feat(common): add Goldilocks (Field64_3) field support — Phase 1

Cargo.toml

@@ -97,12 +97,15 @@ poseidon2 = { path = "poseidon2" }
 # Workspace members - ProveKit
 provekit-bench = { path = "tooling/provekit-bench" }
 provekit-cli = { path = "tooling/cli" }
-provekit-common = { path = "provekit/common" , features = ["provekit_ntt"]}
+# No default features: consumers pick the field (`bn254`/`goldilocks`) plus
+# `parallel`/`provekit_ntt` explicitly — required so the goldilocks build can
+# exclude the default `bn254` feature.
+provekit-common = { path = "provekit/common", default-features = false }
 provekit-ffi = { path = "tooling/provekit-ffi" }
 provekit-gnark = { path = "tooling/provekit-gnark" }
 provekit-prover = { path = "provekit/prover", default-features = false }
 provekit-r1cs-compiler = { path = "provekit/r1cs-compiler" }
-provekit-verifier = { path = "provekit/verifier" }
+provekit-verifier = { path = "provekit/verifier", default-features = false }
 provekit-verifier-server = { path = "tooling/verifier-server" }
 provekit-wasm = { path = "tooling/provekit-wasm" }
 
@@ -130,7 +133,6 @@ rand = "0.9.1"
 rand08 = { package = "rand", version = "0.8" }
 rayon = "1.10.0"
 reqwest = "0.12.23"
-ruint = { version = "1.12.3", features = ["num-traits", "rand"] }
 seq-macro = "0.3.6"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"

playground/passport-input-gen/Cargo.toml

@@ -21,7 +21,7 @@ ark-ff.workspace = true
 base64.workspace = true
 hex.workspace = true
 noirc_abi.workspace = true
-provekit-common.workspace = true
+provekit-common = { workspace = true, features = ["bn254", "parallel", "provekit_ntt"] }
 provekit-prover = { workspace = true, features = ["witness-generation"] }
 serde.workspace = true
 serde_json.workspace = true

provekit/common/Cargo.toml

@@ -1,6 +1,8 @@
 [package]
 name = "provekit-common"
 version = "1.0.0"
+# Warns when both field features are on (silent BN254 precedence); see build.rs.
+build = "build.rs"
 edition.workspace = true
 rust-version.workspace = true
 authors.workspace = true
@@ -9,9 +11,16 @@ homepage.workspace = true
 repository.workspace = true
 
 [features]
-default = ["parallel"]
+default = ["parallel", "bn254"]
+# At least one field feature must be enabled; `bn254` takes precedence when
+# both are on (so `--all-features` builds as BN254). `bn254` is the
+# production default; `goldilocks` selects the Goldilocks cubic extension
+# (Field64_3, ~192 bits) for off-chain, crate-scoped builds only — always
+# pair it with `--no-default-features`.
+bn254 = ["dep:mavros-vm", "dep:mavros-artifacts"]
+goldilocks = []
 parallel = []
-provekit_ntt = []
+provekit_ntt = ["bn254"]
 
 [dependencies]
 # Workspace crates
@@ -41,7 +50,6 @@ hex.workspace = true
 itertools.workspace = true
 postcard.workspace = true
 rayon.workspace = true
-ruint.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 blake3.workspace = true
@@ -53,8 +61,8 @@ zerocopy.workspace = true
 # Target-specific dependencies: only on non-WASM targets
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 zstd.workspace = true
-mavros-vm.workspace = true
-mavros-artifacts.workspace = true
+mavros-vm = { workspace = true, optional = true }
+mavros-artifacts = { workspace = true, optional = true }
 xz2.workspace = true
 
 [package.metadata.cargo-machete]
@@ -69,6 +77,7 @@ proptest.workspace = true
 [[bench]]
 name = "rs_bench"
 harness = false
+required-features = ["bn254"]
 
 [lints]
 workspace = true

provekit/common/build.rs

@@ -0,0 +1,27 @@
+//! Build script for `provekit-common`.
+//!
+//! Surfaces the one field-feature footgun the `compile_error!` in `src/lib.rs`
+//! cannot catch. `bn254` wins cfg precedence over `goldilocks` (so the crate
+//! builds as BN254 whenever both are on — the intended resolution under
+//! `--all-features`, which CI uses). But several BN254-only features pull in
+//! `bn254` transitively (`provekit_ntt`, and the prover's
+//! `witness-generation`), so an explicit `--features goldilocks,<that>` build
+//! silently compiles as BN254 instead of Goldilocks. `compile_error!` only
+//! fires when *no* field is selected, never here.
+//!
+//! A `cargo:warning` makes the override visible without failing the build
+//! (a hard error would break the legitimate `--all-features` path). Build-
+//! script warnings are advisory, so this is safe even under `-D warnings`.
+fn main() {
+    let bn254 = std::env::var_os("CARGO_FEATURE_BN254").is_some();
+    let goldilocks = std::env::var_os("CARGO_FEATURE_GOLDILOCKS").is_some();
+    if bn254 && goldilocks {
+        println!(
+            "cargo:warning=provekit-common: both `bn254` and `goldilocks` features are enabled; \
+             FieldElement is BN254 (bn254 takes precedence), so `goldilocks` is inert. For a real \
+             Goldilocks build use `--no-default-features --features goldilocks` and drop any \
+             feature that pulls in bn254 (provekit_ntt, the prover's witness-generation). This \
+             warning is expected under --all-features."
+        );
+    }
+}

provekit/common/src/file/io/mod.rs

@@ -3,6 +3,8 @@ mod buf_ext;
 mod counting_writer;
 mod json;
 
+#[cfg(feature = "bn254")]
+use crate::{NoirProof, NoirProofScheme, Prover, Verifier};
 use {
     self::{
         bin::{
@@ -13,7 +15,7 @@ use {
         counting_writer::CountingWriter,
         json::{read_json, write_json},
     },
-    crate::{HashConfig, NoirProof, NoirProofScheme, Prover, Verifier},
+    crate::HashConfig,
     anyhow::Result,
     serde::{Deserialize, Serialize},
     std::{ffi::OsStr, path::Path},
@@ -34,6 +36,7 @@ pub(crate) trait MaybeHashAware {
 }
 
 /// Impl for Prover (has hash config).
+#[cfg(feature = "bn254")]
 impl MaybeHashAware for Prover {
     fn maybe_hash_config(&self) -> Option<HashConfig> {
         match self {
@@ -44,20 +47,23 @@ impl MaybeHashAware for Prover {
 }
 
 /// Impl for Verifier (has hash config).
+#[cfg(feature = "bn254")]
 impl MaybeHashAware for Verifier {
     fn maybe_hash_config(&self) -> Option<HashConfig> {
         Some(self.hash_config)
     }
 }
 
 /// Impl for NoirProof (no hash config).
+#[cfg(feature = "bn254")]
 impl MaybeHashAware for NoirProof {
     fn maybe_hash_config(&self) -> Option<HashConfig> {
         None
     }
 }
 
 /// Impl for NoirProofScheme (has hash config).
+#[cfg(feature = "bn254")]
 impl MaybeHashAware for NoirProofScheme {
     fn maybe_hash_config(&self) -> Option<HashConfig> {
         match self {
@@ -67,27 +73,31 @@ impl MaybeHashAware for NoirProofScheme {
     }
 }
 
+#[cfg(feature = "bn254")]
 impl FileFormat for NoirProofScheme {
     const FORMAT: [u8; 8] = crate::binary_format::NOIR_PROOF_SCHEME_FORMAT;
     const EXTENSION: &'static str = "nps";
     const VERSION: (u16, u16) = crate::binary_format::NOIR_PROOF_SCHEME_VERSION;
     const COMPRESSION: Compression = Compression::Zstd;
 }
 
+#[cfg(feature = "bn254")]
 impl FileFormat for Prover {
     const FORMAT: [u8; 8] = crate::binary_format::PROVER_FORMAT;
     const EXTENSION: &'static str = "pkp";
     const VERSION: (u16, u16) = crate::binary_format::PROVER_VERSION;
     const COMPRESSION: Compression = Compression::Xz;
 }
 
+#[cfg(feature = "bn254")]
 impl FileFormat for Verifier {
     const FORMAT: [u8; 8] = crate::binary_format::VERIFIER_FORMAT;
     const EXTENSION: &'static str = "pkv";
     const VERSION: (u16, u16) = crate::binary_format::VERIFIER_VERSION;
     const COMPRESSION: Compression = Compression::Zstd;
 }
 
+#[cfg(feature = "bn254")]
 impl FileFormat for NoirProof {
     const FORMAT: [u8; 8] = crate::binary_format::NOIR_PROOF_FORMAT;
     const EXTENSION: &'static str = "np";