async-openssl 0.2.8

An implementation of SSL streams for async IO backed by OpenSSL
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# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Commands

```bash
# Check
cargo check --all --bins --examples --tests --all-features

# Run tests
cargo test

# Run a single test
cargo test <test_name>

# Lint
cargo clippy --all-features -- -W clippy::all

# Format
cargo fmt

# Check formatting
cargo fmt --all -- --check

# Check docs (warnings as errors)
RUSTDOCFLAGS="-D warnings" cargo doc --no-deps --document-private-items --all-features
```

CI runs with `RUSTFLAGS=-D warnings`, so all warnings are treated as errors.

Minimum supported Rust version: **1.85.0** (edition 2024).

## Architecture

This is a small, focused crate: a single public type `SslStream<S>` wrapping `openssl::ssl::SslStream` to implement `futures_io::AsyncRead` and `AsyncWrite` instead of std's blocking traits. The entire implementation lives in `src/lib.rs`.

**The bridging pattern:** OpenSSL's synchronous I/O model is bridged to async by an internal `StreamWrapper<S>` type that implements std `Read`/`Write` by calling `poll_read`/`poll_write` on the inner async stream. When the async stream returns `Poll::Pending`, `StreamWrapper` returns `WouldBlock`, and the two `cvt`/`cvt_ossl` helpers convert back from `WouldBlock` / `WANT_READ` / `WANT_WRITE` to `Poll::Pending`. The current waker is stored on `StreamWrapper` and updated each time `with_context` is called.

**Feature gate:** `build.rs` detects the OpenSSL version via `DEP_OPENSSL_VERSION_NUMBER` and sets the `ossl111` cfg flag for OpenSSL ≥ 1.1.1. Methods guarded by `#[cfg(ossl111)]` expose TLS 1.3 early-data support.

**Tests** (`src/test.rs`) use `smol` as the async runtime. The `google` test makes a live outbound TLS connection; the `server` test spins up a local TLS server using the self-signed cert/key in `tests/`.