The MIME tree walk had no depth limit, and the nesting comes off the wire.
A boundary line is a few bytes, so one message inside MaxMessageBytes can
declare tens of thousands of multipart levels and pick the recursion depth
of a daemon reading his mail. MaxMIMEDepth stops the walk at 12, well past
the three levels real mail uses, and the headers still come through.
ParseMessage converted the raw message to a string to read it, which copied
up to 2 MiB per mail on a box already holding the resident model. It reads
the bytes directly now. decodeCP1251 collected runes and then copied them
into a string, four bytes a character for the whole body, and writes into a
Builder instead.
No behaviour change to what is read: EXAMINE and BODY.PEEK are still the
only mailbox commands, and no credential reaches a log line.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
claude
4f96bbd6ec