zig-smtp/src/ at f8fa1ada8c0f052103a9e0d96b709653f450bde0 · jcollie.dev/zig-smtp · Tangled

jcollie.dev / zig-smtp

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An SMTP client and server library for Zig implementing RFC 5321.

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zig-smtp / src

6 files

at f8fa1ada8c0f052103a9e0d96b709653f450bde0

Jeffrey C. Ollie Add the CHUNKING extension (RFC 3030) 13d ago

Add the CHUNKING extension (RFC 3030) Command.bdat parses "BDAT <size> [LAST]" strictly. The server advertises CHUNKING and receives chunked messages on both handler paths: the collecting path reassembles raw chunks (no dot-stuffing, max_message_size enforced with 552), and BdatReader adapts the chunk sequence into the streaming handler's reader, replying 250 between chunks and handling RSET/QUIT/protocol violations mid-stream, with unread remainder drained. Framing is strictly length-based: a BDAT without a transaction still consumes its payload octets, and chunk payloads that look like commands are data. The client gains Extensions.chunking, bdat(chunk, last) (verbatim transmission, one flush per chunk), and sendMessageChunked; the CLI gains send --chunking, streaming stdin as BDAT chunks. The exim-client torture script and the byte-for-byte gauntlet unit test gain a BDAT section, and the VM interop suite delivers via CHUNKING to real Postfix and Exim (18 subtests passing). BINARYMIME remains deliberately unimplemented (BODY=BINARYMIME is rejected). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012HBHFhoTYa8TU9GLwobfbx

1 week ago

Add the CHUNKING extension (RFC 3030) Command.bdat parses "BDAT <size> [LAST]" strictly. The server advertises CHUNKING and receives chunked messages on both handler paths: the collecting path reassembles raw chunks (no dot-stuffing, max_message_size enforced with 552), and BdatReader adapts the chunk sequence into the streaming handler's reader, replying 250 between chunks and handling RSET/QUIT/protocol violations mid-stream, with unread remainder drained. Framing is strictly length-based: a BDAT without a transaction still consumes its payload octets, and chunk payloads that look like commands are data. The client gains Extensions.chunking, bdat(chunk, last) (verbatim transmission, one flush per chunk), and sendMessageChunked; the CLI gains send --chunking, streaming stdin as BDAT chunks. The exim-client torture script and the byte-for-byte gauntlet unit test gain a BDAT section, and the VM interop suite delivers via CHUNKING to real Postfix and Exim (18 subtests passing). BINARYMIME remains deliberately unimplemented (BODY=BINARYMIME is rejected). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012HBHFhoTYa8TU9GLwobfbx

1 week ago

Add Exim interop tests; switch client TLS to tls.zig The VM test now also runs the zsmtp client against Exim (ports 2625/2626) over plaintext, STARTTLS, and implicit TLS, with taint-safe appendfile delivery checked in /var/spool/exim-mail. Exim exposed a standard-library TLS bug: std.crypto.tls.Client only advances its record-decryption state upon receiving the TLS 1.3 middlebox-compatibility ChangeCipherSpec record, which is optional and disabled by Exim's OpenSSL setup, so the handshake died with TlsUnexpectedMessage. The client-side Tls wrapper now uses ianic/tls.zig (already used server-side) instead: init is in-place (the connection holds interior pointers), and the flush-through workaround is gone since tls.zig flushes each record to the stream. A sendmail interop test was built and passing but removed again since nixpkgs does not package the sendmail MTA. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012HBHFhoTYa8TU9GLwobfbx

1 week ago

Add the CHUNKING extension (RFC 3030) Command.bdat parses "BDAT <size> [LAST]" strictly. The server advertises CHUNKING and receives chunked messages on both handler paths: the collecting path reassembles raw chunks (no dot-stuffing, max_message_size enforced with 552), and BdatReader adapts the chunk sequence into the streaming handler's reader, replying 250 between chunks and handling RSET/QUIT/protocol violations mid-stream, with unread remainder drained. Framing is strictly length-based: a BDAT without a transaction still consumes its payload octets, and chunk payloads that look like commands are data. The client gains Extensions.chunking, bdat(chunk, last) (verbatim transmission, one flush per chunk), and sendMessageChunked; the CLI gains send --chunking, streaming stdin as BDAT chunks. The exim-client torture script and the byte-for-byte gauntlet unit test gain a BDAT section, and the VM interop suite delivers via CHUNKING to real Postfix and Exim (18 subtests passing). BINARYMIME remains deliberately unimplemented (BODY=BINARYMIME is rejected). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012HBHFhoTYa8TU9GLwobfbx

1 week ago

Add the CHUNKING extension (RFC 3030) Command.bdat parses "BDAT <size> [LAST]" strictly. The server advertises CHUNKING and receives chunked messages on both handler paths: the collecting path reassembles raw chunks (no dot-stuffing, max_message_size enforced with 552), and BdatReader adapts the chunk sequence into the streaming handler's reader, replying 250 between chunks and handling RSET/QUIT/protocol violations mid-stream, with unread remainder drained. Framing is strictly length-based: a BDAT without a transaction still consumes its payload octets, and chunk payloads that look like commands are data. The client gains Extensions.chunking, bdat(chunk, last) (verbatim transmission, one flush per chunk), and sendMessageChunked; the CLI gains send --chunking, streaming stdin as BDAT chunks. The exim-client torture script and the byte-for-byte gauntlet unit test gain a BDAT section, and the VM interop suite delivers via CHUNKING to real Postfix and Exim (18 subtests passing). BINARYMIME remains deliberately unimplemented (BODY=BINARYMIME is rejected). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012HBHFhoTYa8TU9GLwobfbx

1 week ago

RFC review: standards list, doc links, exim-derived protocol gauntlet README gains a Standards section listing every implemented RFC with its per-side coverage (5321, 1870, 6152, 2920, 3207, 8314, 4954, 4616, 2195, draft-murchison-sasl-login, 3463/2034, 6531, and 8446 via tls.zig). Doc comments now link each RFC mention to the datatracker, with section fragments where a section is cited; authLogin's doc notes it has no RFC. The review surfaced two fixes: the server always emitted RFC 3463 enhanced status codes but never advertised ENHANCEDSTATUSCODES (RFC 2034) - now it does; and root.zig's module doc still called TLS an eventual feature. Also adds a protocol gauntlet unit test distilled from exim's test suite (test/scripts/0000-Basic, notably 0019's syntax-error dialogue and the 0008/0100 dotted message lines), asserting the exact 28-reply transcript and resulting envelope. The dialogue was first validated by running exim's own scriptable test client (test/src/client.c, built with zig cc) against zsmtp serve. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012HBHFhoTYa8TU9GLwobfbx

1 week ago