HTTP Parser VS American Fuzzy Lop

It looks not too different from the majority of HTTP parsers out there written in C. Here is an example of NodeJS [0].

[0] https://github.com/nodejs/http-parser/blob/main/http_parser....

NodeJS's HTTP parser used to be a handwritten C lib: http-parser

Whoa, I didn't know that! But yeah, it seems like https://github.com/nodejs/http-parser is based on nginx. It now uses https://github.com/nodejs/llhttp but has some of the same legacy.

On the other hand, deno's HTTP stuff is built on top of Hyper, a Rust library https://github.com/hyperium/hyper

Boost.Beast has its own HTTP parser[0], during the development of which Vinnie Falco (the principle author of Beast) found many bugs/inconsistencies in Node.js's own parser[1]

[0] https://www.boost.org/doc/libs/develop/libs/beast/doc/html/b...

[1] https://github.com/nodejs/http-parser/issues?q=is%3Aissue+au...

For cases where it is necessary to pass local information to/from a callback, the http_parser object's data field can be used.

Legacy HTTP/1.1 suffers a few issues, see the current RFC errata:

https://www.rfc-editor.org/errata_search.php?rfc=7230&rec_st...

There are issues particularly around how whitespace and obsolete line folding should be handled

https://github.com/nodejs/http-parser/issues?q=is%3Aissue+wh...

https://github.com/httpwg/http-core/issues/53

It's not as trivial as a few string splits.

There's picohttpparser and the one used in node.js: https://github.com/nodejs/http-parser

There's some efforts to guide test generation for property based testing to make the instruction pointer explore as large a space as possible.

This effort is more mature in the fuzzing community. See eg American Fuzzy Lop https://github.com/google/AFL

What you're describing, just generating random input to test a program, is sometimes called "blind fuzzing" but the state-of-the-art is far beyond that. Maybe try reading through the documentation of e.g. https://github.com/google/AFL to see what a fuzzer does and why just producing random input isn't even scratching the surface.

for general riscv I used to use this https://github.com/google/AFL I dont know if it supports x64 tho.

Ex ( AFL, WinAFL, HonggFuzz, LibFuzzer, Jazzer )

I wrote this little fuzz test target in order to fuzz it with afl (under ASan and UBSan):

afl, which is trivial to apply to this program:

I made my own version of a TCL interpreter (well, a very TCL like langauge) derived from "picol" available at https://github.com/howerj/pickle. There are many different re-implementations and derivatives of this interpreter but they all seem very "crashy", this one has been significantly hardened by using a fuzzer on it which ran for months called American Fuzzy Lop https://lcamtuf.coredump.cx/afl/ . It is also more suitable for embedded use whilst still not having arbitrary restrictions like many other implementations.

On Linux afl is a very powerful bug-finding tool, and it's a great companion when doing code review. Composes well with ASan and UBSan.

b-, https://lcamtuf.coredump.cx/afl/