From d0811e643cddd796722fb1d0050ad57168da29d4 Mon Sep 17 00:00:00 2001 From: Adriaan de Jong Date: Thu, 30 Jun 2011 10:48:18 +0200 Subject: Refactored username and password authentication code Signed-off-by: Adriaan de Jong Acked-by: James Yonan Signed-off-by: David Sommerseth --- ssl.c | 527 ++---------------------------------------------------------------- 1 file changed, 13 insertions(+), 514 deletions(-) (limited to 'ssl.c') diff --git a/ssl.c b/ssl.c index fbb0d02..ec524e7 100644 --- a/ssl.c +++ b/ssl.c @@ -1086,45 +1086,6 @@ verify_callback (int preverify_ok, X509_STORE_CTX * ctx) /** @} name Function for authenticating a new connection from a remote OpenVPN peer */ - -static bool -tls_lock_username (struct tls_multi *multi, const char *username) -{ - if (multi->locked_username) - { - if (!username || strcmp (username, multi->locked_username)) - { - msg (D_TLS_ERRORS, "TLS Auth Error: username attempted to change from '%s' to '%s' -- tunnel disabled", - multi->locked_username, - np(username)); - - /* disable the tunnel */ - tls_deauthenticate (multi); - return false; - } - } - else - { - if (username) - multi->locked_username = string_alloc (username, NULL); - } - return true; -} - -const char * -tls_username (const struct tls_multi *multi, const bool null) -{ - const char *ret = NULL; - if (multi) - ret = multi->locked_username; - if (ret && strlen (ret)) - return ret; - else if (null) - return NULL; - else - return "UNDEF"; -} - #ifdef ENABLE_X509_TRACK void @@ -1150,234 +1111,6 @@ x509_track_add (const struct x509_track **ll_head, const char *name, int msgleve #endif -#ifdef ENABLE_DEF_AUTH -/* key_state_test_auth_control_file return values, - NOTE: acf_merge indexing depends on these values */ -#define ACF_UNDEFINED 0 -#define ACF_SUCCEEDED 1 -#define ACF_DISABLED 2 -#define ACF_FAILED 3 -#endif - -#ifdef MANAGEMENT_DEF_AUTH -static void -man_def_auth_set_client_reason (struct tls_multi *multi, const char *client_reason) -{ - if (multi->client_reason) - { - free (multi->client_reason); - multi->client_reason = NULL; - } - if (client_reason && strlen (client_reason)) - multi->client_reason = string_alloc (client_reason, NULL); -} - -static inline unsigned int -man_def_auth_test (const struct key_state *ks) -{ - if (management_enable_def_auth (management)) - return ks->mda_status; - else - return ACF_DISABLED; -} -#endif - -#ifdef PLUGIN_DEF_AUTH - -/* - * auth_control_file functions - */ - -static void -key_state_rm_auth_control_file (struct key_state *ks) -{ - if (ks && ks->auth_control_file) - { - delete_file (ks->auth_control_file); - free (ks->auth_control_file); - ks->auth_control_file = NULL; - } -} - -static void -key_state_gen_auth_control_file (struct key_state *ks, const struct tls_options *opt) -{ - struct gc_arena gc = gc_new (); - const char *acf; - - key_state_rm_auth_control_file (ks); - acf = create_temp_file (opt->tmp_dir, "acf", &gc); - if( acf ) { - ks->auth_control_file = string_alloc (acf, NULL); - setenv_str (opt->es, "auth_control_file", ks->auth_control_file); - } /* FIXME: Should have better error handling? */ - gc_free (&gc); -} - -static unsigned int -key_state_test_auth_control_file (struct key_state *ks) -{ - if (ks && ks->auth_control_file) - { - unsigned int ret = ks->auth_control_status; - if (ret == ACF_UNDEFINED) - { - FILE *fp = fopen (ks->auth_control_file, "r"); - if (fp) - { - const int c = fgetc (fp); - if (c == '1') - ret = ACF_SUCCEEDED; - else if (c == '0') - ret = ACF_FAILED; - fclose (fp); - ks->auth_control_status = ret; - } - } - return ret; - } - return ACF_DISABLED; -} - -#endif - -/* - * Return current session authentication state. Return - * value is TLS_AUTHENTICATION_x. - */ - -int -tls_authentication_status (struct tls_multi *multi, const int latency) -{ - bool deferred = false; - bool success = false; - bool active = false; - -#ifdef ENABLE_DEF_AUTH - static const unsigned char acf_merge[] = - { - ACF_UNDEFINED, /* s1=ACF_UNDEFINED s2=ACF_UNDEFINED */ - ACF_UNDEFINED, /* s1=ACF_UNDEFINED s2=ACF_SUCCEEDED */ - ACF_UNDEFINED, /* s1=ACF_UNDEFINED s2=ACF_DISABLED */ - ACF_FAILED, /* s1=ACF_UNDEFINED s2=ACF_FAILED */ - ACF_UNDEFINED, /* s1=ACF_SUCCEEDED s2=ACF_UNDEFINED */ - ACF_SUCCEEDED, /* s1=ACF_SUCCEEDED s2=ACF_SUCCEEDED */ - ACF_SUCCEEDED, /* s1=ACF_SUCCEEDED s2=ACF_DISABLED */ - ACF_FAILED, /* s1=ACF_SUCCEEDED s2=ACF_FAILED */ - ACF_UNDEFINED, /* s1=ACF_DISABLED s2=ACF_UNDEFINED */ - ACF_SUCCEEDED, /* s1=ACF_DISABLED s2=ACF_SUCCEEDED */ - ACF_DISABLED, /* s1=ACF_DISABLED s2=ACF_DISABLED */ - ACF_FAILED, /* s1=ACF_DISABLED s2=ACF_FAILED */ - ACF_FAILED, /* s1=ACF_FAILED s2=ACF_UNDEFINED */ - ACF_FAILED, /* s1=ACF_FAILED s2=ACF_SUCCEEDED */ - ACF_FAILED, /* s1=ACF_FAILED s2=ACF_DISABLED */ - ACF_FAILED /* s1=ACF_FAILED s2=ACF_FAILED */ - }; -#endif - - if (multi) - { - int i; - -#ifdef ENABLE_DEF_AUTH - if (latency && multi->tas_last && multi->tas_last + latency >= now) - return TLS_AUTHENTICATION_UNDEFINED; - multi->tas_last = now; -#endif - - for (i = 0; i < KEY_SCAN_SIZE; ++i) - { - struct key_state *ks = multi->key_scan[i]; - if (DECRYPT_KEY_ENABLED (multi, ks)) - { - active = true; - if (ks->authenticated) - { -#ifdef ENABLE_DEF_AUTH - unsigned int s1 = ACF_DISABLED; - unsigned int s2 = ACF_DISABLED; -#ifdef PLUGIN_DEF_AUTH - s1 = key_state_test_auth_control_file (ks); -#endif -#ifdef MANAGEMENT_DEF_AUTH - s2 = man_def_auth_test (ks); -#endif - ASSERT (s1 < 4 && s2 < 4); - switch (acf_merge[(s1<<2) + s2]) - { - case ACF_SUCCEEDED: - case ACF_DISABLED: - success = true; - ks->auth_deferred = false; - break; - case ACF_UNDEFINED: - if (now < ks->auth_deferred_expire) - deferred = true; - break; - case ACF_FAILED: - ks->authenticated = false; - break; - default: - ASSERT (0); - } -#else - success = true; -#endif - } - } - } - } - -#if 0 - dmsg (D_TLS_ERRORS, "TAS: a=%d s=%d d=%d", active, success, deferred); -#endif - - if (success) - return TLS_AUTHENTICATION_SUCCEEDED; - else if (!active || deferred) - return TLS_AUTHENTICATION_DEFERRED; - else - return TLS_AUTHENTICATION_FAILED; -} - -#ifdef MANAGEMENT_DEF_AUTH -/* - * For deferred auth, this is where the management interface calls (on server) - * to indicate auth failure/success. - */ -bool -tls_authenticate_key (struct tls_multi *multi, const unsigned int mda_key_id, const bool auth, const char *client_reason) -{ - bool ret = false; - if (multi) - { - int i; - man_def_auth_set_client_reason (multi, client_reason); - for (i = 0; i < KEY_SCAN_SIZE; ++i) - { - struct key_state *ks = multi->key_scan[i]; - if (ks->mda_key_id == mda_key_id) - { - ks->mda_status = auth ? ACF_SUCCEEDED : ACF_FAILED; - ret = true; - } - } - } - return ret; -} -#endif - -void -tls_deauthenticate (struct tls_multi *multi) -{ - if (multi) - { - int i, j; - for (i = 0; i < TM_SIZE; ++i) - for (j = 0; j < KS_SIZE; ++j) - multi->session[i].key[j].authenticated = false; - } -} /* * Initialize SSL context. @@ -2658,173 +2391,6 @@ read_string_discard (struct buffer *buf) free (data); } -/* - * Authenticate a client using username/password. - * Runs on server. - * - * If you want to add new authentication methods, - * this is the place to start. - */ - -static bool -verify_user_pass_script (struct tls_session *session, const struct user_pass *up) -{ - struct gc_arena gc = gc_new (); - struct argv argv = argv_new (); - const char *tmp_file = ""; - bool ret = false; - - /* Is username defined? */ - if ((session->opt->ssl_flags & SSLF_AUTH_USER_PASS_OPTIONAL) || strlen (up->username)) - { - /* Set environmental variables prior to calling script */ - setenv_str (session->opt->es, "script_type", "user-pass-verify"); - - if (session->opt->auth_user_pass_verify_script_via_file) - { - struct status_output *so; - - tmp_file = create_temp_file (session->opt->tmp_dir, "up", &gc); - if( tmp_file ) { - so = status_open (tmp_file, 0, -1, NULL, STATUS_OUTPUT_WRITE); - status_printf (so, "%s", up->username); - status_printf (so, "%s", up->password); - if (!status_close (so)) - { - msg (D_TLS_ERRORS, "TLS Auth Error: could not write username/password to file: %s", - tmp_file); - goto done; - } - } else { - msg (D_TLS_ERRORS, "TLS Auth Error: could not create write " - "username/password to temp file"); - } - } - else - { - setenv_str (session->opt->es, "username", up->username); - setenv_str (session->opt->es, "password", up->password); - } - - /* setenv incoming cert common name for script */ - setenv_str (session->opt->es, "common_name", session->common_name); - - /* setenv client real IP address */ - setenv_untrusted (session); - - /* format command line */ - argv_printf (&argv, "%sc %s", session->opt->auth_user_pass_verify_script, tmp_file); - - /* call command */ - ret = openvpn_run_script (&argv, session->opt->es, 0, - "--auth-user-pass-verify"); - - if (!session->opt->auth_user_pass_verify_script_via_file) - setenv_del (session->opt->es, "password"); - } - else - { - msg (D_TLS_ERRORS, "TLS Auth Error: peer provided a blank username"); - } - - done: - if (tmp_file && strlen (tmp_file) > 0) - delete_file (tmp_file); - - argv_reset (&argv); - gc_free (&gc); - return ret; -} - -static int -verify_user_pass_plugin (struct tls_session *session, const struct user_pass *up, const char *raw_username) -{ - int retval = OPENVPN_PLUGIN_FUNC_ERROR; - struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */ - - /* Is username defined? */ - if ((session->opt->ssl_flags & SSLF_AUTH_USER_PASS_OPTIONAL) || strlen (up->username)) - { - /* set username/password in private env space */ - setenv_str (session->opt->es, "username", raw_username); - setenv_str (session->opt->es, "password", up->password); - - /* setenv incoming cert common name for script */ - setenv_str (session->opt->es, "common_name", session->common_name); - - /* setenv client real IP address */ - setenv_untrusted (session); - -#ifdef PLUGIN_DEF_AUTH - /* generate filename for deferred auth control file */ - key_state_gen_auth_control_file (ks, session->opt); -#endif - - /* call command */ - retval = plugin_call (session->opt->plugins, OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY, NULL, NULL, session->opt->es, -1, NULL); - -#ifdef PLUGIN_DEF_AUTH - /* purge auth control filename (and file itself) for non-deferred returns */ - if (retval != OPENVPN_PLUGIN_FUNC_DEFERRED) - key_state_rm_auth_control_file (ks); -#endif - - setenv_del (session->opt->es, "password"); - setenv_str (session->opt->es, "username", up->username); - } - else - { - msg (D_TLS_ERRORS, "TLS Auth Error (verify_user_pass_plugin): peer provided a blank username"); - } - - return retval; -} - -/* - * MANAGEMENT_DEF_AUTH internal ssl.c status codes - */ -#define KMDA_ERROR 0 -#define KMDA_SUCCESS 1 -#define KMDA_UNDEF 2 -#define KMDA_DEF 3 - -#ifdef MANAGEMENT_DEF_AUTH -static int -verify_user_pass_management (struct tls_session *session, const struct user_pass *up, const char *raw_username) -{ - int retval = KMDA_ERROR; - struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */ - - /* Is username defined? */ - if ((session->opt->ssl_flags & SSLF_AUTH_USER_PASS_OPTIONAL) || strlen (up->username)) - { - /* set username/password in private env space */ - setenv_str (session->opt->es, "username", raw_username); - setenv_str (session->opt->es, "password", up->password); - - /* setenv incoming cert common name for script */ - setenv_str (session->opt->es, "common_name", session->common_name); - - /* setenv client real IP address */ - setenv_untrusted (session); - - if (management) - management_notify_client_needing_auth (management, ks->mda_key_id, session->opt->mda_context, session->opt->es); - - setenv_del (session->opt->es, "password"); - setenv_str (session->opt->es, "username", up->username); - - retval = KMDA_SUCCESS; - } - else - { - msg (D_TLS_ERRORS, "TLS Auth Error (verify_user_pass_management): peer provided a blank username"); - } - - return retval; -} -#endif - /* * Handle the reading and writing of key data to and from * the TLS control channel (cleartext). @@ -3091,23 +2657,18 @@ key_method_2_read (struct buffer *buf, struct tls_multi *multi, struct tls_sessi { struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */ struct key_state *ks_lame = &session->key[KS_LAME_DUCK]; /* retiring key */ - struct gc_arena gc = gc_new (); + int key_method_flags; - char *options; - struct user_pass *up; + bool username_status, password_status; - bool man_def_auth = KMDA_UNDEF; + struct gc_arena gc = gc_new (); + char *options; -#ifdef MANAGEMENT_DEF_AUTH - if (management_enable_def_auth (management)) - man_def_auth = KMDA_DEF; -#endif + /* allocate temporary objects */ + ALLOC_ARRAY_CLEAR_GC (options, char, TLS_OPTIONS_LEN, &gc); ASSERT (session->opt->key_method == 2); - /* allocate temporary objects */ - ALLOC_ARRAY_CLEAR_GC (options, char, TLS_OPTIONS_LEN, &gc); - /* discard leading uint32 */ ASSERT (buf_advance (buf, 4)); @@ -3135,21 +2696,17 @@ key_method_2_read (struct buffer *buf, struct tls_multi *multi, struct tls_sessi goto error; } - /* should we check username/password? */ ks->authenticated = false; - if (session->opt->auth_user_pass_verify_script - || plugin_defined (session->opt->plugins, OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY) - || man_def_auth == KMDA_DEF) + + if (verify_user_pass_enabled(session)) { - int s1 = OPENVPN_PLUGIN_FUNC_SUCCESS; - bool s2 = true; - char *raw_username; - bool username_status, password_status; + /* Perform username/password authentication */ + struct user_pass *up; - /* get username/password from plaintext buffer */ 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 (!username_status || !password_status) { CLEAR (*up); @@ -3160,76 +2717,18 @@ key_method_2_read (struct buffer *buf, struct tls_multi *multi, struct tls_sessi } } - /* preserve raw username before string_mod remapping, for plugins */ - ALLOC_ARRAY_CLEAR_GC (raw_username, char, USER_PASS_LEN, &gc); - strcpy (raw_username, up->username); - string_mod (raw_username, CC_PRINT, CC_CRLF, '_'); - - /* enforce character class restrictions in username/password */ - string_mod_sslname (up->username, COMMON_NAME_CHAR_CLASS, session->opt->ssl_flags); - string_mod (up->password, CC_PRINT, CC_CRLF, '_'); - - /* call plugin(s) and/or script */ #ifdef MANAGEMENT_DEF_AUTH /* get peer info from control channel */ free (multi->peer_info); multi->peer_info = read_string_alloc (buf); - - if (man_def_auth == KMDA_DEF) - man_def_auth = verify_user_pass_management (session, up, raw_username); #endif - if (plugin_defined (session->opt->plugins, OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY)) - s1 = verify_user_pass_plugin (session, up, raw_username); - if (session->opt->auth_user_pass_verify_script) - s2 = verify_user_pass_script (session, up); - - /* check sizing of username if it will become our common name */ - if ((session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) && strlen (up->username) >= TLS_USERNAME_LEN) - { - msg (D_TLS_ERRORS, "TLS Auth Error: --username-as-common name specified and username is longer than the maximum permitted Common Name length of %d characters", TLS_USERNAME_LEN); - s1 = OPENVPN_PLUGIN_FUNC_ERROR; - } - - /* auth succeeded? */ - if ((s1 == OPENVPN_PLUGIN_FUNC_SUCCESS -#ifdef PLUGIN_DEF_AUTH - || s1 == OPENVPN_PLUGIN_FUNC_DEFERRED -#endif - ) && s2 && man_def_auth != KMDA_ERROR - && tls_lock_username (multi, up->username)) - { - ks->authenticated = true; -#ifdef PLUGIN_DEF_AUTH - if (s1 == OPENVPN_PLUGIN_FUNC_DEFERRED) - ks->auth_deferred = true; -#endif -#ifdef MANAGEMENT_DEF_AUTH - if (man_def_auth != KMDA_UNDEF) - ks->auth_deferred = true; -#endif - if ((session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME)) - set_common_name (session, up->username); -#ifdef ENABLE_DEF_AUTH - msg (D_HANDSHAKE, "TLS: Username/Password authentication %s for username '%s' %s", - ks->auth_deferred ? "deferred" : "succeeded", - up->username, - (session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : ""); -#else - msg (D_HANDSHAKE, "TLS: Username/Password authentication %s for username '%s' %s", - "succeeded", - up->username, - (session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : ""); -#endif - } - else - { - msg (D_TLS_ERRORS, "TLS Auth Error: Auth Username/Password verification failed for peer"); - } + verify_user_pass(up, multi, session); CLEAR (*up); } else { + /* Session verification should have occurred during TLS negotiation*/ if (!session->verified) { msg (D_TLS_ERRORS, -- cgit