C++ (Cpp) jsvIterateCallbackToBytes Examples

Example #1

File: jswrap_spi_i2c.c Project: RobinLin/Espruino

void jswrap_i2c_writeTo(JsVar *parent, JsVar *addressVar, JsVar *args) {
  IOEventFlags device = jsiGetDeviceFromClass(parent);
  if (!DEVICE_IS_I2C(device)) return;

  bool sendStop = true;
  int address = i2c_get_address(addressVar, &sendStop);

  size_t l = (size_t)jsvIterateCallbackCount(args);
  if (l+256 > jsuGetFreeStack()) {
    jsExceptionHere(JSET_ERROR, "Not enough free stack to send this amount of data");
    return;
  }

  unsigned char *data = (unsigned char *)alloca(l);
  jsvIterateCallbackToBytes(args, data, l);

  jshI2CWrite(device, (unsigned char)address, l, data, sendStop);
}

Example #2

File: jswrap_crypto.c Project: RepRapThailand/Espruino

static NO_INLINE JsVar *jswrap_crypto_AEScrypt(JsVar *message, JsVar *key, JsVar *options, bool encrypt) {
  int err;

  unsigned char iv[16]; // initialisation vector
  memset(iv, 0, 16);

  CryptoMode mode = CM_CBC;

  if (jsvIsObject(options)) {
    JsVar *ivVar = jsvObjectGetChild(options, "iv", 0);
    if (ivVar) {
      jsvIterateCallbackToBytes(ivVar, iv, sizeof(iv));
      jsvUnLock(ivVar);
    }
    JsVar *modeVar = jsvObjectGetChild(options, "mode", 0);
    if (!jsvIsUndefined(modeVar))
      mode = jswrap_crypto_getMode(modeVar);
    jsvUnLock(modeVar);
    if (mode == CM_NONE) return 0;
  } else if (!jsvIsUndefined(options)) {
    jsError("'options' must be undefined, or an Object");
    return 0;
  }



  mbedtls_aes_context aes;
  mbedtls_aes_init( &aes );

  JSV_GET_AS_CHAR_ARRAY(messagePtr, messageLen, message);
  if (!messagePtr) return 0;

  JSV_GET_AS_CHAR_ARRAY(keyPtr, keyLen, key);
  if (!keyPtr) return 0;

  if (encrypt)
    err = mbedtls_aes_setkey_enc( &aes, (unsigned char*)keyPtr, (unsigned int)keyLen*8 );
  else
    err = mbedtls_aes_setkey_dec( &aes, (unsigned char*)keyPtr, (unsigned int)keyLen*8 );
  if (err) {
    jswrap_crypto_error(err);
    return 0;
  }

  char *outPtr = 0;
  JsVar *outVar = jsvNewArrayBufferWithPtr((unsigned int)messageLen, &outPtr);
  if (!outPtr) {
    jsError("Not enough memory for result");
    return 0;
  }



  switch (mode) {
  case CM_CBC:
    err = mbedtls_aes_crypt_cbc( &aes,
                     encrypt ? MBEDTLS_AES_ENCRYPT : MBEDTLS_AES_DECRYPT,
                     messageLen,
                     iv,
                     (unsigned char*)messagePtr,
                     (unsigned char*)outPtr );
    break;
  case CM_CFB:
    err = mbedtls_aes_crypt_cfb8( &aes,
                     encrypt ? MBEDTLS_AES_ENCRYPT : MBEDTLS_AES_DECRYPT,
                     messageLen,
                     iv,
                     (unsigned char*)messagePtr,
                     (unsigned char*)outPtr );
    break;
  case CM_CTR: {
    size_t nc_off = 0;
    unsigned char nonce_counter[16];
    unsigned char stream_block[16];
    memset(nonce_counter, 0, sizeof(nonce_counter));
    memset(stream_block, 0, sizeof(stream_block));
    err = mbedtls_aes_crypt_ctr( &aes,
                     messageLen,
                     &nc_off,
                     nonce_counter,
                     stream_block,
                     (unsigned char*)messagePtr,
                     (unsigned char*)outPtr );
    break;
  }
  case CM_ECB: {
    size_t i = 0;
    while (!err && i+15 < messageLen) {
      err = mbedtls_aes_crypt_ecb( &aes,
                       encrypt ? MBEDTLS_AES_ENCRYPT : MBEDTLS_AES_DECRYPT,
                       (unsigned char*)&messagePtr[i],
                       (unsigned char*)&outPtr[i] );
      i += 16;
    }
    break;
  }
  default:
    err = MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE;
    break;
  }

  mbedtls_aes_free( &aes );
  if (!err) {
    return outVar;
  } else {
    jswrap_crypto_error(err);
    jsvUnLock(outVar);
    return 0;
  }
}