From 8c63257a11c4d8115c104c678de3cfa4af49d2b8 Mon Sep 17 00:00:00 2001
From: Simon Warta <simon@warta.it>
Date: Mon, 27 Mar 2023 10:28:22 +0200
Subject: [PATCH] Add Cache::save_wasm_unchecked

---
 CHANGELOG.md             |  8 ++++++
 packages/vm/src/cache.rs | 55 ++++++++++++++++++++++++++++++++--------
 2 files changed, 52 insertions(+), 11 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e588c6ccbc..9b95cf4e85 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,14 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Added
+
+- cosmwasm-vm: Add `Cache::save_wasm_unchecked` to save Wasm blobs that have
+  been checked before. This is useful for state-sync where we know the Wasm code
+  was checked when it was first uploaded. ([#1635])
+
+[#1635]: https://github.com/CosmWasm/cosmwasm/pull/1635
+
 ### Changed
 
 - cosmwasm-vm: Add checks for table section of Wasm blob ([#1631]).
diff --git a/packages/vm/src/cache.rs b/packages/vm/src/cache.rs
index 3984e5e114..46a64e5e80 100644
--- a/packages/vm/src/cache.rs
+++ b/packages/vm/src/cache.rs
@@ -159,8 +159,27 @@ where
         }
     }
 
+    /// Takes a Wasm bytecode and stores it to the cache.
+    ///
+    /// This performs static checks, compiles the bytescode to a module and
+    /// stores the Wasm file on disk.
+    ///
+    /// This does the same as [`save_wasm_unchecked`] plus the static checks.
+    /// When a Wasm blob is stored the first time, use this function.
     pub fn save_wasm(&self, wasm: &[u8]) -> VmResult<Checksum> {
         check_wasm(wasm, &self.available_capabilities)?;
+        self.save_wasm_unchecked(wasm)
+    }
+
+    /// Takes a Wasm bytecode and stores it to the cache.
+    ///
+    /// This compiles the bytescode to a module and
+    /// stores the Wasm file on disk.
+    ///
+    /// This does the same as [`save_wasm`] but without the static checks.
+    /// When a Wasm blob is stored which was previously checked (e.g. as part of state sync),
+    /// use this function.
+    pub fn save_wasm_unchecked(&self, wasm: &[u8]) -> VmResult<Checksum> {
         let module = compile(wasm, None, &[])?;
 
         let mut cache = self.inner.lock().unwrap();
@@ -431,6 +450,14 @@ mod tests {
 
     static CONTRACT: &[u8] = include_bytes!("../testdata/hackatom.wasm");
     static IBC_CONTRACT: &[u8] = include_bytes!("../testdata/ibc_reflect.wasm");
+    // Invalid because it doesn't contain required memory and exports
+    static INVALID_CONTRACT_WAT: &str = r#"(module
+        (type $t0 (func (param i32) (result i32)))
+        (func $add_one (export "add_one") (type $t0) (param $p0 i32) (result i32)
+            get_local $p0
+            i32.const 1
+            i32.add))
+    "#;
 
     fn default_capabilities() -> HashSet<String> {
         capabilities_from_csv("iterator,staking")
@@ -489,17 +516,7 @@ mod tests {
 
     #[test]
     fn save_wasm_rejects_invalid_contract() {
-        // Invalid because it doesn't contain required memory and exports
-        let wasm = wat::parse_str(
-            r#"(module
-            (type $t0 (func (param i32) (result i32)))
-            (func $add_one (export "add_one") (type $t0) (param $p0 i32) (result i32)
-              get_local $p0
-              i32.const 1
-              i32.add))
-            "#,
-        )
-        .unwrap();
+        let wasm = wat::parse_str(INVALID_CONTRACT_WAT).unwrap();
 
         let cache: Cache<MockApi, MockStorage, MockQuerier> =
             unsafe { Cache::new(make_testing_options()).unwrap() };
@@ -530,6 +547,22 @@ mod tests {
         assert_eq!(cache.stats().misses, 0);
     }
 
+    #[test]
+    fn save_wasm_unchecked_works() {
+        let cache: Cache<MockApi, MockStorage, MockQuerier> =
+            unsafe { Cache::new(make_testing_options()).unwrap() };
+        cache.save_wasm_unchecked(CONTRACT).unwrap();
+    }
+
+    #[test]
+    fn save_wasm_unchecked_accepts_invalid_contract() {
+        let wasm = wat::parse_str(INVALID_CONTRACT_WAT).unwrap();
+
+        let cache: Cache<MockApi, MockStorage, MockQuerier> =
+            unsafe { Cache::new(make_testing_options()).unwrap() };
+        cache.save_wasm_unchecked(&wasm).unwrap();
+    }
+
     #[test]
     fn load_wasm_works() {
         let cache: Cache<MockApi, MockStorage, MockQuerier> =