/release/src-rt-6.x.4708/router/openvpn/src/openvpn/ssl_verify.c
C | 1545 lines | 1164 code | 184 blank | 197 comment | 229 complexity | 4dd9a4d1bc016f5cefaf51d7f21aedda MD5 | raw file
Possible License(s): LGPL-2.0, LGPL-3.0, MPL-2.0-no-copyleft-exception, 0BSD, BSD-3-Clause, WTFPL, CC-BY-SA-3.0, LGPL-2.1, GPL-3.0, GPL-2.0
- /*
- * 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) 2002-2018 OpenVPN Inc <sales@openvpn.net>
- * Copyright (C) 2010-2018 Fox Crypto B.V. <openvpn@fox-it.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
- /**
- * @file Control Channel Verification Module
- */
- #ifdef HAVE_CONFIG_H
- #include "config.h"
- #elif defined(_MSC_VER)
- #include "config-msvc.h"
- #endif
- #include "syshead.h"
- #ifdef ENABLE_CRYPTO
- #include "misc.h"
- #include "manage.h"
- #include "otime.h"
- #include "base64.h"
- #include "ssl_verify.h"
- #include "ssl_verify_backend.h"
- #ifdef ENABLE_CRYPTO_OPENSSL
- #include "ssl_verify_openssl.h"
- #endif
- /** Maximum length of common name */
- #define TLS_USERNAME_LEN 64
- /** Legal characters in an X509 name with --compat-names */
- #define X509_NAME_CHAR_CLASS (CC_ALNUM|CC_UNDERBAR|CC_DASH|CC_DOT|CC_AT|CC_SLASH|CC_COLON|CC_EQUAL)
- /** Legal characters in a common name with --compat-names */
- #define COMMON_NAME_CHAR_CLASS (CC_ALNUM|CC_UNDERBAR|CC_DASH|CC_DOT|CC_AT|CC_SLASH)
- static void
- string_mod_remap_name(char *str, const unsigned int restrictive_flags)
- {
- if (compat_flag(COMPAT_FLAG_QUERY | COMPAT_NAMES)
- && !compat_flag(COMPAT_FLAG_QUERY | COMPAT_NO_NAME_REMAPPING))
- {
- string_mod(str, restrictive_flags, 0, '_');
- }
- else
- {
- string_mod(str, CC_PRINT, CC_CRLF, '_');
- }
- }
- /*
- * Export the untrusted IP address and port to the environment
- */
- static void
- setenv_untrusted(struct tls_session *session)
- {
- setenv_link_socket_actual(session->opt->es, "untrusted", &session->untrusted_addr, SA_IP_PORT);
- }
- /**
- * Wipes the authentication token out of the memory, frees and cleans up related buffers and flags
- *
- * @param multi Pointer to a multi object holding the auth_token variables
- */
- static void
- wipe_auth_token(struct tls_multi *multi)
- {
- if(multi)
- {
- if (multi->auth_token)
- {
- secure_memzero(multi->auth_token, AUTH_TOKEN_SIZE);
- free(multi->auth_token);
- }
- multi->auth_token = NULL;
- multi->auth_token_sent = false;
- }
- }
- /*
- * Remove authenticated state from all sessions in the given tunnel
- */
- static void
- tls_deauthenticate(struct tls_multi *multi)
- {
- if (multi)
- {
- wipe_auth_token(multi);
- for (int i = 0; i < TM_SIZE; ++i)
- {
- for (int j = 0; j < KS_SIZE; ++j)
- {
- multi->session[i].key[j].authenticated = false;
- }
- }
- }
- }
- /*
- * Set the given session's common_name
- */
- static void
- set_common_name(struct tls_session *session, const char *common_name)
- {
- if (session->common_name)
- {
- free(session->common_name);
- session->common_name = NULL;
- #ifdef ENABLE_PF
- session->common_name_hashval = 0;
- #endif
- }
- if (common_name)
- {
- /* FIXME: Last alloc will never be freed */
- session->common_name = string_alloc(common_name, NULL);
- #ifdef ENABLE_PF
- {
- const uint32_t len = (uint32_t) strlen(common_name);
- if (len)
- {
- session->common_name_hashval = hash_func((const uint8_t *)common_name, len+1, 0);
- }
- else
- {
- session->common_name_hashval = 0;
- }
- }
- #endif
- }
- }
- /*
- * Retrieve the common name for the given tunnel's active session. If the
- * common name is NULL or empty, return NULL if null is true, or "UNDEF" if
- * null is false.
- */
- const char *
- tls_common_name(const struct tls_multi *multi, const bool null)
- {
- const char *ret = NULL;
- if (multi)
- {
- ret = multi->session[TM_ACTIVE].common_name;
- }
- if (ret && strlen(ret))
- {
- return ret;
- }
- else if (null)
- {
- return NULL;
- }
- else
- {
- return "UNDEF";
- }
- }
- /*
- * Lock the common name for the given tunnel.
- */
- void
- tls_lock_common_name(struct tls_multi *multi)
- {
- const char *cn = multi->session[TM_ACTIVE].common_name;
- if (cn && !multi->locked_cn)
- {
- multi->locked_cn = string_alloc(cn, NULL);
- }
- }
- /*
- * Lock the username for the given tunnel
- */
- 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";
- }
- }
- void
- cert_hash_remember(struct tls_session *session, const int error_depth,
- const struct buffer *cert_hash)
- {
- if (error_depth >= 0 && error_depth < MAX_CERT_DEPTH)
- {
- if (!session->cert_hash_set)
- {
- ALLOC_OBJ_CLEAR(session->cert_hash_set, struct cert_hash_set);
- }
- if (!session->cert_hash_set->ch[error_depth])
- {
- ALLOC_OBJ(session->cert_hash_set->ch[error_depth], struct cert_hash);
- }
- struct cert_hash *ch = session->cert_hash_set->ch[error_depth];
- ASSERT(sizeof(ch->sha256_hash) == BLEN(cert_hash));
- memcpy(ch->sha256_hash, BPTR(cert_hash), sizeof(ch->sha256_hash));
- }
- }
- void
- cert_hash_free(struct cert_hash_set *chs)
- {
- if (chs)
- {
- int i;
- for (i = 0; i < MAX_CERT_DEPTH; ++i)
- {
- free(chs->ch[i]);
- }
- free(chs);
- }
- }
- bool
- cert_hash_compare(const struct cert_hash_set *chs1, const struct cert_hash_set *chs2)
- {
- if (chs1 && chs2)
- {
- int i;
- for (i = 0; i < MAX_CERT_DEPTH; ++i)
- {
- const struct cert_hash *ch1 = chs1->ch[i];
- const struct cert_hash *ch2 = chs2->ch[i];
- if (!ch1 && !ch2)
- {
- continue;
- }
- else if (ch1 && ch2 && !memcmp(ch1->sha256_hash, ch2->sha256_hash,
- sizeof(ch1->sha256_hash)))
- {
- continue;
- }
- else
- {
- return false;
- }
- }
- return true;
- }
- else if (!chs1 && !chs2)
- {
- return true;
- }
- else
- {
- return false;
- }
- }
- static struct cert_hash_set *
- cert_hash_copy(const struct cert_hash_set *chs)
- {
- struct cert_hash_set *dest = NULL;
- if (chs)
- {
- int i;
- ALLOC_OBJ_CLEAR(dest, struct cert_hash_set);
- for (i = 0; i < MAX_CERT_DEPTH; ++i)
- {
- const struct cert_hash *ch = chs->ch[i];
- if (ch)
- {
- ALLOC_OBJ(dest->ch[i], struct cert_hash);
- memcpy(dest->ch[i]->sha256_hash, ch->sha256_hash,
- sizeof(dest->ch[i]->sha256_hash));
- }
- }
- }
- return dest;
- }
- void
- tls_lock_cert_hash_set(struct tls_multi *multi)
- {
- const struct cert_hash_set *chs = multi->session[TM_ACTIVE].cert_hash_set;
- if (chs && !multi->locked_cert_hash_set)
- {
- multi->locked_cert_hash_set = cert_hash_copy(chs);
- }
- }
- /*
- * Returns the string associated with the given certificate type.
- */
- static const char *
- print_nsCertType(int type)
- {
- switch (type)
- {
- case NS_CERT_CHECK_SERVER:
- return "SERVER";
- case NS_CERT_CHECK_CLIENT:
- return "CLIENT";
- default:
- return "?";
- }
- }
- /*
- * Verify the peer's certificate fields.
- *
- * @param opt the tls options to verify against
- * @param peer_cert the peer's certificate
- * @param subject the peer's extracted subject name
- * @param subject the peer's extracted common name
- */
- static result_t
- verify_peer_cert(const struct tls_options *opt, openvpn_x509_cert_t *peer_cert,
- const char *subject, const char *common_name)
- {
- /* verify certificate nsCertType */
- if (opt->ns_cert_type != NS_CERT_CHECK_NONE)
- {
- if (SUCCESS == x509_verify_ns_cert_type(peer_cert, opt->ns_cert_type))
- {
- msg(D_HANDSHAKE, "VERIFY OK: nsCertType=%s",
- print_nsCertType(opt->ns_cert_type));
- }
- else
- {
- msg(D_HANDSHAKE, "VERIFY nsCertType ERROR: %s, require nsCertType=%s",
- subject, print_nsCertType(opt->ns_cert_type));
- return FAILURE; /* Reject connection */
- }
- }
- /* verify certificate ku */
- if (opt->remote_cert_ku[0] != 0)
- {
- if (SUCCESS == x509_verify_cert_ku(peer_cert, opt->remote_cert_ku, MAX_PARMS))
- {
- msg(D_HANDSHAKE, "VERIFY KU OK");
- }
- else
- {
- msg(D_HANDSHAKE, "VERIFY KU ERROR");
- return FAILURE; /* Reject connection */
- }
- }
- /* verify certificate eku */
- if (opt->remote_cert_eku != NULL)
- {
- if (SUCCESS == x509_verify_cert_eku(peer_cert, opt->remote_cert_eku))
- {
- msg(D_HANDSHAKE, "VERIFY EKU OK");
- }
- else
- {
- msg(D_HANDSHAKE, "VERIFY EKU ERROR");
- return FAILURE; /* Reject connection */
- }
- }
- /* verify X509 name or username against --verify-x509-[user]name */
- if (opt->verify_x509_type != VERIFY_X509_NONE)
- {
- if ( (opt->verify_x509_type == VERIFY_X509_SUBJECT_DN
- && strcmp(opt->verify_x509_name, subject) == 0)
- || (opt->verify_x509_type == VERIFY_X509_SUBJECT_RDN
- && strcmp(opt->verify_x509_name, common_name) == 0)
- || (opt->verify_x509_type == VERIFY_X509_SUBJECT_RDN_PREFIX
- && strncmp(opt->verify_x509_name, common_name,
- strlen(opt->verify_x509_name)) == 0) )
- {
- msg(D_HANDSHAKE, "VERIFY X509NAME OK: %s", subject);
- }
- else
- {
- msg(D_HANDSHAKE, "VERIFY X509NAME ERROR: %s, must be %s",
- subject, opt->verify_x509_name);
- return FAILURE; /* Reject connection */
- }
- }
- return SUCCESS;
- }
- /*
- * Export the subject, common_name, and raw certificate fields to the
- * environment for later verification by scripts and plugins.
- */
- static void
- verify_cert_set_env(struct env_set *es, openvpn_x509_cert_t *peer_cert, int cert_depth,
- const char *subject, const char *common_name,
- const struct x509_track *x509_track)
- {
- char envname[64];
- char *serial = NULL;
- struct gc_arena gc = gc_new();
- /* Save X509 fields in environment */
- if (x509_track)
- {
- x509_setenv_track(x509_track, es, cert_depth, peer_cert);
- }
- else
- {
- x509_setenv(es, cert_depth, peer_cert);
- }
- /* export subject name string as environmental variable */
- openvpn_snprintf(envname, sizeof(envname), "tls_id_%d", cert_depth);
- setenv_str(es, envname, subject);
- #if 0
- /* export common name string as environmental variable */
- openvpn_snprintf(envname, sizeof(envname), "tls_common_name_%d", cert_depth);
- setenv_str(es, envname, common_name);
- #endif
- /* export X509 cert fingerprints */
- {
- struct buffer sha1 = x509_get_sha1_fingerprint(peer_cert, &gc);
- struct buffer sha256 = x509_get_sha256_fingerprint(peer_cert, &gc);
- openvpn_snprintf(envname, sizeof(envname), "tls_digest_%d", cert_depth);
- setenv_str(es, envname,
- format_hex_ex(BPTR(&sha1), BLEN(&sha1), 0, 1, ":", &gc));
- openvpn_snprintf(envname, sizeof(envname), "tls_digest_sha256_%d",
- cert_depth);
- setenv_str(es, envname,
- format_hex_ex(BPTR(&sha256), BLEN(&sha256), 0, 1, ":", &gc));
- }
- /* export serial number as environmental variable */
- serial = backend_x509_get_serial(peer_cert, &gc);
- openvpn_snprintf(envname, sizeof(envname), "tls_serial_%d", cert_depth);
- setenv_str(es, envname, serial);
- /* export serial number in hex as environmental variable */
- serial = backend_x509_get_serial_hex(peer_cert, &gc);
- openvpn_snprintf(envname, sizeof(envname), "tls_serial_hex_%d", cert_depth);
- setenv_str(es, envname, serial);
- gc_free(&gc);
- }
- /*
- * call --tls-verify plug-in(s)
- */
- static result_t
- verify_cert_call_plugin(const struct plugin_list *plugins, struct env_set *es,
- int cert_depth, openvpn_x509_cert_t *cert, char *subject)
- {
- if (plugin_defined(plugins, OPENVPN_PLUGIN_TLS_VERIFY))
- {
- int ret;
- struct argv argv = argv_new();
- argv_printf(&argv, "%d %s", cert_depth, subject);
- ret = plugin_call_ssl(plugins, OPENVPN_PLUGIN_TLS_VERIFY, &argv, NULL, es, cert_depth, cert);
- argv_reset(&argv);
- if (ret == OPENVPN_PLUGIN_FUNC_SUCCESS)
- {
- msg(D_HANDSHAKE, "VERIFY PLUGIN OK: depth=%d, %s",
- cert_depth, subject);
- }
- else
- {
- msg(D_HANDSHAKE, "VERIFY PLUGIN ERROR: depth=%d, %s",
- cert_depth, subject);
- return FAILURE; /* Reject connection */
- }
- }
- return SUCCESS;
- }
- static const char *
- verify_cert_export_cert(openvpn_x509_cert_t *peercert, const char *tmp_dir, struct gc_arena *gc)
- {
- FILE *peercert_file;
- const char *peercert_filename = "";
- /* create tmp file to store peer cert */
- if (!tmp_dir
- || !(peercert_filename = create_temp_file(tmp_dir, "pcf", gc)))
- {
- msg (M_WARN, "Failed to create peer cert file");
- return NULL;
- }
- /* write peer-cert in tmp-file */
- peercert_file = fopen(peercert_filename, "w+");
- if (!peercert_file)
- {
- msg(M_ERR, "Failed to open temporary file : %s", peercert_filename);
- return NULL;
- }
- if (SUCCESS != x509_write_pem(peercert_file, peercert))
- {
- msg(M_ERR, "Error writing PEM file containing certificate");
- }
- fclose(peercert_file);
- return peercert_filename;
- }
- /*
- * run --tls-verify script
- */
- static result_t
- verify_cert_call_command(const char *verify_command, struct env_set *es,
- int cert_depth, openvpn_x509_cert_t *cert, char *subject, const char *verify_export_cert)
- {
- const char *tmp_file = NULL;
- int ret;
- struct gc_arena gc = gc_new();
- struct argv argv = argv_new();
- setenv_str(es, "script_type", "tls-verify");
- if (verify_export_cert)
- {
- tmp_file = verify_cert_export_cert(cert, verify_export_cert, &gc);
- if (!tmp_file)
- {
- ret = false;
- goto cleanup;
- }
- setenv_str(es, "peer_cert", tmp_file);
- }
- argv_parse_cmd(&argv, verify_command);
- argv_printf_cat(&argv, "%d %s", cert_depth, subject);
- argv_msg_prefix(D_TLS_DEBUG, &argv, "TLS: executing verify command");
- ret = openvpn_run_script(&argv, es, 0, "--tls-verify script");
- if (verify_export_cert)
- {
- if (tmp_file)
- {
- platform_unlink(tmp_file);
- }
- }
- cleanup:
- gc_free(&gc);
- argv_reset(&argv);
- if (ret)
- {
- msg(D_HANDSHAKE, "VERIFY SCRIPT OK: depth=%d, %s",
- cert_depth, subject);
- return SUCCESS;
- }
- msg(D_HANDSHAKE, "VERIFY SCRIPT ERROR: depth=%d, %s",
- cert_depth, subject);
- return FAILURE; /* Reject connection */
- }
- /*
- * check peer cert against CRL directory
- */
- static result_t
- verify_check_crl_dir(const char *crl_dir, openvpn_x509_cert_t *cert)
- {
- result_t ret = FAILURE;
- char fn[256];
- int fd = -1;
- struct gc_arena gc = gc_new();
- char *serial = backend_x509_get_serial(cert, &gc);
- if (!openvpn_snprintf(fn, sizeof(fn), "%s%c%s", crl_dir, OS_SPECIFIC_DIRSEP, serial))
- {
- msg(D_HANDSHAKE, "VERIFY CRL: filename overflow");
- goto cleanup;
- }
- fd = platform_open(fn, O_RDONLY, 0);
- if (fd >= 0)
- {
- msg(D_HANDSHAKE, "VERIFY CRL: certificate serial number %s is revoked", serial);
- goto cleanup;
- }
- ret = SUCCESS;
- cleanup:
- if (fd != -1)
- {
- close(fd);
- }
- gc_free(&gc);
- return ret;
- }
- result_t
- verify_cert(struct tls_session *session, openvpn_x509_cert_t *cert, int cert_depth)
- {
- result_t ret = FAILURE;
- char *subject = NULL;
- char common_name[TLS_USERNAME_LEN+1] = {0}; /* null-terminated */
- const struct tls_options *opt;
- struct gc_arena gc = gc_new();
- opt = session->opt;
- ASSERT(opt);
- session->verified = false;
- /* get the X509 name */
- subject = x509_get_subject(cert, &gc);
- if (!subject)
- {
- msg(D_TLS_ERRORS, "VERIFY ERROR: depth=%d, could not extract X509 "
- "subject string from certificate", cert_depth);
- goto cleanup;
- }
- /* enforce character class restrictions in X509 name */
- string_mod_remap_name(subject, X509_NAME_CHAR_CLASS);
- string_replace_leading(subject, '-', '_');
- /* extract the username (default is CN) */
- if (SUCCESS != backend_x509_get_username(common_name, sizeof(common_name),
- opt->x509_username_field, cert))
- {
- if (!cert_depth)
- {
- msg(D_TLS_ERRORS, "VERIFY ERROR: could not extract %s from X509 "
- "subject string ('%s') -- note that the username length is "
- "limited to %d characters",
- opt->x509_username_field,
- subject,
- TLS_USERNAME_LEN);
- goto cleanup;
- }
- }
- /* enforce character class restrictions in common name */
- string_mod_remap_name(common_name, COMMON_NAME_CHAR_CLASS);
- /* warn if cert chain is too deep */
- if (cert_depth >= MAX_CERT_DEPTH)
- {
- msg(D_TLS_ERRORS, "TLS Error: Convoluted certificate chain detected with depth [%d] greater than %d", cert_depth, MAX_CERT_DEPTH);
- goto cleanup; /* Reject connection */
- }
- /* verify level 1 cert, i.e. the CA that signed our leaf cert */
- if (cert_depth == 1 && opt->verify_hash)
- {
- struct buffer ca_hash = {0};
- switch (opt->verify_hash_algo)
- {
- case MD_SHA1:
- ca_hash = x509_get_sha1_fingerprint(cert, &gc);
- break;
- case MD_SHA256:
- ca_hash = x509_get_sha256_fingerprint(cert, &gc);
- break;
- default:
- /* This should normally not happen at all; the algorithm used
- * is parsed by add_option() [options.c] and set to a predefined
- * value in an enumerated type. So if this unlikely scenario
- * happens, consider this a failure
- */
- msg(M_WARN, "Unexpected invalid algorithm used with "
- "--verify-hash (%i)", opt->verify_hash_algo);
- ret = FAILURE;
- goto cleanup;
- }
- if (memcmp(BPTR(&ca_hash), opt->verify_hash, BLEN(&ca_hash)))
- {
- msg(D_TLS_ERRORS, "TLS Error: level-1 certificate hash verification failed");
- goto cleanup;
- }
- }
- /* save common name in session object */
- if (cert_depth == 0)
- {
- set_common_name(session, common_name);
- }
- session->verify_maxlevel = max_int(session->verify_maxlevel, cert_depth);
- /* export certificate values to the environment */
- verify_cert_set_env(opt->es, cert, cert_depth, subject, common_name,
- opt->x509_track);
- /* export current untrusted IP */
- setenv_untrusted(session);
- /* If this is the peer's own certificate, verify it */
- if (cert_depth == 0 && SUCCESS != verify_peer_cert(opt, cert, subject, common_name))
- {
- goto cleanup;
- }
- /* call --tls-verify plug-in(s), if registered */
- if (SUCCESS != verify_cert_call_plugin(opt->plugins, opt->es, cert_depth, cert, subject))
- {
- goto cleanup;
- }
- /* run --tls-verify script */
- if (opt->verify_command && SUCCESS != verify_cert_call_command(opt->verify_command,
- opt->es, cert_depth, cert, subject, opt->verify_export_cert))
- {
- goto cleanup;
- }
- /* check peer cert against CRL */
- if (opt->crl_file)
- {
- if (opt->ssl_flags & SSLF_CRL_VERIFY_DIR)
- {
- if (SUCCESS != verify_check_crl_dir(opt->crl_file, cert))
- {
- goto cleanup;
- }
- }
- else
- {
- if (tls_verify_crl_missing(opt))
- {
- msg(D_TLS_ERRORS, "VERIFY ERROR: CRL not loaded");
- goto cleanup;
- }
- }
- }
- msg(D_HANDSHAKE, "VERIFY OK: depth=%d, %s", cert_depth, subject);
- session->verified = true;
- ret = SUCCESS;
- cleanup:
- if (ret != SUCCESS)
- {
- tls_clear_error(); /* always? */
- session->verified = false; /* double sure? */
- }
- gc_free(&gc);
- return ret;
- }
- /* ***************************************************************************
- * Functions for the management of deferred authentication when using
- * user/password authentication.
- *************************************************************************** */
- #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
- 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))
- {
- /* FIXME: Last alloc will never be freed */
- 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 MANAGEMENT_DEF_AUTH */
- #ifdef PLUGIN_DEF_AUTH
- /*
- * auth_control_file functions
- */
- void
- key_state_rm_auth_control_file(struct key_state *ks)
- {
- if (ks && ks->auth_control_file)
- {
- platform_unlink(ks->auth_control_file);
- free(ks->auth_control_file);
- ks->auth_control_file = NULL;
- }
- }
- static bool
- key_state_gen_auth_control_file(struct key_state *ks, const struct tls_options *opt)
- {
- struct gc_arena gc = gc_new();
- key_state_rm_auth_control_file(ks);
- const char *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);
- }
- gc_free(&gc);
- return acf;
- }
- 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 /* ifdef PLUGIN_DEF_AUTH */
- /*
- * 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 /* ENABLE_DEF_AUTH */
- 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 /* ENABLE_DEF_AUTH */
- 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 /* PLUGIN_DEF_AUTH */
- #ifdef MANAGEMENT_DEF_AUTH
- s2 = man_def_auth_test(ks);
- #endif /* MANAGEMENT_DEF_AUTH */
- 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 /* !ENABLE_DEF_AUTH */
- success = true;
- #endif /* ENABLE_DEF_AUTH */
- }
- }
- }
- }
- #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 /* ifdef MANAGEMENT_DEF_AUTH */
- /* ****************************************************************************
- * Functions to verify username and password
- *
- * Authenticate a client using username/password.
- * Runs on server.
- *
- * If you want to add new authentication methods,
- * this is the place to start.
- *************************************************************************** */
- /*
- * Verify the user name and password using a script
- */
- 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_parse_cmd(&argv, session->opt->auth_user_pass_verify_script);
- argv_printf_cat(&argv, "%s", 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)
- {
- platform_unlink(tmp_file);
- }
- argv_reset(&argv);
- gc_free(&gc);
- return ret;
- }
- /*
- * Verify the username and password using a plugin
- */
- 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;
- #ifdef PLUGIN_DEF_AUTH
- struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */
- #endif
- /* 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 ? raw_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);
- #ifdef PLUGIN_DEF_AUTH
- /* generate filename for deferred auth control file */
- if (!key_state_gen_auth_control_file(ks, session->opt))
- {
- msg (D_TLS_ERRORS, "TLS Auth Error (%s): "
- "could not create deferred auth control file", __func__);
- goto cleanup;
- }
- #endif
- /* call command */
- retval = plugin_call(session->opt->plugins, OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY, NULL, NULL, session->opt->es);
- #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");
- if (raw_username)
- {
- 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");
- }
- cleanup:
- return retval;
- }
- #ifdef MANAGEMENT_DEF_AUTH
- /*
- * MANAGEMENT_DEF_AUTH internal ssl_verify.c status codes
- */
- #define KMDA_ERROR 0
- #define KMDA_SUCCESS 1
- #define KMDA_UNDEF 2
- #define KMDA_DEF 3
- 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 ? raw_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);
- 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");
- if (raw_username)
- {
- 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 /* ifdef MANAGEMENT_DEF_AUTH */
- /*
- * Main username/password verification entry point
- */
- void
- verify_user_pass(struct user_pass *up, struct tls_multi *multi,
- struct tls_session *session)
- {
- int s1 = OPENVPN_PLUGIN_FUNC_SUCCESS;
- bool s2 = true;
- struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */
- struct gc_arena gc = gc_new();
- char *raw_username = NULL;
- #ifdef MANAGEMENT_DEF_AUTH
- int man_def_auth = KMDA_UNDEF;
- if (management_enable_def_auth(management))
- {
- man_def_auth = KMDA_DEF;
- }
- #endif
- /*
- * Preserve the raw username before string_mod remapping, for plugins
- * and management clients when in --compat-names mode
- */
- if (compat_flag(COMPAT_FLAG_QUERY | COMPAT_NAMES))
- {
- 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_remap_name(up->username, COMMON_NAME_CHAR_CLASS);
- string_mod(up->password, CC_PRINT, CC_CRLF, '_');
- /* If server is configured with --auth-gen-token and we have an
- * authentication token for this client, this authentication
- * round will be done internally using the token instead of
- * calling any external authentication modules.
- */
- if (session->opt->auth_token_generate && multi->auth_token_sent
- && NULL != multi->auth_token)
- {
- unsigned int ssl_flags = session->opt->ssl_flags;
- /* Ensure that the username has not changed */
- if (!tls_lock_username(multi, up->username))
- {
- /* auth-token cleared in tls_lock_username() on failure */
- ks->authenticated = false;
- goto done;
- }
- /* If auth-token lifetime has been enabled,
- * ensure the token has not expired
- */
- if (session->opt->auth_token_lifetime > 0
- && (multi->auth_token_tstamp + session->opt->auth_token_lifetime) < now)
- {
- msg(D_HANDSHAKE, "Auth-token for client expired\n");
- wipe_auth_token(multi);
- ks->authenticated = false;
- goto done;
- }
- /* The core authentication of the token itself */
- if (memcmp_constant_time(multi->auth_token, up->password,
- strlen(multi->auth_token)) != 0)
- {
- ks->authenticated = false;
- tls_deauthenticate(multi);
- msg(D_TLS_ERRORS, "TLS Auth Error: Auth-token verification "
- "failed for username '%s' %s", up->username,
- (ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : "");
- }
- else
- {
- ks->authenticated = true;
- if (ssl_flags & SSLF_USERNAME_AS_COMMON_NAME)
- {
- set_common_name(session, up->username);
- }
- msg(D_HANDSHAKE, "TLS: Username/auth-token authentication "
- "succeeded for username '%s' %s",
- up->username,
- (ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : "");
- }
- goto done;
- }
- /* call plugin(s) and/or script */
- #ifdef MANAGEMENT_DEF_AUTH
- 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
- #ifdef MANAGEMENT_DEF_AUTH
- && man_def_auth != KMDA_ERROR
- #endif
- && 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->auth_token_generate) && (NULL == multi->auth_token))
- {
- /* Server is configured with --auth-gen-token but no token has yet
- * been generated for this client. Generate one and save it.
- */
- uint8_t tok[AUTH_TOKEN_SIZE];
- if (!rand_bytes(tok, AUTH_TOKEN_SIZE))
- {
- msg( M_FATAL, "Failed to get enough randomness for "
- "authentication token");
- }
- /* The token should be longer than the input when
- * being base64 encoded
- */
- ASSERT(openvpn_base64_encode(tok, AUTH_TOKEN_SIZE,
- &multi->auth_token) > AUTH_TOKEN_SIZE);
- multi->auth_token_tstamp = now;
- dmsg(D_SHOW_KEYS, "Generated token for client: %s",
- multi->auth_token);
- }
- 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");
- }
- done:
- gc_free(&gc);
- }
- void
- verify_final_auth_checks(struct tls_multi *multi, struct tls_session *session)
- {
- struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */
- /* While it shouldn't really happen, don't allow the common name to be NULL */
- if (!session->common_name)
- {
- set_common_name(session, "");
- }
- /* Don't allow the CN to change once it's been locked */
- if (ks->authenticated && multi->locked_cn)
- {
- const char *cn = session->common_name;
- if (cn && strcmp(cn, multi->locked_cn))
- {
- msg(D_TLS_ERRORS, "TLS Auth Error: TLS object CN attempted to change from '%s' to '%s' -- tunnel disabled",
- multi->locked_cn,
- cn);
- /* change the common name back to its original value and disable the tunnel */
- set_common_name(session, multi->locked_cn);
- tls_deauthenticate(multi);
- }
- }
- /* Don't allow the cert hashes to change once they have been locked */
- if (ks->authenticated && multi->locked_cert_hash_set)
- {
- const struct cert_hash_set *chs = session->cert_hash_set;
- if (chs && !cert_hash_compare(chs, multi->locked_cert_hash_set))
- {
- msg(D_TLS_ERRORS, "TLS Auth Error: TLS object CN=%s client-provided SSL certs unexpectedly changed during mid-session reauth",
- session->common_name);
- /* disable the tunnel */
- tls_deauthenticate(multi);
- }
- }
- /* verify --client-config-dir based authentication */
- if (ks->authenticated && session->opt->client_config_dir_exclusive)
- {
- struct gc_arena gc = gc_new();
- const char *cn = session->common_name;
- const char *path = gen_path(session->opt->client_config_dir_exclusive, cn, &gc);
- if (!cn || !strcmp(cn, CCD_DEFAULT) || !test_file(path))
- {
- ks->authenticated = false;
- wipe_auth_token(multi);
- msg(D_TLS_ERRORS, "TLS Auth Error: --client-config-dir authentication failed for common name '%s' file='%s'",
- session->common_name,
- path ? path : "UNDEF");
- }
- gc_free(&gc);
- }
- }
- void
- tls_x509_clear_env(struct env_set *es)
- {
- struct env_item *item = es->list;
- while (item)
- {
- struct env_item *next = item->next;
- if (item->string
- && 0 == strncmp("X509_", item->string, strlen("X509_")))
- {
- env_set_del(es, item->string);
- }
- item = next;
- }
- }
- #endif /* ENABLE_CRYPTO */