mbed-os/features/netsocket/TLSSocketWrapper.cpp

700 lines
19 KiB
C++

/*
* Copyright (c) 2018 ARM Limited
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "TLSSocketWrapper.h"
#include "platform/Callback.h"
#include "drivers/Timer.h"
#include "events/mbed_events.h"
#define TRACE_GROUP "TLSW"
#include "mbed-trace/mbed_trace.h"
#include "mbedtls/debug.h"
#include "mbed_error.h"
#include "Kernel.h"
// This class requires Mbed TLS SSL/TLS client code
#if defined(MBEDTLS_SSL_CLI_C)
TLSSocketWrapper::TLSSocketWrapper(Socket *transport, const char *hostname, control_transport control) :
_transport(transport),
_timeout(-1),
#ifdef MBEDTLS_X509_CRT_PARSE_C
_cacert(NULL),
_clicert(NULL),
#endif
_ssl_conf(NULL),
_connect_transport(control == TRANSPORT_CONNECT || control == TRANSPORT_CONNECT_AND_CLOSE),
_close_transport(control == TRANSPORT_CLOSE || control == TRANSPORT_CONNECT_AND_CLOSE),
_tls_initialized(false),
_handshake_completed(false),
_cacert_allocated(false),
_clicert_allocated(false),
_ssl_conf_allocated(false)
{
mbedtls_entropy_init(&_entropy);
mbedtls_ctr_drbg_init(&_ctr_drbg);
mbedtls_ssl_init(&_ssl);
#if defined(MBEDTLS_X509_CRT_PARSE_C)
mbedtls_pk_init(&_pkctx);
#endif
if (hostname) {
set_hostname(hostname);
}
}
TLSSocketWrapper::~TLSSocketWrapper()
{
if (_transport) {
close();
}
mbedtls_entropy_free(&_entropy);
mbedtls_ctr_drbg_free(&_ctr_drbg);
mbedtls_ssl_free(&_ssl);
#if defined(MBEDTLS_X509_CRT_PARSE_C)
mbedtls_pk_free(&_pkctx);
set_own_cert(NULL);
set_ca_chain(NULL);
#endif
set_ssl_config(NULL);
}
void TLSSocketWrapper::set_hostname(const char *hostname)
{
#ifdef MBEDTLS_X509_CRT_PARSE_C
mbedtls_ssl_set_hostname(&_ssl, hostname);
#endif
}
nsapi_error_t TLSSocketWrapper::set_root_ca_cert(const void *root_ca, size_t len)
{
#if !defined(MBEDTLS_X509_CRT_PARSE_C)
return NSAPI_ERROR_UNSUPPORTED;
#else
mbedtls_x509_crt *crt;
crt = new (std::nothrow) mbedtls_x509_crt;
if (!crt) {
return NSAPI_ERROR_NO_MEMORY;
}
mbedtls_x509_crt_init(crt);
/* Parse CA certification */
int ret;
if ((ret = mbedtls_x509_crt_parse(crt, static_cast<const unsigned char *>(root_ca),
len)) != 0) {
print_mbedtls_error("mbedtls_x509_crt_parse", ret);
return NSAPI_ERROR_PARAMETER;
}
set_ca_chain(crt);
_cacert_allocated = true;
return NSAPI_ERROR_OK;
#endif
}
nsapi_error_t TLSSocketWrapper::set_root_ca_cert(const char *root_ca_pem)
{
return set_root_ca_cert(root_ca_pem, strlen(root_ca_pem) + 1);
}
nsapi_error_t TLSSocketWrapper::set_client_cert_key(const char *client_cert_pem, const char *client_private_key_pem)
{
return set_client_cert_key(client_cert_pem, strlen(client_cert_pem) + 1, client_private_key_pem, strlen(client_private_key_pem) + 1);
}
nsapi_error_t TLSSocketWrapper::set_client_cert_key(const void *client_cert, size_t client_cert_len,
const void *client_private_key_pem, size_t client_private_key_len)
{
#if !defined(MBEDTLS_X509_CRT_PARSE_C) || !defined(MBEDTLS_PK_C)
return NSAPI_ERROR_UNSUPPORTED;
#else
int ret;
mbedtls_x509_crt *crt = new mbedtls_x509_crt;
mbedtls_x509_crt_init(crt);
if ((ret = mbedtls_x509_crt_parse(crt, static_cast<const unsigned char *>(client_cert),
client_cert_len)) != 0) {
print_mbedtls_error("mbedtls_x509_crt_parse", ret);
return NSAPI_ERROR_PARAMETER;
}
mbedtls_pk_init(&_pkctx);
if ((ret = mbedtls_pk_parse_key(&_pkctx, static_cast<const unsigned char *>(client_private_key_pem),
client_private_key_len, NULL, 0)) != 0) {
print_mbedtls_error("mbedtls_pk_parse_key", ret);
return NSAPI_ERROR_PARAMETER;
}
set_own_cert(crt);
_clicert_allocated = true;
return NSAPI_ERROR_OK;
#endif /* MBEDTLS_X509_CRT_PARSE_C */
}
nsapi_error_t TLSSocketWrapper::start_handshake(bool first_call)
{
const char DRBG_PERS[] = "mbed TLS client";
int ret;
if (!_transport) {
return NSAPI_ERROR_NO_SOCKET;
}
if (_tls_initialized) {
return continue_handshake();
}
#ifdef MBEDTLS_X509_CRT_PARSE_C
tr_info("Starting TLS handshake with %s", _ssl.hostname);
#else
tr_info("Starting TLS handshake");
#endif
/*
* Initialize TLS-related stuf.
*/
if ((ret = mbedtls_ctr_drbg_seed(&_ctr_drbg, mbedtls_entropy_func, &_entropy,
(const unsigned char *) DRBG_PERS,
sizeof(DRBG_PERS))) != 0) {
print_mbedtls_error("mbedtls_crt_drbg_init", ret);
return NSAPI_ERROR_PARAMETER;
}
mbedtls_ssl_conf_rng(get_ssl_config(), mbedtls_ctr_drbg_random, &_ctr_drbg);
#if MBED_CONF_TLS_SOCKET_DEBUG_LEVEL > 0
mbedtls_ssl_conf_verify(get_ssl_config(), my_verify, NULL);
mbedtls_ssl_conf_dbg(get_ssl_config(), my_debug, NULL);
mbedtls_debug_set_threshold(MBED_CONF_TLS_SOCKET_DEBUG_LEVEL);
#endif
tr_debug("mbedtls_ssl_setup()");
if ((ret = mbedtls_ssl_setup(&_ssl, get_ssl_config())) != 0) {
print_mbedtls_error("mbedtls_ssl_setup", ret);
return NSAPI_ERROR_PARAMETER;
}
_transport->set_blocking(false);
_transport->sigio(mbed::callback(this, &TLSSocketWrapper::event));
mbedtls_ssl_set_bio(&_ssl, this, ssl_send, ssl_recv, NULL);
_tls_initialized = true;
ret = continue_handshake();
if (first_call) {
if (ret == NSAPI_ERROR_ALREADY) {
ret = NSAPI_ERROR_IN_PROGRESS; // If first call should return IN_PROGRESS
}
if (ret == NSAPI_ERROR_IS_CONNECTED) {
ret = NSAPI_ERROR_OK; // If we happened to complete the request on the first call, return OK.
}
}
return ret;
}
nsapi_error_t TLSSocketWrapper::continue_handshake()
{
int ret;
if (_handshake_completed) {
return NSAPI_ERROR_IS_CONNECTED;
}
if (!_tls_initialized) {
return NSAPI_ERROR_NO_CONNECTION;
}
while (true) {
ret = mbedtls_ssl_handshake(&_ssl);
if (_timeout && (ret == MBEDTLS_ERR_SSL_WANT_READ || ret == MBEDTLS_ERR_SSL_WANT_WRITE)) {
uint32_t flag;
flag = _event_flag.wait_any(1, _timeout);
if (flag & osFlagsError) {
break;
}
} else {
break;
}
}
if (ret < 0) {
print_mbedtls_error("mbedtls_ssl_handshake", ret);
if (ret == MBEDTLS_ERR_SSL_WANT_READ || ret == MBEDTLS_ERR_SSL_WANT_WRITE) {
return NSAPI_ERROR_ALREADY;
} else {
return NSAPI_ERROR_AUTH_FAILURE;
}
}
#ifdef MBEDTLS_X509_CRT_PARSE_C
/* It also means the handshake is done, time to print info */
tr_info("TLS connection to %s established", _ssl.hostname);
#else
tr_info("TLS connection established");
#endif
#ifdef MBEDTLS_X509_CRT_PARSE_C
/* Prints the server certificate and verify it. */
const size_t buf_size = 1024;
char *buf = new char[buf_size];
mbedtls_x509_crt_info(buf, buf_size, "\r ",
mbedtls_ssl_get_peer_cert(&_ssl));
tr_debug("Server certificate:\r\n%s\r\n", buf);
uint32_t flags = mbedtls_ssl_get_verify_result(&_ssl);
if (flags != 0) {
/* Verification failed. */
mbedtls_x509_crt_verify_info(buf, buf_size, "\r ! ", flags);
tr_error("Certificate verification failed:\r\n%s", buf);
} else {
/* Verification succeeded. */
tr_info("Certificate verification passed");
}
delete[] buf;
#endif
_handshake_completed = true;
return NSAPI_ERROR_IS_CONNECTED;
}
nsapi_error_t TLSSocketWrapper::send(const void *data, nsapi_size_t size)
{
int ret;
if (!_transport) {
return NSAPI_ERROR_NO_SOCKET;
}
tr_debug("send %d", size);
while (true) {
if (!_handshake_completed) {
ret = continue_handshake();
if (ret != NSAPI_ERROR_IS_CONNECTED) {
if (ret == NSAPI_ERROR_ALREADY) {
ret = NSAPI_ERROR_NO_CONNECTION;
}
return ret;
}
}
ret = mbedtls_ssl_write(&_ssl, (const unsigned char *) data, size);
if (_timeout == 0) {
break;
} else if (ret == MBEDTLS_ERR_SSL_WANT_WRITE || ret == MBEDTLS_ERR_SSL_WANT_READ) {
uint32_t flag;
flag = _event_flag.wait_any(1, _timeout);
if (flag & osFlagsError) {
// Timeout break
break;
}
} else {
break;
}
}
if (ret == MBEDTLS_ERR_SSL_WANT_WRITE ||
ret == MBEDTLS_ERR_SSL_WANT_READ) {
// translate to socket error
return NSAPI_ERROR_WOULD_BLOCK;
}
if (ret < 0) {
print_mbedtls_error("mbedtls_ssl_write", ret);
return NSAPI_ERROR_DEVICE_ERROR;
}
return ret; // Assume "non negative errorcode" to be propagated from Socket layer
}
nsapi_size_or_error_t TLSSocketWrapper::sendto(const SocketAddress &, const void *data, nsapi_size_t size)
{
// Ignore the SocketAddress
return send(data, size);
}
nsapi_size_or_error_t TLSSocketWrapper::recv(void *data, nsapi_size_t size)
{
int ret;
if (!_transport) {
return NSAPI_ERROR_NO_SOCKET;
}
while (true) {
if (!_handshake_completed) {
ret = continue_handshake();
if (ret != NSAPI_ERROR_IS_CONNECTED) {
if (ret == NSAPI_ERROR_ALREADY) {
ret = NSAPI_ERROR_NO_CONNECTION;
}
return ret;
}
}
ret = mbedtls_ssl_read(&_ssl, (unsigned char *) data, size);
if (_timeout == 0) {
break;
} else if (ret == MBEDTLS_ERR_SSL_WANT_WRITE || ret == MBEDTLS_ERR_SSL_WANT_READ) {
uint32_t flag;
flag = _event_flag.wait_any(1, _timeout);
if (flag & osFlagsError) {
// Timeout break
break;
}
} else {
break;
}
}
if (ret == MBEDTLS_ERR_SSL_WANT_WRITE ||
ret == MBEDTLS_ERR_SSL_WANT_READ) {
// translate to socket error
return NSAPI_ERROR_WOULD_BLOCK;
} else if (ret == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY) {
/* MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY is not considered as error.
* Just ignore here. Once connection is closed, mbedtls_ssl_read()
* will return 0.
*/
return 0;
} else if (ret < 0) {
print_mbedtls_error("mbedtls_ssl_read", ret);
// There is no mapping of TLS error codes to Socket API so return most generic error to application
return NSAPI_ERROR_DEVICE_ERROR;
}
return ret;
}
nsapi_size_or_error_t TLSSocketWrapper::recvfrom(SocketAddress *address, void *data, nsapi_size_t size)
{
return recv(data, size);
}
void TLSSocketWrapper::print_mbedtls_error(MBED_UNUSED const char *name, MBED_UNUSED int err)
{
// Avoid pulling in mbedtls_strerror when trace is not enabled
#if defined FEA_TRACE_SUPPORT && defined MBEDTLS_ERROR_C
char *buf = new char[128];
mbedtls_strerror(err, buf, 128);
tr_err("%s() failed: -0x%04x (%d): %s", name, -err, err, buf);
delete[] buf;
#else
tr_err("%s() failed: -0x%04x (%d)", name, -err, err);
#endif
}
#if MBED_CONF_TLS_SOCKET_DEBUG_LEVEL > 0
void TLSSocketWrapper::my_debug(void *ctx, int level, const char *file, int line,
const char *str)
{
const char *p, *basename;
(void) ctx;
/* Extract basename from file */
for (p = basename = file; *p != '\0'; p++) {
if (*p == '/' || *p == '\\') {
basename = p + 1;
}
}
tr_debug("%s:%04d: |%d| %s", basename, line, level, str);
}
int TLSSocketWrapper::my_verify(void *data, mbedtls_x509_crt *crt, int depth, uint32_t *flags)
{
const uint32_t buf_size = 1024;
char *buf = new char[buf_size];
(void) data;
tr_debug("\nVerifying certificate at depth %d:\n", depth);
mbedtls_x509_crt_info(buf, buf_size - 1, " ", crt);
tr_debug("%s", buf);
if (*flags == 0) {
tr_info("No verification issue for this certificate\n");
} else {
mbedtls_x509_crt_verify_info(buf, buf_size, " ! ", *flags);
tr_info("%s\n", buf);
}
delete[] buf;
return 0;
}
#endif /* MBED_CONF_TLS_SOCKET_DEBUG_LEVEL > 0 */
int TLSSocketWrapper::ssl_recv(void *ctx, unsigned char *buf, size_t len)
{
int recv;
TLSSocketWrapper *my = static_cast<TLSSocketWrapper *>(ctx);
if (!my->_transport) {
return NSAPI_ERROR_NO_SOCKET;
}
recv = my->_transport->recv(buf, len);
if (NSAPI_ERROR_WOULD_BLOCK == recv) {
return MBEDTLS_ERR_SSL_WANT_READ;
} else if (recv < 0) {
tr_error("Socket recv error %d", recv);
}
// Propagate also Socket errors to SSL, it allows negative error codes to be returned here.
return recv;
}
int TLSSocketWrapper::ssl_send(void *ctx, const unsigned char *buf, size_t len)
{
int size = -1;
TLSSocketWrapper *my = static_cast<TLSSocketWrapper *>(ctx);
if (!my->_transport) {
return NSAPI_ERROR_NO_SOCKET;
}
size = my->_transport->send(buf, len);
if (NSAPI_ERROR_WOULD_BLOCK == size) {
return MBEDTLS_ERR_SSL_WANT_WRITE;
} else if (size < 0) {
tr_error("Socket send error %d", size);
}
// Propagate also Socket errors to SSL, it allows negative error codes to be returned here.
return size;
}
#if defined(MBEDTLS_X509_CRT_PARSE_C)
mbedtls_x509_crt *TLSSocketWrapper::get_own_cert()
{
return _clicert;
}
int TLSSocketWrapper::set_own_cert(mbedtls_x509_crt *crt)
{
int ret = 0;
if (_clicert && _clicert_allocated) {
mbedtls_x509_crt_free(_clicert);
delete _clicert;
_clicert_allocated = false;
}
_clicert = crt;
if (crt) {
if ((ret = mbedtls_ssl_conf_own_cert(get_ssl_config(), _clicert, &_pkctx)) != 0) {
print_mbedtls_error("mbedtls_ssl_conf_own_cert", ret);
}
}
return ret;
}
mbedtls_x509_crt *TLSSocketWrapper::get_ca_chain()
{
return _cacert;
}
void TLSSocketWrapper::set_ca_chain(mbedtls_x509_crt *crt)
{
if (_cacert && _cacert_allocated) {
mbedtls_x509_crt_free(_cacert);
delete _cacert;
_cacert_allocated = false;
}
_cacert = crt;
tr_debug("mbedtls_ssl_conf_ca_chain()");
mbedtls_ssl_conf_ca_chain(get_ssl_config(), _cacert, NULL);
}
#endif /* MBEDTLS_X509_CRT_PARSE_C */
mbedtls_ssl_config *TLSSocketWrapper::get_ssl_config()
{
if (!_ssl_conf) {
int ret;
_ssl_conf = new mbedtls_ssl_config;
mbedtls_ssl_config_init(_ssl_conf);
_ssl_conf_allocated = true;
if ((ret = mbedtls_ssl_config_defaults(_ssl_conf,
MBEDTLS_SSL_IS_CLIENT,
MBEDTLS_SSL_TRANSPORT_STREAM,
MBEDTLS_SSL_PRESET_DEFAULT)) != 0) {
print_mbedtls_error("mbedtls_ssl_config_defaults", ret);
set_ssl_config(NULL);
MBED_ERROR(MBED_MAKE_ERROR(MBED_MODULE_NETWORK_STACK, MBED_ERROR_CODE_OUT_OF_MEMORY), "mbedtls_ssl_config_defaults() failed");
return NULL;
}
/* It is possible to disable authentication by passing
* MBEDTLS_SSL_VERIFY_NONE in the call to mbedtls_ssl_conf_authmode()
*/
mbedtls_ssl_conf_authmode(get_ssl_config(), MBEDTLS_SSL_VERIFY_REQUIRED);
}
return _ssl_conf;
}
void TLSSocketWrapper::set_ssl_config(mbedtls_ssl_config *conf)
{
if (_ssl_conf && _ssl_conf_allocated) {
mbedtls_ssl_config_free(_ssl_conf);
delete _ssl_conf;
_ssl_conf_allocated = false;
}
_ssl_conf = conf;
}
mbedtls_ssl_context *TLSSocketWrapper::get_ssl_context()
{
return &_ssl;
}
nsapi_error_t TLSSocketWrapper::close()
{
if (!_transport) {
return NSAPI_ERROR_NO_SOCKET;
}
tr_info("Closing TLS");
int ret = 0;
if (_handshake_completed) {
_transport->set_blocking(true);
ret = mbedtls_ssl_close_notify(&_ssl);
if (ret) {
print_mbedtls_error("mbedtls_ssl_close_notify", ret);
}
_handshake_completed = false;
}
if (_close_transport) {
int ret2 = _transport->close();
if (!ret) {
ret = ret2;
}
}
_transport = NULL;
return ret;
}
nsapi_error_t TLSSocketWrapper::connect(const SocketAddress &address)
{
nsapi_error_t ret = NSAPI_ERROR_OK;
if (!_transport) {
return NSAPI_ERROR_NO_SOCKET;
}
if (!is_handshake_started() && _connect_transport) {
ret = _transport->connect(address);
if (ret && ret != NSAPI_ERROR_IS_CONNECTED) {
return ret;
}
}
return start_handshake(ret == NSAPI_ERROR_OK);
}
nsapi_error_t TLSSocketWrapper::bind(const SocketAddress &address)
{
if (!_transport) {
return NSAPI_ERROR_NO_SOCKET;
}
return _transport->bind(address);
}
void TLSSocketWrapper::set_blocking(bool blocking)
{
set_timeout(blocking ? -1 : 0);
}
void TLSSocketWrapper::set_timeout(int timeout)
{
_timeout = timeout;
if (!is_handshake_started() && timeout != -1 && _connect_transport) {
// If we have not yet connected the transport, we need to modify its blocking mode as well.
// After connection is initiated, it is already set to non blocking mode
_transport->set_timeout(timeout);
}
}
void TLSSocketWrapper::sigio(mbed::Callback<void()> func)
{
if (!_transport) {
return;
}
_sigio = func;
_transport->sigio(mbed::callback(this, &TLSSocketWrapper::event));
}
nsapi_error_t TLSSocketWrapper::setsockopt(int level, int optname, const void *optval, unsigned optlen)
{
if (!_transport) {
return NSAPI_ERROR_NO_SOCKET;
}
return _transport->setsockopt(level, optname, optval, optlen);
}
nsapi_error_t TLSSocketWrapper::getsockopt(int level, int optname, void *optval, unsigned *optlen)
{
if (!_transport) {
return NSAPI_ERROR_NO_SOCKET;
}
return _transport->getsockopt(level, optname, optval, optlen);
}
Socket *TLSSocketWrapper::accept(nsapi_error_t *err)
{
if (err) {
*err = NSAPI_ERROR_UNSUPPORTED;
}
return NULL;
}
nsapi_error_t TLSSocketWrapper::listen(int)
{
return NSAPI_ERROR_UNSUPPORTED;
}
void TLSSocketWrapper::event()
{
_event_flag.set(1);
if (_sigio) {
_sigio();
}
}
bool TLSSocketWrapper::is_handshake_started() const
{
return _tls_initialized;
}
nsapi_error_t TLSSocketWrapper::getpeername(SocketAddress *address)
{
if (!_handshake_completed) {
return NSAPI_ERROR_NO_CONNECTION;
}
return _transport->getpeername(address);
}
#endif /* MBEDTLS_SSL_CLI_C */