Use libdeflater to inflate

src/deflate/deflater.rs

@@ -1,6 +1,6 @@
 use crate::atomicmin::AtomicMin;
 use crate::{PngError, PngResult};
-use libdeflater::{CompressionError, CompressionLvl, Compressor};
+use libdeflater::*;
 
 pub fn deflate(data: &[u8], level: u8, max_size: &AtomicMin) -> PngResult<Vec<u8>> {
     let mut compressor = Compressor::new(CompressionLvl::new(level.into()).unwrap());
@@ -23,3 +23,16 @@ pub fn deflate(data: &[u8], level: u8, max_size: &AtomicMin) -> PngResult<Vec<u8
     dest.truncate(len);
     Ok(dest)
 }
+
+pub fn inflate(data: &[u8], out_size: usize) -> PngResult<Vec<u8>> {
+    let mut decompressor = Decompressor::new();
+    let mut dest = vec![0; out_size];
+    let len = decompressor
+        .zlib_decompress(data, &mut dest)
+        .map_err(|err| match err {
+            DecompressionError::BadData => PngError::InvalidData,
+            DecompressionError::InsufficientSpace => PngError::new("inflated data too long"),
+        })?;
+    dest.truncate(len);
+    Ok(dest)
+}

src/deflate/mod.rs

@@ -14,6 +14,8 @@ pub mod miniz_stream;
 mod deflater;
 #[cfg(feature = "libdeflater")]
 pub use deflater::deflate as libdeflater_deflate;
+#[cfg(feature = "libdeflater")]
+pub use deflater::inflate as libdeflater_inflate;
 
 #[cfg(any(target_arch = "x86_64", target_arch = "aarch64"))]
 pub mod cfzlib;

src/lib.rs

@@ -26,7 +26,7 @@ mod rayon;
 
 use crate::atomicmin::AtomicMin;
 use crate::colors::BitDepth;
-use crate::deflate::inflate;
+use crate::deflate::libdeflater_inflate;
 use crate::evaluate::Evaluator;
 use crate::png::PngData;
 use crate::png::PngImage;
@@ -948,7 +948,9 @@ fn srgb_rendering_intent(mut iccp: &[u8]) -> Option<u8> {
     if compression_method != 0 {
         return None; // The profile is supposed to be compressed (method 0)
     }
-    let icc_data = inflate(compressed_data).ok()?;
+    // The decompressed size is unknown so we have to guess the required buffer size
+    let max_size = (compressed_data.len() * 2).max(1000);
+    let icc_data = libdeflater_inflate(compressed_data, max_size).ok()?;
 
     let rendering_intent = *icc_data.get(67)?;
 

src/png/mod.rs

@@ -112,7 +112,7 @@ impl PngData {
             None => return Err(PngError::ChunkMissing("IHDR")),
         };
         let ihdr_header = parse_ihdr_header(&ihdr)?;
-        let raw_data = deflate::inflate(idat_headers.as_ref())?;
+        let raw_data = deflate::libdeflater_inflate(idat_headers.as_ref(), ihdr_header.raw_data_size())?;
 
         // Reject files with incorrect width/height or truncated data
         if raw_data.len() != ihdr_header.raw_data_size() {