esp-idf/components/mbedtls/port/dynamic/esp_ssl_srv.c
Li Jingyi c88af419a3 mbedtls: fix ssl server crash when enable mbedtls dynamic buffer
Not free keycert until MBEDTLS_SSL_CLIENT_KEY_EXCHANGE for rsa key exchange methods, because keycert will be used to parse client key exchange.
2022-05-20 11:21:48 +00:00

219 lines
6.9 KiB
C

/*
* SPDX-FileCopyrightText: 2020-2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <sys/param.h>
#include "esp_mbedtls_dynamic_impl.h"
int __real_mbedtls_ssl_handshake_server_step(mbedtls_ssl_context *ssl);
int __wrap_mbedtls_ssl_handshake_server_step(mbedtls_ssl_context *ssl);
static const char *TAG = "SSL Server";
#ifdef CONFIG_MBEDTLS_DYNAMIC_FREE_CONFIG_DATA
/**
* Check if ciphersuite uses rsa key exchange methods.
*/
static bool ssl_ciphersuite_uses_rsa_key_ex(mbedtls_ssl_context *ssl)
{
const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
ssl->MBEDTLS_PRIVATE(handshake)->ciphersuite_info;
if (ciphersuite_info->MBEDTLS_PRIVATE(key_exchange) == MBEDTLS_KEY_EXCHANGE_RSA ||
ciphersuite_info->MBEDTLS_PRIVATE(key_exchange) == MBEDTLS_KEY_EXCHANGE_RSA_PSK) {
return true;
} else {
return false;
}
}
#endif
static int manage_resource(mbedtls_ssl_context *ssl, bool add)
{
int state = add ? ssl->MBEDTLS_PRIVATE(state) : ssl->MBEDTLS_PRIVATE(state) - 1;
if (ssl->MBEDTLS_PRIVATE(state) == MBEDTLS_SSL_HANDSHAKE_OVER || ssl->MBEDTLS_PRIVATE(handshake) == NULL) {
return 0;
}
if (!add) {
if (!ssl->MBEDTLS_PRIVATE(out_left)) {
CHECK_OK(esp_mbedtls_free_tx_buffer(ssl));
}
}
switch (state) {
case MBEDTLS_SSL_HELLO_REQUEST:
ssl->MBEDTLS_PRIVATE(major_ver) = MBEDTLS_SSL_MAJOR_VERSION_3;
break;
case MBEDTLS_SSL_CLIENT_HELLO:
if (add) {
CHECK_OK(esp_mbedtls_add_rx_buffer(ssl));
} else {
CHECK_OK(esp_mbedtls_free_rx_buffer(ssl));
}
break;
case MBEDTLS_SSL_SERVER_HELLO:
if (add) {
size_t buffer_len = MBEDTLS_SSL_OUT_BUFFER_LEN;
CHECK_OK(esp_mbedtls_add_tx_buffer(ssl, buffer_len));
}
break;
case MBEDTLS_SSL_SERVER_CERTIFICATE:
if (add) {
size_t buffer_len = 3;
mbedtls_ssl_key_cert *key_cert = ssl->MBEDTLS_PRIVATE(conf)->MBEDTLS_PRIVATE(key_cert);
while (key_cert && key_cert->cert) {
size_t num;
buffer_len += esp_mbedtls_get_crt_size(key_cert->cert, &num);
buffer_len += num * 3;
key_cert = key_cert->next;
}
buffer_len = MAX(buffer_len, MBEDTLS_SSL_OUT_BUFFER_LEN);
CHECK_OK(esp_mbedtls_add_tx_buffer(ssl, buffer_len));
} else {
#ifdef CONFIG_MBEDTLS_DYNAMIC_FREE_CONFIG_DATA
/**
* Not free keycert->cert until MBEDTLS_SSL_CLIENT_KEY_EXCHANGE for rsa key exchange methods.
* For ssl server will use keycert->cert to parse client key exchange.
*/
if (!ssl_ciphersuite_uses_rsa_key_ex(ssl)) {
esp_mbedtls_free_keycert_cert(ssl);
}
#endif
}
break;
case MBEDTLS_SSL_SERVER_KEY_EXCHANGE:
if (add) {
size_t buffer_len = MBEDTLS_SSL_OUT_BUFFER_LEN;
CHECK_OK(esp_mbedtls_add_tx_buffer(ssl, buffer_len));
} else {
#ifdef CONFIG_MBEDTLS_DYNAMIC_FREE_CONFIG_DATA
esp_mbedtls_free_dhm(ssl);
/**
* Not free keycert->key and keycert until MBEDTLS_SSL_CLIENT_KEY_EXCHANGE for rsa key exchange methods.
* For ssl server will use keycert->key to parse client key exchange.
*/
if (!ssl_ciphersuite_uses_rsa_key_ex(ssl)) {
esp_mbedtls_free_keycert_key(ssl);
esp_mbedtls_free_keycert(ssl);
}
#endif
}
break;
case MBEDTLS_SSL_CERTIFICATE_REQUEST:
if (add) {
size_t buffer_len = MBEDTLS_SSL_OUT_BUFFER_LEN;
CHECK_OK(esp_mbedtls_add_tx_buffer(ssl, buffer_len));
}
break;
case MBEDTLS_SSL_SERVER_HELLO_DONE:
if (add) {
size_t buffer_len = MBEDTLS_SSL_OUT_BUFFER_LEN;
CHECK_OK(esp_mbedtls_add_tx_buffer(ssl, buffer_len));
}
break;
case MBEDTLS_SSL_CLIENT_CERTIFICATE:
if (add) {
CHECK_OK(esp_mbedtls_add_rx_buffer(ssl));
} else {
CHECK_OK(esp_mbedtls_free_rx_buffer(ssl));
#ifdef CONFIG_MBEDTLS_DYNAMIC_FREE_CA_CERT
esp_mbedtls_free_cacert(ssl);
#endif
}
break;
case MBEDTLS_SSL_CLIENT_KEY_EXCHANGE:
if (add) {
CHECK_OK(esp_mbedtls_add_rx_buffer(ssl));
} else {
CHECK_OK(esp_mbedtls_free_rx_buffer(ssl));
#ifdef CONFIG_MBEDTLS_DYNAMIC_FREE_CONFIG_DATA
/**
* Free keycert after MBEDTLS_SSL_CLIENT_KEY_EXCHANGE for rsa key exchange methods.
* For ssl server will use keycert->cert and keycert->key to parse client key exchange.
*/
if (ssl_ciphersuite_uses_rsa_key_ex(ssl)) {
esp_mbedtls_free_keycert_cert(ssl);
esp_mbedtls_free_keycert_key(ssl);
esp_mbedtls_free_keycert(ssl);
}
#endif
}
break;
case MBEDTLS_SSL_CERTIFICATE_VERIFY:
if (add) {
CHECK_OK(esp_mbedtls_add_rx_buffer(ssl));
} else {
CHECK_OK(esp_mbedtls_free_rx_buffer(ssl));
}
break;
case MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC:
if (add) {
CHECK_OK(esp_mbedtls_add_rx_buffer(ssl));
} else {
CHECK_OK(esp_mbedtls_free_rx_buffer(ssl));
}
break;
case MBEDTLS_SSL_CLIENT_FINISHED:
if (add) {
CHECK_OK(esp_mbedtls_add_rx_buffer(ssl));
} else {
CHECK_OK(esp_mbedtls_free_rx_buffer(ssl));
}
break;
case MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC:
if (add) {
size_t buffer_len = MBEDTLS_SSL_OUT_BUFFER_LEN;
CHECK_OK(esp_mbedtls_add_tx_buffer(ssl, buffer_len));
}
break;
case MBEDTLS_SSL_SERVER_FINISHED:
if (add) {
size_t buffer_len = MBEDTLS_SSL_OUT_BUFFER_LEN;
CHECK_OK(esp_mbedtls_add_tx_buffer(ssl, buffer_len));
}
break;
case MBEDTLS_SSL_FLUSH_BUFFERS:
break;
case MBEDTLS_SSL_HANDSHAKE_WRAPUP:
break;
default:
break;
}
return 0;
}
int __wrap_mbedtls_ssl_handshake_server_step(mbedtls_ssl_context *ssl)
{
CHECK_OK(manage_resource(ssl, true));
CHECK_OK(__real_mbedtls_ssl_handshake_server_step(ssl));
CHECK_OK(manage_resource(ssl, false));
return 0;
}