HyperHTTP 2.1.0

Security

• Strip credentialed headers on unsafe redirects. Authorization,
  Proxy-Authorization, and Cookie are now removed whenever a redirect
  crosses origins (scheme/host/port) or downgrades from https:// to
  http://. Previously, a compromised or malicious upstream could capture
  tokens by returning a Location: pointing at an attacker domain. Auth
  helpers re-apply their own headers on every attempt, so same-origin
  chains still work transparently. (C1)
• Reject CRLF / NUL / non-token characters in request construction.
  Header names must now be valid RFC 7230 tokens; header values, request
  methods, request targets, URL hostnames, multipart field names, and
  multipart filenames are rejected if they contain \r, \n, or \0.
  Previously these were written verbatim to the wire, enabling HTTP
  request-smuggling, header injection, and multipart-part smuggling. (C2)
• Cap decompressed response size. New max_decompressed_size
Client knob (default 64 MiB) applied inside every decoder
  (gzip/deflate/brotli/zstd). Brotli input is also bounded pre-decode
  because the C decoder cannot stream, which previously made a ~1 KB
  brotli payload inflatable to unlimited memory. Raises
  hyperhttp.DecompressionError. (H1)
• Consumer-driven HTTP/2 flow control. Per-stream DATA queues are
  now bounded (32 chunks) and acknowledge_received_data fires only
  after the consumer drains each chunk. Previously the reader pre-acked
  every DATA frame, letting a hostile server stream an unbounded body
  regardless of the advertised window. (H2)
• Cap response body size. New max_response_size Client knob
  enforces a maximum raw-body byte count across both the streaming
  (aiter_bytes, aiter_raw) and materialising (aread) paths. An
  oversize Content-Length is rejected before any bytes are read.
  Raises hyperhttp.ResponseTooLarge. (H3)
• Fix pool waiter cancellation race. A transport handed off to a
  waiter whose acquire() had just timed out is now reclaimed back to
  the pool. Previously the connection could be stranded in the active
  set, slowly exhausting max_connections. (M1)
• Never leak Proxy-Authorization to origin servers. The H1
  transport now strips any user-supplied Proxy-Authorization header
  before writing the request head; on absolute-form (plain HTTP via
  HTTP proxy) the value from the proxy URL always wins. H2 already
  filtered this hop-by-hop header. (M2)
• Warn on verify=False. Disabling TLS verification now emits
  hyperhttp.InsecureRequestWarning at Client construction and
  on every create_ssl_context call, so misconfiguration surfaces
  in tests/CI instead of shipping silently. (M3)
• Scrub URLs in retry logs; validate redirect references. The
  retry handler now logs URL.sanitized() (no query string, no
  userinfo), so retry loops don't exfiltrate ?api_key= or
  user:pass@ credentials. URL.join() rejects CR/LF/NUL/TAB in
  the redirect reference. New URL.sanitized() helper.

Added

• hyperhttp.InsecureRequestWarning (exported from top-level).
• hyperhttp.ResponseTooLarge, hyperhttp.DecompressionError
  exceptions (exported).
• hyperhttp.LocalProtocolError is now exported from the top level.
• Client(max_response_size=..., max_decompressed_size=...) knobs.
• URL.sanitized() returns a log-safe string with query and userinfo
  redacted.

Changed

• HTTP/1 header insertion (Headers.add, Headers.set, bulk update,
  constructor) now validates names and values. This replaces silent
  corruption with an explicit LocalProtocolError for anything that
  would corrupt the wire framing.

• Client now emits InsecureRequestWarning at construction when
  verify=False is passed (and no ssl_context override is provided).

• MockTransport / MockResponse / Router: in-memory transport for
  tests. Accepts a callable handler (sync or async), a replay sequence,
  a single response, or a route mapping. Pass as
  Client(transport=MockTransport(...)) — the entire production stack
  (retries, auth, event hooks, cookies, redirects) runs, only the socket
  is replaced. Recorded calls are exposed via mock.calls, mock.call_count,
  mock.last_request, and mock.reset(). Handlers can raise any
  hyperhttp exception to exercise failure paths.

• Event hooks: Client(event_hooks={"request": [...], "response": [...]}).
  Hooks are sync or async callables that fire once per network attempt,
  unlocking OpenTelemetry / distributed tracing, structured logging,
  request signing (AWS SigV4, OAuth1), and per-request metrics. The
  event_hooks dict is also writable on a live client.

• Authentication helpers: hyperhttp.BasicAuth, hyperhttp.BearerAuth,
  hyperhttp.DigestAuth, and the extensible hyperhttp.Auth base class.
  Configure with Client(auth=...) or per-request client.get(..., auth=...).
  auth=("user", "pass") is shorthand for BasicAuth; auth=None on a
  request disables a client-level default. DigestAuth handles the
  401 → WWW-Authenticate → retry round-trip and supports MD5, SHA-256,
  SHA-512-256, their -sess variants, and qop=auth.

• HTTP and HTTPS proxy support via the new proxies= and trust_env= client
  arguments. HTTPS targets are tunnelled via CONNECT; environment variables
  (HTTP_PROXY, HTTPS_PROXY, ALL_PROXY, NO_PROXY) are honoured by
  default. New hyperhttp.ProxyURL helper and hyperhttp.ProxyError exception.

• multipart/form-data uploads via Client.post(files=..., data=...). File
  parts stream directly from disk in 1 MiB chunks with a pre-computed
  Content-Length (no chunked framing overhead), so a 10 GiB upload uses
  O(chunk) memory. New hyperhttp.MultipartEncoder and
  hyperhttp.MultipartFile for advanced control. Local benchmark
  (examples/benchmark_multipart.py) measures ~3.8 GiB/s on 100 MiB
  loopback uploads — 2.7× httpx and 4.4× aiohttp on the same host.

• H1 transport now honours explicit Content-Length (or a content_length
  attribute) on async-iterable bodies, skipping chunked framing whenever the
  size is known up front.

• py.typed marker so downstream type checkers pick up the public type hints.

• SECURITY.md with a disclosure policy.

Changed

• Minimum supported Python is now 3.9. Classifiers and tool configs
  (black, ruff, mypy) updated accordingly.