public void TestBadArguments()
{
V1DocumentHeaders documentHeaders = new V1DocumentHeaders(Passphrase.Empty, 37);
Assert.Throws <ArgumentNullException>(() =>
{
documentHeaders.WriteWithHmac(null);
});
Assert.Throws <ArgumentNullException>(() =>
{
documentHeaders.WriteWithoutHmac(null);
});
Assert.Throws <ArgumentNullException>(() =>
{
documentHeaders.Headers.Hmac = null;
});
}
/// <summary>
/// Write a copy of the current encrypted stream. Used to change meta-data
/// and encryption key(s) etc.
/// </summary>
/// <param name="outputStream"></param>
public void CopyEncryptedTo(V1DocumentHeaders outputDocumentHeaders, Stream cipherStream)
{
if (outputDocumentHeaders == null)
{
throw new ArgumentNullException("outputDocumentHeaders");
}
if (cipherStream == null)
{
throw new ArgumentNullException("cipherStream");
}
if (!cipherStream.CanSeek)
{
throw new ArgumentException("The output stream must support seek in order to back-track and write the HMAC.");
}
if (!PassphraseIsValid)
{
throw new InternalErrorException("Passphrase is not valid.");
}
using (V1HmacStream hmacStreamOutput = new V1HmacStream(outputDocumentHeaders.HmacSubkey.Key, cipherStream))
{
outputDocumentHeaders.WriteWithHmac(hmacStreamOutput);
using (V1AxCryptDataStream encryptedDataStream = CreateEncryptedDataStream(_reader.InputStream, DocumentHeaders.CipherTextLength))
{
encryptedDataStream.CopyTo(hmacStreamOutput);
if (Hmac != DocumentHeaders.Headers.Hmac)
{
throw new Axantum.AxCrypt.Core.Runtime.IncorrectDataException("HMAC validation error in the input stream.", ErrorStatus.HmacValidationError);
}
}
outputDocumentHeaders.Headers.Hmac = hmacStreamOutput.HmacResult;
// Rewind and rewrite the headers, now with the updated HMAC
outputDocumentHeaders.WriteWithoutHmac(cipherStream);
cipherStream.Position = cipherStream.Length;
}
}