http_client.c

// esp_http_client.c
#include <dirent.h>
#include <sys/stat.h>
#include "esp_log.h"
#include <stdio.h>

#include "esp_http_client.h"

#define MAX_HTTP_RECV_BUFFER 	128

static const char* TAG = "HTTP_CLIENT";

int downloadAndSaveFile(char * url, FILE * f, const char * cert_pem)
{
  char *buffer = (char*)malloc(MAX_HTTP_RECV_BUFFER);
  if (buffer == NULL) {
    return -1;
  }
  esp_http_client_config_t config = {
    .url = url,
    .cert_pem = cert_pem,
    .timeout_ms = 20000,
  };

  esp_http_client_handle_t client = esp_http_client_init(&config);
  esp_err_t err;
  if ((err = esp_http_client_open(client, 0)) != ESP_OK) {
    ESP_LOGE(TAG, "esp_http_client_open failed: %d", err);
    free(buffer);
    return -1;
  }
  int content_length = esp_http_client_fetch_headers(client);
  int total_read_len = 0, read_len;
  while (total_read_len < content_length) {
    read_len = esp_http_client_read(client, buffer, MAX_HTTP_RECV_BUFFER);
    fwrite(buffer, sizeof(uint8_t), read_len, f);
    if (read_len <= 0) {
      break;
    }
    total_read_len += read_len;
    ESP_LOGV(TAG, "esp_http_client_read data received: %d, total %d", read_len, total_read_len);
  }
  ESP_LOGV(TAG, "connection closed, cleaning up, total %d bytes received", total_read_len);
  esp_http_client_close(client);
  esp_http_client_cleanup(client);
  free(buffer);	

  return 0;
}