Use hashes of uncompressed chunks.

Author: veluca93

pixie-server/Cargo.lock

@@ -29,6 +29,7 @@ futures = "0.3.30"
 tokio-stream = { version = "0.1.17", features = ["sync"] }
 chrono = "0.4.41"
 tokio-util = "0.7.15"
+lz4_flex = "0.11.5"
 
 [dependencies.pixie-shared]
 path = "../pixie-shared"

pixie-server/Cargo.toml

@@ -1,6 +1,6 @@
 use crate::state::{atomic_write, State, CHUNKS_DIR, IMAGES_DIR};
 use anyhow::{ensure, Context, Result};
-use pixie_shared::{ChunkHash, ChunkStats, ChunksStats, Image, ImagesStats};
+use pixie_shared::{ChunkHash, ChunkStats, ChunksStats, Image, ImagesStats, MAX_CHUNK_SIZE};
 use tokio::sync::watch;
 
 impl State {
@@ -29,7 +29,13 @@ impl State {
     /// Store the given chunk to the database.
     pub fn add_chunk(&self, data: &[u8]) -> Result<()> {
         let mut res = Ok(());
-        let hash = *blake3::hash(data).as_bytes();
+        let dec = lz4_flex::decompress(data, MAX_CHUNK_SIZE)?;
+        ensure!(
+            dec.len() <= MAX_CHUNK_SIZE,
+            "Decompressed chunk size is too big: {}",
+            dec.len()
+        );
+        let hash = *blake3::hash(&dec).as_bytes();
         let path = self.storage_dir.join(CHUNKS_DIR).join(hex::encode(hash));
         self.images_stats.send_if_modified(|images_stats| {
             res = (|| {

pixie-server/src/state/images.rs

@@ -198,8 +198,7 @@ pub async fn flash(os: UefiOS, server_addr: SocketAddrV4) -> Result<()> {
         let mut buf = vec![0; size];
         for &offset in &pos {
             disk.read(offset as u64, &mut buf).await.unwrap();
-            let cdata = lz4_flex::compress(&buf);
-            if blake3::hash(&cdata).as_bytes() == &hash {
+            if blake3::hash(&buf).as_bytes() == &hash {
                 found = Some(offset);
                 break;
             }

pixie-uefi/src/flash.rs

@@ -113,7 +113,7 @@ pub async fn store(os: UefiOS, server_address: SocketAddrV4) -> Result<()> {
             let mut data = vec![0; chunk_info.size];
             disk.read(chunk_info.start as u64, &mut data).await?;
             let cdata = compress(&data);
-            let hash = blake3::hash(&cdata).into();
+            let hash = blake3::hash(&data).into();
             let chunk = Chunk {
                 hash,
                 start: chunk_info.start,