#include "mbedtls/md.h"
#include <string.h>

// Function to compute the hash
void hashSHA256(const char *input, size_t inputLength, unsigned char *outputBuffer) {
  mbedtls_md_context_t ctx;
  mbedtls_md_type_t md_type = MBEDTLS_MD_SHA256;

  mbedtls_md_init(&ctx);
  if (mbedtls_md_setup(&ctx, mbedtls_md_info_from_type(md_type), 0) == 0) {
    mbedtls_md_starts(&ctx);
    mbedtls_md_update(&ctx, (const unsigned char *)input, inputLength);
    mbedtls_md_finish(&ctx, outputBuffer);
  }
  mbedtls_md_free(&ctx);
}

void setup() {
  Serial.begin(115200);
  while (!Serial) {}

  // Example input
  const char input[] = "Hello, SHA-256!";
  unsigned char output[32]; // SHA-256 outputs a 32 byte hash

  // Compute the hash
  hashSHA256(input, strlen(input), output);

  // Print the hash in hexadecimal format
  Serial.print("SHA-256 hash: ");
  for (int i = 0; i < 32; i++) {
    char str[3];
    sprintf(str, "%02x", output[i]);
    Serial.print(str);
  }
  Serial.println();
}

void loop() {
  // No operation
  delay(10000);
}