add gz header fuzz test

Author: folkertdev

test-libz-rs-sys/src/deflate.rs

@@ -2540,3 +2540,166 @@ fn test_deflate_get_dict() {
         dictionary
     });
 }
+
+#[derive(Debug, Clone)]
+struct GzHeaderData {
+    text: i32,
+    time: core::ffi::c_ulong,
+    os: i32,
+    extra: Vec<u8>,
+    name: CString,
+    comment: CString,
+    hcrc: i32,
+}
+
+impl GzHeaderData {
+    fn as_gz_header(&mut self) -> libz_rs_sys::gz_header {
+        libz_rs_sys::gz_header {
+            text: self.text,
+            time: self.time,
+            xflags: 0,
+            os: self.os,
+            extra: self.extra.as_mut_ptr(),
+            extra_len: self.extra.len().try_into().unwrap(),
+            extra_max: 0,                              // doesn't matter for writing.
+            name: self.name.as_ptr() as *mut u8, // hack: UB if written to, but we shouldn't write during deflate.
+            name_max: 0,                         // doesn't matter for writing.
+            comment: self.comment.as_ptr() as *mut u8, // hack: UB if written to, but we shouldn't write during deflate.
+            comm_max: 0,                               // doesn't matter for writing.
+            hcrc: self.hcrc,
+            done: 0, // doesn't matter for writing.
+        }
+    }
+}
+
+#[derive(Debug)]
+struct Input {
+    source: String,
+    config: DeflateConfig,
+    flush: DeflateFlush,
+    header: GzHeaderData,
+}
+
+#[test]
+fn test_gzip_deflate_config() {
+    let input = 	Input {
+	    source: "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0~\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0_\0\0\0\0%\0\0\0\0\0\0\0\0\0\u{13}\0\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}i\\\\\\\\\\\\\\\\\\\\\\\\\\b\\\\\\\\\\\\\\\\\\\\\\\\\0\0\0\0\0\0\\\\\0\0\0\0\0\0\0\0\0\0\0\0\0\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{1a}\u{1b}\u{1b}&\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\0\u{3}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\\\\\\\0\0\0\0\0\0\0_\0\0\0\0%\0\0\0\0\0\0\0\0\0\u{13}\0\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}i\\\\\\\\\\\\\\\\\\\\\\\\\\b\\\\\\\\\\\\\\\\\\\\\\\\\0\0\0\0\0\0\\\\\0\0\0\0\0\0\0\0\0\0\0\0\0\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{1a}\u{1b}\u{1b}&\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\0\u{3}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\\\\\\\\\\\\L\\\\L\\\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\0\u{3}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\u{7f}\\\\\\\\\\\\L\\\\L\\*".to_owned(),
+	    config: DeflateConfig {
+	        level: -1,
+	        method: Method::Deflated,
+	        window_bits: 31,
+	        mem_level: 1,
+	        strategy: Strategy::Fixed,
+	    },
+	    flush: DeflateFlush::Block,
+	    header: GzHeaderData {
+	        text: -120653576,
+	        time: 17940362863843014904u64 as _, // may truncate, that's fine.
+	        os: -1,
+	        extra: vec![
+	            0,
+	        ],
+	        name: CString::default(),
+	        comment: CString::from(c"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"),
+	        hcrc: 1548508252,
+	    },
+	};
+
+    assert_eq_rs_ng!({
+        let Input {
+            ref source,
+            config,
+            flush,
+            ref header,
+        } = input;
+
+        let mut header = header.clone();
+
+        // Initialize stream.
+        let mut stream = core::mem::MaybeUninit::zeroed();
+        let err = unsafe {
+            deflateInit2_(
+                stream.as_mut_ptr(),
+                config.level,
+                config.method as i32,
+                config.window_bits,
+                config.mem_level,
+                config.strategy as i32,
+                zlibVersion(),
+                size_of::<z_stream>() as c_int,
+            )
+        };
+
+        assert_eq!(err, ReturnCode::Ok as i32);
+
+        let streamp = unsafe { stream.assume_init_mut() };
+
+        // Create header.
+        let mut header = unsafe {
+            #[allow(clippy::useless_transmute)]
+            core::mem::transmute::<libz_rs_sys::gz_header, gz_header>(header.as_gz_header())
+        };
+        let err = unsafe { deflateSetHeader(streamp, &mut header as gz_headerp) };
+        if err != ReturnCode::Ok as i32 {
+            // Deallocate, so that we don't trigger ASAN leak detector.
+            let err = unsafe { deflateEnd(streamp) };
+            assert_eq!(err, ReturnCode::Ok as i32);
+            return;
+        }
+
+        let bound = unsafe { deflateBound(streamp, source.len() as _) };
+        let buf_size = match flush {
+            DeflateFlush::NoFlush | DeflateFlush::Finish => bound,
+            // Other flush options might require more than `bound` bytes, so add a safety margin. We
+            // _could_ catch Z_BUF_ERROR to allocate more memory, but that's not interesting right now.
+            // (In fact, it's more interesting if NoFlush/Finish triggers UB write if we're
+            // miscalculating)
+            DeflateFlush::PartialFlush
+            | DeflateFlush::SyncFlush
+            | DeflateFlush::FullFlush
+            | DeflateFlush::Block => bound * 2,
+        };
+
+        // We deliberately use uninitialized memory as the input buffer here, to simulate how these
+        // functions will likely be used from C, and to catch us ever reading uninitialized memory.
+        let mut dest: Vec<u8> = Vec::with_capacity(buf_size as usize);
+
+        let max = c_uint::MAX as usize;
+
+        let mut left = dest.capacity();
+        let mut source_len = source.len();
+
+        streamp.next_in = source.as_ptr().cast_mut().cast();
+        streamp.next_out = dest.as_mut_ptr().cast();
+
+        loop {
+            if streamp.avail_out == 0 {
+                streamp.avail_out = Ord::min(left, max) as _;
+                left -= streamp.avail_out as usize;
+            }
+
+            if streamp.avail_in == 0 {
+                streamp.avail_in = Ord::min(source_len, max) as _;
+                source_len -= streamp.avail_in as usize;
+            }
+
+            let flush = if source_len > 0 {
+                flush
+            } else {
+                DeflateFlush::Finish
+            };
+
+            let err = unsafe { deflate(streamp, flush as i32) };
+            if ReturnCode::from(err) != ReturnCode::Ok {
+                break;
+            }
+        }
+
+        unsafe { dest.set_len(streamp.total_out as usize) }
+
+        let err = unsafe { deflateEnd(streamp) };
+        assert_eq!(ReturnCode::from(err), ReturnCode::Ok);
+
+        Some(dest)
+    });
+}

test-libz-rs-sys/src/gz.rs

@@ -1,10 +1,9 @@
-use zlib_rs::c_api::*;
-
 use z_rs::{
     gzFile_s, gzbuffer, gzclearerr, gzclose, gzclose_r, gzclose_w, gzdirect, gzdopen, gzerror,
     gzflush, gzfread, gzfwrite, gzgetc, gzgetc_, gzgets, gzoffset, gzopen, gzopen64, gzputc,
     gzputs, gzread, gzrewind, gzseek, gzsetparams, gztell, gzungetc, gzwrite,
 };
+use zlib_rs::c_api::*;
 
 use libc::size_t;
 use std::ffi::{c_char, c_int, c_uint, c_void, CStr, CString};