tls_openssl.c

IEEE 802.11a/b/g 服务器端AP

	const char *str;
	int w;

	wpa_printf(MSG_DEBUG, "SSL: (where=0x%x ret=0x%x)", where, ret);
	w = where & ~SSL_ST_MASK;
	if (w & SSL_ST_CONNECT)
		str = "SSL_connect";
	else if (w & SSL_ST_ACCEPT)
		str = "SSL_accept";
	else
		str = "undefined";

	if (where & SSL_CB_LOOP) {
		wpa_printf(MSG_DEBUG, "SSL: %s:%s",
			   str, SSL_state_string_long(ssl));
	} else if (where & SSL_CB_ALERT) {
		wpa_printf(MSG_INFO, "SSL: SSL3 alert: %s:%s:%s",
			   where & SSL_CB_READ ?
			   "read (remote end reported an error)" :
			   "write (local SSL3 detected an error)",
			   SSL_alert_type_string_long(ret),
			   SSL_alert_desc_string_long(ret));
		if ((ret >> 8) == SSL3_AL_FATAL) {
			struct tls_connection *conn =
				SSL_get_app_data((SSL *) ssl);
			if (where & SSL_CB_READ)
				conn->read_alerts++;
			else
				conn->write_alerts++;
		}
	} else if (where & SSL_CB_EXIT && ret <= 0) {
		wpa_printf(MSG_DEBUG, "SSL: %s:%s in %s",
			   str, ret == 0 ? "failed" : "error",
			   SSL_state_string_long(ssl));
	}
}


#ifndef OPENSSL_NO_ENGINE
/**
 * tls_engine_load_dynamic_generic - load any openssl engine
 * @pre: an array of commands and values that load an engine initialized
 *       in the engine specific function
 * @post: an array of commands and values that initialize an already loaded
 *        engine (or %NULL if not required)
 * @id: the engine id of the engine to load (only required if post is not %NULL
 *
 * This function is a generic function that loads any openssl engine.
 *
 * Returns: 0 on success, -1 on failure
 */
static int tls_engine_load_dynamic_generic(const char *pre[],
					   const char *post[], const char *id)
{
	ENGINE *engine;
	const char *dynamic_id = "dynamic";

	engine = ENGINE_by_id(id);
	if (engine) {
		ENGINE_free(engine);
		wpa_printf(MSG_DEBUG, "ENGINE: engine '%s' is already "
			   "available", id);
		return 0;
	}
	ERR_clear_error();

	engine = ENGINE_by_id(dynamic_id);
	if (engine == NULL) {
		wpa_printf(MSG_INFO, "ENGINE: Can't find engine %s [%s]",
			   dynamic_id,
			   ERR_error_string(ERR_get_error(), NULL));
		return -1;
	}

	/* Perform the pre commands. This will load the engine. */
	while (pre && pre[0]) {
		wpa_printf(MSG_DEBUG, "ENGINE: '%s' '%s'", pre[0], pre[1]);
		if (ENGINE_ctrl_cmd_string(engine, pre[0], pre[1], 0) == 0) {
			wpa_printf(MSG_INFO, "ENGINE: ctrl cmd_string failed: "
				   "%s %s [%s]", pre[0], pre[1],
				   ERR_error_string(ERR_get_error(), NULL));
			ENGINE_free(engine);
			return -1;
		}
		pre += 2;
	}

	/*
	 * Free the reference to the "dynamic" engine. The loaded engine can
	 * now be looked up using ENGINE_by_id().
	 */
	ENGINE_free(engine);

	engine = ENGINE_by_id(id);
	if (engine == NULL) {
		wpa_printf(MSG_INFO, "ENGINE: Can't find engine %s [%s]",
			   id, ERR_error_string(ERR_get_error(), NULL));
		return -1;
	}

	while (post && post[0]) {
		wpa_printf(MSG_DEBUG, "ENGINE: '%s' '%s'", post[0], post[1]);
		if (ENGINE_ctrl_cmd_string(engine, post[0], post[1], 0) == 0) {
			wpa_printf(MSG_DEBUG, "ENGINE: ctrl cmd_string failed:"
				" %s %s [%s]", post[0], post[1],
				   ERR_error_string(ERR_get_error(), NULL));
			ENGINE_remove(engine);
			ENGINE_free(engine);
			return -1;
		}
		post += 2;
	}
	ENGINE_free(engine);

	return 0;
}


/**
 * tls_engine_load_dynamic_pkcs11 - load the pkcs11 engine provided by opensc
 * @pkcs11_so_path: pksc11_so_path from the configuration
 * @pcks11_module_path: pkcs11_module_path from the configuration
 */
static int tls_engine_load_dynamic_pkcs11(const char *pkcs11_so_path,
					  const char *pkcs11_module_path)
{
	char *engine_id = "pkcs11";
	const char *pre_cmd[] = {
		"SO_PATH", NULL /* pkcs11_so_path */,
		"ID", NULL /* engine_id */,
		"LIST_ADD", "1",
		/* "NO_VCHECK", "1", */
		"LOAD", NULL,
		NULL, NULL
	};
	const char *post_cmd[] = {
		"MODULE_PATH", NULL /* pkcs11_module_path */,
		NULL, NULL
	};

	if (!pkcs11_so_path || !pkcs11_module_path)
		return 0;

	pre_cmd[1] = pkcs11_so_path;
	pre_cmd[3] = engine_id;
	post_cmd[1] = pkcs11_module_path;

	wpa_printf(MSG_DEBUG, "ENGINE: Loading pkcs11 Engine from %s",
		   pkcs11_so_path);

	return tls_engine_load_dynamic_generic(pre_cmd, post_cmd, engine_id);
}


/**
 * tls_engine_load_dynamic_opensc - load the opensc engine provided by opensc
 * @opensc_so_path: opensc_so_path from the configuration
 */
static int tls_engine_load_dynamic_opensc(const char *opensc_so_path)
{
	char *engine_id = "opensc";
	const char *pre_cmd[] = {
		"SO_PATH", NULL /* opensc_so_path */,
		"ID", NULL /* engine_id */,
		"LIST_ADD", "1",
		"LOAD", NULL,
		NULL, NULL
	};

	if (!opensc_so_path)
		return 0;

	pre_cmd[1] = opensc_so_path;
	pre_cmd[3] = engine_id;

	wpa_printf(MSG_DEBUG, "ENGINE: Loading OpenSC Engine from %s",
		   opensc_so_path);

	return tls_engine_load_dynamic_generic(pre_cmd, NULL, engine_id);
}
#endif /* OPENSSL_NO_ENGINE */


void * tls_init(const struct tls_config *conf)
{
	SSL_CTX *ssl;

	if (tls_openssl_ref_count == 0) {
		SSL_load_error_strings();
		SSL_library_init();
		/* TODO: if /dev/urandom is available, PRNG is seeded
		 * automatically. If this is not the case, random data should
		 * be added here. */

#ifdef PKCS12_FUNCS
		PKCS12_PBE_add();
#endif  /* PKCS12_FUNCS */
	}
	tls_openssl_ref_count++;

	ssl = SSL_CTX_new(TLSv1_method());
	if (ssl == NULL)
		return NULL;

	SSL_CTX_set_info_callback(ssl, ssl_info_cb);

#ifndef OPENSSL_NO_ENGINE
	if (conf &&
	    (conf->opensc_engine_path || conf->pkcs11_engine_path ||
	     conf->pkcs11_module_path)) {
		wpa_printf(MSG_DEBUG, "ENGINE: Loading dynamic engine");
		ERR_load_ENGINE_strings();
		ENGINE_load_dynamic();

		if (tls_engine_load_dynamic_opensc(conf->opensc_engine_path) ||
		    tls_engine_load_dynamic_pkcs11(conf->pkcs11_engine_path,
						   conf->pkcs11_module_path)) {
			tls_deinit(ssl);
			return NULL;
		}
	}
#endif /* OPENSSL_NO_ENGINE */

	return ssl;
}


void tls_deinit(void *ssl_ctx)
{
	SSL_CTX *ssl = ssl_ctx;
	SSL_CTX_free(ssl);

	tls_openssl_ref_count--;
	if (tls_openssl_ref_count == 0) {
#ifndef OPENSSL_NO_ENGINE
		ENGINE_cleanup();
#endif /* OPENSSL_NO_ENGINE */
		CRYPTO_cleanup_all_ex_data();
		ERR_remove_state(0);
		ERR_free_strings();
		EVP_cleanup();
	}
}


static int tls_engine_init(struct tls_connection *conn, const char *engine_id,
			   const char *pin, const char *key_id,
			   const char *cert_id, const char *ca_cert_id)
{
#ifndef OPENSSL_NO_ENGINE
	int ret = -1;
	if (engine_id == NULL) {
		wpa_printf(MSG_ERROR, "ENGINE: Engine ID not set");
		return -1;
	}
	if (pin == NULL) {
		wpa_printf(MSG_ERROR, "ENGINE: Smartcard PIN not set");
		return -1;
	}
	if (key_id == NULL) {
		wpa_printf(MSG_ERROR, "ENGINE: Key Id not set");
		return -1;
	}

	ERR_clear_error();
	conn->engine = ENGINE_by_id(engine_id);
	if (!conn->engine) {
		wpa_printf(MSG_ERROR, "ENGINE: engine %s not available [%s]",
			   engine_id, ERR_error_string(ERR_get_error(), NULL));
		goto err;
	}
	if (ENGINE_init(conn->engine) != 1) {
		wpa_printf(MSG_ERROR, "ENGINE: engine init failed "
			   "(engine: %s) [%s]", engine_id,
			   ERR_error_string(ERR_get_error(), NULL));
		goto err;
	}
	wpa_printf(MSG_DEBUG, "ENGINE: engine initialized");

	if (ENGINE_ctrl_cmd_string(conn->engine, "PIN", pin, 0) == 0) {
		wpa_printf(MSG_ERROR, "ENGINE: cannot set pin [%s]",
			   ERR_error_string(ERR_get_error(), NULL));
		goto err;
	}
	/* load private key first in-case PIN is required for cert */
	conn->private_key = ENGINE_load_private_key(conn->engine,
						    key_id, NULL, NULL);
	if (!conn->private_key) {
		wpa_printf(MSG_ERROR, "ENGINE: cannot load private key with id"
				" '%s' [%s]", key_id,
			   ERR_error_string(ERR_get_error(), NULL));
		ret = TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED;
		goto err;
	}

	/* handle a certificate and/or CA certificate */
	if (cert_id || ca_cert_id) {
		const char *cmd_name = "LOAD_CERT_CTRL";

		/* test if the engine supports a LOAD_CERT_CTRL */
		if (!ENGINE_ctrl(conn->engine, ENGINE_CTRL_GET_CMD_FROM_NAME,
				 0, (void *)cmd_name, NULL)) {
			wpa_printf(MSG_ERROR, "ENGINE: engine does not support"
				   " loading certificates");
			ret = TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED;
			goto err;
		}
	}

	return 0;

err:
	if (conn->engine) {
		ENGINE_free(conn->engine);
		conn->engine = NULL;
	}

	if (conn->private_key) {
		EVP_PKEY_free(conn->private_key);
		conn->private_key = NULL;
	}

	return ret;
#else /* OPENSSL_NO_ENGINE */
	return 0;
#endif /* OPENSSL_NO_ENGINE */
}


static void tls_engine_deinit(struct tls_connection *conn)
{
#ifndef OPENSSL_NO_ENGINE
	wpa_printf(MSG_DEBUG, "ENGINE: engine deinit");
	if (conn->private_key) {
		EVP_PKEY_free(conn->private_key);
		conn->private_key = NULL;
	}
	if (conn->engine) {
		ENGINE_finish(conn->engine);
		conn->engine = NULL;
	}
#endif /* OPENSSL_NO_ENGINE */
}


int tls_get_errors(void *ssl_ctx)
{
	int count = 0;
	unsigned long err;

	while ((err = ERR_get_error())) {
		wpa_printf(MSG_INFO, "TLS - SSL error: %s",
			   ERR_error_string(err, NULL));
		count++;
	}

	return count;
}

struct tls_connection * tls_connection_init(void *ssl_ctx)
{
	SSL_CTX *ssl = ssl_ctx;
	struct tls_connection *conn;
	long options;

	conn = os_zalloc(sizeof(*conn));
	if (conn == NULL)
		return NULL;
	conn->ssl = SSL_new(ssl);
	if (conn->ssl == NULL) {
		tls_show_errors(MSG_INFO, __func__,
				"Failed to initialize new SSL connection");
		os_free(conn);
		return NULL;
	}

	SSL_set_app_data(conn->ssl, conn);
	options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 |
		SSL_OP_SINGLE_DH_USE;
#ifdef SSL_OP_NO_COMPRESSION
	options |= SSL_OP_NO_COMPRESSION;
#endif /* SSL_OP_NO_COMPRESSION */
	SSL_set_options(conn->ssl, options);

	conn->ssl_in = BIO_new(BIO_s_mem());
	if (!conn->ssl_in) {
		tls_show_errors(MSG_INFO, __func__,
				"Failed to create a new BIO for ssl_in");
		SSL_free(conn->ssl);
		os_free(conn);
		return NULL;
	}

	conn->ssl_out = BIO_new(BIO_s_mem());
	if (!conn->ssl_out) {
		tls_show_errors(MSG_INFO, __func__,
				"Failed to create a new BIO for ssl_out");
		SSL_free(conn->ssl);
		BIO_free(conn->ssl_in);
		os_free(conn);
		return NULL;
	}

	SSL_set_bio(conn->ssl, conn->ssl_in, conn->ssl_out);

	return conn;
}


void tls_connection_deinit(void *ssl_ctx, struct tls_connection *conn)
{
	if (conn == NULL)
		return;
	SSL_free(conn->ssl);
	tls_engine_deinit(conn);
	os_free(conn->subject_match);
	os_free(conn->altsubject_match);
	os_free(conn->session_ticket);
	os_free(conn);
}


int tls_connection_established(void *ssl_ctx, struct tls_connection *conn)
{
	return conn ? SSL_is_init_finished(conn->ssl) : 0;
}


int tls_connection_shutdown(void *ssl_ctx, struct tls_connection *conn)
{
	if (conn == NULL)
		return -1;

	/* Shutdown previous TLS connection without notifying the peer
	 * because the connection was already terminated in practice
	 * and "close notify" shutdown alert would confuse AS. */
	SSL_set_quiet_shutdown(conn->ssl, 1);
	SSL_shutdown(conn->ssl);
	return 0;
}


static int tls_match_altsubject_component(X509 *cert, int type,
					  const char *value, size_t len)
{
	GENERAL_NAME *gen;
	void *ext;
	int i, found = 0;

	ext = X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL);

	for (i = 0; ext && i < sk_GENERAL_NAME_num(ext); i++) {
		gen = sk_GENERAL_NAME_value(ext, i);
		if (gen->type != type)
			continue;
		if (os_strlen((char *) gen->d.ia5->data) == len &&
		    os_memcmp(value, gen->d.ia5->data, len) == 0)
			found++;
	}

	return found;
}


static int tls_match_altsubject(X509 *cert, const char *match)
{
	int type;
	const char *pos, *end;
	size_t len;

	pos = match;
	do {
		if (os_strncmp(pos, "EMAIL:", 6) == 0) {
			type = GEN_EMAIL;
			pos += 6;
		} else if (os_strncmp(pos, "DNS:", 4) == 0) {
			type = GEN_DNS;
			pos += 4;
		} else if (os_strncmp(pos, "URI:", 4) == 0) {
			type = GEN_URI;
			pos += 4;
		} else {
			wpa_printf(MSG_INFO, "TLS: Invalid altSubjectName "
				   "match '%s'", pos);
			return 0;
		}
		end = os_strchr(pos, ';');
		while (end) {
			if (os_strncmp(end + 1, "EMAIL:", 6) == 0 ||
			    os_strncmp(end + 1, "DNS:", 4) == 0 ||
			    os_strncmp(end + 1, "URI:", 4) == 0)
				break;
			end = os_strchr(end + 1, ';');
		}
		if (end)
			len = end - pos;
		else
			len = os_strlen(pos);
		if (tls_match_altsubject_component(cert, type, pos, len) > 0)
			return 1;
		pos = end + 1;
	} while (end);

	return 0;
}


static int tls_verify_cb(int preverify_ok, X509_STORE_CTX *x509_ctx)
{
	char buf[256];
	X509 *err_cert;
	int err, depth;
	SSL *ssl;
	struct tls_connection *conn;
	char *match, *altmatch;

	err_cert = X509_STORE_CTX_get_current_cert(x509_ctx);
	err = X509_STORE_CTX_get_error(x509_ctx);
	depth = X509_STORE_CTX_get_error_depth(x509_ctx);
	ssl = X509_STORE_CTX_get_ex_data(x509_ctx,
					 SSL_get_ex_data_X509_STORE_CTX_idx());
	X509_NAME_oneline(X509_get_subject_name(err_cert), buf, sizeof(buf));

	conn = SSL_get_app_data(ssl);
	match = conn ? conn->subject_match : NULL;
	altmatch = conn ? conn->altsubject_match : NULL;

	if (!preverify_ok) {
		wpa_printf(MSG_WARNING, "TLS: Certificate verification failed,"
			   " error %d (%s) depth %d for '%s'", err,
			   X509_verify_cert_error_string(err), depth, buf);
	} else {
		wpa_printf(MSG_DEBUG, "TLS: tls_verify_cb - "