Split Artifact::deserialize into two functions to prevent panics

wasmerio · Aug 23, 2022 · c0672d2 · c0672d2
1 parent ec95964
commit c0672d2
Showing 1 changed file with 23 additions and 10 deletions.
diff --git a/lib/compiler/src/engine/artifact.rs b/lib/compiler/src/engine/artifact.rs
@@ -96,14 +96,33 @@ impl Artifact {
         ))
     }
 
+
     /// Deserialize a ArtifactBuild
     ///
     /// # Safety
+    /// 
     /// This function is unsafe because rkyv reads directly without validating
-    /// the data.
-    pub unsafe fn deserialize(engine: &Engine, bytes: &[u8]) -> Result<Self, DeserializeError> {
+    /// the data. This function does not check whether the `Artifact` is an object file 
+    /// (use [`deserialize`] instead)
+    pub unsafe fn deserialize_unchecked(engine: &Engine, bytes: &[u8]) -> Result<Self, DeserializeError> {
+        let bytes = &bytes[ArtifactBuild::MAGIC_HEADER.len()..];
+        let metadata_len = MetadataHeader::parse(bytes)?;
+        let metadata_slice: &[u8] = &bytes[MetadataHeader::LEN..][..metadata_len];
+        let serializable = SerializableModule::deserialize(metadata_slice)?;
+        let artifact = ArtifactBuild::from_serializable(serializable);
+        let mut inner_engine = engine.inner_mut();
+        Self::from_parts(&mut inner_engine, artifact).map_err(DeserializeError::Compiler)
+    }
+
+    /// Deserialize a ArtifactBuild
+    ///
+    /// # Error
+    /// 
+    /// Returns an error if the bytes are not deserializable. If you don't 
+    /// want this behaviour, use [`deserialize_unchecked`]
+    pub fn deserialize(engine: &Engine, bytes: &[u8]) -> Result<Self, DeserializeError> {
         if !ArtifactBuild::is_deserializable(bytes) {
-            let static_artifact = Self::deserialize_object(engine, bytes);
+            let static_artifact = unsafe { Self::deserialize_object(engine, bytes) };
             match static_artifact {
                 Ok(v) => {
                     return Ok(v);
@@ -116,13 +135,7 @@ impl Artifact {
                 "The provided bytes are not wasmer-universal".to_string(),
             ));
         }
-        let bytes = &bytes[ArtifactBuild::MAGIC_HEADER.len()..];
-        let metadata_len = MetadataHeader::parse(bytes)?;
-        let metadata_slice: &[u8] = &bytes[MetadataHeader::LEN..][..metadata_len];
-        let serializable = SerializableModule::deserialize(metadata_slice)?;
-        let artifact = ArtifactBuild::from_serializable(serializable);
-        let mut inner_engine = engine.inner_mut();
-        Self::from_parts(&mut inner_engine, artifact).map_err(DeserializeError::Compiler)
+        unsafe { Self::deserialize_unchecked(engine, bytes) }
     }
 
     /// Construct a `ArtifactBuild` from component parts.