json-archive/fuzz/fuzz_targets/fuzz_mutations.rs

115 lines
No EOL
4 KiB
Rust

#![no_main]
use libfuzzer_sys::fuzz_target;
use json_archive::{ArchiveReader, ReadMode};
use std::io::Write;
use tempfile::NamedTempFile;
fn create_archive_content(data: &[u8]) -> Vec<u8> {
// Start with a simple base archive
let base = r#"{"version":1,"created":"2025-01-01T00:00:00Z","initial":{"id":1}}
["observe", "obs-1", "2025-01-01T00:00:00Z", 1]
["add", "/name", "test", "obs-1"]"#;
let mut result = base.as_bytes().to_vec();
// Apply simple mutations based on fuzz input
if data.is_empty() {
return result;
}
// Keep mutations small and realistic
let max_size = 4096; // 4KB limit
for (i, &byte) in data.iter().take(16).enumerate() {
if result.len() > max_size {
break;
}
match byte % 8 {
0 => {
// Truncate at random position
let pos = (byte as usize) % result.len().max(1);
result.truncate(pos);
}
1 => {
// Insert invalid UTF-8
let pos = (byte as usize) % (result.len() + 1);
result.insert(pos, 0xFF);
}
2 => {
// Corrupt a quote
if let Some(pos) = result.iter().position(|&b| b == b'"') {
result[pos] = b'X';
}
}
3 => {
// Insert extra newline
let pos = (byte as usize) % (result.len() + 1);
result.insert(pos, b'\n');
}
4 => {
// Corrupt JSON bracket
if let Some(pos) = result.iter().position(|&b| b == b'[' || b == b'{') {
result[pos] = b'?';
}
}
5 => {
// Insert random byte
let pos = (byte as usize) % (result.len() + 1);
result.insert(pos, byte);
}
6 => {
// Remove a character
if !result.is_empty() {
let pos = (byte as usize) % result.len();
result.remove(pos);
}
}
_ => {
// Add some garbage line
let insertion = format!("\n[\"garbage\", {}]", i);
let pos = (byte as usize) % (result.len() + 1);
result.splice(pos..pos, insertion.bytes());
}
}
}
result
}
fuzz_target!(|data: &[u8]| {
let archive_content = create_archive_content(data);
if let Ok(mut temp_file) = NamedTempFile::new() {
if temp_file.write_all(&archive_content).is_ok() {
// Test both validation modes
for mode in [ReadMode::FullValidation, ReadMode::AppendSeek] {
if let Ok(reader) = ArchiveReader::new(temp_file.path(), mode) {
let result = reader.read(temp_file.path());
// Should never panic, regardless of input malformation
match result {
Ok(read_result) => {
// Basic invariants that should hold for any successful parse
let _ = &read_result.final_state;
let _ = &read_result.diagnostics;
// Observation count should be reasonable
assert!(read_result.observation_count < 100000);
// If we have diagnostics, they should be well-formed
for diagnostic in read_result.diagnostics.diagnostics() {
assert!(!diagnostic.description.is_empty());
}
},
Err(_) => {
// It's fine for the parser to reject malformed input
// Just make sure it doesn't panic
}
}
}
}
}
}
});