From ce5985918fd28a9b581eb465e016b9ac18ec62a3 Mon Sep 17 00:00:00 2001
From: DaniPopes <57450786+DaniPopes@users.noreply.github.com>
Date: Tue, 20 Feb 2024 12:33:30 +0200
Subject: [PATCH] feat(cast): add `wallet sign --no-hash` (#7180)

* feat(cast): add `wallet sign --no-hash`

* doc

* doc
---
 crates/cast/bin/cmd/wallet/mod.rs   | 22 ++++++++++++++--------
 crates/wallets/src/error.rs         |  2 ++
 crates/wallets/src/wallet_signer.rs | 14 ++++++++++++++
 3 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/crates/cast/bin/cmd/wallet/mod.rs b/crates/cast/bin/cmd/wallet/mod.rs
index 051eb3d4295bc..5850c523a368d 100644
--- a/crates/cast/bin/cmd/wallet/mod.rs
+++ b/crates/cast/bin/cmd/wallet/mod.rs
@@ -78,12 +78,13 @@ pub enum WalletSubcommands {
     /// Sign a message or typed data.
     #[clap(visible_alias = "s")]
     Sign {
-        /// The message or typed data to sign.
+        /// The message, typed data, or hash to sign.
+        ///
+        /// Messages starting with 0x are expected to be hex encoded, which get decoded before
+        /// being signed.
         ///
-        /// Messages starting with 0x are expected to be hex encoded,
-        /// which get decoded before being signed.
         /// The message will be prefixed with the Ethereum Signed Message header and hashed before
-        /// signing.
+        /// signing, unless `--no-hash` is provided.
         ///
         /// Typed data can be provided as a json string or a file name.
         /// Use --data flag to denote the message is a string of typed data.
@@ -92,15 +93,18 @@ pub enum WalletSubcommands {
         /// The data should be formatted as JSON.
         message: String,
 
-        /// If provided, the message will be treated as typed data.
+        /// Treat the message as JSON typed data.
         #[clap(long)]
         data: bool,
 
-        /// If provided, the message will be treated as a file name containing typed data. Requires
-        /// --data.
+        /// Treat the message as a file containing JSON typed data. Requires `--data`.
         #[clap(long, requires = "data")]
         from_file: bool,
 
+        /// Treat the message as a raw 32-byte hash and sign it directly without hashing it again.
+        #[clap(long, conflicts_with = "data")]
+        no_hash: bool,
+
         #[clap(flatten)]
         wallet: WalletOpts,
     },
@@ -247,7 +251,7 @@ impl WalletSubcommands {
                 let addr = wallet.address();
                 println!("{}", addr.to_alloy().to_checksum(None));
             }
-            WalletSubcommands::Sign { message, data, from_file, wallet } => {
+            WalletSubcommands::Sign { message, data, from_file, no_hash, wallet } => {
                 let wallet = wallet.signer().await?;
                 let sig = if data {
                     let typed_data: TypedData = if from_file {
@@ -258,6 +262,8 @@ impl WalletSubcommands {
                         serde_json::from_str(&message)?
                     };
                     wallet.sign_typed_data(&typed_data).await?
+                } else if no_hash {
+                    wallet.sign_hash(&message.parse()?).await?
                 } else {
                     wallet.sign_message(Self::hex_str_to_bytes(&message)?).await?
                 };
diff --git a/crates/wallets/src/error.rs b/crates/wallets/src/error.rs
index bee0796fd622f..6588f5e22cc17 100644
--- a/crates/wallets/src/error.rs
+++ b/crates/wallets/src/error.rs
@@ -23,4 +23,6 @@ pub enum WalletSignerError {
     Io(#[from] std::io::Error),
     #[error(transparent)]
     InvalidHex(#[from] FromHexError),
+    #[error("{0} cannot sign raw hashes")]
+    CannotSignRawHash(&'static str),
 }
diff --git a/crates/wallets/src/wallet_signer.rs b/crates/wallets/src/wallet_signer.rs
index baafebeb5f561..ed7b99a0c5761 100644
--- a/crates/wallets/src/wallet_signer.rs
+++ b/crates/wallets/src/wallet_signer.rs
@@ -1,4 +1,5 @@
 use crate::error::WalletSignerError;
+use alloy_primitives::B256;
 use async_trait::async_trait;
 use ethers_core::types::{
     transaction::{eip2718::TypedTransaction, eip712::Eip712},
@@ -153,6 +154,19 @@ impl Signer for &WalletSigner {
     }
 }
 
+impl WalletSigner {
+    pub async fn sign_hash(&self, hash: &B256) -> Result<Signature> {
+        match self {
+            // TODO: AWS can sign hashes but utilities aren't exposed in ethers-signers.
+            // TODO: Implement with alloy-signer.
+            Self::Aws(_aws) => Err(WalletSignerError::CannotSignRawHash("AWS")),
+            Self::Ledger(_) => Err(WalletSignerError::CannotSignRawHash("Ledger")),
+            Self::Local(wallet) => wallet.sign_hash(hash.0.into()).map_err(Into::into),
+            Self::Trezor(_) => Err(WalletSignerError::CannotSignRawHash("Trezor")),
+        }
+    }
+}
+
 /// Signers that require user action to be obtained.
 #[derive(Debug, Clone)]
 pub enum PendingSigner {