128-CBC-SHA256"}, - {"ECDHE-RSA-AES128-SHA384", "TLS-ECDHE-RSA-WITH-AES-128-CBC-SHA384"}, - {"ECDHE-RSA-AES128-SHA", "TLS-ECDHE-RSA-WITH-AES-128-CBC-SHA"}, - {"ECDHE-RSA-AES256-GCM-SHA384", "TLS-ECDHE-RSA-WITH-AES-256-GCM-SHA384"}, - {"ECDHE-RSA-AES256-SHA256", "TLS-ECDHE-RSA-WITH-AES-256-CBC-SHA256"}, - {"ECDHE-RSA-AES256-SHA384", "TLS-ECDHE-RSA-WITH-AES-256-CBC-SHA384"}, - {"ECDHE-RSA-AES256-SHA", "TLS-ECDHE-RSA-WITH-AES-256-CBC-SHA"}, - {"ECDHE-RSA-CAMELLIA128-SHA256", "TLS-ECDHE-RSA-WITH-CAMELLIA-128-CBC-SHA256"}, - {"ECDHE-RSA-CAMELLIA128-SHA", "TLS-ECDHE-RSA-WITH-CAMELLIA-128-CBC-SHA"}, - {"ECDHE-RSA-CAMELLIA256-SHA256", "TLS-ECDHE-RSA-WITH-CAMELLIA-256-CBC-SHA256"}, - {"ECDHE-RSA-CAMELLIA256-SHA", "TLS-ECDHE-RSA-WITH-CAMELLIA-256-CBC-SHA"}, - {"ECDHE-RSA-DES-CBC3-SHA", "TLS-ECDHE-RSA-WITH-3DES-EDE-CBC-SHA"}, - {"ECDHE-RSA-DES-CBC-SHA", "TLS-ECDHE-RSA-WITH-DES-CBC-SHA"}, - {"ECDHE-RSA-RC4-SHA", "TLS-ECDHE-RSA-WITH-RC4-128-SHA"}, - {"ECDH-RSA-AES128-GCM-SHA256", "TLS-ECDH-RSA-WITH-AES-128-GCM-SHA256"}, - {"ECDH-RSA-AES128-SHA256", "TLS-ECDH-RSA-WITH-AES-128-CBC-SHA256"}, - {"ECDH-RSA-AES128-SHA384", "TLS-ECDH-RSA-WITH-AES-128-CBC-SHA384"}, - {"ECDH-RSA-AES128-SHA", "TLS-ECDH-RSA-WITH-AES-128-CBC-SHA"}, - {"ECDH-RSA-AES256-GCM-SHA384", "TLS-ECDH-RSA-WITH-AES-256-GCM-SHA384"}, - {"ECDH-RSA-AES256-SHA256", "TLS-ECDH-RSA-WITH-AES-256-CBC-SHA256"}, - {"ECDH-RSA-AES256-SHA384", "TLS-ECDH-RSA-WITH-AES-256-CBC-SHA384"}, - {"ECDH-RSA-AES256-SHA", "TLS-ECDH-RSA-WITH-AES-256-CBC-SHA"}, - {"ECDH-RSA-CAMELLIA128-SHA256", "TLS-ECDH-RSA-WITH-CAMELLIA-128-CBC-SHA256"}, - {"ECDH-RSA-CAMELLIA128-SHA", "TLS-ECDH-RSA-WITH-CAMELLIA-128-CBC-SHA"}, - {"ECDH-RSA-CAMELLIA256-SHA256", "TLS-ECDH-RSA-WITH-CAMELLIA-256-CBC-SHA256"}, - {"ECDH-RSA-CAMELLIA256-SHA", "TLS-ECDH-RSA-WITH-CAMELLIA-256-CBC-SHA"}, - {"ECDH-RSA-DES-CBC3-SHA", "TLS-ECDH-RSA-WITH-3DES-EDE-CBC-SHA"}, - {"ECDH-RSA-DES-CBC-SHA", "TLS-ECDH-RSA-WITH-DES-CBC-SHA"}, - {"ECDH-RSA-RC4-SHA", "TLS-ECDH-RSA-WITH-RC4-128-SHA"}, - {"EDH-DSS-DES-CBC3-SHA", "TLS-DHE-DSS-WITH-3DES-EDE-CBC-SHA"}, - {"EDH-DSS-DES-CBC-SHA", "TLS-DHE-DSS-WITH-DES-CBC-SHA"}, - {"EDH-RSA-DES-CBC3-SHA", "TLS-DHE-RSA-WITH-3DES-EDE-CBC-SHA"}, - {"EDH-RSA-DES-CBC-SHA", "TLS-DHE-RSA-WITH-DES-CBC-SHA"}, - {"EXP-DES-CBC-SHA", "TLS-RSA-EXPORT-WITH-DES40-CBC-SHA"}, - {"EXP-EDH-DSS-DES-CBC-SHA", "TLS-DH-DSS-EXPORT-WITH-DES40-CBC-SHA"}, - {"EXP-EDH-RSA-DES-CBC-SHA", "TLS-DH-RSA-EXPORT-WITH-DES40-CBC-SHA"}, - {"EXP-RC2-CBC-MD5", "TLS-RSA-EXPORT-WITH-RC2-CBC-40-MD5"}, - {"EXP-RC4-MD5", "TLS-RSA-EXPORT-WITH-RC4-40-MD5"}, - {"NULL-MD5", "TLS-RSA-WITH-NULL-MD5"}, - {"NULL-SHA256", "TLS-RSA-WITH-NULL-SHA256"}, - {"NULL-SHA", "TLS-RSA-WITH-NULL-SHA"}, - {"PSK-3DES-EDE-CBC-SHA", "TLS-PSK-WITH-3DES-EDE-CBC-SHA"}, - {"PSK-AES128-CBC-SHA", "TLS-PSK-WITH-AES-128-CBC-SHA"}, - {"PSK-AES256-CBC-SHA", "TLS-PSK-WITH-AES-256-CBC-SHA"}, - {"PSK-RC4-SHA", "TLS-PSK-WITH-RC4-128-SHA"}, - {"RC4-MD5", "TLS-RSA-WITH-RC4-128-MD5"}, - {"RC4-SHA", "TLS-RSA-WITH-RC4-128-SHA"}, - {"SEED-SHA", "TLS-RSA-WITH-SEED-CBC-SHA"}, - {"SRP-DSS-3DES-EDE-CBC-SHA", "TLS-SRP-SHA-DSS-WITH-3DES-EDE-CBC-SHA"}, - {"SRP-DSS-AES-128-CBC-SHA", "TLS-SRP-SHA-DSS-WITH-AES-128-CBC-SHA"}, - {"SRP-DSS-AES-256-CBC-SHA", "TLS-SRP-SHA-DSS-WITH-AES-256-CBC-SHA"}, - {"SRP-RSA-3DES-EDE-CBC-SHA", "TLS-SRP-SHA-RSA-WITH-3DES-EDE-CBC-SHA"}, - {"SRP-RSA-AES-128-CBC-SHA", "TLS-SRP-SHA-RSA-WITH-AES-128-CBC-SHA"}, - {"SRP-RSA-AES-256-CBC-SHA", "TLS-SRP-SHA-RSA-WITH-AES-256-CBC-SHA"}, - {NULL, NULL} -}; - -const tls_cipher_name_pair * -tls_get_cipher_name_pair (const char * cipher_name, size_t len) { - const tls_cipher_name_pair * pair = tls_cipher_name_translation_table; - - while (pair->openssl_name != NULL) { - if ((strlen(pair->openssl_name) == len && 0 == memcmp (cipher_name, pair->openssl_name, len)) || - (strlen(pair->iana_name) == len && 0 == memcmp (cipher_name, pair->iana_name, len))) { - return pair; - } - pair++; - } - - // No entry found, return NULL - return NULL; -} - -/* - * Max number of bytes we will add - * for data structures common to both - * data and control channel packets. - * (opcode only). - */ -void -tls_adjust_frame_parameters(struct frame *frame) -{ - frame_add_to_extra_frame (frame, 1); /* space for opcode */ -} - -/* - * Max number of bytes we will add - * to control channel packet. - */ -static void -tls_init_control_channel_frame_parameters(const struct frame *data_channel_frame, - struct frame *frame) -{ - /* - * frame->extra_frame is already initialized with tls_auth buffer requirements, - * if --tls-auth is enabled. - */ - - /* inherit link MTU and extra_link from data channel */ - frame->link_mtu = data_channel_frame->link_mtu; - frame->extra_link = data_channel_frame->extra_link; - - /* set extra_frame */ - tls_adjust_frame_parameters (frame); - reliable_ack_adjust_frame_parameters (frame, CONTROL_SEND_ACK_MAX); - frame_add_to_extra_frame (frame, SID_SIZE + sizeof (packet_id_type)); - - /* set dynamic link MTU to minimum value */ - frame_set_mtu_dynamic (frame, 0, SET_MTU_TUN); -} - -void -init_ssl_lib () -{ - tls_init_lib (); - - crypto_init_lib (); -} - -void -free_ssl_lib () -{ - crypto_uninit_lib (); - prng_uninit(); - - tls_free_lib(); -} - -/* - * OpenSSL library calls pem_password_callback if the - * private key is protected by a password. - */ - -static struct user_pass passbuf; /* GLOBAL */ - -void -pem_password_setup (const char *auth_file) -{ - if (!strlen (passbuf.password)) - get_user_pass (&passbuf, auth_file, UP_TYPE_PRIVATE_KEY, GET_USER_PASS_MANAGEMENT|GET_USER_PASS_SENSITIVE|GET_USER_PASS_PASSWORD_ONLY); -} - -int -pem_password_callback (char *buf, int size, int rwflag, void *u) -{ - if (buf) - { - /* prompt for password even if --askpass wasn't specified */ - pem_password_setup (NULL); - strncpynt (buf, passbuf.password, size); - purge_user_pass (&passbuf, false); - - return strlen (buf); - } - return 0; -} - -/* - * Auth username/password handling - */ - -static bool auth_user_pass_enabled; /* GLOBAL */ -static struct user_pass auth_user_pass; /* GLOBAL */ - -#ifdef ENABLE_CLIENT_CR -static char *auth_challenge; /* GLOBAL */ -#endif - -void -auth_user_pass_setup (const char *auth_file, const struct static_challenge_info *sci) -{ - auth_user_pass_enabled = true; - if (!auth_user_pass.defined) - { -#if AUTO_USERID - get_user_pass_auto_userid (&auth_user_pass, auth_file); -#else -# ifdef ENABLE_CLIENT_CR - if (auth_challenge) /* dynamic challenge/response */ - get_user_pass_cr (&auth_user_pass, - auth_file, - UP_TYPE_AUTH, - GET_USER_PASS_MANAGEMENT|GET_USER_PASS_SENSITIVE|GET_USER_PASS_DYNAMIC_CHALLENGE, - auth_challenge); - else if (sci) /* static challenge response */ - { - int flags = GET_USER_PASS_MANAGEMENT|GET_USER_PASS_SENSITIVE|GET_USER_PASS_STATIC_CHALLENGE; - if (sci->flags & SC_ECHO) - flags |= GET_USER_PASS_STATIC_CHALLENGE_ECHO; - get_user_pass_cr (&auth_user_pass, - auth_file, - UP_TYPE_AUTH, - flags, - sci->challenge_text); - } - else -# endif - get_user_pass (&auth_user_pass, auth_file, UP_TYPE_AUTH, GET_USER_PASS_MANAGEMENT|GET_USER_PASS_SENSITIVE); -#endif - } -} - -/* - * Disable password caching - */ -void -ssl_set_auth_nocache (void) -{ - passbuf.nocache = true; - auth_user_pass.nocache = true; -} - -/* - * Set an authentication token - */ -void -ssl_set_auth_token (const char *token) -{ - set_auth_token (&auth_user_pass, token); -} - -/* - * Forget private key password AND auth-user-pass username/password. - */ -void -ssl_purge_auth (const bool auth_user_pass_only) -{ - if (!auth_user_pass_only) - { -#ifdef ENABLE_PKCS11 - pkcs11_logout (); -#endif - purge_user_pass (&passbuf, true); - } - purge_user_pass (&auth_user_pass, true); -#ifdef ENABLE_CLIENT_CR - ssl_purge_auth_challenge(); -#endif -} - -#ifdef ENABLE_CLIENT_CR - -void -ssl_purge_auth_challenge (void) -{ - free (auth_challenge); - auth_challenge = NULL; -} - -void -ssl_put_auth_challenge (const char *cr_str) -{ - ssl_purge_auth_challenge(); - auth_challenge = string_alloc(cr_str, NULL); -} - -#endif - -/* - * Parse a TLS version string, returning a TLS_VER_x constant. - * If version string is not recognized and extra == "or-highest", - * return tls_version_max(). - */ -int -tls_version_min_parse(const char *vstr, const char *extra) -{ - const int max_version = tls_version_max(); - if (!strcmp(vstr, "1.0") && TLS_VER_1_0 <= max_version) - return TLS_VER_1_0; - else if (!strcmp(vstr, "1.1") && TLS_VER_1_1 <= max_version) - return TLS_VER_1_1; - else if (!strcmp(vstr, "1.2") && TLS_VER_1_2 <= max_version) - return TLS_VER_1_2; - else if (extra && !strcmp(extra, "or-highest")) - return max_version; - else - return TLS_VER_BAD; -} - -/* - * Initialize SSL context. - * All files are in PEM format. - */ -void -init_ssl (const struct options *options, struct tls_root_ctx *new_ctx) -{ - ASSERT(NULL != new_ctx); - - tls_clear_error(); - - if (options->tls_server) - { - tls_ctx_server_new(new_ctx); - tls_ctx_load_dh_params(new_ctx, options->dh_file, options->dh_file_inline); - } - else /* if client */ - { - tls_ctx_client_new(new_ctx); - } - - tls_ctx_set_options(new_ctx, options->ssl_flags); - - if (options->pkcs12_file) - { - if (0 != tls_ctx_load_pkcs12(new_ctx, options->pkcs12_file, - options->pkcs12_file_inline, !options->ca_file)) - goto err; - } -#ifdef ENABLE_PKCS11 - else if (options->pkcs11_providers[0]) - { - if (!tls_ctx_use_pkcs11 (new_ctx, options->pkcs11_id_management, options->pkcs11_id)) - { - msg (M_WARN, "Cannot load certificate \"%s\" using PKCS#11 interface", - options->pkcs11_id); - goto err; - } - } -#endif -#ifdef ENABLE_CRYPTOAPI - else if (options->cryptoapi_cert) - { - tls_ctx_load_cryptoapi(new_ctx, options->cryptoapi_cert); - } -#endif -#ifdef MANAGMENT_EXTERNAL_KEY - else if ((options->management_flags & MF_EXTERNAL_KEY) && options->cert_file) - { - tls_ctx_use_external_private_key(new_ctx, options->cert_file, - options->cert_file_inline); - } -#endif - else - { - /* Load Certificate */ - if (options->cert_file) - { - tls_ctx_load_cert_file(new_ctx, options->cert_file, options->cert_file_inline); - } - - /* Load Private Key */ - if (options->priv_key_file) - { - if (0 != tls_ctx_load_priv_file(new_ctx, options->priv_key_file, options->priv_key_file_inline)) - goto err; - } - } - - if (options->ca_file || options->ca_path) - { - tls_ctx_load_ca(new_ctx, options->ca_file, options->ca_file_inline, - options->ca_path, options->tls_server); - } - - /* Load extra certificates that are part of our own certificate - chain but shouldn't be included in the verify chain */ - if (options->extra_certs_file || options->extra_certs_file_inline) - { - tls_ctx_load_extra_certs(new_ctx, options->extra_certs_file, options->extra_certs_file_inline); - } - - /* Allowable ciphers */ - tls_ctx_restrict_ciphers(new_ctx, options->cipher_list); - -#ifdef ENABLE_CRYPTO_POLARSSL - /* Personalise the random by mixing in the certificate */ - tls_ctx_personalise_random (new_ctx); -#endif - - tls_clear_error (); - return; - - err: - tls_clear_error (); - tls_ctx_free (new_ctx); - return; -} - -/* - * Map internal constants to ascii names. - */ -static const char * -state_name (int state) -{ - switch (state) - { - case S_UNDEF: - return "S_UNDEF"; - case S_INITIAL: - return "S_INITIAL"; - case S_PRE_START: - return "S_PRE_START"; - case S_START: - return "S_START"; - case S_SENT_KEY: - return "S_SENT_KEY"; - case S_GOT_KEY: - return "S_GOT_KEY"; - case S_ACTIVE: - return "S_ACTIVE"; - case S_NORMAL_OP: - return "S_NORMAL_OP"; - case S_ERROR: - return "S_ERROR"; - default: - return "S_???"; - } -} - -static const char * -packet_opcode_name (int op) -{ - switch (op) - { - case P_CONTROL_HARD_RESET_CLIENT_V1: - return "P_CONTROL_HARD_RESET_CLIENT_V1"; - case P_CONTROL_HARD_RESET_SERVER_V1: - return "P_CONTROL_HARD_RESET_SERVER_V1"; - case P_CONTROL_HARD_RESET_CLIENT_V2: - return "P_CONTROL_HARD_RESET_CLIENT_V2"; - case P_CONTROL_HARD_RESET_SERVER_V2: - return "P_CONTROL_HARD_RESET_SERVER_V2"; - case P_CONTROL_SOFT_RESET_V1: - return "P_CONTROL_SOFT_RESET_V1"; - case P_CONTROL_V1: - return "P_CONTROL_V1"; - case P_ACK_V1: - return "P_ACK_V1"; - case P_DATA_V1: - return "P_DATA_V1"; - default: - return "P_???"; - } -} - -static const char * -session_index_name (int index) -{ - switch (index) - { - case TM_ACTIVE: - return "TM_ACTIVE"; - case TM_UNTRUSTED: - return "TM_UNTRUSTED"; - case TM_LAME_DUCK: - return "TM_LAME_DUCK"; - default: - return "TM_???"; - } -} - -/* - * For debugging. - */ -static const char * -print_key_id (struct tls_multi *multi, struct gc_arena *gc) -{ - int i; - struct buffer out = alloc_buf_gc (256, gc); - - for (i = 0; i < KEY_SCAN_SIZE; ++i) - { - struct key_state *ks = multi->key_scan[i]; - buf_printf (&out, " [key#%d state=%s id=%d sid=%s]", i, - state_name (ks->state), ks->key_id, - session_id_print (&ks->session_id_remote, gc)); - } - - return BSTR (&out); -} - -/* - * Given a key_method, return true if op - * represents the required form of hard_reset. - * - * If key_method = 0, return true if any - * form of hard reset is used. - */ -static bool -is_hard_reset (int op, int key_method) -{ - if (!key_method || key_method == 1) - if (op == P_CONTROL_HARD_RESET_CLIENT_V1 || op == P_CONTROL_HARD_RESET_SERVER_V1) - return true; - - if (!key_method || key_method >= 2) - if (op == P_CONTROL_HARD_RESET_CLIENT_V2 || op == P_CONTROL_HARD_RESET_SERVER_V2) - return true; - - return false; -} - -/** @addtogroup control_processor - * @{ */ - -/** @name Functions for initialization and cleanup of key_state structures - * @{ */ - -/** - * Initialize a \c key_state structure. - * @ingroup control_processor - * - * This function initializes a \c key_state structure associated with a \c - * tls_session. It sets up the structure's SSL-BIO, sets the object's \c - * key_state.state to \c S_INITIAL, and sets the session ID and key ID two - * appropriate values based on the \c tls_session's internal state. It - * also initializes a new set of structures for the \link reliable - * Reliability Layer\endlink. - * - * @param session - A pointer to the \c tls_session structure - * associated with the \a ks argument. - * @param ks - A pointer to the \c key_state structure to be - * initialized. This structure should already have - * been allocated before calling this function. - */ -static void -key_state_init (struct tls_session *session, struct key_state *ks) -{ - update_time (); - - CLEAR (*ks); - - /* - * Build TLS object that reads/writes ciphertext - * to/from memory BIOs. - */ - key_state_ssl_init(&ks->ks_ssl, &session->opt->ssl_ctx, session->opt->server, - session); - - /* Set control-channel initiation mode */ - ks->initial_opcode = session->initial_opcode; - session->initial_opcode = P_CONTROL_SOFT_RESET_V1; - ks->state = S_INITIAL; - ks->key_id = session->key_id; - - /* - * key_id increments to KEY_ID_MASK then recycles back to 1. - * This way you know that if key_id is 0, it is the first key. - */ - ++session->key_id; - session->key_id &= P_KEY_ID_MASK; - if (!session->key_id) - session->key_id = 1; - - /* allocate key source material object */ - ALLOC_OBJ_CLEAR (ks->key_src, struct key_source2); - - /* allocate reliability objects */ - ALLOC_OBJ_CLEAR (ks->send_reliable, struct reliable); - ALLOC_OBJ_CLEAR (ks->rec_reliable, struct reliable); - ALLOC_OBJ_CLEAR (ks->rec_ack, struct reliable_ack); - - /* allocate buffers */ - ks->plaintext_read_buf = alloc_buf (TLS_CHANNEL_BUF_SIZE); - ks->plaintext_write_buf = alloc_buf (TLS_CHANNEL_BUF_SIZE); - ks->ack_write_buf = alloc_buf (BUF_SIZE (&session->opt->frame)); - reliable_init (ks->send_reliable, BUF_SIZE (&session->opt->frame), - FRAME_HEADROOM (&session->opt->frame), TLS_RELIABLE_N_SEND_BUFFERS, - ks->key_id ? false : session->opt->xmit_hold); - reliable_init (ks->rec_reliable, BUF_SIZE (&session->opt->frame), - FRAME_HEADROOM (&session->opt->frame), TLS_RELIABLE_N_REC_BUFFERS, - false); - reliable_set_timeout (ks->send_reliable, session->opt->packet_timeout); - - /* init packet ID tracker */ - packet_id_init (&ks->packet_id, - session->opt->tcp_mode, - session->opt->replay_window, - session->opt->replay_time, - "SSL", ks->key_id); - -#ifdef MANAGEMENT_DEF_AUTH - ks->mda_key_id = session->opt->mda_context->mda_key_id_counter++; -#endif -} - - -/** - * Cleanup a \c key_state structure. - * @ingroup control_processor - * - * This function cleans up a \c key_state structure. It frees the - * associated SSL-BIO, and the structures allocated for the \link reliable - * Reliability Layer\endlink. - * - * @param ks - A pointer to the \c key_state structure to be - * cleaned up. - * @param clear - Whether the memory allocated for the \a ks object - * should be overwritten with 0s. - */ -static void -key_state_free (struct key_state *ks, bool clear) -{ - ks->state = S_UNDEF; - - key_state_ssl_free(&ks->ks_ssl); - - free_key_ctx_bi (&ks->key); - free_buf (&ks->plaintext_read_buf); - free_buf (&ks->plaintext_write_buf); - free_buf (&ks->ack_write_buf); - buffer_list_free(ks->paybuf); - - if (ks->send_reliable) - { - reliable_free (ks->send_reliable); - free (ks->send_reliable); - } - - if (ks->rec_reliable) - { - reliable_free (ks->rec_reliable); - free (ks->rec_reliable); - } - - if (ks->rec_ack) - free (ks->rec_ack); - - if (ks->key_src) - free (ks->key_src); - - packet_id_free (&ks->packet_id); - -#ifdef PLUGIN_DEF_AUTH - key_state_rm_auth_control_file (ks); -#endif - - if (clear) - CLEAR (*ks); -} - -/** @} name Functions for initialization and cleanup of key_state structures */ - -/** @} addtogroup control_processor */ - - -/* - * Must be called if we move a tls_session in memory. - */ -static inline void tls_session_set_self_referential_pointers (struct tls_session* session) { - session->tls_auth.packet_id = &session->tls_auth_pid; -} - - -/** @addtogroup control_processor - * @{ */ - -/** @name Functions for initialization and cleanup of tls_session structures - * @{ */ - -/** - * Initialize a \c tls_session structure. - * @ingroup control_processor - * - * This function initializes a \c tls_session structure. This includes - * generating a random session ID, and initializing the \c KS_PRIMARY \c - * key_state in the \c tls_session.key array. - * - * @param multi - A pointer to the \c tls_multi structure - * associated with the \a session argument. - * @param session - A pointer to the \c tls_session structure to be - * initialized. This structure should already have - * been allocated before calling this function. - */ -static void -tls_session_init (struct tls_multi *multi, struct tls_session *session) -{ - struct gc_arena gc = gc_new (); - - dmsg (D_TLS_DEBUG, "TLS: tls_session_init: entry"); - - CLEAR (*session); - - /* Set options data to point to parent's option structure */ - session->opt = &multi->opt; - - /* Randomize session # if it is 0 */ - while (!session_id_defined(&session->session_id)) - session_id_random (&session->session_id); - - /* Are we a TLS server or client? */ - ASSERT (session->opt->key_method >= 1); - if (session->opt->key_method == 1) - { - session->initial_opcode = session->opt->server ? - P_CONTROL_HARD_RESET_SERVER_V1 : P_CONTROL_HARD_RESET_CLIENT_V1; - } - else /* session->opt->key_method >= 2 */ - { - session->initial_opcode = session->opt->server ? - P_CONTROL_HARD_RESET_SERVER_V2 : P_CONTROL_HARD_RESET_CLIENT_V2; - } - - /* Initialize control channel authentication parameters */ - session->tls_auth = session->opt->tls_auth; - - /* Set session internal pointers (also called if session object is moved in memory) */ - tls_session_set_self_referential_pointers (session); - - /* initialize packet ID replay window for --tls-auth */ - packet_id_init (session->tls_auth.packet_id, - session->opt->tcp_mode, - session->opt->replay_window, - session->opt->replay_time, - "TLS_AUTH", session->key_id); - - /* load most recent packet-id to replay protect on --tls-auth */ - packet_id_persist_load_obj (session->tls_auth.pid_persist, session->tls_auth.packet_id); - - key_state_init (session, &session->key[KS_PRIMARY]); - - dmsg (D_TLS_DEBUG, "TLS: tls_session_init: new session object, sid=%s", - session_id_print (&session->session_id, &gc)); - - gc_free (&gc); -} - -/** - * Clean up a \c tls_session structure. - * @ingroup control_processor - * - * This function cleans up a \c tls_session structure. This includes - * cleaning up all associated \c key_state structures. - * - * @param session - A pointer to the \c tls_session structure to be - * cleaned up. - * @param clear - Whether the memory allocated for the \a session - * object should be overwritten with 0s. - */ -static void -tls_session_free (struct tls_session *session, bool clear) -{ - int i; - - if (session->tls_auth.packet_id) - packet_id_free (session->tls_auth.packet_id); - - for (i = 0; i < KS_SIZE; ++i) - key_state_free (&session->key[i], false); - - if (session->common_name) - free (session->common_name); - - cert_hash_free (session->cert_hash_set); - - if (clear) - CLEAR (*session); -} - -/** @} name Functions for initialization and cleanup of tls_session structures */ - -/** @} addtogroup control_processor */ - - -static void -move_session (struct tls_multi* multi, int dest, int src, bool reinit_src) -{ - msg (D_TLS_DEBUG_LOW, "TLS: move_session: dest=%s src=%s reinit_src=%d", - session_index_name(dest), - session_index_name(src), - reinit_src); - ASSERT (src != dest); - ASSERT (src >= 0 && src < TM_SIZE); - ASSERT (dest >= 0 && dest < TM_SIZE); - tls_session_free (&multi->session[dest], false); - multi->session[dest] = multi->session[src]; - tls_session_set_self_referential_pointers (&multi->session[dest]); - - if (reinit_src) - tls_session_init (multi, &multi->session[src]); - else - CLEAR (multi->session[src]); - - dmsg (D_TLS_DEBUG, "TLS: move_session: exit"); -} - -static void -reset_session (struct tls_multi *multi, struct tls_session *session) -{ - tls_session_free (session, false); - tls_session_init (multi, session); -} - -#if 0 -/* - * Transmit a TLS reset on our untrusted channel. - */ -static void -initiate_untrusted_session (struct tls_multi *multi, struct sockaddr_in *to) -{ - struct tls_session *session = &multi->session[TM_UNTRUSTED]; - struct key_state *ks = &session->key[KS_PRIMARY]; - - reset_session (multi, session); - ks->remote_addr = *to; - msg (D_TLS_DEBUG_LOW, "TLS: initiate_untrusted_session: addr=%s", print_sockaddr (to)); -} -#endif - -/* - * Used to determine in how many seconds we should be - * called again. - */ -static inline void -compute_earliest_wakeup (interval_t *earliest, interval_t seconds_from_now) { - if (seconds_from_now < *earliest) - *earliest = seconds_from_now; - if (*earliest < 0) - *earliest = 0; -} - -/* - * Return true if "lame duck" or retiring key has expired and can - * no longer be used. - */ -static inline bool -lame_duck_must_die (const struct tls_session* session, interval_t *wakeup) -{ - const struct key_state* lame = &session->key[KS_LAME_DUCK]; - if (lame->state >= S_INITIAL) - { - const time_t local_now = now; - ASSERT (lame->must_die); /* a lame duck key must always have an expiration */ - if (local_now < lame->must_die) - { - compute_earliest_wakeup (wakeup, lame->must_die - local_now); - return false; - } - else - return true; - } - else if (lame->state == S_ERROR) - return true; - else - return false; -} - -struct tls_multi * -tls_multi_init (struct tls_options *tls_options) -{ - struct tls_multi *ret; - - ALLOC_OBJ_CLEAR (ret, struct tls_multi); - - /* get command line derived options */ - ret->opt = *tls_options; - - /* set up pointer to HMAC object for TLS packet authentication */ - ret->opt.tls_auth.key_ctx_bi = &ret->opt.tls_auth_key; - - /* set up list of keys to be scanned by data channel encrypt and decrypt routines */ - ASSERT (SIZE (ret->key_scan) == 3); - ret->key_scan[0] = &ret->session[TM_ACTIVE].key[KS_PRIMARY]; - ret->key_scan[1] = &ret->session[TM_ACTIVE].key[KS_LAME_DUCK]; - ret->key_scan[2] = &ret->session[TM_LAME_DUCK].key[KS_LAME_DUCK]; - - return ret; -} - -void -tls_multi_init_finalize (struct tls_multi* multi, const struct frame* frame) -{ - tls_init_control_channel_frame_parameters (frame, &multi->opt.frame); - - /* initialize the active and untrusted sessions */ - - tls_session_init (multi, &multi->session[TM_ACTIVE]); - - if (!multi->opt.single_session) - tls_session_init (multi, &multi->session[TM_UNTRUSTED]); -} - -/* - * Initialize and finalize a standalone tls-auth verification object. - */ - -struct tls_auth_standalone * -tls_auth_standalone_init (struct tls_options *tls_options, - struct gc_arena *gc) -{ - struct tls_auth_standalone *tas; - - ALLOC_OBJ_CLEAR_GC (tas, struct tls_auth_standalone, gc); - - /* set up pointer to HMAC object for TLS packet authentication */ - tas->tls_auth_key = tls_options->tls_auth_key; - tas->tls_auth_options.key_ctx_bi = &tas->tls_auth_key; - tas->tls_auth_options.flags |= CO_PACKET_ID_LONG_FORM; - - /* get initial frame parms, still need to finalize */ - tas->frame = tls_options->frame; - - return tas; -} - -void -tls_auth_standalone_finalize (struct tls_auth_standalone *tas, - const struct frame *frame) -{ - tls_init_control_channel_frame_parameters (frame, &tas->frame); -} - -/* - * Set local and remote option compatibility strings. - * Used to verify compatibility of local and remote option - * sets. - */ -void -tls_multi_init_set_options (struct tls_multi* multi, - const char *local, - const char *remote) -{ -#ifdef ENABLE_OCC - /* initialize options string */ - multi->opt.local_options = local; - multi->opt.remote_options = remote; -#endif -} - -/* - * Cleanup a tls_multi structure and free associated memory allocations. - */ -void -tls_multi_free (struct tls_multi *multi, bool clear) -{ - int i; - - ASSERT (multi); - -#ifdef MANAGEMENT_DEF_AUTH - man_def_auth_set_client_reason(multi, NULL); - -#endif -#if P2MP_SERVER - free (multi->peer_info); -#endif - - if (multi->locked_cn) - free (multi->locked_cn); - - if (multi->locked_username) - free (multi->locked_username); - - cert_hash_free (multi->locked_cert_hash_set); - - for (i = 0; i < TM_SIZE; ++i) - tls_session_free (&multi->session[i], false); - - if (clear) - CLEAR (*multi); - - free(multi); -} - - -/* - * Move a packet authentication HMAC + related fields to or from the front - * of the buffer so it can be processed by encrypt/decrypt. - */ - -/* - * Dependent on hmac size, opcode size, and session_id size. - * Will assert if too small. - */ -#define SWAP_BUF_SIZE 256 - -static bool -swap_hmac (struct buffer *buf, const struct crypto_options *co, bool incoming) -{ - struct key_ctx *ctx; - - ASSERT (co); - - ctx = (incoming ? &co->key_ctx_bi->decrypt : &co->key_ctx_bi->encrypt); - ASSERT (ctx->hmac); - - { - /* hmac + packet_id (8 bytes) */ - const int hmac_size = hmac_ctx_size (ctx->hmac) + packet_id_size (true); - - /* opcode + session_id */ - const int osid_size = 1 + SID_SIZE; - - int e1, e2; - uint8_t *b = BPTR (buf); - uint8_t buf1[SWAP_BUF_SIZE]; - uint8_t buf2[SWAP_BUF_SIZE]; - - if (incoming) - { - e1 = osid_size; - e2 = hmac_size; - } - else - { - e1 = hmac_size; - e2 = osid_size; - } - - ASSERT (e1 <= SWAP_BUF_SIZE && e2 <= SWAP_BUF_SIZE); - - if (buf->len >= e1 + e2) - { - memcpy (buf1, b, e1); - memcpy (buf2, b + e1, e2); - memcpy (b, buf2, e2); - memcpy (b + e2, buf1, e1); - return true; - } - else - return false; - } -} - -#undef SWAP_BUF_SIZE - -/* - * Write a control channel authentication record. - */ -static void -write_control_auth (struct tls_session *session, - struct key_state *ks, - struct buffer *buf, - struct link_socket_actual **to_link_addr, - int opcode, - int max_ack, - bool prepend_ack) -{ - uint8_t *header; - struct buffer null = clear_buf (); - - ASSERT (link_socket_actual_defined (&ks->remote_addr)); - ASSERT (reliable_ack_write - (ks->rec_ack, buf, &ks->session_id_remote, max_ack, prepend_ack)); - ASSERT (session_id_write_prepend (&session->session_id, buf)); - ASSERT (header = buf_prepend (buf, 1)); - *header = ks->key_id | (opcode << P_OPCODE_SHIFT); - if (session->tls_auth.key_ctx_bi->encrypt.hmac) - { - /* no encryption, only write hmac */ - openvpn_encrypt (buf, null, &session->tls_auth, NULL); - ASSERT (swap_hmac (buf, &session->tls_auth, false)); - } - *to_link_addr = &ks->remote_addr; -} - -/* - * Read a control channel authentication record. - */ -static bool -read_control_auth (struct buffer *buf, - const struct crypto_options *co, - const struct link_socket_actual *from) -{ - struct gc_arena gc = gc_new (); - - if (co->key_ctx_bi->decrypt.hmac) - { - struct buffer null = clear_buf (); - - /* move the hmac record to the front of the packet */ - if (!swap_hmac (buf, co, true)) - { - msg (D_TLS_ERRORS, - "TLS Error: cannot locate HMAC in incoming packet from %s", - print_link_socket_actual (from, &gc)); - gc_free (&gc); - return false; - } - - /* authenticate only (no decrypt) and remove the hmac record - from the head of the buffer */ - openvpn_decrypt (buf, null, co, NULL); - if (!buf->len) - { - msg (D_TLS_ERRORS, - "TLS Error: incoming packet authentication failed from %s", - print_link_socket_actual (from, &gc)); - gc_free (&gc); - return false; - } - - } - - /* advance buffer pointer past opcode & session_id since our caller - already read it */ - buf_advance (buf, SID_SIZE + 1); - - gc_free (&gc); - return true; -} - -/* - * For debugging, print contents of key_source2 structure. - */ - -static void -key_source_print (const struct key_source *k, - const char *prefix) -{ - struct gc_arena gc = gc_new (); - - VALGRIND_MAKE_READABLE ((void *)k->pre_master, sizeof (k->pre_master)); - VALGRIND_MAKE_READABLE ((void *)k->random1, sizeof (k->random1)); - VALGRIND_MAKE_READABLE ((void *)k->random2, sizeof (k->random2)); - - dmsg (D_SHOW_KEY_SOURCE, - "%s pre_master: %s", - prefix, - format_hex (k->pre_master, sizeof (k->pre_master), 0, &gc)); - dmsg (D_SHOW_KEY_SOURCE, - "%s random1: %s", - prefix, - format_hex (k->random1, sizeof (k->random1), 0, &gc)); - dmsg (D_SHOW_KEY_SOURCE, - "%s random2: %s", - prefix, - format_hex (k->random2, sizeof (k->random2), 0, &gc)); - - gc_free (&gc); -} - -static void -key_source2_print (const struct key_source2 *k) -{ - key_source_print (&k->client, "Client"); - key_source_print (&k->server, "Server"); -} - -/* - * Generate the hash required by for the \c tls1_PRF function. - * - * @param md_kt Message digest to use - * @param sec Secret to base the hash on - * @param sec_len Length of the secret - * @param seed Seed to hash - * @param seed_len Length of the seed - * @param out Output buffer - * @param olen Length of the output buffer - */ -void -tls1_P_hash(const md_kt_t *md_kt, - const uint8_t *sec, - int sec_len, - const uint8_t *seed, - int seed_len, - uint8_t *out, - int olen) -{ - struct gc_arena gc = gc_new (); - int chunk; - hmac_ctx_t ctx; - hmac_ctx_t ctx_tmp; - uint8_t A1[MAX_HMAC_KEY_LENGTH]; - unsigned int A1_len; - -#ifdef ENABLE_DEBUG - const int olen_orig = olen; - const uint8_t *out_orig = out; -#endif - - CLEAR(ctx); - CLEAR(ctx_tmp); - - dmsg (D_SHOW_KEY_SOURCE, "tls1_P_hash sec: %s", format_hex (sec, sec_len, 0, &gc)); - dmsg (D_SHOW_KEY_SOURCE, "tls1_P_hash seed: %s", format_hex (seed, seed_len, 0, &gc)); - - chunk = md_kt_size(md_kt); - A1_len = md_kt_size(md_kt); - - hmac_ctx_init(&ctx, sec, sec_len, md_kt); - hmac_ctx_init(&ctx_tmp, sec, sec_len, md_kt); - - hmac_ctx_update(&ctx,seed,seed_len); - hmac_ctx_final(&ctx, A1); - - for (;;) - { - hmac_ctx_reset(&ctx); - hmac_ctx_reset(&ctx_tmp); - hmac_ctx_update(&ctx,A1,A1_len); - hmac_ctx_update(&ctx_tmp,A1,A1_len); - hmac_ctx_update(&ctx,seed,seed_len); - - if (olen > chunk) - { - hmac_ctx_final(&ctx, out); - out+=chunk; - olen-=chunk; - hmac_ctx_final(&ctx_tmp, A1); /* calc the next A1 value */ - } - else /* last one */ - { - hmac_ctx_final(&ctx, A1); - memcpy(out,A1,olen); - break; - } - } - hmac_ctx_cleanup(&ctx); - hmac_ctx_cleanup(&ctx_tmp); - CLEAR (A1); - - dmsg (D_SHOW_KEY_SOURCE, "tls1_P_hash out: %s", format_hex (out_orig, olen_orig, 0, &gc)); - gc_free (&gc); -} - -/* - * Use the TLS PRF function for generating data channel keys. - * This code is based on the OpenSSL library. - * - * TLS generates keys as such: - * - * master_secret[48] = PRF(pre_master_secret[48], "master secret", - * ClientHello.random[32] + ServerHello.random[32]) - * - * key_block[] = PRF(SecurityParameters.master_secret[48], - * "key expansion", - * SecurityParameters.server_random[32] + - * SecurityParameters.client_random[32]); - * - * Notes: - * - * (1) key_block contains a full set of 4 keys. - * (2) The pre-master secret is generated by the client. - */ -static void -tls1_PRF(uint8_t *label, - int label_len, - const uint8_t *sec, - int slen, - uint8_t *out1, - int olen) -{ - struct gc_arena gc = gc_new (); - const md_kt_t *md5 = md_kt_get("MD5"); - const md_kt_t *sha1 = md_kt_get("SHA1"); - int len,i; - const uint8_t *S1,*S2; - uint8_t *out2; - - out2 = (uint8_t *) gc_malloc (olen, false, &gc); - - len=slen/2; - S1=sec; - S2= &(sec[len]); - len+=(slen&1); /* add for odd, make longer */ - - tls1_P_hash(md5 ,S1,len,label,label_len,out1,olen); - tls1_P_hash(sha1,S2,len,label,label_len,out2,olen); - - for (i=0; i<olen; i++) - out1[i]^=out2[i]; - - memset (out2, 0, olen); - - dmsg (D_SHOW_KEY_SOURCE, "tls1_PRF out[%d]: %s", olen, format_hex (out1, olen, 0, &gc)); - - gc_free (&gc); -} - -static void -openvpn_PRF (const uint8_t *secret, - int secret_len, - const char *label, - const uint8_t *client_seed, - int client_seed_len, - const uint8_t *server_seed, - int server_seed_len, - const struct session_id *client_sid, - const struct session_id *server_sid, - uint8_t *output, - int output_len) -{ - /* concatenate seed components */ - - struct buffer seed = alloc_buf (strlen (label) - + client_seed_len - + server_seed_len - + SID_SIZE * 2); - - ASSERT (buf_write (&seed, label, strlen (label))); - ASSERT (buf_write (&seed, client_seed, client_seed_len)); - ASSERT (buf_write (&seed, server_seed, server_seed_len)); - - if (client_sid) - ASSERT (buf_write (&seed, client_sid->id, SID_SIZE)); - if (server_sid) - ASSERT (buf_write (&seed, server_sid->id, SID_SIZE)); - - /* compute PRF */ - tls1_PRF (BPTR(&seed), BLEN(&seed), secret, secret_len, output, output_len); - - buf_clear (&seed); - free_buf (&seed); - - VALGRIND_MAKE_READABLE ((void *)output, output_len); -} - -/* - * Using source entropy from local and remote hosts, mix into - * master key. - */ -static bool -generate_key_expansion (struct key_ctx_bi *key, - const struct key_type *key_type, - const struct key_source2 *key_src, - const struct session_id *client_sid, - const struct session_id *server_sid, - bool server) -{ - uint8_t master[48]; - struct key2 key2; - bool ret = false; - int i; - - CLEAR (master); - CLEAR (key2); - - /* debugging print of source key material */ - key_source2_print (key_src); - - /* compute master secret */ - openvpn_PRF (key_src->client.pre_master, - sizeof(key_src->client.pre_master), - KEY_EXPANSION_ID " master secret", - key_src->client.random1, - sizeof(key_src->client.random1), - key_src->server.random1, - sizeof(key_src->server.random1), - NULL, - NULL, - master, - sizeof(master)); - - /* compute key expansion */ - openvpn_PRF (master, - sizeof(master), - KEY_EXPANSION_ID " key expansion", - key_src->client.random2, - sizeof(key_src->client.random2), - key_src->server.random2, - sizeof(key_src->server.random2), - client_sid, - server_sid, - (uint8_t*)key2.keys, - sizeof(key2.keys)); - - key2.n = 2; - - key2_print (&key2, key_type, "Master Encrypt", "Master Decrypt"); - - /* check for weak keys */ - for (i = 0; i < 2; ++i) - { - fixup_key (&key2.keys[i], key_type); - if (!check_key (&key2.keys[i], key_type)) - { - msg (D_TLS_ERRORS, "TLS Error: Bad dynamic key generated"); - goto exit; - } - } - - /* Initialize OpenSSL key contexts */ - - ASSERT (server == true || server == false); - - init_key_ctx (&key->encrypt, - &key2.keys[(int)server], - key_type, - OPENVPN_OP_ENCRYPT, - "Data Channel Encrypt"); - - init_key_ctx (&key->decrypt, - &key2.keys[1-(int)server], - key_type, - OPENVPN_OP_DECRYPT, - "Data Channel Decrypt"); - - ret = true; - - exit: - CLEAR (master); - CLEAR (key2); - - return ret; -} - -static bool -random_bytes_to_buf (struct buffer *buf, - uint8_t *out, - int outlen) -{ - if (!rand_bytes (out, outlen)) - msg (M_FATAL, "ERROR: Random number generator cannot obtain entropy for key generation [SSL]"); - if (!buf_write (buf, out, outlen)) - return false; - return true; -} - -static bool -key_source2_randomize_write (struct key_source2 *k2, - struct buffer *buf, - bool server) -{ - struct key_source *k = &k2->client; - if (server) - k = &k2->server; - - CLEAR (*k); - - if (!server) - { - if (!random_bytes_to_buf (buf, k->pre_master, sizeof (k->pre_master))) - return false; - } - - if (!random_bytes_to_buf (buf, k->random1, sizeof (k->random1))) - return false; - if (!random_bytes_to_buf (buf, k->random2, sizeof (k->random2))) - return false; - - return true; -} - -static int -key_source2_read (struct key_source2 *k2, - struct buffer *buf, - bool server) -{ - struct key_source *k = &k2->client; - - if (!server) - k = &k2->server; - - CLEAR (*k); - - if (server) - { - if (!buf_read (buf, k->pre_master, sizeof (k->pre_master))) - return 0; - } - - if (!buf_read (buf, k->random1, sizeof (k->random1))) - return 0; - if (!buf_read (buf, k->random2, sizeof (k->random2))) - return 0; - - return 1; -} - -static void -flush_payload_buffer (struct key_state *ks) -{ - struct buffer *b; - - while ((b = buffer_list_peek (ks->paybuf))) - { - key_state_write_plaintext_const (&ks->ks_ssl, b->data, b->len); - buffer_list_pop (ks->paybuf); - } -} - -/* true if no in/out acknowledgements pending */ -#define FULL_SYNC \ - (reliable_empty(ks->send_reliable) && reliable_ack_empty (ks->rec_ack)) - -/* - * Move the active key to the lame duck key and reinitialize the - * active key. - */ -static void -key_state_soft_reset (struct tls_session *session) -{ - struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */ - struct key_state *ks_lame = &session->key[KS_LAME_DUCK]; /* retiring key */ - - ks->must_die = now + session->opt->transition_window; /* remaining lifetime of old key */ - key_state_free (ks_lame, false); - *ks_lame = *ks; - - key_state_init (session, ks); - ks->session_id_remote = ks_lame->session_id_remote; - ks->remote_addr = ks_lame->remote_addr; -} - -/* - * Read/write strings from/to a struct buffer with a u16 length prefix. - */ - -static bool -write_empty_string (struct buffer *buf) -{ - if (!buf_write_u16 (buf, 0)) - return false; - return true; -} - -static bool -write_string (struct buffer *buf, const char *str, const int maxlen) -{ - const int len = strlen (str) + 1; - if (len < 1 || (maxlen >= 0 && len > maxlen)) - return false; - if (!buf_write_u16 (buf, len)) - return false; - if (!buf_write (buf, str, len)) - return false; - return true; -} - -static bool -read_string (struct buffer *buf, char *str, const unsigned int capacity) -{ - const int len = buf_read_u16 (buf); - if (len < 1 || len > (int)capacity) - return false; - if (!buf_read (buf, str, len)) - return false; - str[len-1] = '\0'; - return true; -} - -static char * -read_string_alloc (struct buffer *buf) -{ - const int len = buf_read_u16 (buf); - char *str; - - if (len < 1) - return NULL; - str = (char *) malloc(len); - check_malloc_return(str); - if (!buf_read (buf, str, len)) - { - free (str); - return NULL; - } - str[len-1] = '\0'; - return str; -} - -void -read_string_discard (struct buffer *buf) -{ - char *data = read_string_alloc(buf); - if (data) - free (data); -} - -/* - * Handle the reading and writing of key data to and from - * the TLS control channel (cleartext). - */ - -static bool -key_method_1_write (struct buffer *buf, struct tls_session *session) -{ - struct key key; - struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */ - - ASSERT (session->opt->key_method == 1); - ASSERT (buf_init (buf, 0)); - - generate_key_random (&key, &session->opt->key_type); - if (!check_key (&key, &session->opt->key_type)) - { - msg (D_TLS_ERRORS, "TLS Error: Bad encrypting key generated"); - return false; - } - - if (!write_key (&key, &session->opt->key_type, buf)) - { - msg (D_TLS_ERRORS, "TLS Error: write_key failed"); - return false; - } - - init_key_ctx (&ks->key.encrypt, &key, &session->opt->key_type, - OPENVPN_OP_ENCRYPT, "Data Channel Encrypt"); - CLEAR (key); - - /* send local options string */ - { - const char *local_options = local_options_string (session); - const int optlen = strlen (local_options) + 1; - if (!buf_write (buf, local_options, optlen)) - { - msg (D_TLS_ERRORS, "TLS Error: KM1 write options failed"); - return false; - } - } - - return true; -} - -static bool -push_peer_info(struct buffer *buf, struct tls_session *session) -{ - struct gc_arena gc = gc_new (); - bool ret = false; - -#ifdef ENABLE_PUSH_PEER_INFO - if (session->opt->push_peer_info_detail > 0) - { - struct env_set *es = session->opt->es; - struct env_item *e; - struct buffer out = alloc_buf_gc (512*3, &gc); - - /* push version */ - buf_printf (&out, "IV_VER=%s\n", PACKAGE_VERSION); - - /* push platform */ -#if defined(TARGET_LINUX) - buf_printf (&out, "IV_PLAT=linux\n"); -#elif defined(TARGET_SOLARIS) - buf_printf (&out, "IV_PLAT=solaris\n"); -#elif defined(TARGET_OPENBSD) - buf_printf (&out, "IV_PLAT=openbsd\n"); -#elif defined(TARGET_DARWIN) - buf_printf (&out, "IV_PLAT=mac\n"); -#elif defined(TARGET_NETBSD) - buf_printf (&out, "IV_PLAT=netbsd\n"); -#elif defined(TARGET_FREEBSD) - buf_printf (&out, "IV_PLAT=freebsd\n"); -#elif defined(TARGET_ANDROID) - buf_printf (&out, "IV_PLAT=android\n"); -#elif defined(WIN32) - buf_printf (&out, "IV_PLAT=win\n"); -#endif - - /* push compression status */ -#ifdef USE_COMP - comp_generate_peer_info_string(&session->opt->comp_options, &out); -#endif - - if (session->opt->push_peer_info_detail >= 2) - { - /* push mac addr */ - struct route_gateway_info rgi; - get_default_gateway (&rgi); - if (rgi.flags & RGI_HWADDR_DEFINED) - buf_printf (&out, "IV_HWADDR=%s\n", format_hex_ex (rgi.hwaddr, 6, 0, 1, ":", &gc)); - } - - /* push env vars that begin with UV_ and IV_GUI_VER */ - for (e=es->list; e != NULL; e=e->next) - { - if (e->string) - { - if (((strncmp(e->string, "UV_", 3)==0 && session->opt->push_peer_info_detail >= 2) - || (strncmp(e->string,"IV_GUI_VER=",sizeof("IV_GUI_VER=")-1)==0)) - && buf_safe(&out, strlen(e->string)+1)) - buf_printf (&out, "%s\n", e->string); - } - } - - if (!write_string(buf, BSTR(&out), -1)) - goto error; - } - else -#endif - { - if (!write_empty_string (buf)) /* no peer info */ - goto error; - } - ret = true; - - error: - gc_free (&gc); - return ret; -} - -static bool -key_method_2_write (struct buffer *buf, struct tls_session *session) -{ - struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */ - - ASSERT (session->opt->key_method == 2); - ASSERT (buf_init (buf, 0)); - - /* write a uint32 0 */ - if (!buf_write_u32 (buf, 0)) - goto error; - - /* write key_method + flags */ - if (!buf_write_u8 (buf, (session->opt->key_method & KEY_METHOD_MASK))) - goto error; - - /* write key source material */ - if (!key_source2_randomize_write (ks->key_src, buf, session->opt->server)) - goto error; - - /* write options string */ - { - if (!write_string (buf, local_options_string (session), TLS_OPTIONS_LEN)) - goto error; - } - - /* write username/password if specified */ - if (auth_user_pass_enabled) - { -#ifdef ENABLE_CLIENT_CR - auth_user_pass_setup (NULL, session->opt->sci); -#else - auth_user_pass_setup (NULL, NULL); -#endif - if (!write_string (buf, auth_user_pass.username, -1)) - goto error; - if (!write_string (buf, auth_user_pass.password, -1)) - goto error; - purge_user_pass (&auth_user_pass, false); - } - else - { - if (!write_empty_string (buf)) /* no username */ - goto error; - if (!write_empty_string (buf)) /* no password */ - goto error; - } - - if (!push_peer_info (buf, session)) - goto error; - - /* - * generate tunnel keys if server - */ - if (session->opt->server) - { - if (ks->authenticated) - { - if (!generate_key_expansion (&ks->key, - &session->opt->key_type, - ks->key_src, - &ks->session_id_remote, - &session->session_id, - true)) - { - msg (D_TLS_ERRORS, "TLS Error: server generate_key_expansion failed"); - goto error; - } - } - - CLEAR (*ks->key_src); - } - - return true; - - error: - msg (D_TLS_ERRORS, "TLS Error: Key Method #2 write failed"); - CLEAR (*ks->key_src); - return false; -} - -static bool -key_method_1_read (struct buffer *buf, struct tls_session *session) -{ - int status; - struct key key; - struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */ - - ASSERT (session->opt->key_method == 1); - - if (!session->verified) - { - msg (D_TLS_ERRORS, - "TLS Error: Certificate verification failed (key-method 1)"); - goto error; - } - - status = read_key (&key, &session->opt->key_type, buf); - if (status != 1) - { - msg (D_TLS_ERRORS, - "TLS Error: Error reading data channel key from plaintext buffer"); - goto error; - } - - if (!check_key (&key, &session->opt->key_type)) - { - msg (D_TLS_ERRORS, "TLS Error: Bad decrypting key received from peer"); - goto error; - } - - if (buf->len < 1) - { - msg (D_TLS_ERRORS, "TLS Error: Missing options string"); - goto error; - } - -#ifdef ENABLE_OCC - /* compare received remote options string - with our locally computed options string */ - if (!session->opt->disable_occ && - !options_cmp_equal_safe ((char *) BPTR (buf), session->opt->remote_options, buf->len)) - { - options_warning_safe ((char *) BPTR (buf), session->opt->remote_options, buf->len); - } -#endif - - buf_clear (buf); - - init_key_ctx (&ks->key.decrypt, &key, &session->opt->key_type, - OPENVPN_OP_DECRYPT, "Data Channel Decrypt"); - CLEAR (key); - ks->authenticated = true; - return true; - - error: - buf_clear (buf); - CLEAR (key); - return false; -} - -static bool -key_method_2_read (struct buffer *buf, struct tls_multi *multi, struct tls_session *session) -{ - struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */ - - int key_method_flags; - bool username_status, password_status; - - struct gc_arena gc = gc_new (); - char *options; - struct user_pass *up; - - /* allocate temporary objects */ - ALLOC_ARRAY_CLEAR_GC (options, char, TLS_OPTIONS_LEN, &gc); - - ASSERT (session->opt->key_method == 2); - - /* discard leading uint32 */ - ASSERT (buf_advance (buf, 4)); - - /* get key method */ - key_method_flags = buf_read_u8 (buf); - if ((key_method_flags & KEY_METHOD_MASK) != 2) - { - msg (D_TLS_ERRORS, - "TLS ERROR: Unknown key_method/flags=%d received from remote host", - key_method_flags); - goto error; - } - - /* get key source material (not actual keys yet) */ - if (!key_source2_read (ks->key_src, buf, session->opt->server)) - { - msg (D_TLS_ERRORS, "TLS Error: Error reading remote data channel key source entropy from plaintext buffer"); - goto error; - } - - /* get options */ - if (!read_string (buf, options, TLS_OPTIONS_LEN)) - { - msg (D_TLS_ERRORS, "TLS Error: Failed to read required OCC options string"); - goto error; - } - - ks->authenticated = false; - - /* always extract username + password fields from buf, even if not - * authenticating for it, because otherwise we can't get at the - * peer_info data which follows behind - */ - ALLOC_OBJ_CLEAR_GC (up, struct user_pass, &gc); - username_status = read_string (buf, up->username, USER_PASS_LEN); - password_status = read_string (buf, up->password, USER_PASS_LEN); - -#if P2MP_SERVER - /* get peer info from control channel */ - free (multi->peer_info); - multi->peer_info = read_string_alloc (buf); - if ( multi->peer_info ) - output_peer_info_env (session->opt->es, multi->peer_info); -#endif - - if (verify_user_pass_enabled(session)) - { - /* Perform username/password authentication */ - if (!username_status || !password_status) - { - CLEAR (*up); - if (!(session->opt->ssl_flags & SSLF_AUTH_USER_PASS_OPTIONAL)) - { - msg (D_TLS_ERRORS, "TLS Error: Auth Username/Password was not provided by peer"); - goto error; - } - } - - verify_user_pass(up, multi, session); - } - else - { - /* Session verification should have occurred during TLS negotiation*/ - if (!session->verified) - { - msg (D_TLS_ERRORS, - "TLS Error: Certificate verification failed (key-method 2)"); - goto error; - } - ks->authenticated = true; - } - - /* clear username and password from memory */ - CLEAR (*up); - - /* Perform final authentication checks */ - if (ks->authenticated) - { - verify_final_auth_checks(multi, session); - } - -#ifdef ENABLE_OCC - /* check options consistency */ - if (!session->opt->disable_occ && - !options_cmp_equal (options, session->opt->remote_options)) - { - options_warning (options, session->opt->remote_options); - if (session->opt->ssl_flags & SSLF_OPT_VERIFY) - { - msg (D_TLS_ERRORS, "Option inconsistency warnings triggering disconnect due to --opt-verify"); - ks->authenticated = false; - } - } -#endif - - buf_clear (buf); - - /* - * Call OPENVPN_PLUGIN_TLS_FINAL plugin if defined, for final - * veto opportunity over authentication decision. - */ - if (ks->authenticated && plugin_defined (session->opt->plugins, OPENVPN_PLUGIN_TLS_FINAL)) - { - if (plugin_call (session->opt->plugins, OPENVPN_PLUGIN_TLS_FINAL, NULL, NULL, session->opt->es) != OPENVPN_PLUGIN_FUNC_SUCCESS) - ks->authenticated = false; - } - - /* - * Generate tunnel keys if client - */ - if (!session->opt->server) - { - if (!generate_key_expansion (&ks->key, - &session->opt->key_type, - ks->key_src, - &session->session_id, - &ks->session_id_remote, - false)) - { - msg (D_TLS_ERRORS, "TLS Error: client generate_key_expansion failed"); - goto error; - } - - CLEAR (*ks->key_src); - } - - gc_free (&gc); - return true; - - error: - CLEAR (*ks->key_src); - buf_clear (buf); - gc_free (&gc); - return false; -} - -static int -auth_deferred_expire_window (const struct tls_options *o) -{ - int ret = o->handshake_window; - const int r2 = o->renegotiate_seconds / 2; - - if (o->renegotiate_seconds && r2 < ret) - ret = r2; - return ret; -} - -/* - * This is the primary routine for processing TLS stuff inside the - * the main event loop. When this routine exits - * with non-error status, it will set *wakeup to the number of seconds - * when it wants to be called again. - * - * Return value is true if we have placed a packet in *to_link which we - * want to send to our peer. - */ -static bool -tls_process (struct tls_multi *multi, - struct tls_session *session, - struct buffer *to_link, - struct link_socket_actual **to_link_addr, - struct link_socket_info *to_link_socket_info, - interval_t *wakeup) -{ - struct gc_arena gc = gc_new (); - struct buffer *buf; - bool state_change = false; - bool active = false; - struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */ - struct key_state *ks_lame = &session->key[KS_LAME_DUCK]; /* retiring key */ - - /* Make sure we were initialized and that we're not in an error state */ - ASSERT (ks->state != S_UNDEF); - ASSERT (ks->state != S_ERROR); - ASSERT (session_id_defined (&session->session_id)); - - /* Should we trigger a soft reset? -- new key, keeps old key for a while */ - if (ks->state >= S_ACTIVE && - ((session->opt->renegotiate_seconds - && now >= ks->established + session->opt->renegotiate_seconds) - || (session->opt->renegotiate_bytes - && ks->n_bytes >= session->opt->renegotiate_bytes) - || (session->opt->renegotiate_packets - && ks->n_packets >= session->opt->renegotiate_packets) - || (packet_id_close_to_wrapping (&ks->packet_id.send)))) - { - msg (D_TLS_DEBUG_LOW, - "TLS: soft reset sec=%d bytes=" counter_format "/%d pkts=" counter_format "/%d", - (int)(ks->established + session->opt->renegotiate_seconds - now), - ks->n_bytes, session->opt->renegotiate_bytes, - ks->n_packets, session->opt->renegotiate_packets); - key_state_soft_reset (session); - } - - /* Kill lame duck key transition_window seconds after primary key negotiation */ - if (lame_duck_must_die (session, wakeup)) { - key_state_free (ks_lame, true); - msg (D_TLS_DEBUG_LOW, "TLS: tls_process: killed expiring key"); - } - - do - { - update_time (); - - dmsg (D_TLS_DEBUG, "TLS: tls_process: chg=%d ks=%s lame=%s to_link->len=%d wakeup=%d", - state_change, - state_name (ks->state), - state_name (ks_lame->state), - to_link->len, - *wakeup); - - state_change = false; - - /* - * TLS activity is finished once we get to S_ACTIVE, - * though we will still process acknowledgements. - * - * CHANGED with 2.0 -> now we may send tunnel configuration - * info over the control channel. - */ - if (true) - { - /* Initial handshake */ - if (ks->state == S_INITIAL) - { - buf = reliable_get_buf_output_sequenced (ks->send_reliable); - if (buf) - { - ks->must_negotiate = now + session->opt->handshake_window; - ks->auth_deferred_expire = now + auth_deferred_expire_window (session->opt); - - /* null buffer */ - reliable_mark_active_outgoing (ks->send_reliable, buf, ks->initial_opcode); - INCR_GENERATED; - - ks->state = S_PRE_START; - state_change = true; - dmsg (D_TLS_DEBUG, "TLS: Initial Handshake, sid=%s", - session_id_print (&session->session_id, &gc)); - -#ifdef ENABLE_MANAGEMENT - if (management && ks->initial_opcode != P_CONTROL_SOFT_RESET_V1) - { - management_set_state (management, - OPENVPN_STATE_WAIT, - NULL, - 0, - 0); - } -#endif - } - } - - /* Are we timed out on receive? */ - if (now >= ks->must_negotiate) - { - if (ks->state < S_ACTIVE) - { - msg (D_TLS_ERRORS, - "TLS Error: TLS key negotiation failed to occur within %d seconds (check your network connectivity)", - session->opt->handshake_window); - goto error; - } - else /* assume that ks->state == S_ACTIVE */ - { - dmsg (D_TLS_DEBUG_MED, "STATE S_NORMAL_OP"); - ks->state = S_NORMAL_OP; - ks->must_negotiate = 0; - } - } - - /* Wait for Initial Handshake ACK */ - if (ks->state == S_PRE_START && FULL_SYNC) - { - ks->state = S_START; - state_change = true; - dmsg (D_TLS_DEBUG_MED, "STATE S_START"); - } - - /* Wait for ACK */ - if (((ks->state == S_GOT_KEY && !session->opt->server) || - (ks->state == S_SENT_KEY && session->opt->server))) - { - if (FULL_SYNC) - { - ks->established = now; - dmsg (D_TLS_DEBUG_MED, "STATE S_ACTIVE"); - if (check_debug_level (D_HANDSHAKE)) - print_details (&ks->ks_ssl, "Control Channel:"); - state_change = true; - ks->state = S_ACTIVE; - INCR_SUCCESS; - - /* Set outgoing address for data channel packets */ - link_socket_set_outgoing_addr (NULL, to_link_socket_info, &ks->remote_addr, session->common_name, session->opt->es); - - /* Flush any payload packets that were buffered before our state transitioned to S_ACTIVE */ - flush_payload_buffer (ks); - -#ifdef MEASURE_TLS_HANDSHAKE_STATS - show_tls_performance_stats(); -#endif - } - } - - /* Reliable buffer to outgoing TCP/UDP (send up to CONTROL_SEND_ACK_MAX ACKs - for previously received packets) */ - if (!to_link->len && reliable_can_send (ks->send_reliable)) - { - int opcode; - struct buffer b; - - buf = reliable_send (ks->send_reliable, &opcode); - ASSERT (buf); - b = *buf; - INCR_SENT; - - write_control_auth (session, ks, &b, to_link_addr, opcode, - CONTROL_SEND_ACK_MAX, true); - *to_link = b; - active = true; - state_change = true; - dmsg (D_TLS_DEBUG, "Reliable -> TCP/UDP"); - break; - } - -#ifndef TLS_AGGREGATE_ACK - /* Send 1 or more ACKs (each received control packet gets one ACK) */ - if (!to_link->len && !reliable_ack_empty (ks->rec_ack)) - { - buf = &ks->ack_write_buf; - ASSERT (buf_init (buf, FRAME_HEADROOM (&multi->opt.frame))); - write_control_auth (session, ks, buf, to_link_addr, P_ACK_V1, - RELIABLE_ACK_SIZE, false); - *to_link = *buf; - active = true; - state_change = true; - dmsg (D_TLS_DEBUG, "Dedicated ACK -> TCP/UDP"); - break; - } -#endif - - /* Write incoming ciphertext to TLS object */ - buf = reliable_get_buf_sequenced (ks->rec_reliable); - if (buf) - { - int status = 0; - if (buf->len) - { - status = key_state_write_ciphertext (&ks->ks_ssl, buf); - if (status == -1) - { - msg (D_TLS_ERRORS, - "TLS Error: Incoming Ciphertext -> TLS object write error"); - goto error; - } - } - else - { - status = 1; - } - if (status == 1) - { - reliable_mark_deleted (ks->rec_reliable, buf, true); - state_change = true; - dmsg (D_TLS_DEBUG, "Incoming Ciphertext -> TLS"); - } - } - - /* Read incoming plaintext from TLS object */ - buf = &ks->plaintext_read_buf; - if (!buf->len) - { - int status; - - ASSERT (buf_init (buf, 0)); - status = key_state_read_plaintext (&ks->ks_ssl, buf, TLS_CHANNEL_BUF_SIZE); - update_time (); - if (status == -1) - { - msg (D_TLS_ERRORS, "TLS Error: TLS object -> incoming plaintext read error"); - goto error; - } - if (status == 1) - { - state_change = true; - dmsg (D_TLS_DEBUG, "TLS -> Incoming Plaintext"); - } -#if 0 /* show null plaintext reads */ - if (!status) - msg (M_INFO, "TLS plaintext read -> NULL return"); -#endif - } - - /* Send Key */ - buf = &ks->plaintext_write_buf; - if (!buf->len && ((ks->state == S_START && !session->opt->server) || - (ks->state == S_GOT_KEY && session->opt->server))) - { - if (session->opt->key_method == 1) - { - if (!key_method_1_write (buf, session)) - goto error; - } - else if (session->opt->key_method == 2) - { - if (!key_method_2_write (buf, session)) - goto error; - } - else - { - ASSERT (0); - } - - state_change = true; - dmsg (D_TLS_DEBUG_MED, "STATE S_SENT_KEY"); - ks->state = S_SENT_KEY; - } - - /* Receive Key */ - buf = &ks->plaintext_read_buf; - if (buf->len - && ((ks->state == S_SENT_KEY && !session->opt->server) - || (ks->state == S_START && session->opt->server))) - { - if (session->opt->key_method == 1) - { - if (!key_method_1_read (buf, session)) - goto error; - } - else if (session->opt->key_method == 2) - { - if (!key_method_2_read (buf, multi, session)) - goto error; - } - else - { - ASSERT (0); - } - - state_change = true; - dmsg (D_TLS_DEBUG_MED, "STATE S_GOT_KEY"); - ks->state = S_GOT_KEY; - } - - /* Write outgoing plaintext to TLS object */ - buf = &ks->plaintext_write_buf; - if (buf->len) - { - int status = key_state_write_plaintext (&ks->ks_ssl, buf); - if (status == -1) - { - msg (D_TLS_ERRORS, - "TLS ERROR: Outgoing Plaintext -> TLS object write error"); - goto error; - } - if (status == 1) - { - state_change = true; - dmsg (D_TLS_DEBUG, "Outgoing Plaintext -> TLS"); - } - } - - /* Outgoing Ciphertext to reliable buffer */ - if (ks->state >= S_START) - { - buf = reliable_get_buf_output_sequenced (ks->send_reliable); - if (buf) - { - int status = key_state_read_ciphertext (&ks->ks_ssl, buf, PAYLOAD_SIZE_DYNAMIC (&multi->opt.frame)); - if (status == -1) - { - msg (D_TLS_ERRORS, - "TLS Error: Ciphertext -> reliable TCP/UDP transport read error"); - goto error; - } - if (status == 1) - { - reliable_mark_active_outgoing (ks->send_reliable, buf, P_CONTROL_V1); - INCR_GENERATED; - state_change = true; - dmsg (D_TLS_DEBUG, "Outgoing Ciphertext -> Reliable"); - } - } - } - } - } - while (state_change); - - update_time (); - -#ifdef TLS_AGGREGATE_ACK - /* Send 1 or more ACKs (each received control packet gets one ACK) */ - if (!to_link->len && !reliable_ack_empty (ks->rec_ack)) - { - buf = &ks->ack_write_buf; - ASSERT (buf_init (buf, FRAME_HEADROOM (&multi->opt.frame))); - write_control_auth (session, ks, buf, to_link_addr, P_ACK_V1, - RELIABLE_ACK_SIZE, false); - *to_link = *buf; - active = true; - state_change = true; - dmsg (D_TLS_DEBUG, "Dedicated ACK -> TCP/UDP"); - } -#endif - - /* When should we wake up again? */ - { - if (ks->state >= S_INITIAL) - { - compute_earliest_wakeup (wakeup, - reliable_send_timeout (ks->send_reliable)); - - if (ks->must_negotiate) - compute_earliest_wakeup (wakeup, ks->must_negotiate - now); - } - - if (ks->established && session->opt->renegotiate_seconds) - compute_earliest_wakeup (wakeup, - ks->established + session->opt->renegotiate_seconds - now); - - /* prevent event-loop spinning by setting minimum wakeup of 1 second */ - if (*wakeup <= 0) - { - *wakeup = 1; - - /* if we had something to send to remote, but to_link was busy, - let caller know we need to be called again soon */ - active = true; - } - - dmsg (D_TLS_DEBUG, "TLS: tls_process: timeout set to %d", *wakeup); - - gc_free (&gc); - return active; - } - -error: - tls_clear_error(); - ks->state = S_ERROR; - msg (D_TLS_ERRORS, "TLS Error: TLS handshake failed"); - INCR_ERROR; - gc_free (&gc); - return false; -} - -/* - * Called by the top-level event loop. - * - * Basically decides if we should call tls_process for - * the active or untrusted sessions. - */ - -int -tls_multi_process (struct tls_multi *multi, - struct buffer *to_link, - struct link_socket_actual **to_link_addr, - struct link_socket_info *to_link_socket_info, - interval_t *wakeup) -{ - struct gc_arena gc = gc_new (); - int i; - int active = TLSMP_INACTIVE; - bool error = false; - int tas; - - perf_push (PERF_TLS_MULTI_PROCESS); - - tls_clear_error (); - - /* - * Process each session object having state of S_INITIAL or greater, - * and which has a defined remote IP addr. - */ - - for (i = 0; i < TM_SIZE; ++i) - { - struct tls_session *session = &multi->session[i]; - struct key_state *ks = &session->key[KS_PRIMARY]; - struct key_state *ks_lame = &session->key[KS_LAME_DUCK]; - - /* set initial remote address */ - if (i == TM_ACTIVE && ks->state == S_INITIAL && - link_socket_actual_defined (&to_link_socket_info->lsa->actual)) - ks->remote_addr = to_link_socket_info->lsa->actual; - - dmsg (D_TLS_DEBUG, - "TLS: tls_multi_process: i=%d state=%s, mysid=%s, stored-sid=%s, stored-ip=%s", - i, - state_name (ks->state), - session_id_print (&session->session_id, &gc), - session_id_print (&ks->session_id_remote, &gc), - print_link_socket_actual (&ks->remote_addr, &gc)); - - if (ks->state >= S_INITIAL && link_socket_actual_defined (&ks->remote_addr)) - { - struct link_socket_actual *tla = NULL; - - update_time (); - - if (tls_process (multi, session, to_link, &tla, - to_link_socket_info, wakeup)) - active = TLSMP_ACTIVE; - - /* - * If tls_process produced an outgoing packet, - * return the link_socket_actual object (which - * contains the outgoing address). - */ - if (tla) - { - multi->to_link_addr = *tla; - *to_link_addr = &multi->to_link_addr; - } - - /* - * If tls_process hits an error: - * (1) If the session has an unexpired lame duck key, preserve it. - * (2) Reinitialize the session. - * (3) Increment soft error count - */ - if (ks->state == S_ERROR) - { - ++multi->n_soft_errors; - - if (i == TM_ACTIVE) - error = true; - - if (i == TM_ACTIVE - && ks_lame->state >= S_ACTIVE - && !multi->opt.single_session) - move_session (multi, TM_LAME_DUCK, TM_ACTIVE, true); - else - reset_session (multi, session); - } - } - } - - update_time (); - - tas = tls_authentication_status (multi, TLS_MULTI_AUTH_STATUS_INTERVAL); - - /* - * If lame duck session expires, kill it. - */ - if (lame_duck_must_die (&multi->session[TM_LAME_DUCK], wakeup)) { - tls_session_free (&multi->session[TM_LAME_DUCK], true); - msg (D_TLS_DEBUG_LOW, "TLS: tls_multi_process: killed expiring key"); - } - - /* - * If untrusted session achieves TLS authentication, - * move it to active session, usurping any prior session. - * - * A semi-trusted session is one in which the certificate authentication - * succeeded (if cert verification is enabled) but the username/password - * verification failed. A semi-trusted session can forward data on the - * TLS control channel but not on the tunnel channel. - */ - if (DECRYPT_KEY_ENABLED (multi, &multi->session[TM_UNTRUSTED].key[KS_PRIMARY])) { - move_session (multi, TM_ACTIVE, TM_UNTRUSTED, true); - msg (D_TLS_DEBUG_LOW, "TLS: tls_multi_process: untrusted session promoted to %strusted", - tas == TLS_AUTHENTICATION_SUCCEEDED ? "" : "semi-"); - } - - /* - * A hard error means that TM_ACTIVE hit an S_ERROR state and that no - * other key state objects are S_ACTIVE or higher. - */ - if (error) - { - for (i = 0; i < (int) SIZE (multi->key_scan); ++i) - { - if (multi->key_scan[i]->state >= S_ACTIVE) - goto nohard; - } - ++multi->n_hard_errors; - } - nohard: - -#ifdef ENABLE_DEBUG - /* DEBUGGING -- flood peer with repeating connection attempts */ - { - const int throw_level = GREMLIN_CONNECTION_FLOOD_LEVEL (multi->opt.gremlin); - if (throw_level) - { - for (i = 0; i < (int) SIZE (multi->key_scan); ++i) - { - if (multi->key_scan[i]->state >= throw_level) - { - ++multi->n_hard_errors; - ++multi->n_soft_errors; - } - } - } - } -#endif - - perf_pop (); - gc_free (&gc); - - return (tas == TLS_AUTHENTICATION_FAILED) ? TLSMP_KILL : active; -} - -/* - * Pre and post-process the encryption & decryption buffers in order - * to implement a multiplexed TLS channel over the TCP/UDP port. - */ - -/* - * - * When we are in TLS mode, this is the first routine which sees - * an incoming packet. - * - * If it's a data packet, we set opt so that our caller can - * decrypt it. We also give our caller the appropriate decryption key. - * - * If it's a control packet, we authenticate it and process it, - * possibly creating a new tls_session if it represents the - * first packet of a new session. For control packets, we will - * also zero the size of *buf so that our caller ignores the - * packet on our return. - * - * Note that openvpn only allows one active session at a time, - * so a new session (once authenticated) will always usurp - * an old session. - * - * Return true if input was an authenticated control channel - * packet. - * - * If we are running in TLS thread mode, all public routines - * below this point must be called with the L_TLS lock held. - */ - -bool -tls_pre_decrypt (struct tls_multi *multi, - const struct link_socket_actual *from, - struct buffer *buf, - struct crypto_options *opt) -{ - struct gc_arena gc = gc_new (); - bool ret = false; - - if (buf->len > 0) - { - int i; - int op; - int key_id; - - /* get opcode and key ID */ - { - uint8_t c = *BPTR (buf); - op = c >> P_OPCODE_SHIFT; - key_id = c & P_KEY_ID_MASK; - } - - if (op == P_DATA_V1) - { /* data channel packet */ - for (i = 0; i < KEY_SCAN_SIZE; ++i) - { - struct key_state *ks = multi->key_scan[i]; - - /* - * This is the basic test of TLS state compatibility between a local OpenVPN - * instance and its remote peer. - * - * If the test fails, it tells us that we are getting a packet from a source - * which claims reference to a prior negotiated TLS session, but the local - * OpenVPN instance has no memory of such a negotiation. - * - * It almost always occurs on UDP sessions when the passive side of the - * connection is restarted without the active side restarting as well (the - * passive side is the server which only listens for the connections, the - * active side is the client which initiates connections). - */ - if (DECRYPT_KEY_ENABLED (multi, ks) - && key_id == ks->key_id - && ks->authenticated -#ifdef ENABLE_DEF_AUTH - && !ks->auth_deferred -#endif - && link_socket_actual_match (from, &ks->remote_addr)) - { - /* return appropriate data channel decrypt key in opt */ - opt->key_ctx_bi = &ks->key; - opt->packet_id = multi->opt.replay ? &ks->packet_id : NULL; - opt->pid_persist = NULL; - opt->flags &= multi->opt.crypto_flags_and; - opt->flags |= multi->opt.crypto_flags_or; - ASSERT (buf_advance (buf, 1)); - ++ks->n_packets; - ks->n_bytes += buf->len; - dmsg (D_TLS_KEYSELECT, - "TLS: tls_pre_decrypt, key_id=%d, IP=%s", - key_id, print_link_socket_actual (from, &gc)); - gc_free (&gc); - return ret; - } -#if 0 /* keys out of sync? */ - else - { - dmsg (D_TLS_ERRORS, "TLS_PRE_DECRYPT: [%d] dken=%d rkid=%d lkid=%d auth=%d def=%d match=%d", - i, - DECRYPT_KEY_ENABLED (multi, ks), - key_id, - ks->key_id, - ks->authenticated, -#ifdef ENABLE_DEF_AUTH - ks->auth_deferred, -#else - -1, -#endif - link_socket_actual_match (from, &ks->remote_addr)); - } -#endif - } - - msg (D_TLS_ERRORS, - "TLS Error: local/remote TLS keys are out of sync: %s [%d]", - print_link_socket_actual (from, &gc), key_id); - goto error_lite; - } - else /* control channel packet */ - { - bool do_burst = false; - bool new_link = false; - struct session_id sid; /* remote session ID */ - - /* verify legal opcode */ - if (op < P_FIRST_OPCODE || op > P_LAST_OPCODE) - { - msg (D_TLS_ERRORS, - "TLS Error: unknown opcode received from %s op=%d", - print_link_socket_actual (from, &gc), op); - goto error; - } - - /* hard reset ? */ - if (is_hard_reset (op, 0)) - { - /* verify client -> server or server -> client connection */ - if (((op == P_CONTROL_HARD_RESET_CLIENT_V1 - || op == P_CONTROL_HARD_RESET_CLIENT_V2) && !multi->opt.server) - || ((op == P_CONTROL_HARD_RESET_SERVER_V1 - || op == P_CONTROL_HARD_RESET_SERVER_V2) && multi->opt.server)) - { - msg (D_TLS_ERRORS, - "TLS Error: client->client or server->server connection attempted from %s", - print_link_socket_actual (from, &gc)); - goto error; - } - } - - /* - * Authenticate Packet - */ - dmsg (D_TLS_DEBUG, "TLS: control channel, op=%s, IP=%s", - packet_opcode_name (op), print_link_socket_actual (from, &gc)); - - /* get remote session-id */ - { - struct buffer tmp = *buf; - buf_advance (&tmp, 1); - if (!session_id_read (&sid, &tmp) || !session_id_defined (&sid)) - { - msg (D_TLS_ERRORS, - "TLS Error: session-id not found in packet from %s", - print_link_socket_actual (from, &gc)); - goto error; - } - } - - /* use session ID to match up packet with appropriate tls_session object */ - for (i = 0; i < TM_SIZE; ++i) - { - struct tls_session *session = &multi->session[i]; - struct key_state *ks = &session->key[KS_PRIMARY]; - - dmsg (D_TLS_DEBUG, - "TLS: initial packet test, i=%d state=%s, mysid=%s, rec-sid=%s, rec-ip=%s, stored-sid=%s, stored-ip=%s", - i, - state_name (ks->state), - session_id_print (&session->session_id, &gc), - session_id_print (&sid, &gc), - print_link_socket_actual (from, &gc), - session_id_print (&ks->session_id_remote, &gc), - print_link_socket_actual (&ks->remote_addr, &gc)); - - if (session_id_equal (&ks->session_id_remote, &sid)) - /* found a match */ - { - if (i == TM_LAME_DUCK) { - msg (D_TLS_ERRORS, - "TLS ERROR: received control packet with stale session-id=%s", - session_id_print (&sid, &gc)); - goto error; - } - dmsg (D_TLS_DEBUG, - "TLS: found match, session[%d], sid=%s", - i, session_id_print (&sid, &gc)); - break; - } - } - - /* - * Initial packet received. - */ - - if (i == TM_SIZE && is_hard_reset (op, 0)) - { - struct tls_session *session = &multi->session[TM_ACTIVE]; - struct key_state *ks = &session->key[KS_PRIMARY]; - - if (!is_hard_reset (op, multi->opt.key_method)) - { - msg (D_TLS_ERRORS, "TLS ERROR: initial packet local/remote key_method mismatch, local key_method=%d, op=%s", - multi->opt.key_method, - packet_opcode_name (op)); - goto error; - } - - /* - * If we have no session currently in progress, the initial packet will - * open a new session in TM_ACTIVE rather than TM_UNTRUSTED. - */ - if (!session_id_defined (&ks->session_id_remote)) - { - if (multi->opt.single_session && multi->n_sessions) - { - msg (D_TLS_ERRORS, - "TLS Error: Cannot accept new session request from %s due to session context expire or --single-session [1]", - print_link_socket_actual (from, &gc)); - goto error; - } - -#ifdef ENABLE_MANAGEMENT - if (management) - { - management_set_state (management, - OPENVPN_STATE_AUTH, - NULL, - 0, - 0); - } -#endif - - msg (D_TLS_DEBUG_LOW, - "TLS: Initial packet from %s, sid=%s", - print_link_socket_actual (from, &gc), - session_id_print (&sid, &gc)); - - do_burst = true; - new_link = true; - i = TM_ACTIVE; - session->untrusted_addr = *from; - } - } - - if (i == TM_SIZE && is_hard_reset (op, 0)) - { - /* - * No match with existing sessions, - * probably a new session. - */ - struct tls_session *session = &multi->session[TM_UNTRUSTED]; - - /* - * If --single-session, don't allow any hard-reset connection request - * unless it the the first packet of the session. - */ - if (multi->opt.single_session) - { - msg (D_TLS_ERRORS, - "TLS Error: Cannot accept new session request from %s due to session context expire or --single-session [2]", - print_link_socket_actual (from, &gc)); - goto error; - } - - if (!is_hard_reset (op, multi->opt.key_method)) - { - msg (D_TLS_ERRORS, "TLS ERROR: new session local/remote key_method mismatch, local key_method=%d, op=%s", - multi->opt.key_method, - packet_opcode_name (op)); - goto error; - } - - if (!read_control_auth (buf, &session->tls_auth, from)) - goto error; - - /* - * New session-initiating control packet is authenticated at this point, - * assuming that the --tls-auth command line option was used. - * - * Without --tls-auth, we leave authentication entirely up to TLS. - */ - msg (D_TLS_DEBUG_LOW, - "TLS: new session incoming connection from %s", - print_link_socket_actual (from, &gc)); - - new_link = true; - i = TM_UNTRUSTED; - session->untrusted_addr = *from; - } - else - { - struct tls_session *session = &multi->session[i]; - struct key_state *ks = &session->key[KS_PRIMARY]; - - /* - * Packet must belong to an existing session. - */ - if (i != TM_ACTIVE && i != TM_UNTRUSTED) - { - msg (D_TLS_ERRORS, - "TLS Error: Unroutable control packet received from %s (si=%d op=%s)", - print_link_socket_actual (from, &gc), - i, - packet_opcode_name (op)); - goto error; - } - - /* - * Verify remote IP address - */ - if (!new_link && !link_socket_actual_match (&ks->remote_addr, from)) - { - msg (D_TLS_ERRORS, "TLS Error: Received control packet from unexpected IP addr: %s", - print_link_socket_actual (from, &gc)); - goto error; - } - - /* - * Remote is requesting a key renegotiation - */ - if (op == P_CONTROL_SOFT_RESET_V1 - && DECRYPT_KEY_ENABLED (multi, ks)) - { - if (!read_control_auth (buf, &session->tls_auth, from)) - goto error; - - key_state_soft_reset (session); - - dmsg (D_TLS_DEBUG, - "TLS: received P_CONTROL_SOFT_RESET_V1 s=%d sid=%s", - i, session_id_print (&sid, &gc)); - } - else - { - /* - * Remote responding to our key renegotiation request? - */ - if (op == P_CONTROL_SOFT_RESET_V1) - do_burst = true; - - if (!read_control_auth (buf, &session->tls_auth, from)) - goto error; - - dmsg (D_TLS_DEBUG, - "TLS: received control channel packet s#=%d sid=%s", - i, session_id_print (&sid, &gc)); - } - } - - /* - * We have an authenticated packet (if --tls-auth was set). - * Now pass to our reliability level which deals with - * packet acknowledgements, retransmits, sequencing, etc. - */ - { - struct tls_session *session = &multi->session[i]; - struct key_state *ks = &session->key[KS_PRIMARY]; - - /* Make sure we were initialized and that we're not in an error state */ - ASSERT (ks->state != S_UNDEF); - ASSERT (ks->state != S_ERROR); - ASSERT (session_id_defined (&session->session_id)); - - /* Let our caller know we processed a control channel packet */ - ret = true; - - /* - * Set our remote address and remote session_id - */ - if (new_link) - { - ks->session_id_remote = sid; - ks->remote_addr = *from; - ++multi->n_sessions; - } - else if (!link_socket_actual_match (&ks->remote_addr, from)) - { - msg (D_TLS_ERRORS, - "TLS Error: Existing session control channel packet from unknown IP address: %s", - print_link_socket_actual (from, &gc)); - goto error; - } - - /* - * Should we do a retransmit of all unacknowledged packets in - * the send buffer? This improves the start-up efficiency of the - * initial key negotiation after the 2nd peer comes online. - */ - if (do_burst && !session->burst) - { - reliable_schedule_now (ks->send_reliable); - session->burst = true; - } - - /* Check key_id */ - if (ks->key_id != key_id) - { - msg (D_TLS_ERRORS, - "TLS ERROR: local/remote key IDs out of sync (%d/%d) ID: %s", - ks->key_id, key_id, print_key_id (multi, &gc)); - goto error; - } - - /* - * Process incoming ACKs for packets we can now - * delete from reliable send buffer - */ - { - /* buffers all packet IDs to delete from send_reliable */ - struct reliable_ack send_ack; - - send_ack.len = 0; - if (!reliable_ack_read (&send_ack, buf, &session->session_id)) - { - msg (D_TLS_ERRORS, - "TLS Error: reading acknowledgement record from packet"); - goto error; - } - reliable_send_purge (ks->send_reliable, &send_ack); - } - - if (op != P_ACK_V1 && reliable_can_get (ks->rec_reliable)) - { - packet_id_type id; - - /* Extract the packet ID from the packet */ - if (reliable_ack_read_packet_id (buf, &id)) - { - /* Avoid deadlock by rejecting packet that would de-sequentialize receive buffer */ - if (reliable_wont_break_sequentiality (ks->rec_reliable, id)) - { - if (reliable_not_replay (ks->rec_reliable, id)) - { - /* Save incoming ciphertext packet to reliable buffer */ - struct buffer *in = reliable_get_buf (ks->rec_reliable); - ASSERT (in); - ASSERT (buf_copy (in, buf)); - reliable_mark_active_incoming (ks->rec_reliable, in, id, op); - } - - /* Process outgoing acknowledgment for packet just received, even if it's a replay */ - reliable_ack_acknowledge_packet_id (ks->rec_ack, id); - } - } - } - } - } - } - - done: - buf->len = 0; - opt->key_ctx_bi = NULL; - opt->packet_id = NULL; - opt->pid_persist = NULL; - opt->flags &= multi->opt.crypto_flags_and; - gc_free (&gc); - return ret; - - error: - ++multi->n_soft_errors; - error_lite: - tls_clear_error(); - goto done; -} - -/* - * This function is similar to tls_pre_decrypt, except it is called - * when we are in server mode and receive an initial incoming - * packet. Note that we don't modify - * any state in our parameter objects. The purpose is solely to - * determine whether we should generate a client instance - * object, in which case true is returned. - * - * This function is essentially the first-line HMAC firewall - * on the UDP port listener in --mode server mode. - */ -bool -tls_pre_decrypt_lite (const struct tls_auth_standalone *tas, - const struct link_socket_actual *from, - const struct buffer *buf) - -{ - struct gc_arena gc = gc_new (); - bool ret = false; - - if (buf->len > 0) - { - int op; - int key_id; - - /* get opcode and key ID */ - { - uint8_t c = *BPTR (buf); - op = c >> P_OPCODE_SHIFT; - key_id = c & P_KEY_ID_MASK; - } - - /* this packet is from an as-yet untrusted source, so - scrutinize carefully */ - - if (op != P_CONTROL_HARD_RESET_CLIENT_V2) - { - /* - * This can occur due to bogus data or DoS packets. - */ - dmsg (D_TLS_STATE_ERRORS, - "TLS State Error: No TLS state for client %s, opcode=%d", - print_link_socket_actual (from, &gc), - op); - goto error; - } - - if (key_id != 0) - { - dmsg (D_TLS_STATE_ERRORS, - "TLS State Error: Unknown key ID (%d) received from %s -- 0 was expected", - key_id, - print_link_socket_actual (from, &gc)); - goto error; - } - - if (buf->len > EXPANDED_SIZE_DYNAMIC (&tas->frame)) - { - dmsg (D_TLS_STATE_ERRORS, - "TLS State Error: Large packet (size %d) received from %s -- a packet no larger than %d bytes was expected", - buf->len, - print_link_socket_actual (from, &gc), - EXPANDED_SIZE_DYNAMIC (&tas->frame)); - goto error; - } - - { - struct buffer newbuf = clone_buf (buf); - struct crypto_options co = tas->tls_auth_options; - bool status; - - /* - * We are in read-only mode at this point with respect to TLS - * control channel state. After we build a new client instance - * object, we will process this session-initiating packet for real. - */ - co.flags |= CO_IGNORE_PACKET_ID; - - /* HMAC test, if --tls-auth was specified */ - status = read_control_auth (&newbuf, &co, from); - free_buf (&newbuf); - if (!status) - goto error; - - /* - * At this point, if --tls-auth is being used, we know that - * the packet has passed the HMAC test, but we don't know if - * it is a replay yet. We will attempt to defeat replays - * by not advancing to the S_START state until we - * receive an ACK from our first reply to the client - * that includes an HMAC of our randomly generated 64 bit - * session ID. - * - * On the other hand if --tls-auth is not being used, we - * will proceed to begin the TLS authentication - * handshake with only cursory integrity checks having - * been performed, since we will be leaving the task - * of authentication solely up to TLS. - */ - - ret = true; - } - } - gc_free (&gc); - return ret; - - error: - tls_clear_error(); - gc_free (&gc); - return ret; -} - -/* Choose the key with which to encrypt a data packet */ -void -tls_pre_encrypt (struct tls_multi *multi, - struct buffer *buf, struct crypto_options *opt) -{ - multi->save_ks = NULL; - if (buf->len > 0) - { - int i; - struct key_state *ks_select = NULL; - for (i = 0; i < KEY_SCAN_SIZE; ++i) - { - struct key_state *ks = multi->key_scan[i]; - if (ks->state >= S_ACTIVE - && ks->authenticated -#ifdef ENABLE_DEF_AUTH - && !ks->auth_deferred -#endif - ) - { - if (!ks_select) - ks_select = ks; - if (now >= ks->auth_deferred_expire) - { - ks_select = ks; - break; - } - } - } - - if (ks_select) - { - opt->key_ctx_bi = &ks_select->key; - opt->packet_id = multi->opt.replay ? &ks_select->packet_id : NULL; - opt->pid_persist = NULL; - opt->flags &= multi->opt.crypto_flags_and; - opt->flags |= multi->opt.crypto_flags_or; - multi->save_ks = ks_select; - dmsg (D_TLS_KEYSELECT, "TLS: tls_pre_encrypt: key_id=%d", ks_select->key_id); - return; - } - else - { - struct gc_arena gc = gc_new (); - dmsg (D_TLS_KEYSELECT, "TLS Warning: no data channel send key available: %s", - print_key_id (multi, &gc)); - gc_free (&gc); - } - } - - buf->len = 0; - opt->key_ctx_bi = NULL; - opt->packet_id = NULL; - opt->pid_persist = NULL; - opt->flags &= multi->opt.crypto_flags_and; -} - -/* Prepend the appropriate opcode to encrypted buffer prior to TCP/UDP send */ -void -tls_post_encrypt (struct tls_multi *multi, struct buffer *buf) -{ - struct key_state *ks; - uint8_t *op; - - ks = multi->save_ks; - multi->save_ks = NULL; - if (buf->len > 0) - { - ASSERT (ks); - ASSERT (op = buf_prepend (buf, 1)); - *op = (P_DATA_V1 << P_OPCODE_SHIFT) | ks->key_id; - ++ks->n_packets; - ks->n_bytes += buf->len; - } -} - -/* - * Send a payload over the TLS control channel. - * Called externally. - */ - -bool -tls_send_payload (struct tls_multi *multi, - const uint8_t *data, - int size) -{ - struct tls_session *session; - struct key_state *ks; - bool ret = false; - - tls_clear_error(); - - ASSERT (multi); - - session = &multi->session[TM_ACTIVE]; - ks = &session->key[KS_PRIMARY]; - - if (ks->state >= S_ACTIVE) - { - if (key_state_write_plaintext_const (&ks->ks_ssl, data, size) == 1) - ret = true; - } - else - { - if (!ks->paybuf) - ks->paybuf = buffer_list_new (0); - buffer_list_push_data (ks->paybuf, data, (size_t)size); - ret = true; - } - - - tls_clear_error(); - - return ret; -} - -bool -tls_rec_payload (struct tls_multi *multi, - struct buffer *buf) -{ - struct tls_session *session; - struct key_state *ks; - bool ret = false; - - tls_clear_error(); - - ASSERT (multi); - - session = &multi->session[TM_ACTIVE]; - ks = &session->key[KS_PRIMARY]; - - if (ks->state >= S_ACTIVE && BLEN (&ks->plaintext_read_buf)) - { - if (buf_copy (buf, &ks->plaintext_read_buf)) - ret = true; - ks->plaintext_read_buf.len = 0; - } - - tls_clear_error(); - - return ret; -} - -/* - * Dump a human-readable rendition of an openvpn packet - * into a garbage collectable string which is returned. - */ -const char * -protocol_dump (struct buffer *buffer, unsigned int flags, struct gc_arena *gc) -{ - struct buffer out = alloc_buf_gc (256, gc); - struct buffer buf = *buffer; - - uint8_t c; - int op; - int key_id; - - int tls_auth_hmac_size = (flags & PD_TLS_AUTH_HMAC_SIZE_MASK); - - if (buf.len <= 0) - { - buf_printf (&out, "DATA UNDEF len=%d", buf.len); - goto done; - } - - if (!(flags & PD_TLS)) - goto print_data; - - /* - * Initial byte (opcode) - */ - if (!buf_read (&buf, &c, sizeof (c))) - goto done; - op = (c >> P_OPCODE_SHIFT); - key_id = c & P_KEY_ID_MASK; - buf_printf (&out, "%s kid=%d", packet_opcode_name (op), key_id); - - if (op == P_DATA_V1) - goto print_data; - - /* - * Session ID - */ - { - struct session_id sid; - - if (!session_id_read (&sid, &buf)) - goto done; - if (flags & PD_VERBOSE) - buf_printf (&out, " sid=%s", session_id_print (&sid, gc)); - } - - /* - * tls-auth hmac + packet_id - */ - if (tls_auth_hmac_size) - { - struct packet_id_net pin; - uint8_t tls_auth_hmac[MAX_HMAC_KEY_LENGTH]; - - ASSERT (tls_auth_hmac_size <= MAX_HMAC_KEY_LENGTH); - - if (!buf_read (&buf, tls_auth_hmac, tls_auth_hmac_size)) - goto done; - if (flags & PD_VERBOSE) - buf_printf (&out, " tls_hmac=%s", format_hex (tls_auth_hmac, tls_auth_hmac_size, 0, gc)); - - if (!packet_id_read (&pin, &buf, true)) - goto done; - buf_printf(&out, " pid=%s", packet_id_net_print (&pin, (flags & PD_VERBOSE), gc)); - } - - /* - * ACK list - */ - buf_printf (&out, " %s", reliable_ack_print(&buf, (flags & PD_VERBOSE), gc)); - - if (op == P_ACK_V1) - goto done; - - /* - * Packet ID - */ - { - packet_id_type l; - if (!buf_read (&buf, &l, sizeof (l))) - goto done; - l = ntohpid (l); - buf_printf (&out, " pid=" packet_id_format, (packet_id_print_type)l); - } - -print_data: - if (flags & PD_SHOW_DATA) - buf_printf (&out, " DATA %s", format_hex (BPTR (&buf), BLEN (&buf), 80, gc)); - else - buf_printf (&out, " DATA len=%d", buf.len); - -done: - return BSTR (&out); -} - -#else -static void dummy(void) {} -#endif /* ENABLE_CRYPTO && ENABLE_SSL*/ |