public string UncryptMessage(CryptoAnswer answer)
        {
            // Objeto auxiliar na construção da string descriptografada.
            StringBuilder sb = new StringBuilder();

            // Converte a string em um array de caracteres.
            char[] letters = answer.EncryptedText
                             .ToLower()
                             .ToCharArray();

            foreach (char letter in letters)
            {
                char newLetter          = letter;
                int  letterNumericValue = (int)letter;

                // Verifica se a letra está dentro do limite de a a z.
                if (letterNumericValue >= 97 &&
                    letterNumericValue <= 122)
                {
                    newLetter = Convert.ToChar(letter - answer.NumSteps);
                }

                sb.Append(newLetter);
            }

            return(sb.ToString());
        }
示例#2
0
        public static CryptoAnswer RecreateObject()
        {
            CryptoAnswer result = null;

            using (TextReader reader = new StreamReader(FILE_NAME))
            {
                result = JsonConvert.DeserializeObject <CryptoAnswer>(
                    reader.ReadToEnd());
            };

            return(result);
        }
        public CryptoAnswer DownloadData()
        {
            if (CryptoAnswer.HasFile)
            {
                return(CryptoAnswer.RecreateObject());
            }

            var request = new RestRequest("/generate-data",
                                          DataFormat.Json);

            request.AddQueryParameter("token",
                                      _codenationSecrets.Token);

            IRestResponse <CryptoAnswer> response = _client
                                                    .Execute <CryptoAnswer>(request);

            return(response.Data);
        }
        public string CalculateHash(CryptoAnswer answer)
        {
            // Objeto auxiliar na construção da string descriptografada.
            StringBuilder sb = new StringBuilder();

            using (SHA1Managed sha = new SHA1Managed())
            {
                // Converte a string descriptografada em um array de bytes.
                byte[] encodedString = Encoding.Default
                                       .GetBytes(answer.UncryptedText);

                // Calcula o hash, de fato, da string.
                byte[] hash = sha.ComputeHash(encodedString);

                foreach (byte b in hash)
                {
                    sb.Append(b.ToString("x2"));
                }
            }

            return(sb.ToString());
        }