From b46f1e2e3cf341a9108ab9916ff82ea259722162 Mon Sep 17 00:00:00 2001 From: copercini Date: Thu, 30 Mar 2017 19:01:09 -0300 Subject: [PATCH] Support self signed certificates (#291) * Support self signed certificates Fix for https://github.com/espressif/arduino-esp32/issues/265 mbedtls_ssl_conf_authmode was defined before mbedtls_ssl_config_defaults causing several bugs when no CA certificate is defined. * Implement Arduino's log facility Replace printf by ESP log handling * Remove \n from debug messages log_ doesn't need \n to break line. --- libraries/WiFiClientSecure/src/ssl_client.cpp | 186 +++++------------- 1 file changed, 44 insertions(+), 142 deletions(-) diff --git a/libraries/WiFiClientSecure/src/ssl_client.cpp b/libraries/WiFiClientSecure/src/ssl_client.cpp index 72294b24..0b7c3fea 100644 --- a/libraries/WiFiClientSecure/src/ssl_client.cpp +++ b/libraries/WiFiClientSecure/src/ssl_client.cpp @@ -1,118 +1,55 @@ /* Provide SSL/TLS functions to ESP32 with Arduino IDE * -* Adapted from the ssl_client1 example in mbedtls. +* Adapted from the ssl_client1 example of mbedtls. * * Original Copyright (C) 2006-2015, ARM Limited, All Rights Reserved, Apache 2.0 License. * Additions Copyright (C) 2017 Evandro Luis Copercini, Apache 2.0 License. */ #include "Arduino.h" +#include #include #include #include #include #include - #include "ssl_client.h" - const char *pers = "esp32-tls"; -#define DEBUG //Comment to supress debug messages - -#ifdef DEBUG -#define DEBUG_PRINT(...) printf( __VA_ARGS__ ) -#else -#define DEBUG_PRINT(x) -#endif - -#ifdef CONFIG_MBEDTLS_DEBUG - -#define MBEDTLS_DEBUG_LEVEL 4 - -/* mbedtls debug function that translates mbedTLS debug output -to ESP_LOGx debug output. - -MBEDTLS_DEBUG_LEVEL 4 means all mbedTLS debug output gets sent here, -and then filtered to the ESP logging mechanism. -*/ -static void mbedtls_debug(void *ctx, int level, - const char *file, int line, - const char *str) -{ - const char *MBTAG = "mbedtls"; - char *file_sep; - - /* Shorten 'file' from the whole file path to just the filename - - This is a bit wasteful because the macros are compiled in with - the full _FILE_ path in each case. - */ - file_sep = rindex(file, '/'); - if (file_sep) { - file = file_sep + 1; - } - - switch (level) { - case 1: - printf( "%s:%d %s \n", file, line, str); - break; - case 2: - case 3: - printf( "%s:%d %s \n", file, line, str); - case 4: - printf( "%s:%d %s \n", file, line, str); - break; - default: - printf( "Unexpected log level %d: %s \n", level, str); - break; - } -} - -#endif - - static int handle_error(int err) { #ifdef MBEDTLS_ERROR_C char error_buf[100]; - mbedtls_strerror(err, error_buf, 100); - printf("\n%s\n", error_buf); + log_e("%s", error_buf); #endif - printf("\nMbedTLS message code: %d\n", err); + log_e("MbedTLS message code: %d", err); return err; } - void ssl_init(sslclient_context *ssl_client) { - /* - * Initialize the RNG and the session data - */ - mbedtls_ssl_init(&ssl_client->ssl_ctx); mbedtls_ssl_config_init(&ssl_client->ssl_conf); - mbedtls_ctr_drbg_init(&ssl_client->drbg_ctx); } - int start_ssl_client(sslclient_context *ssl_client, uint32_t ipAddress, uint32_t port, const char *rootCABuff, const char *cli_cert, const char *cli_key) { char buf[512]; int ret, flags, len, timeout; int enable = 1; - DEBUG_PRINT("Free heap before TLS %u\n", xPortGetFreeHeapSize()); - + log_i("Free heap before TLS %u", xPortGetFreeHeapSize()); + log_i("Starting socket"); ssl_client->socket = -1; - + ssl_client->socket = lwip_socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (ssl_client->socket < 0) { - printf("\r\nERROR opening socket\r\n"); + log_e("ERROR opening socket"); return ssl_client->socket; } @@ -129,33 +66,35 @@ int start_ssl_client(sslclient_context *ssl_client, uint32_t ipAddress, uint32_t lwip_setsockopt(ssl_client->socket, IPPROTO_TCP, TCP_NODELAY, &enable, sizeof(enable)); lwip_setsockopt(ssl_client->socket, SOL_SOCKET, SO_KEEPALIVE, &enable, sizeof(enable)); } else { - printf("\r\nConnect to Server failed!\r\n"); + log_e("Connect to Server failed!"); return -1; - } fcntl( ssl_client->socket, F_SETFL, fcntl( ssl_client->socket, F_GETFL, 0 ) | O_NONBLOCK ); - - DEBUG_PRINT( "Seeding the random number generator\n"); + log_i("Seeding the random number generator"); mbedtls_entropy_init(&ssl_client->entropy_ctx); ret = mbedtls_ctr_drbg_seed(&ssl_client->drbg_ctx, mbedtls_entropy_func, &ssl_client->entropy_ctx, (const unsigned char *) pers, strlen(pers)); - - - - if (ret < 0) { return handle_error(ret); } + log_i("Setting up the SSL/TLS structure..."); + + if ((ret = mbedtls_ssl_config_defaults(&ssl_client->ssl_conf, + MBEDTLS_SSL_IS_CLIENT, + MBEDTLS_SSL_TRANSPORT_STREAM, + MBEDTLS_SSL_PRESET_DEFAULT)) != 0) { + return handle_error(ret); + } /* MBEDTLS_SSL_VERIFY_REQUIRED if a CA certificate is defined on Arduino IDE and MBEDTLS_SSL_VERIFY_NONE if not. */ if (rootCABuff != NULL) { - DEBUG_PRINT( "Loading CA cert\n"); + log_i("Loading CA cert"); mbedtls_x509_crt_init(&ssl_client->ca_cert); mbedtls_ssl_conf_authmode(&ssl_client->ssl_conf, MBEDTLS_SSL_VERIFY_REQUIRED); ret = mbedtls_x509_crt_parse(&ssl_client->ca_cert, (const unsigned char *)rootCABuff, strlen(rootCABuff) + 1); @@ -163,35 +102,25 @@ int start_ssl_client(sslclient_context *ssl_client, uint32_t ipAddress, uint32_t //mbedtls_ssl_conf_verify(&ssl_client->ssl_ctx, my_verify, NULL ); if (ret < 0) { return handle_error(ret); - - - - } } else { - mbedtls_ssl_conf_authmode(&ssl_client->ssl_conf, MBEDTLS_SSL_VERIFY_NONE); + log_i("WARNING: Use certificates for a more secure communication!"); } if (cli_cert != NULL && cli_key != NULL) { mbedtls_x509_crt_init(&ssl_client->client_cert); mbedtls_pk_init(&ssl_client->client_key); - DEBUG_PRINT( "Loading CRT cert\n"); + log_i("Loading CRT cert"); ret = mbedtls_x509_crt_parse(&ssl_client->client_cert, (const unsigned char *)cli_cert, strlen(cli_cert) + 1); - - - - if (ret < 0) { return handle_error(ret); } - DEBUG_PRINT( "Loading private key\n"); + log_i("Loading private key"); ret = mbedtls_pk_parse_key(&ssl_client->client_key, (const unsigned char *)cli_key, strlen(cli_key) + 1, NULL, 0); - - if (ret != 0) { return handle_error(ret); @@ -203,48 +132,29 @@ int start_ssl_client(sslclient_context *ssl_client, uint32_t ipAddress, uint32_t /* // TODO: implement match CN verification - DEBUG_PRINT( "Setting hostname for TLS session...\n"); + log_i("Setting hostname for TLS session..."); // Hostname set here should match CN in server certificate if((ret = mbedtls_ssl_set_hostname(&ssl_client->ssl_ctx, host)) != 0) { return handle_error(ret); - + } - */ - - DEBUG_PRINT( "Setting up the SSL/TLS structure...\n"); - - if ((ret = mbedtls_ssl_config_defaults(&ssl_client->ssl_conf, - MBEDTLS_SSL_IS_CLIENT, - MBEDTLS_SSL_TRANSPORT_STREAM, - MBEDTLS_SSL_PRESET_DEFAULT)) != 0) { - return handle_error(ret); - - } + */ mbedtls_ssl_conf_rng(&ssl_client->ssl_conf, mbedtls_ctr_drbg_random, &ssl_client->drbg_ctx); -#ifdef CONFIG_MBEDTLS_DEBUG - mbedtls_debug_set_threshold(MBEDTLS_DEBUG_LEVEL); - mbedtls_ssl_conf_dbg(&ssl_client->ssl_conf, mbedtls_debug, NULL); -#endif if ((ret = mbedtls_ssl_setup(&ssl_client->ssl_ctx, &ssl_client->ssl_conf)) != 0) { return handle_error(ret); - } mbedtls_ssl_set_bio(&ssl_client->ssl_ctx, &ssl_client->socket, mbedtls_net_send, mbedtls_net_recv, NULL ); - DEBUG_PRINT( "Performing the SSL/TLS handshake...\n"); + log_i("Performing the SSL/TLS handshake..."); while ((ret = mbedtls_ssl_handshake(&ssl_client->ssl_ctx)) != 0) { - if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE && ret != -76) { + if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE && ret != -76) { //workaround for bug: https://github.com/espressif/esp-idf/issues/434 return handle_error(ret); - - - - } delay(10); vPortYield(); @@ -252,32 +162,28 @@ int start_ssl_client(sslclient_context *ssl_client, uint32_t ipAddress, uint32_t if (cli_cert != NULL && cli_key != NULL) { - DEBUG_PRINT("Protocol is %s \nCiphersuite is %s\n", mbedtls_ssl_get_version(&ssl_client->ssl_ctx), mbedtls_ssl_get_ciphersuite(&ssl_client->ssl_ctx)); + log_i("Protocol is %s Ciphersuite is %s", mbedtls_ssl_get_version(&ssl_client->ssl_ctx), mbedtls_ssl_get_ciphersuite(&ssl_client->ssl_ctx)); if ((ret = mbedtls_ssl_get_record_expansion(&ssl_client->ssl_ctx)) >= 0) { - DEBUG_PRINT("Record expansion is %d\n", ret); + log_i("Record expansion is %d", ret); } else { - DEBUG_PRINT("Record expansion is unknown (compression)\n"); - + log_i("Record expansion is unknown (compression)"); } } - - DEBUG_PRINT( "Verifying peer X.509 certificate...\n"); + log_i("Verifying peer X.509 certificate..."); if ((flags = mbedtls_ssl_get_verify_result(&ssl_client->ssl_ctx)) != 0) { - printf( "Failed to verify peer certificate!\n"); + log_e("Failed to verify peer certificate!"); bzero(buf, sizeof(buf)); mbedtls_x509_crt_verify_info(buf, sizeof(buf), " ! ", flags); - printf( "verification info: %s\n", buf); + log_e("verification info: %s", buf); stop_ssl_socket(ssl_client, rootCABuff, cli_cert, cli_key); //It's not safe continue. return handle_error(ret); } else { - DEBUG_PRINT( "Certificate verified.\n"); + log_i("Certificate verified."); } - - - DEBUG_PRINT("Free heap after TLS %u\n", xPortGetFreeHeapSize()); + log_i("Free heap after TLS %u", xPortGetFreeHeapSize()); return ssl_client->socket; } @@ -285,7 +191,7 @@ int start_ssl_client(sslclient_context *ssl_client, uint32_t ipAddress, uint32_t void stop_ssl_socket(sslclient_context *ssl_client, const char *rootCABuff, const char *cli_cert, const char *cli_key) { - DEBUG_PRINT( "\nCleaning SSL connection.\n"); + log_i("Cleaning SSL connection."); if (ssl_client->socket >= 0) { close(ssl_client->socket); @@ -313,13 +219,12 @@ void stop_ssl_socket(sslclient_context *ssl_client, const char *rootCABuff, cons int data_to_read(sslclient_context *ssl_client) { - int ret, res; ret = mbedtls_ssl_read(&ssl_client->ssl_ctx, NULL, 0); - //printf("RET: %i\n",ret); //for low level debug + //log_e("RET: %i",ret); //for low level debug res = mbedtls_ssl_get_bytes_avail(&ssl_client->ssl_ctx); - //printf("RES: %i\n",res); - if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE && ret < 0 && ret != -76) { //RC:76 sockets is not connected + //log_e("RES: %i",res); + if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE && ret < 0 && ret != -76) { return handle_error(ret); } @@ -327,33 +232,30 @@ int data_to_read(sslclient_context *ssl_client) } - int send_ssl_data(sslclient_context *ssl_client, const uint8_t *data, uint16_t len) { - //DEBUG_PRINT( "Writing HTTP request...\n"); //for low level debug + //log_i("Writing HTTP request..."); //for low level debug int ret = -1; while ((ret = mbedtls_ssl_write(&ssl_client->ssl_ctx, data, len)) <= 0) { - if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE && ret != -76) { //RC:76 sockets is not connected + if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE && ret != -76) { return handle_error(ret); - } } len = ret; - //DEBUG_PRINT( "%d bytes written\n", len); //for low level debug + //log_i("%d bytes written", len); //for low level debug return ret; } - int get_ssl_receive(sslclient_context *ssl_client, uint8_t *data, int length) { - //DEBUG_PRINT( "Reading HTTP response...\n"); //for low level debug + //log_i( "Reading HTTP response..."); //for low level debug int ret = -1; ret = mbedtls_ssl_read(&ssl_client->ssl_ctx, data, length); - //DEBUG_PRINT( "%d bytes readed\n", ret); //for low level debug + //log_i( "%d bytes readed", ret); //for low level debug return ret; }