Arduino ESP32 Base64 encoding with MBedTLS

encode_base64_mbedtls.cpp

#include "mbedtls/base64.h"
#include "mbedtls/error.h"

size_t get_encoded_size(size_t plain_data_size) {
  return (4 * ceil((double)plain_data_size / 3)) + 1;
}

void setup() {
  const char *test_data_p = "Hello world";
  
  size_t test_data_length = strlen(test_data_p);
  size_t encoded_data_size = get_encoded_size(test_data_length);
  
  uint8_t *encode_data_buff = (uint8_t*)malloc(encoded_data_size);
  if (encode_data_buff == NULL) {
    printf("Failed to allocate %zu bytes...\n", encoded_data_size);
    return;
  }
  
  size_t encode_data_length = 0;
  int res = mbedtls_base64_encode(
    encode_data_buff,
    encoded_data_size,
    &encode_data_length,
    (const uint8_t*)test_data_p,
    test_data_length
  );
 
  if (res != 0) {
    char err_buff_str[128];
    mbedtls_strerror(res, err_buff_str, sizeof(err_buff_str));
    printf("Failed encode data, error: %s\n", err_buff_str);
    free(encode_data_buff);
    return;
  }

  printf("Data [%zu]: %s\n", test_data_length, test_data_p);
  printf("Encoded data [%zu]: %s\n", strlen((char*)encode_data_buff), (char*)encode_data_buff);
  free(encode_data_buff);
}

void loop() {
  delay(10);
}