tls_openssl.c

hostapd源代码

 * 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 */
		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)
{
#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;
	}
	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;
	}
	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;

	conn = wpa_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");
		free(conn);
		return NULL;
	}

	SSL_set_app_data(conn->ssl, conn);
	SSL_set_options(conn->ssl,
			SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 |
			SSL_OP_SINGLE_DH_USE);

	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);
		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);
		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;
	free(conn->pre_shared_secret);
	SSL_free(conn->ssl);
	tls_engine_deinit(conn);
	free(conn->subject_match);
	free(conn->altsubject_match);
	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(X509 *cert, const char *match)
{
	GENERAL_NAME *gen;
	char *field, *tmp;
	void *ext;
	int i, found = 0;
	size_t len;

	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);
		switch (gen->type) {
		case GEN_EMAIL:
			field = "EMAIL";
			break;
		case GEN_DNS:
			field = "DNS";
			break;
		case GEN_URI:
			field = "URI";
			break;
		default:
			field = NULL;
			wpa_printf(MSG_DEBUG, "TLS: altSubjectName: "
				   "unsupported type=%d", gen->type);
			break;
		}

		if (!field)
			continue;

		wpa_printf(MSG_DEBUG, "TLS: altSubjectName: %s:%s",
			   field, gen->d.ia5->data);
		len = strlen(field) + 1 + strlen((char *) gen->d.ia5->data) +
			1;
		tmp = malloc(len);
		if (tmp == NULL)
			continue;
		snprintf(tmp, len, "%s:%s", field, gen->d.ia5->data);
		if (strstr(tmp, match))
			found++;
		free(tmp);
	}

	return found;
}


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 - "
			   "preverify_ok=%d err=%d (%s) depth=%d buf='%s'",
			   preverify_ok, err,
			   X509_verify_cert_error_string(err), depth, buf);
		if (depth == 0 && match && strstr(buf, match) == NULL) {
			wpa_printf(MSG_WARNING, "TLS: Subject '%s' did not "
				   "match with '%s'", buf, match);
			preverify_ok = 0;
		} else if (depth == 0 && altmatch &&
			   !tls_match_altsubject(err_cert, altmatch)) {
			wpa_printf(MSG_WARNING, "TLS: altSubjectName match "
				   "'%s' not found", altmatch);
			preverify_ok = 0;
		}
	}

	return preverify_ok;
}


#ifndef OPENSSL_NO_STDIO
static int tls_load_ca_der(void *_ssl_ctx, const char *ca_cert)
{
	SSL_CTX *ssl_ctx = _ssl_ctx;
	X509_LOOKUP *lookup;
	int ret = 0;

	lookup = X509_STORE_add_lookup(ssl_ctx->cert_store,
				       X509_LOOKUP_file());
	if (lookup == NULL) {
		tls_show_errors(MSG_WARNING, __func__,
				"Failed add lookup for X509 store");
		return -1;
	}

	if (!X509_LOOKUP_load_file(lookup, ca_cert, X509_FILETYPE_ASN1)) {
		unsigned long err = ERR_peek_error();
		tls_show_errors(MSG_WARNING, __func__,
				"Failed load CA in DER format");
		if (ERR_GET_LIB(err) == ERR_LIB_X509 &&
		    ERR_GET_REASON(err) == X509_R_CERT_ALREADY_IN_HASH_TABLE) {
			wpa_printf(MSG_DEBUG, "OpenSSL: %s - ignoring "
				   "cert already in hash table error",
				   __func__);
		} else
			ret = -1;
	}

	return ret;
}
#endif /* OPENSSL_NO_STDIO */


static int tls_connection_ca_cert(void *_ssl_ctx, struct tls_connection *conn,
				  const char *ca_cert, const u8 *ca_cert_blob,
				  size_t ca_cert_blob_len, const char *ca_path)
{
	SSL_CTX *ssl_ctx = _ssl_ctx;

	if (ca_cert_blob) {
		X509 *cert = d2i_X509(NULL, (OPENSSL_d2i_TYPE) &ca_cert_blob,
				      ca_cert_blob_len);
		if (cert == NULL) {
			tls_show_errors(MSG_WARNING, __func__,
					"Failed to parse ca_cert_blob");
			return -1;
		}

		if (!X509_STORE_add_cert(ssl_ctx->cert_store, cert)) {
			tls_show_errors(MSG_WARNING, __func__,
					"Failed to add ca_cert_blob to "
					"certificate store");
			X509_free(cert);
			return -1;
		}
		X509_free(cert);
		wpa_printf(MSG_DEBUG, "OpenSSL: %s - added ca_cert_blob "
			   "to certificate store", __func__);
		SSL_set_verify(conn->ssl, SSL_VERIFY_PEER, tls_verify_cb);
		return 0;
	}

#ifdef CONFIG_NATIVE_WINDOWS
	if (ca_cert && tls_cryptoapi_ca_cert(ssl_ctx, conn->ssl, ca_cert) ==
	    0) {
		wpa_printf(MSG_DEBUG, "OpenSSL: Added CA certificates from "
			   "system certificate store");
		SSL_set_verify(conn->ssl, SSL_VERIFY_PEER, tls_verify_cb);
		return 0;
	}
#endif /* CONFIG_NATIVE_WINDOWS */

	if (ca_cert || ca_path) {
#ifndef OPENSSL_NO_STDIO
		if (SSL_CTX_load_verify_locations(ssl_ctx, ca_cert, ca_path) !=
		    1) {
			tls_show_errors(MSG_WARNING, __func__,
					"Failed to load root certificates");
			if (ca_cert &&
			    tls_load_ca_der(ssl_ctx, ca_cert) == 0) {