fix(barz): Replace u32 parameters with i32 (#4504)

* Disallow to use unsigned integer parameters within class methods

Author: satoshiotomakan

rust/tw_evm/src/ffi/barz.rs

@@ -41,18 +41,18 @@ pub unsafe extern "C" fn tw_barz_get_counterfactual_address(
 
 /// Returns the init code parameter of ERC-4337 User Operation
 ///
-/// \param factory The address of the factory contract.
+/// \param factory The address of the factory contract
 /// \param public_key Public key for the verification facet
-/// \param verification_facet The address of the verification facet.
-/// \param salt The salt of the init code.
+/// \param verification_facet The address of the verification facet
+/// \param salt The salt of the init code; Must be non-negative
 /// \return The init code.
 #[tw_ffi(ty = static_function, class = TWBarz, name = GetInitCode)]
 #[no_mangle]
 pub unsafe extern "C" fn tw_barz_get_init_code(
     factory: Nonnull<TWString>,
     public_key: NonnullMut<TWPublicKey>,
     verification_facet: Nonnull<TWString>,
-    salt: u32,
+    salt: i32,
 ) -> NullableMut<TWData> {
     let factory_address = try_or_else!(TWString::from_ptr_as_ref(factory), std::ptr::null_mut);
     let factory_address = try_or_else!(factory_address.as_str(), std::ptr::null_mut);
@@ -63,6 +63,8 @@ pub unsafe extern "C" fn tw_barz_get_init_code(
         std::ptr::null_mut
     );
     let verification_facet = try_or_else!(verification_facet.as_str(), std::ptr::null_mut);
+    let salt = try_or_else!(salt.try_into(), std::ptr::null_mut);
+
     let init_code = try_or_else!(
         get_init_code(
             factory_address,
@@ -117,18 +119,20 @@ pub unsafe extern "C" fn tw_barz_get_formatted_signature(
 ///
 /// \param msg_hash Original msgHash
 /// \param barzAddress The address of Barz wallet signing the message
-/// \param chainId The chainId of the network the verification will happen
+/// \param chainId The chainId of the network the verification will happen; Must be non-negative
 /// \return The final hash to be signed.
 #[tw_ffi(ty = static_function, class = TWBarz, name = GetPrefixedMsgHash)]
 #[no_mangle]
 pub unsafe extern "C" fn tw_barz_get_prefixed_msg_hash(
     msg_hash: Nonnull<TWData>,
     barz_address: Nonnull<TWString>,
-    chain_id: u32,
+    chain_id: i32,
 ) -> NullableMut<TWData> {
     let msg_hash = try_or_else!(TWData::from_ptr_as_ref(msg_hash), std::ptr::null_mut);
     let barz_address = try_or_else!(TWString::from_ptr_as_ref(barz_address), std::ptr::null_mut);
     let barz_address = try_or_else!(barz_address.as_str(), std::ptr::null_mut);
+    let chain_id = try_or_else!(chain_id.try_into(), std::ptr::null_mut);
+
     let prefixed_msg_hash = try_or_else!(
         get_prefixed_msg_hash(msg_hash.as_slice(), barz_address, chain_id),
         std::ptr::null_mut

rust/tw_macros/src/lib.rs

@@ -2,6 +2,7 @@ use proc_macro::TokenStream;
 
 mod code_gen;
 mod tw_ffi;
+mod utils;
 
 #[proc_macro_attribute]
 pub fn tw_ffi(attr: TokenStream, item: TokenStream) -> TokenStream {

rust/tw_macros/src/tw_ffi.rs

@@ -12,6 +12,7 @@ use std::fs;
 use std::path::Path;
 
 use crate::code_gen::{TWArg, TWConfig, TWFunction};
+use crate::utils::is_uint;
 
 pub mod keywords {
     use syn::custom_keyword;
@@ -134,6 +135,13 @@ pub fn tw_ffi(attr: TokenStream2, item: TokenStream2) -> Result<TokenStream2> {
     };
 
     let class = args.class.unwrap().to_string();
+    // TODO add support for structs.
+    if func_args.iter().any(|arg| is_uint(&arg.ty)) {
+        return Err(syn::Error::new(
+            proc_macro2::Span::call_site(),
+            "Unsigned integers are not supported within class methods. Consider using 'struct' or signed integers. See https://kotlinlang.org/docs/inline-classes.html#mangling"
+        ));
+    }
     let docs = func
         .attrs
         .iter()

rust/tw_macros/src/utils.rs

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: Apache-2.0
+//
+// Copyright © 2017 Trust Wallet.
+
+pub fn is_uint(ty: &str) -> bool {
+    matches!(ty, "u8" | "u16" | "u32" | "u64" | "u128" | "usize")
+}