perf(crypto): wire keccak_permute ecall into merkle/transcript/grinding

Cargo.toml

@@ -9,6 +9,11 @@ members = [
   "crypto/math-cuda",
   "bin/cli",
 ]
+# Riscv-only bare-metal crate, path-dependent from crypto/crypto (target-gated),
+# ethrex-crypto, and guest programs. Without this exclude, Cargo auto-adopts it as
+# a member (nothing else claims it), so `cargo test` runs its unit tests on host,
+# which link against riscv-only symbols and abort.
+exclude = ["syscalls"]
 
 resolver = "2"
 

crypto/crypto/Cargo.toml

@@ -23,6 +23,9 @@ memmap2 = { version = "0.9", optional = true }
 tempfile = { version = "3", optional = true }
 libc = { version = "0.2", optional = true }
 
+[target.'cfg(target_arch = "riscv64")'.dependencies]
+lambda-vm-syscalls = { path = "../../syscalls" }
+
 [dev-dependencies]
 math = { path = "../math", features = ["test-utils"] }
 rand = "0.8.5"

crypto/crypto/src/fiat_shamir/default_transcript.rs

@@ -1,6 +1,8 @@
 use crate::fiat_shamir::is_transcript::{IsStarkTranscript, IsTranscript};
 
+use crate::hash::platform_keccak::PlatformKeccak256 as Keccak256;
 use core::marker::PhantomData;
+use digest::Digest;
 use math::{
     field::{
         element::FieldElement,
@@ -9,7 +11,6 @@ use math::{
     traits::ByteConversion,
 };
 use rand_chacha::{ChaCha20Rng, rand_core::SeedableRng};
-use sha3::{Digest, Keccak256};
 
 pub struct DefaultTranscript<F: HasDefaultTranscript> {
     hasher: Keccak256,

crypto/crypto/src/hash/mod.rs

@@ -1,2 +1,3 @@
+pub mod platform_keccak;
 pub mod poseidon;
 pub mod sha3;

crypto/crypto/src/hash/platform_keccak.rs

@@ -0,0 +1,58 @@
+//! Keccak-256 implementation selected per target: the `keccak_permute`
+//! precompile on the riscv64 guest, plain software `sha3::Keccak256` on host.
+//! Wraps `lambda_vm_syscalls::keccak::Keccak256` with the `digest` crate
+//! traits so it's a drop-in replacement anywhere a `D: Digest` is expected
+//! (Merkle tree backends, Fiat-Shamir transcript).
+
+#[cfg(target_arch = "riscv64")]
+mod imp {
+    use digest::{
+        FixedOutput, FixedOutputReset, HashMarker, Output, OutputSizeUser, Reset, Update,
+    };
+    use lambda_vm_syscalls::keccak::Keccak256 as SyscallKeccak256;
+
+    #[derive(Clone, Default)]
+    pub struct PlatformKeccak256(SyscallKeccak256);
+
+    impl HashMarker for PlatformKeccak256 {}
+
+    impl OutputSizeUser for PlatformKeccak256 {
+        type OutputSize = digest::typenum::U32;
+    }
+
+    impl Update for PlatformKeccak256 {
+        fn update(&mut self, data: &[u8]) {
+            self.0.update(data);
+        }
+    }
+
+    impl FixedOutput for PlatformKeccak256 {
+        fn finalize_into(self, out: &mut Output<Self>) {
+            let mut bytes = [0u8; 32];
+            self.0.finalize(&mut bytes);
+            out.copy_from_slice(&bytes);
+        }
+    }
+
+    impl Reset for PlatformKeccak256 {
+        fn reset(&mut self) {
+            *self = Self::default();
+        }
+    }
+
+    impl FixedOutputReset for PlatformKeccak256 {
+        fn finalize_into_reset(&mut self, out: &mut Output<Self>) {
+            let mut bytes = [0u8; 32];
+            self.0.clone().finalize(&mut bytes);
+            out.copy_from_slice(&bytes);
+            Reset::reset(self);
+        }
+    }
+}
+
+#[cfg(not(target_arch = "riscv64"))]
+mod imp {
+    pub type PlatformKeccak256 = sha3::Keccak256;
+}
+
+pub use imp::PlatformKeccak256;

crypto/crypto/src/merkle_tree/backends/types.rs

@@ -1,4 +1,4 @@
-use sha3::Keccak256;
+use crate::hash::platform_keccak::PlatformKeccak256 as Keccak256;
 
 use super::{
     field_element::FieldElementBackend,

crypto/stark/Cargo.toml

@@ -16,7 +16,7 @@ math = { path = "../math", features = [
 crypto = { path = "../crypto", features = ["std", "serde"] }
 thiserror = "1.0.38"
 log = "0.4.17"
-sha3 = "0.10.8"
+digest = "0.10.7"
 serde = { version = "1.0", features = ["derive"] }
 itertools = "0.11.0"
 

crypto/stark/src/grinding.rs

@@ -1,6 +1,7 @@
+use crypto::hash::platform_keccak::PlatformKeccak256 as Keccak256;
+use digest::Digest;
 #[cfg(feature = "parallel")]
 use rayon::prelude::{IntoParallelIterator, ParallelIterator};
-use sha3::{Digest, Keccak256};
 
 const PREFIX: [u8; 8] = [0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xed];
 

executor/programs/rust/keccak_precompile/.cargo/config.toml

@@ -0,0 +1,5 @@
+[target.riscv64im-lambda-vm-elf]
+rustflags = [
+  "--cfg", "getrandom_backend=\"custom\"",
+  "-C", "passes=lower-atomic"
+]