/// <summary>
/// Decrypt the data using the given key and passed IV
/// </summary>
public static string DecryptData(SymmetricCipherResults cipherResults,
SymmetricAlgorithmTypeEnum symmetricAlgorithm,
string key)
{
key = SymmetricOperation.MakeKeyLegalSize(symmetricAlgorithm, key);
byte[] IV = Convert.FromBase64String(cipherResults.IV);
string PlainText = SymmetricOperation.DecryptFromBase64(symmetricAlgorithm,
cipherResults.CipherText, key, IV, System.Text.Encoding.UTF8);
return(PlainText);
}
/// <summary>
/// Decrypt data from the secure string.
/// </summary>
public static string GetDataFromSecureString(string secretKey, byte[] bufInitVector, string base64Data)
{
secretKey = SymmetricOperation.MakeKeyLegalSize(AlgorithmType, secretKey);
// Decrypt the secret string and make sure that is not expired
string plainStr = SymmetricOperation.DecryptFromBase64(AlgorithmType,
base64Data, secretKey, bufInitVector, ASCIIEncoding.ASCII);
//Parse data to remove the salt and the expiration timestamp
plainStr = plainStr.Substring(SaltLength);
string sExpirationTim = plainStr.Substring(plainStr.Length - 14);
DateTime dtExpirationTim = DateTime.ParseExact(sExpirationTim,
"yyyyMMddHHmmss",
System.Globalization.DateTimeFormatInfo.InvariantInfo);
// Check if the contetn should expire
if (dtExpirationTim > DateTime.Now)
{
return(plainStr.Substring(0, plainStr.Length - 14));
}
return(string.Empty);
//Bad format
}
