ref(merkle): rework API

.gitignore

@@ -5,3 +5,5 @@
 **/node_modules/
 
 docs/build/
+
+**/.DS_Store

Cargo.toml

@@ -5,6 +5,7 @@ members = [
   "lib/grip",
   "lib/grip-proc",
   "examples/erc20",
+  "examples/merkle-proofs",
 ]
 # Explicitly set the resolver to version 2, which is the default for packages
 # with edition >= 2021.

examples/merkle-proofs/Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "merkle-proofs-example"
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+publish = false
+version = "0.0.0"
+
+[dependencies]
+crypto = { path = "../../lib/crypto", features = ["merkle", "multi-proof"] }
+alloy-primitives.workspace = true
+alloy-sol-types.workspace = true
+stylus-sdk.workspace = true
+stylus-proc.workspace = true
+mini-alloc.workspace = true
+
+[features]
+default = []
+
+# Enables using the standard library. This is not included in the default
+# features, because this crate is meant to be used in a `no_std` environment.
+# Currently, the std feature is only used for testing purposes.
+std = []
+
+[lib]
+crate-type = ["lib", "cdylib"]

examples/merkle-proofs/src/lib.rs

@@ -0,0 +1,91 @@
+#![cfg_attr(not(feature = "std"), no_std, no_main)]
+extern crate alloc;
+
+use alloc::vec::Vec;
+
+use alloy_primitives::B256;
+use crypto::{
+    merkle::{self, Verifier},
+    KeccakBuilder,
+};
+use stylus_proc::SolidityError;
+use stylus_sdk::{
+    alloy_sol_types::sol,
+    prelude::{entrypoint, external, sol_storage},
+};
+
+sol! {
+    error MerkleProofInvalidMultiProofLength();
+    error MerkleProofInvalidRootChild();
+    error MerkleProofInvalidTotalHashes();
+}
+
+#[global_allocator]
+static ALLOC: mini_alloc::MiniAlloc = mini_alloc::MiniAlloc::INIT;
+
+#[cfg(not(any(
+    test,
+    feature = "std",
+    target_arch = "wasm32-unknown-unknown"
+)))]
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    loop {}
+}
+
+#[derive(SolidityError)]
+pub enum VerifierError {
+    InvalidProofLength(MerkleProofInvalidMultiProofLength),
+    InvalidRootChild(MerkleProofInvalidRootChild),
+    InvalidTotalHashes(MerkleProofInvalidTotalHashes),
+}
+
+impl core::convert::From<merkle::MultiProofError> for VerifierError {
+    fn from(value: merkle::MultiProofError) -> Self {
+        match value {
+            merkle::MultiProofError::InvalidProofLength => {
+                VerifierError::InvalidProofLength(
+                    MerkleProofInvalidMultiProofLength {},
+                )
+            }
+            merkle::MultiProofError::InvalidRootChild => {
+                VerifierError::InvalidRootChild(MerkleProofInvalidRootChild {})
+            }
+            merkle::MultiProofError::InvalidTotalHashes => {
+                VerifierError::InvalidTotalHashes(
+                    MerkleProofInvalidTotalHashes {},
+                )
+            }
+        }
+    }
+}
+
+sol_storage! {
+    #[entrypoint]
+    struct VerifierContract { }
+}
+
+#[external]
+impl VerifierContract {
+    pub fn verify(&self, proof: Vec<B256>, root: B256, leaf: B256) -> bool {
+        let proof: Vec<[u8; 32]> = proof.into_iter().map(|m| *m).collect();
+        Verifier::<KeccakBuilder>::verify(&proof, *root, *leaf)
+    }
+
+    pub fn verify_multi_proof(
+        &self,
+        proof: Vec<B256>,
+        proof_flags: Vec<bool>,
+        root: B256,
+        leaves: Vec<B256>,
+    ) -> Result<bool, VerifierError> {
+        let proof: Vec<[u8; 32]> = proof.into_iter().map(|m| *m).collect();
+        let leaves: Vec<[u8; 32]> = leaves.into_iter().map(|m| *m).collect();
+        Ok(Verifier::<KeccakBuilder>::verify_multi_proof(
+            &proof,
+            &proof_flags,
+            *root,
+            &leaves,
+        )?)
+    }
+}

lib/crypto/Cargo.toml

@@ -8,12 +8,16 @@ license.workspace = true
 repository.workspace = true
 version = "0.1.0"
 
+[dependencies]
+mini-alloc.workspace = true
+tiny-keccak = { version = "2.0.2", features = ["keccak"] }
+
 [dev-dependencies]
-alloy-primitives = { version = "0.6.4", default-features = false }
-const-hex = { version = "1.11.1", default-features = false }
+hex-literal = "0.4.1"
 rand = "0.8.5"
 
 [features]
-default = []
+std = []
+
 merkle = []
-multi_proof = ["merkle"]
+multi-proof = ["merkle"]