Merge branch 'feature/update_mbedtls_from_esp_idf' into 'master'

mbedtls: bring mbedtls and openssl based on mbedtls from esp-idf

See merge request sdk/ESP8266_RTOS_SDK!1106

components/esp8266/CMakeLists.txt

@@ -38,6 +38,7 @@ else()
         "source/system_api.c"
         "source/task_wdt.c"
         "source/rom.c"
+        "source/hw_random.c"
         "driver/adc.c"
         "driver/gpio.c"
         "driver/hw_timer.c"

components/esp8266/include/esp_system.h

@@ -183,6 +183,16 @@ uint32_t esp_get_minimum_free_heap_size( void );
  */
 uint32_t esp_random(void);
 
+/**
+ * @brief Fill a buffer with random bytes from hardware RNG
+ *
+ * @note This function has the same restrictions regarding available entropy as esp_random()
+ *
+ * @param buf Pointer to buffer to fill with random numbers.
+ * @param len Length of buffer in bytes
+ */
+void esp_fill_random(void *buf, size_t len);
+
 typedef enum {
     FLASH_SIZE_4M_MAP_256_256 = 0,  /**<  Flash size : 4Mbits. Map : 256KBytes + 256KBytes */
     FLASH_SIZE_2M,                  /**<  Flash size : 2Mbits. Map : 256KBytes */

components/esp8266/source/hw_random.c

@@ -0,0 +1,33 @@
+// Copyright 2019-2020 Espressif Systems (Shanghai) PTE LTD
+//
+// 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 <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include <sys/param.h>
+#include "esp_system.h"
+
+void esp_fill_random(void *buf, size_t len)
+{
+    assert(buf != NULL);
+    uint8_t *buf_bytes = (uint8_t *)buf;
+    while (len > 0) {
+        uint32_t word = esp_random();
+        uint32_t to_copy = MIN(sizeof(word), len);
+        memcpy(buf_bytes, &word, to_copy);
+        buf_bytes += to_copy;
+        len -= to_copy;
+    }
+}