chore(forge): cheat eip712 struct hash (#10626)

Author: 0xrusowsky

crates/cheatcodes/assets/cheatcodes.json

@@ -2910,6 +2910,29 @@ interface Vm {
     ///  * `typeName`: Name of the type (i.e. "Transaction").
     #[cheatcode(group = Utilities)]
     function eip712HashType(string calldata bindingsPath, string calldata typeName) external pure returns (bytes32 typeHash);
+
+    /// Generates the struct hash of the canonical EIP-712 type representation and its abi-encoded data.
+    ///
+    /// Supports 2 different inputs:
+    ///  1. Name of the type (i.e. "PermitSingle"):
+    ///     * requires previous binding generation with `forge bind-json`.
+    ///     * bindings will be retrieved from the path configured in `foundry.toml`.
+    ///
+    ///  2. String representation of the type (i.e. "Foo(Bar bar) Bar(uint256 baz)").
+    ///     * Note: the cheatcode will use the canonical type even if the input is malformated
+    ///             with the wrong order of elements or with extra whitespaces.
+    #[cheatcode(group = Utilities)]
+    function eip712HashStruct(string calldata typeNameOrDefinition, bytes calldata abiEncodedData) external pure returns (bytes32 typeHash);
+
+    /// Generates the struct hash of the canonical EIP-712 type representation and its abi-encoded data.
+    /// Requires previous binding generation with `forge bind-json`.
+    ///
+    /// Params:
+    ///  * `bindingsPath`: path where the output of `forge bind-json` is stored.
+    ///  * `typeName`: Name of the type (i.e. "PermitSingle").
+    ///  * `abiEncodedData`: ABI-encoded data for the struct that is being hashed.
+    #[cheatcode(group = Utilities)]
+    function eip712HashStruct(string calldata bindingsPath, string calldata typeName, bytes calldata abiEncodedData) external pure returns (bytes32 typeHash);
 }
 }
 

crates/cheatcodes/spec/src/vm.rs

@@ -1,8 +1,8 @@
 //! Implementations of [`Utilities`](spec::Group::Utilities) cheatcodes.
 
 use crate::{Cheatcode, Cheatcodes, CheatcodesExecutor, CheatsCtxt, Result, Vm::*};
-use alloy_dyn_abi::{eip712_parser::EncodeType, DynSolType, DynSolValue};
-use alloy_primitives::{aliases::B32, keccak256, map::HashMap, B64, U256};
+use alloy_dyn_abi::{eip712_parser::EncodeType, DynSolType, DynSolValue, Resolver};
+use alloy_primitives::{aliases::B32, keccak256, map::HashMap, Bytes, B64, U256};
 use alloy_sol_types::SolValue;
 use foundry_common::{ens::namehash, fs, TYPE_BINDING_PREFIX};
 use foundry_config::fs_permissions::FsAccessKind;
@@ -321,16 +321,7 @@ impl Cheatcode for eip712HashType_0Call {
     fn apply(&self, state: &mut Cheatcodes) -> Result {
         let Self { typeNameOrDefinition } = self;
 
-        let type_def = if typeNameOrDefinition.contains('(') {
-            // If the input contains '(', it must be the type definition
-            EncodeType::parse(typeNameOrDefinition).and_then(|parsed| parsed.canonicalize())?
-        } else {
-            // Otherwise, it must be the type name
-            let path = state
-                .config
-                .ensure_path_allowed(&state.config.bind_json_path, FsAccessKind::Read)?;
-            get_type_def_from_bindings(typeNameOrDefinition, path, &state.config.root)?
-        };
+        let type_def = get_canonical_type_def(typeNameOrDefinition, state, None)?;
 
         Ok(keccak256(type_def.as_bytes()).to_vec())
     }
@@ -347,8 +338,49 @@ impl Cheatcode for eip712HashType_1Call {
     }
 }
 
-/// Gets the type definition from the bindings in the provided path. Assumes that read validation
-/// for the path has already been checked.
+impl Cheatcode for eip712HashStruct_0Call {
+    fn apply(&self, state: &mut Cheatcodes) -> Result {
+        let Self { typeNameOrDefinition, abiEncodedData } = self;
+
+        let type_def = get_canonical_type_def(typeNameOrDefinition, state, None)?;
+        let primary = &type_def[..type_def.find('(').unwrap_or(type_def.len())];
+
+        get_struct_hash(primary, &type_def, abiEncodedData)
+    }
+}
+
+impl Cheatcode for eip712HashStruct_1Call {
+    fn apply(&self, state: &mut Cheatcodes) -> Result {
+        let Self { bindingsPath, typeName, abiEncodedData } = self;
+
+        let path = state.config.ensure_path_allowed(bindingsPath, FsAccessKind::Read)?;
+        let type_def = get_type_def_from_bindings(typeName, path, &state.config.root)?;
+
+        get_struct_hash(typeName, &type_def, abiEncodedData)
+    }
+}
+
+fn get_canonical_type_def(
+    name_or_def: &String,
+    state: &mut Cheatcodes,
+    path: Option<PathBuf>,
+) -> Result<String> {
+    let type_def = if name_or_def.contains('(') {
+        // If the input contains '(', it must be the type definition
+        EncodeType::parse(name_or_def).and_then(|parsed| parsed.canonicalize())?
+    } else {
+        // Otherwise, it must be the type name
+        let path = path.as_ref().unwrap_or(&state.config.bind_json_path);
+        let path = state.config.ensure_path_allowed(path, FsAccessKind::Read)?;
+        get_type_def_from_bindings(name_or_def, path, &state.config.root)?
+    };
+
+    Ok(type_def)
+}
+
+/// Gets the type definition from the bindings in the provided path.
+///
+/// Assumes that read validation for the path has already been checked.
 fn get_type_def_from_bindings(name: &String, path: PathBuf, root: &PathBuf) -> Result<String> {
     let content = fs::read_to_string(&path)?;
 
@@ -380,3 +412,40 @@ fn get_type_def_from_bindings(name: &String, path: PathBuf, root: &PathBuf) -> R
         }
     }
 }
+
+fn get_struct_hash(primary: &str, type_def: &String, abi_encoded_data: &Bytes) -> Result {
+    let mut resolver = Resolver::default();
+
+    // Populate the resolver by ingesting the canonical type definition, and then get the
+    // corresponding `DynSolType` of the primary type.
+    resolver
+        .ingest_string(type_def)
+        .map_err(|e| fmt_err!("Resolver failed to ingest type definition: {e}"))?;
+
+    let resolved_sol_type = resolver
+        .resolve(primary)
+        .map_err(|e| fmt_err!("Failed to resolve EIP-712 primary type '{primary}': {e}"))?;
+
+    // ABI-decode the bytes into `DynSolValue::CustomStruct`.
+    let sol_value = resolved_sol_type.abi_decode(abi_encoded_data.as_ref()).map_err(|e| {
+        fmt_err!("Failed to ABI decode using resolved_sol_type directly for '{primary}': {e}.")
+    })?;
+
+    // Use the resolver to properly encode the data.
+    let encoded_data: Vec<u8> = resolver
+        .encode_data(&sol_value)
+        .map_err(|e| fmt_err!("Failed to EIP-712 encode data for struct '{primary}': {e}"))?
+        .ok_or_else(|| fmt_err!("EIP-712 data encoding returned 'None' for struct '{primary}'"))?;
+
+    // Compute the type hash of the primary type.
+    let type_hash = resolver
+        .type_hash(primary)
+        .map_err(|e| fmt_err!("Failed to compute typeHash for EIP712 type '{primary}': {e}"))?;
+
+    // Compute the struct hash of the concatenated type hash and encoded data.
+    let mut bytes_to_hash = Vec::with_capacity(32 + encoded_data.len());
+    bytes_to_hash.extend_from_slice(type_hash.as_slice());
+    bytes_to_hash.extend_from_slice(&encoded_data);
+
+    Ok(keccak256(&bytes_to_hash).to_vec())
+}