/// <summary>
/// Serialize the HTTP content to a stream as an asynchronous operation.
/// </summary>
/// <param name="stream">The target stream.</param>
/// <param name="context">Information about the transport (channel binding token, for example). This parameter may be null.</param>
/// <returns>The task object representing the asynchronous operation.</returns>
protected override async Task SerializeToStreamAsync(Stream stream, TransportContext context)
{
if (!_contentToBeDecrypted.Headers.ContentEncoding.Contains(Constants.ENCRYPTED_CONTENT_ENCODING))
{
throw new NotSupportedException($"Encryption type not supported or stream isn't encrypted. The only sypported encryption type is '{Constants.ENCRYPTED_CONTENT_ENCODING}'.");
}
Stream streamToBeDecrypted = await _contentToBeDecrypted.ReadAsStreamAsync().ConfigureAwait(false);
await Aes128GcmEncoding.DecodeAsync(streamToBeDecrypted, stream, _keyLocator).ConfigureAwait(false);
}
/// <summary>
/// Determines whether the HTTP content has a valid length in bytes.
/// </summary>
/// <param name="length">The length in bytes of the HTTP content.</param>
/// <returns>True if length is a valid length, otherwise false.</returns>
protected override bool TryComputeLength(out long length)
{
length = 0;
bool hasValidLength = false;
if (_length.HasValue)
{
length = _length.Value;
hasValidLength = true;
}
else
{
HttpContentTryComputeLengthDelegate httpContentTryComputeLengthDelegateInstance = (HttpContentTryComputeLengthDelegate)_httpContentTryComputeLengthMethodInfo.CreateDelegate(_httpContentTryComputeLengthDelegateType, _contentToBeEncrypted);
if (httpContentTryComputeLengthDelegateInstance(out long sourceLength))
{
_length = length = Aes128GcmEncoding.ComputeEncodedLength(sourceLength, (byte)(_keyId?.Length ?? 0), _recordSize);
hasValidLength = true;
}
}
return(hasValidLength);
}
/// <summary>
/// Serialize the HTTP content to a stream as an asynchronous operation.
/// </summary>
/// <param name="stream">The target stream.</param>
/// <param name="context">Information about the transport (channel binding token, for example). This parameter may be null.</param>
/// <returns>The task object representing the asynchronous operation.</returns>
protected override async Task SerializeToStreamAsync(Stream stream, TransportContext context)
{
Stream streamToBeEncrypted = await _contentToBeEncrypted.ReadAsStreamAsync().ConfigureAwait(false);
await Aes128GcmEncoding.EncodeAsync(streamToBeEncrypted, stream, _key, _keyId, _recordSize).ConfigureAwait(false);
}
/// <summary>
/// Instantiates a new <see cref="Aes128GcmDecodedContent"/>.
/// </summary>
/// <param name="contentToBeDecrypted">The content which will be decoded.</param>
/// <param name="keyProvider">The function which is able to provide the keying material based on the keying material identificator.</param>
public Aes128GcmDecodedContent(HttpContent contentToBeDecrypted, Func <string, byte[]> keyProvider)
: this(contentToBeDecrypted, Aes128GcmEncoding.ConvertToByteArrayBasedKeyProvider(keyProvider))
{
}
/// <summary>
/// Instantiates a new <see cref="Aes128GcmEncodingHandler"/>.
/// </summary>
/// <param name="keyProvider">The function which is able to provide the keying material based on the keying material identificator.</param>
public Aes128GcmEncodingHandler(Func <string, byte[]> keyProvider)
: this(Aes128GcmEncoding.ConvertToByteArrayBasedKeyProvider(keyProvider))
{
}
