refactor(hashing): introduce Hashable derive macro and migrate server types

server/Cargo.lock

@@ -696,12 +696,25 @@ dependencies = [
 name = "arbiter-crypto"
 version = "0.1.0"
 dependencies = [
+ "alloy",
  "base64",
+ "chrono",
+ "hmac",
  "memsafe",
  "ml-dsa",
  "rand 0.10.0",
 ]
 
+[[package]]
+name = "arbiter-macros"
+version = "0.1.0"
+dependencies = [
+ "arbiter-crypto",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
 [[package]]
 name = "arbiter-proto"
 version = "0.1.0"
@@ -736,6 +749,7 @@ dependencies = [
  "alloy",
  "anyhow",
  "arbiter-crypto",
+ "arbiter-macros",
  "arbiter-proto",
  "arbiter-tokens-registry",
  "argon2",

server/Cargo.toml

@@ -47,3 +47,4 @@ miette = { version = "7.6.0", features = ["fancy", "serde"] }
 mutants = "0.0.4"
 ml-dsa = { version = "0.1.0-rc.8", features = ["zeroize"] }
 base64 = "0.22.1"
+hmac = "0.12.1"

server/crates/arbiter-crypto/Cargo.toml

@@ -8,6 +8,9 @@ ml-dsa = {workspace = true, optional = true }
 rand = {workspace = true, optional = true}
 base64 = {workspace = true, optional = true }
 memsafe = {version = "0.4.0", optional = true}
+hmac.workspace = true
+alloy.workspace = true
+chrono.workspace = true
 
 [lints]
 workspace = true

server/crates/arbiter-crypto/src/authn/v1.rs

@@ -1,4 +1,5 @@
 use base64::{Engine as _, prelude::BASE64_STANDARD};
+use hmac::digest::Digest;
 use ml_dsa::{
     EncodedVerifyingKey, Error, KeyGen, MlDsa87, Seed, Signature as MlDsaSignature,
     SigningKey as MlDsaSigningKey, VerifyingKey as MlDsaVerifyingKey, signature::Keypair as _,
@@ -17,6 +18,12 @@ pub type KeyParams = MlDsa87;
 #[derive(Clone, Debug, PartialEq)]
 pub struct PublicKey(Box<MlDsaVerifyingKey<KeyParams>>);
 
+impl crate::hashing::Hashable for PublicKey {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.to_bytes());
+    }
+}
+
 #[derive(Clone, Debug, PartialEq)]
 pub struct Signature(Box<MlDsaSignature<KeyParams>>);
 
@@ -25,7 +32,7 @@ pub struct SigningKey(Box<MlDsaSigningKey<KeyParams>>);
 
 impl PublicKey {
     pub fn to_bytes(&self) -> Vec<u8> {
-        self.0.encode().to_vec()
+        self.0.encode().0.to_vec()
     }
 
     pub fn verify(&self, nonce: i32, context: &[u8], signature: &Signature) -> bool {
@@ -39,7 +46,7 @@ impl PublicKey {
 
 impl Signature {
     pub fn to_bytes(&self) -> Vec<u8> {
-        self.0.encode().to_vec()
+        self.0.encode().0.to_vec()
     }
 }
 

server/crates/arbiter-crypto/src/hashing.rs

@@ -1,21 +1,25 @@
-use hmac::digest::Digest;
+pub use hmac::digest::Digest;
 use std::collections::HashSet;
 
 /// Deterministically hash a value by feeding its fields into the hasher in a consistent order.
+#[diagnostic::on_unimplemented(
+    note = "for local types consider adding `#[derive(arbiter_macros::Hashable)]` to your `{Self}` type",
+    note = "for types from other crates check whether the crate offers a `Hashable` implementation"
+)]
 pub trait Hashable {
     fn hash<H: Digest>(&self, hasher: &mut H);
 }
 
 macro_rules! impl_numeric {
-($($t:ty),*) => {
+    ($($t:ty),*) => {
-    $(
+        $(
-        impl Hashable for $t {
+            impl Hashable for $t {
-            fn hash<H: Digest>(&self, hasher: &mut H) {
+                fn hash<H: Digest>(&self, hasher: &mut H) {
-                hasher.update(&self.to_be_bytes());
+                    hasher.update(&self.to_be_bytes());
+                }
             }
-        }
+        )*
-    )*
+    };
-};
 }
 
 impl_numeric!(u8, u16, u32, u64, i8, i16, i32, i64);

server/crates/arbiter-crypto/src/lib.rs

@@ -1,5 +1,5 @@
 #[cfg(feature = "authn")]
 pub mod authn;
-
+pub mod hashing;
 #[cfg(feature = "safecell")]
 pub mod safecell;

server/crates/arbiter-macros/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "arbiter-macros"
+version = "0.1.0"
+edition = "2024"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0"
+quote = "1.0"
+syn = { version = "2.0", features = ["derive", "fold", "full", "visit-mut"] }
+
+[dev-dependencies]
+arbiter-crypto = { path = "../arbiter-crypto" }
+
+[lints]
+workspace = true

server/crates/arbiter-macros/src/hashable.rs

@@ -0,0 +1,133 @@
+use proc_macro2::{Span, TokenStream, TokenTree};
+use quote::quote;
+use syn::parse_quote;
+use syn::spanned::Spanned;
+use syn::{DataStruct, DeriveInput, Fields, Generics, Index};
+
+use crate::utils::{HASHABLE_TRAIT_PATH, HMAC_DIGEST_PATH};
+
+pub(crate) fn derive(input: &DeriveInput) -> TokenStream {
+    match &input.data {
+        syn::Data::Struct(struct_data) => hashable_struct(input, struct_data),
+        syn::Data::Enum(_) => {
+            syn::Error::new_spanned(input, "Hashable can currently be derived only for structs")
+                .to_compile_error()
+        }
+        syn::Data::Union(_) => {
+            syn::Error::new_spanned(input, "Hashable cannot be derived for unions")
+                .to_compile_error()
+        }
+    }
+}
+
+fn hashable_struct(input: &DeriveInput, struct_data: &syn::DataStruct) -> TokenStream {
+    let ident = &input.ident;
+    let hashable_trait = HASHABLE_TRAIT_PATH.to_path();
+    let hmac_digest = HMAC_DIGEST_PATH.to_path();
+    let generics = add_hashable_bounds(input.generics.clone(), &hashable_trait);
+    let field_accesses = collect_field_accesses(struct_data);
+    let hash_calls = build_hash_calls(&field_accesses, &hashable_trait);
+
+    let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
+
+    quote! {
+        #[automatically_derived]
+        impl #impl_generics #hashable_trait for #ident #ty_generics #where_clause {
+            fn hash<H: #hmac_digest>(&self, hasher: &mut H) {
+                #(#hash_calls)*
+            }
+        }
+    }
+}
+
+fn add_hashable_bounds(mut generics: Generics, hashable_trait: &syn::Path) -> Generics {
+    for type_param in generics.type_params_mut() {
+        type_param.bounds.push(parse_quote!(#hashable_trait));
+    }
+
+    generics
+}
+
+struct FieldAccess {
+    access: TokenStream,
+    span: Span,
+}
+
+fn collect_field_accesses(struct_data: &DataStruct) -> Vec<FieldAccess> {
+    match &struct_data.fields {
+        Fields::Named(fields) => {
+            // Keep deterministic alphabetical order for named fields.
+            // Do not remove this sort, because it keeps hash output stable regardless of source order.
+            let mut named_fields = fields
+                .named
+                .iter()
+                .map(|field| {
+                    let name = field
+                        .ident
+                        .as_ref()
+                        .expect("Fields::Named(fields) must have names")
+                        .clone();
+                    (name.to_string(), name)
+                })
+                .collect::<Vec<_>>();
+
+            named_fields.sort_by(|a, b| a.0.cmp(&b.0));
+
+            named_fields
+                .into_iter()
+                .map(|(_, name)| FieldAccess {
+                    access: quote! { #name },
+                    span: name.span(),
+                })
+                .collect()
+        }
+        Fields::Unnamed(fields) => fields
+            .unnamed
+            .iter()
+            .enumerate()
+            .map(|(i, field)| FieldAccess {
+                access: {
+                    let index = Index::from(i);
+                    quote! { #index }
+                },
+                span: field.ty.span(),
+            })
+            .collect(),
+        Fields::Unit => Vec::new(),
+    }
+}
+
+fn build_hash_calls(
+    field_accesses: &[FieldAccess],
+    hashable_trait: &syn::Path,
+) -> Vec<TokenStream> {
+    field_accesses
+        .iter()
+        .map(|field| {
+            let access = &field.access;
+            let call = quote! {
+                #hashable_trait::hash(&self.#access, hasher);
+            };
+
+            respan(call, field.span)
+        })
+        .collect()
+}
+
+/// Recursively set span on all tokens, including interpolated ones.
+fn respan(tokens: TokenStream, span: Span) -> TokenStream {
+    tokens
+        .into_iter()
+        .map(|tt| match tt {
+            TokenTree::Group(g) => {
+                let mut new = proc_macro2::Group::new(g.delimiter(), respan(g.stream(), span));
+                new.set_span(span);
+                TokenTree::Group(new)
+            }
+            mut other => {
+                other.set_span(span);
+                other
+            }
+        })
+        .collect()
+}

server/crates/arbiter-macros/src/lib.rs

@@ -0,0 +1,10 @@
+use syn::{DeriveInput, parse_macro_input};
+
+mod hashable;
+mod utils;
+
+#[proc_macro_derive(Hashable)]
+pub fn derive_hashable(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+    hashable::derive(&input).into()
+}

server/crates/arbiter-macros/src/utils.rs

@@ -0,0 +1,19 @@
+pub struct ToPath(pub &'static str);
+
+impl ToPath {
+    pub fn to_path(&self) -> syn::Path {
+        syn::parse_str(self.0).expect("Invalid path")
+    }
+}
+
+macro_rules! ensure_path {
+    ($path:path) => {{
+        #[cfg(test)]
+        #[expect(unused_imports)]
+        use $path as _;
+        ToPath(stringify!($path))
+    }};
+}
+
+pub const HASHABLE_TRAIT_PATH: ToPath = ensure_path!(::arbiter_crypto::hashing::Hashable);
+pub const HMAC_DIGEST_PATH: ToPath = ensure_path!(::arbiter_crypto::hashing::Digest);

server/crates/arbiter-server/Cargo.toml

@@ -18,6 +18,7 @@ diesel-async = { version = "0.8.0", features = [
 ] }
 arbiter-proto.path = "../arbiter-proto"
 arbiter-crypto.path = "../arbiter-crypto"
+arbiter-macros.path = "../arbiter-macros"
 tracing.workspace = true
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 tonic.workspace = true
@@ -44,7 +45,7 @@ restructed = "0.2.2"
 strum = { version = "0.28.0", features = ["derive"] }
 pem = "3.0.6"
 sha2.workspace = true
-hmac = "0.12"
+hmac.workspace = true
 spki.workspace = true
 alloy.workspace = true
 prost-types.workspace = true

server/crates/arbiter-server/src/actors/client/mod.rs

@@ -5,7 +5,7 @@ use tracing::{error, info};
 
 use crate::{
     actors::{GlobalActors, client::session::ClientSession},
-    crypto::integrity::{Integrable, hashing::Hashable},
+    crypto::integrity::Integrable,
     db,
 };
 
@@ -15,6 +15,7 @@ pub struct ClientProfile {
     pub metadata: ClientMetadata,
 }
 
+#[derive(arbiter_macros::Hashable)]
 pub struct ClientCredentials {
     pub pubkey: authn::PublicKey,
     pub nonce: i32,
@@ -24,13 +25,6 @@ impl Integrable for ClientCredentials {
     const KIND: &'static str = "client_credentials";
 }
 
-impl Hashable for ClientCredentials {
-    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
-        hasher.update(self.pubkey.to_bytes());
-        self.nonce.hash(hasher);
-    }
-}
-
 pub struct ClientConnection {
     pub(crate) db: db::DatabasePool,
     pub(crate) actors: GlobalActors,

server/crates/arbiter-server/src/actors/user_agent/mod.rs

@@ -5,7 +5,7 @@ use crate::{
 };
 use arbiter_crypto::authn;
 
-#[derive(Debug)]
+#[derive(Debug, arbiter_macros::Hashable)]
 pub struct UserAgentCredentials {
     pub pubkey: authn::PublicKey,
     pub nonce: i32,
@@ -38,18 +38,3 @@ pub mod session;
 
 pub use auth::authenticate;
 pub use session::UserAgentSession;
-
-use crate::crypto::integrity::hashing::Hashable;
-
-impl Hashable for authn::PublicKey {
-    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
-        hasher.update(self.to_bytes());
-    }
-}
-
-impl Hashable for UserAgentCredentials {
-    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
-        self.pubkey.hash(hasher);
-        self.nonce.hash(hasher);
-    }
-}

server/crates/arbiter-server/src/crypto/integrity/v1.rs

@@ -1,6 +1,6 @@
-use crate::{actors::keyholder, crypto::integrity::hashing::Hashable};
+use crate::actors::keyholder;
-use arbiter_crypto::safecell::SafeCellHandle as _;
+use arbiter_crypto::hashing::Hashable;
-use hmac::{Hmac, Mac as _};
+use hmac::Hmac;
 use sha2::Sha256;
 
 use diesel::{ExpressionMethods as _, QueryDsl, dsl::insert_into, sqlite::Sqlite};
@@ -8,8 +8,6 @@ use diesel_async::{AsyncConnection, RunQueryDsl};
 use kameo::{actor::ActorRef, error::SendError};
 use sha2::Digest as _;
 
-pub mod hashing;
-
 use crate::{
     actors::keyholder::{KeyHolder, SignIntegrity, VerifyIntegrity},
     db::{
@@ -203,10 +201,6 @@ mod tests {
     use diesel::{ExpressionMethods as _, QueryDsl};
     use diesel_async::RunQueryDsl;
     use kameo::{actor::ActorRef, prelude::Spawn};
-    
-    use sha2::Digest;
-
-    
 
     use crate::{
         actors::keyholder::{Bootstrap, KeyHolder},
@@ -215,20 +209,11 @@ mod tests {
     use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 
     use super::{Error, Integrable, sign_entity, verify_entity};
-    use super::hashing::Hashable;
+    #[derive(Clone, arbiter_macros::Hashable)]
-
-    #[derive(Clone)]
     struct DummyEntity {
         payload_version: i32,
         payload: Vec<u8>,
     }
-
-    impl Hashable for DummyEntity {
-        fn hash<H: Digest>(&self, hasher: &mut H) {
-            self.payload_version.hash(hasher);
-            self.payload.hash(hasher);
-        }
-    }
     impl Integrable for DummyEntity {
         const KIND: &'static str = "dummy_entity";
     }

server/crates/arbiter-server/src/evm/policies.rs

@@ -127,19 +127,19 @@ pub enum SpecificMeaning {
     TokenTransfer(token_transfers::Meaning),
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, arbiter_macros::Hashable)]
 pub struct TransactionRateLimit {
     pub count: u32,
     pub window: Duration,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, arbiter_macros::Hashable)]
 pub struct VolumeRateLimit {
     pub max_volume: U256,
     pub window: Duration,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, arbiter_macros::Hashable)]
 pub struct SharedGrantSettings {
     pub wallet_access_id: i32,
     pub chain: ChainId,
@@ -200,7 +200,7 @@ pub enum SpecificGrant {
     TokenTransfer(token_transfers::Settings),
 }
 
-#[derive(Debug)]
+#[derive(Debug, arbiter_macros::Hashable)]
 pub struct CombinedSettings<PolicyGrant> {
     pub shared: SharedGrantSettings,
     pub specific: PolicyGrant,
@@ -219,38 +219,3 @@ impl<P: Integrable> Integrable for CombinedSettings<P> {
     const KIND: &'static str = P::KIND;
     const VERSION: i32 = P::VERSION;
 }
-
-use crate::crypto::integrity::hashing::Hashable;
-
-impl Hashable for TransactionRateLimit {
-    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
-        self.count.hash(hasher);
-        self.window.hash(hasher);
-    }
-}
-
-impl Hashable for VolumeRateLimit {
-    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
-        self.max_volume.hash(hasher);
-        self.window.hash(hasher);
-    }
-}
-
-impl Hashable for SharedGrantSettings {
-    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
-        self.wallet_access_id.hash(hasher);
-        self.chain.hash(hasher);
-        self.valid_from.hash(hasher);
-        self.valid_until.hash(hasher);
-        self.max_gas_fee_per_gas.hash(hasher);
-        self.max_priority_fee_per_gas.hash(hasher);
-        self.rate_limit.hash(hasher);
-    }
-}
-
-impl<P: Hashable> Hashable for CombinedSettings<P> {
-    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
-        self.shared.hash(hasher);
-        self.specific.hash(hasher);
-    }
-}

server/crates/arbiter-server/src/evm/policies/ether_transfer/mod.rs

@@ -52,7 +52,7 @@ impl From<Meaning> for SpecificMeaning {
 }
 
 // A grant for ether transfers, which can be scoped to specific target addresses and volume limits
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, arbiter_macros::Hashable)]
 pub struct Settings {
     pub target: Vec<Address>,
     pub limit: VolumeRateLimit,
@@ -61,15 +61,6 @@ impl Integrable for Settings {
     const KIND: &'static str = "EtherTransfer";
 }
 
-use crate::crypto::integrity::hashing::Hashable;
-
-impl Hashable for Settings {
-    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
-        self.target.hash(hasher);
-        self.limit.hash(hasher);
-    }
-}
-
 impl From<Settings> for SpecificGrant {
     fn from(val: Settings) -> SpecificGrant {
         SpecificGrant::EtherTransfer(val)

server/crates/arbiter-server/src/evm/policies/ether_transfer/tests.rs

@@ -340,7 +340,7 @@ proptest::proptest! {
     ) {
         use rand::{SeedableRng, seq::SliceRandom};
         use sha2::Digest;
-        use crate::crypto::integrity::hashing::Hashable;
+        use arbiter_crypto::hashing::Hashable;
 
         let addrs: Vec<Address> = raw_addrs.iter().map(|b| Address::from(*b)).collect();
         let mut shuffled = addrs.clone();

server/crates/arbiter-server/src/evm/policies/token_transfers/mod.rs

@@ -62,7 +62,7 @@ impl From<Meaning> for SpecificMeaning {
 }
 
 // A grant for token transfers, which can be scoped to specific target addresses and volume limits
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, arbiter_macros::Hashable)]
 pub struct Settings {
     pub token_contract: Address,
     pub target: Option<Address>,
@@ -72,16 +72,6 @@ impl Integrable for Settings {
     const KIND: &'static str = "TokenTransfer";
 }
 
-use crate::crypto::integrity::hashing::Hashable;
-
-impl Hashable for Settings {
-    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
-        self.token_contract.hash(hasher);
-        self.target.hash(hasher);
-        self.volume_limits.hash(hasher);
-    }
-}
-
 impl From<Settings> for SpecificGrant {
     fn from(val: Settings) -> SpecificGrant {
         SpecificGrant::TokenTransfer(val)

server/crates/arbiter-server/src/evm/policies/token_transfers/tests.rs

@@ -419,7 +419,7 @@ proptest::proptest! {
     ) {
         use rand::{SeedableRng, seq::SliceRandom};
         use sha2::Digest;
-        use crate::crypto::integrity::hashing::Hashable;
+        use arbiter_crypto::hashing::Hashable;
 
         let limits: Vec<VolumeRateLimit> = raw_limits
             .iter()