/// <summary>
/// Decrypts a string using the <see cref="Aes"/> algorithm.
/// </summary>
/// <param name="s">The encrypted string.</param>
/// <param name="data">The <see cref="CryptographicData"/> used to encrypt the string.</param>
/// <returns>Returns the decrypted string.</returns>
public async Task <string> AesDecryptAsync(string s, CryptographicData data)
{
var transform = aes.CreateDecryptor(data.AesKey, data.AesIV);
var memoryStream = new MemoryStream(Convert.FromBase64String(s));
var cryptoStream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Read);
var reader = new StreamReader(cryptoStream);
var decrypted = await reader.ReadToEndAsync();
reader.Dispose();
cryptoStream.Dispose();
memoryStream.Dispose();
transform.Dispose();
return(decrypted);
}
/// <summary>
/// Encrypts a string using the <see cref="Aes"/> algorithm.
/// </summary>
/// <param name="s">The cipher string.</param>
/// <param name="data">The <see cref="CryptographicData"/> that should be used.</param>
/// <returns>Returns the encrypted string.</returns>
public async Task <string> AesEncryptAsync(string s, CryptographicData data)
{
var transform = aes.CreateEncryptor(data.AesKey, data.AesIV);
var memoryStream = new MemoryStream();
using (var cryptoStream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write)) {
using (var writer = new StreamWriter(cryptoStream)) {
await writer.WriteAsync(s);
}
}
var encrypted = Convert.ToBase64String(memoryStream.ToArray());
memoryStream.Dispose();
transform.Dispose();
return(encrypted);
}
/// <summary>
/// Validates a signature for a string using the <see cref="HMACSHA256"/> algorithm.
/// </summary>
/// <param name="s">The string to check.</param>
/// <param name="signature">The signature to validate.</param>
/// <param name="data">The <see cref="CryptographicData"/> used to create the signature.</param>
/// <returns>Returns "true" if the signature is valid, otherwise "false".</returns>
public bool HmacValidateSignature(string s, string signature, CryptographicData data)
{
hmac = new HMACSHA256(data.HmacKey);
return(string.Equals(signature, HmacCreateSignature(s, data)));
}
/// <summary>
/// Creates a signature for a string using the <see cref="HMACSHA256"/> algorithm.
/// </summary>
/// <param name="s">The string to sign.</param>
/// <param name="data">The <see cref="CryptographicData"/> that should be used.</param>
/// <returns>Returns the signature for the string.</returns>
public string HmacCreateSignature(string s, CryptographicData data)
{
hmac = new HMACSHA256(data.HmacKey);
return(Convert.ToBase64String(hmac.ComputeHash(Encoding.UTF8.GetBytes(s))));
}
