Noir Parser Fuzzer

A parser fuzzer for the Noir language.

Installation

To install the dependency required by the bnf-to-pest.py script:

pip install -r requirements.txt

Usage

BNF to Pest grammar

To convert the grammar.bnf file into the grammar.pest file, run:

python bnf-to-pest.py

Pest setup

To boostrap Pest:

cd generator_as_pest_fork
cargo build --package pest_bootstrap

Fuzzing setup

To setup afl:

cargo install cargo-afl

You need make installed.

Fuzzing

To fuzz:

cd tester_for_pest

# make sure you run "afl build" instead of "build", and rebuild every time
# so that the debug binary is updated 
cargo afl build

cargo afl fuzz -i in -o out target/debug/tester_for_pest

To list 10 first crashes:

cd tester_for_pest
ls -U out/default/crashes/ | head -10

To get detailed information for a crash, provide the tester with the crash input file name:

cd tester_for_pest
mkdir debug
cargo afl run -- out/default/crashes/id\:000000\,sig\:06\,src\:000000+000084\,time\:15815\,execs\:14618\,op\:splice\,rep\:16

Debug information about the case will be included in the debug directory.

To get information for every crash in a directory, provide the tester with the --all option and the directory's path:

cd tester_for_pest
mkdir debug
cargo afl run -- --all out/default/crashes/
ls debug

Progress

• BNF formal grammar
• converting BNF into Pest
• parsing
• generation
• fuzzing
• grammar compliance
• fix for found issues
• perfect grammar compliance

Reports

• noir-lang/noir#2375 - "parser does not allow parenthesizing in two type locations #2375" (closed)
• noir-lang/noir#2996 - "should the parser allow constructors in parentheses within if condition and `for`` range? #2996" (closed)
• noir-lang/noir#3232 - "Parsing ambiguity with expressions and lambdas #3232" (open)