v2.0.0 — HTTP framing and response hardening

Security hardening for request/response framing, resource limits, and Rack compatibility. This major release includes changes to non-streaming retries and response-hook types.

Breaking changes

• Non-streaming requests no longer automatically retry transport failures.
  This prevents replay with consumed request input; applications that require
  retries must implement them with a fresh body and an explicit retry policy.
• Rack 3 response hooks receive arrays for repeated header values, including
  Set-Cookie, and non-streaming statuses are integers. Update hooks that
  assumed newline-separated headers or string statuses. Rack 2 retains its
  newline-separated header representation.
• Invalid or ambiguous HTTP framing is now rejected, incomplete responses fail,
  and uploads without a known length use fresh chunked framing. Backends must
  accept properly framed HTTP/1.1 requests and send valid, complete responses.

Security

• Reframe decoded request bodies without a CONTENT_LENGTH using chunked
  encoding instead of sending body bytes after Content-Length: 0. Bound
  known-length input streams so excess bytes cannot become another backend
  request; malformed lengths and prematurely ended uploads return 400.
• Reject ambiguous backend framing (Transfer-Encoding with Content-Length,
  conflicting or invalid lengths, and unsupported transfer codings) with 502.
• Strip response headers named by the backend's Connection fields as well as
  the standard hop-by-hop headers.
• Enforce max_response_length before buffering each chunk in non-streaming
  mode, including rejecting declared oversized responses before reading them.
• Detect premature EOF in fixed-length responses: return 502 before sending
  headers, or raise while streaming so the server aborts the incomplete transfer.
• Disable Net::HTTP transport retries in non-streaming mode as well as streaming
  mode, preventing replay with an already-consumed request body.

Fixed

• Return integer statuses in non-streaming mode and preserve multiple response
  header values as arrays on Rack 3 (including Set-Cookie). Rack 2 keeps its
  newline-separated representation.
• Remove entity headers forbidden by Rack on 1xx/204/304 responses. HEAD and
  304 representation sizes no longer incorrectly trigger the response body cap.
• Replace a remaining live-host test with a local fixture and simulate failed
  DNS resolution without sending external DNS queries. Add offline adversarial
  framing, size-limit, retry, and Rack::Lint regression checks.

See the upgrade guide before upgrading.

Install with gem "rack-proxy", "~> 2.0".

Full changelog: v1.0.2...v2.0.0