code: func AESDecryptWithECB(cryptStr, key []byte) ([]byte, error) {
  	cb, err := aes.NewCipher(key)
  	if err != nil {
  		return nil, errors.Trace(err)
  	}
  	mode := newECBDecrypter(cb)
  	return aesDecrypt(cryptStr, mode)
  }
docs: // AESDecryptWithECB decrypts data using AES with ECB mode.