/// <summary>
/// Calculates hash for data contained within an <see cref="EncryptionData"/> with a prefixed
/// salt value contained within an <see cref="EncryptionData"/>. A "salt" is random data
/// prefixed to every hashed value to prevent common dictionary attacks.
/// </summary>
/// <param name="data">The data to be used to hash.</param>
/// <param name="salt">The salt to use during the hash.</param>
/// <returns>a string containing the hash of the data provided.</returns>
public string Compute(EncryptionData data, EncryptionData salt)
{
return(_algorithm.Calculate(data, salt).Hex);
}
/// <summary>
/// Calculates hash for fixed length <see cref="EncryptionData"/>.
/// </summary>
/// <param name="data">The data to be used to hash.</param>
/// <returns>the hash of the data provided.</returns>
public EncryptionData Calculate(EncryptionData data)
{
Value.Bytes = _hashAlgorithm.ComputeHash(Check.NotNull(data, nameof(data)).Bytes);
return(Value);
}
/// <summary>
/// Calculates hash for data contained within an <see cref="EncryptionData"/> with a prefixed
/// salt value contained within an <see cref="EncryptionData"/>. A "salt" is random data
/// prefixed to every hashed value to prevent common dictionary attacks.
/// </summary>
/// <param name="data">The data to be used to hash.</param>
/// <param name="salt">The salt to use during the hash.</param>
/// <returns>a byte array containing the hash of the data provided.</returns>
public byte[] ComputeToBytes(EncryptionData data, EncryptionData salt)
{
return(_algorithm.Calculate(data, salt).Bytes);
}
public EncryptionData Decrypt(EncryptionData publicKey, EncryptionData encrypted, EncryptionData iv)
{
if (publicKey == null)
{
throw new ArgumentNullException(nameof(publicKey));
}
if (encrypted == null)
{
throw new ArgumentNullException(nameof(encrypted));
}
if (iv == null)
{
throw new ArgumentNullException(nameof(iv));
}
var decryptedMessage = new EncryptionData
{
EncodingToUse = Encoding.UTF8
};
var key = CngKey.Import(publicKey.Bytes, CngKeyBlobFormat.EccPublicBlob);
var derivedKey = _dh.DeriveKeyMaterial(key);
_encryptor.Key = derivedKey;
_encryptor.IV = iv.Bytes;
MemoryStream stream = null;
try
{
stream = new MemoryStream();
using (var decryption = _encryptor.CreateDecryptor())
{
using (var cryptStream = new CryptoStream(stream, decryption, CryptoStreamMode.Write))
{
cryptStream.Write(encrypted.Bytes, 0, encrypted.Bytes.Length);
decryptedMessage.Bytes = stream.ToArray();
}
}
}
finally
{
stream?.Dispose();
}
return(decryptedMessage);
}