Skip to content

Fix overlapping ChaCha20Poly1305 buffers on OpenSSL #4

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
axlibproject wants to merge 4 commits into
base: master
Choose a base branch
from
Open

Fix overlapping ChaCha20Poly1305 buffers on OpenSSL #4

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
78673a5
Fix overlapping ChaCha20Poly1305 buffers on OpenSSL
Nov 8, 2026
9fed5b4
Fix incomplete unencrypted reads and preserve buffered data
axlibproject Nov 8, 2026
c5c488b
Fix HTTP lines spanning multiple TCP reads or encrypted frames
axlibproject Nov 8, 2026
d658d2c
Fix connection lifecycle, chunked responses, pairing and cross-platfo…
axlibproject Nov 8, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
150 changes: 111 additions & 39 deletions HomeKitDotNet/Connection.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,8 @@ public class Connection : IDisposable
Channel<HttpResponseMessage> responses = Channel.CreateUnbounded<HttpResponseMessage>();
public event EventHandler<HttpResponseMessage>? EventReceived;
CancellationTokenSource token = new CancellationTokenSource();
private Task m_pReceiveTask = Task.CompletedTask;
private int m_nDisposed;

public Connection()
{
Expand All @@ -46,27 +48,34 @@ public async Task ConnectAsync(IPEndPoint ep, CancellationToken cancellationToke
await client.ConnectAsync(ep.Address, ep.Port, cancellationToken);
writer = new EncryptedStreamWriter(client.GetStream());
reader = new EncryptedStreamReader(client.GetStream());
await Task.Factory.StartNew(ReceiveLoop, token.Token);
m_pReceiveTask = Task.Run(ReceiveLoop);
}

public void Dispose()
{
token.Cancel();
token.Dispose();
client.Dispose();
// Close pending response waits as well as the socket, allowing repeated disposal.
if (Interlocked.Exchange(ref m_nDisposed, 1) == 0)
{
token.Cancel();
client.Dispose();
responses.Writer.TryComplete(new IOException("The HAP connection was closed."));
}
}

public async Task EnableEncryption(byte[] writeKey, byte[] readKey)
{
AssertConnected();
// Await the plaintext reader before enabling encrypted framing.
token.Cancel();
await m_pReceiveTask;
ObjectDisposedException.ThrowIf(Volatile.Read(ref m_nDisposed) != 0, this);
token.Dispose();

writer.EnableEncryption(new ChaCha20Poly1305(writeKey));
reader.EnableDecryption(new ChaCha20Poly1305(readKey));

token = new CancellationTokenSource();
await Task.Factory.StartNew(ReceiveLoop, token.Token);
m_pReceiveTask = Task.Run(ReceiveLoop);
}

public async Task<HttpResponseMessage> Get(string path, CancellationToken token)
Expand Down Expand Up @@ -98,11 +107,14 @@ public async Task<HttpResponseMessage> PostTLVs(string path, CancellationToken t

public async Task ReceiveLoop()
{
// Keep the token belonging to this loop during an encryption transition.
CancellationToken cancellationToken = token.Token;

try
{
while (!token.IsCancellationRequested)
while (!cancellationToken.IsCancellationRequested)
{
string? line = await reader!.ReadLineAsync(token.Token);
string? line = await reader!.ReadLineAsync(cancellationToken);
if (line == null)
throw new EndOfStreamException();
string[] parts = line.Split(' ', 3);
Expand All @@ -122,53 +134,103 @@ public async Task ReceiveLoop()
if (parts.Length == 2 && parts[0].Equals("Content-Type", StringComparison.InvariantCultureIgnoreCase))
type = parts[1];
if (parts.Length == 2 && parts[0].Equals("Transfer-Encoding", StringComparison.InvariantCultureIgnoreCase))
chunked = parts[1].Equals("chunked", StringComparison.InvariantCultureIgnoreCase);
line = await reader.ReadLineAsync(token.Token);
{
foreach (string encoding in parts[1].Split(',', StringSplitOptions.TrimEntries))
{
if (encoding.Equals("chunked", StringComparison.OrdinalIgnoreCase))
chunked = true;
}

}
line = await reader.ReadLineAsync(cancellationToken);
}
if (line == null)
throw new EndOfStreamException();
if (contentLen != 0)
// Chunked framing includes extensions, a final terminator and optional trailers.
if (chunked)
{
response.Content = new ByteArrayContent(await ReadChunkedBodyAsync(cancellationToken));
}
else if (contentLen != 0)
{
byte[] contentBytes = new byte[contentLen];
await reader.ReadBytesAsync(contentBytes, contentLen, token.Token);
await reader.ReadBytesAsync(contentBytes, contentLen, cancellationToken);
response.Content = new ByteArrayContent(contentBytes);
response.Content.Headers.ContentType = new MediaTypeHeaderValue(type);
}
else if (chunked)

if (MediaTypeHeaderValue.TryParse(type, out MediaTypeHeaderValue? contentType))
response.Content.Headers.ContentType = contentType;

if (protocol == "EVENT/1.0")
{
byte[] chunk = new byte[1024];
MemoryStream ms = new MemoryStream();
if (!int.TryParse((await reader.ReadLineAsync(token.Token)).Split(' ')[0], NumberStyles.HexNumber, null, out int chunkSize))
throw new EndOfStreamException("Truncated chunk read");

while (chunkSize > 0)
// Subscribers read from the beginning; the connection owns the response.
try
{
if (chunkSize > chunk.Length)
chunk = new byte[chunkSize];
await reader.ReadBytesAsync(chunk, chunkSize, token.Token);
ms.Write(chunk, 0, chunkSize);
await reader.Seek(2, token.Token); //CRLF after chunk
if (!int.TryParse((await reader.ReadLineAsync(token.Token)).Split(' ')[0], NumberStyles.HexNumber, null, out chunkSize))
throw new EndOfStreamException("Truncated chunk read");
}
Delegate[] arHandlers = EventReceived?.GetInvocationList() ?? [];

foreach (Delegate pHandler in arHandlers)
{
Stream pContent = response.Content.ReadAsStream();
pContent.Position = 0;
((EventHandler<HttpResponseMessage>)pHandler).Invoke(this, response);
}

await reader.Seek(2, token.Token); //CRLF after chunk
response.Content = new ByteArrayContent(ms.ToArray());
response.Content.Headers.ContentType = new MediaTypeHeaderValue(type);
}
finally
{
response.Dispose();
}
}
if (protocol == "EVENT/1.0")
EventReceived?.Invoke(this, response);
else
{
responses.Writer.TryWrite(response);
}
}
}
catch (OperationCanceledException) { } // Ignore
catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested) { } // Ignore
catch (Exception e)
{
Console.WriteLine("Error: " + e.ToString());
// Propagate reader failures instead of leaving requests waiting indefinitely.
responses.Writer.TryComplete(e);
Dispose();
}
}

private async Task<byte[]> ReadChunkedBodyAsync(CancellationToken cancellationToken)
{
// Reassemble chunks and consume trailers before reading the next response.
const int nMaxBodyLength = 16 * 1024 * 1024;
using MemoryStream pBody = new MemoryStream();
int nLength;

do
{
string sLine = await reader!.ReadLineAsync(cancellationToken);
int nExtension = sLine.IndexOf(';');
string sSize = nExtension >= 0 ? sLine.Substring(0, nExtension) : sLine;

if (!int.TryParse(sSize, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out nLength) || nLength < 0 || nLength > nMaxBodyLength - pBody.Length)
throw new InvalidDataException("Invalid HAP HTTP chunk size.");

if (nLength > 0)
{
byte[] arChunk = new byte[nLength];
await reader.ReadBytesAsync(arChunk, nLength, cancellationToken);
pBody.Write(arChunk);

if ((await reader.ReadLineAsync(cancellationToken)).Length != 0)
throw new InvalidDataException("Invalid HAP HTTP chunk terminator.");
}
}
while (nLength != 0);

while ((await reader!.ReadLineAsync(cancellationToken)).Length != 0)
{
}

return pBody.ToArray();
}

protected async Task<HttpResponseMessage> SendAsync(HttpMethod method, string path, ByteArrayContent? content, CancellationToken token)
{
AssertConnected();
Expand All @@ -187,13 +249,23 @@ protected async Task<HttpResponseMessage> SendAsync(HttpMethod method, string pa
msg.Append($"Content-Type: {content.Headers.ContentType}\r\n");
}
msg.Append("\r\n");
await semaphore.WaitAsync(token);
// Cancelled or timed-out requests must not leave a reusable, desynchronized session.
using CancellationTokenSource pLifetime = CancellationTokenSource.CreateLinkedTokenSource(token, this.token.Token);
await semaphore.WaitAsync(pLifetime.Token);
pLifetime.CancelAfter(TimeSpan.FromSeconds(15));
using CancellationTokenRegistration pRegistration = pLifetime.Token.Register(Dispose);

try{
await writer.WriteAsync(Encoding.UTF8.GetBytes(msg.ToString()), token);
await writer.WriteAsync(Encoding.UTF8.GetBytes(msg.ToString()), pLifetime.Token);
if (contentStream != null)
await writer.WriteAsync(contentStream, token);
await writer.FlushAsync(token);
return await responses.Reader.ReadAsync(token);
await writer.WriteAsync(contentStream, pLifetime.Token);
await writer.FlushAsync(pLifetime.Token);
return await responses.Reader.ReadAsync(pLifetime.Token);
}
catch
{
Dispose();
throw;
}
finally
{
Expand Down
Loading