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());
}
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());
}