A Content-Length of 2^63 or more is accepted, then framed as no body #61

What happens

The validator accepts Content-Length values up to ulong.MaxValue: SemIsValidContentLengthValue (UltraHardenedParser.FullHeader.ROM.cs:371) compares 20-digit values against "18446744073709551615" (:410). The framing parse, though, accumulates in a signed long and gives up on overflow:

// BodyFramingDetector.cs, ParseContentLengthDigits
result = result * 10 + (b - '0');
if (result < 0) return -1; // overflow   (:160)

DetectBodyFraming then turns that -1 into NoBody (:52, :56):

Why it matters

As in #60, the body is read as the next request. A front end that takes the header at its word, waiting for the body or refusing it, disagrees with the back end about where the request ends. A header the parser accepted should never be framed as no body.

Responses share the parse: DetectResponseBodyFraming returns UntilClose for Content-Length: 9223372036854775808 (:131).

Fix

Either refuse these values (413), or frame them as long.MaxValue, which a server then refuses as too large instead of reading past it. Ktron's Kotlin port does the latter, in MDA2AV/Ktron@c6504d6.

main (f5d2cc1) and the NuGet package 0.3.7 both give the table above.