feat: add eip-7702 helpers

crates/alloy/Cargo.toml

@@ -85,10 +85,10 @@ full = [
     "kzg",
     "network",
     "provider-http", # includes `providers`
-    "provider-ws", # includes `providers`
-    "provider-ipc", # includes `providers`
-    "rpc-types", # includes `rpc-types-eth`
-    "signer-local", # includes `signers`
+    "provider-ws",   # includes `providers`
+    "provider-ipc",  # includes `providers`
+    "rpc-types",     # includes `rpc-types-eth`
+    "signer-local",  # includes `signers`
 ]
 
 # configuration
@@ -218,6 +218,7 @@ arbitrary = [
 k256 = [
     "alloy-core/k256",
     "alloy-consensus?/k256",
+    "alloy-eips?/k256",
     "alloy-network?/k256",
     "alloy-rpc-types?/k256",
 ]

crates/consensus/Cargo.toml

@@ -50,7 +50,7 @@ serde_json.workspace = true
 [features]
 default = ["std"]
 std = ["alloy-eips/std", "c-kzg?/std"]
-k256 = ["alloy-primitives/k256"]
+k256 = ["alloy-primitives/k256", "alloy-eips/k256"]
 kzg = ["dep:c-kzg", "alloy-eips/kzg", "std"]
 arbitrary = [
     "std",

crates/eips/Cargo.toml

@@ -70,6 +70,7 @@ serde = [
 kzg = ["kzg-sidecar", "sha2", "dep:derive_more", "dep:c-kzg", "dep:once_cell"]
 kzg-sidecar = ["sha2"]
 sha2 = ["dep:sha2"]
+k256 = ["alloy-primitives/k256"]
 ssz = [
     "std",
     "dep:ethereum_ssz",

crates/eips/README.md

@@ -18,3 +18,4 @@ Contains constants, helpers, and basic data structures for consensus EIPs.
 - [EIP-7002](https://eips.ethereum.org/EIPS/eip-7002)
 - [EIP-7251](https://eips.ethereum.org/EIPS/eip-7251)
 - [EIP-7685](https://eips.ethereum.org/EIPS/eip-7685)
+- [EIP-7702](https://eips.ethereum.org/EIPS/eip-7702)

crates/eips/src/eip7702/auth_list.rs

@@ -0,0 +1,140 @@
+use core::ops::Deref;
+
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
+use alloy_primitives::{keccak256, Address, ChainId, B256};
+#[cfg(feature = "k256")]
+use alloy_primitives::{Signature, SignatureError};
+use alloy_rlp::{BufMut, Decodable, Encodable, Header, RlpDecodable, RlpEncodable};
+
+/// An unsigned EIP-7702 authorization.
+#[derive(Debug, Clone, RlpEncodable, RlpDecodable)]
+pub struct Authorization {
+    chain_id: ChainId,
+    address: Address,
+    nonce: OptionalNonce,
+}
+
+impl Authorization {
+    /// Get the `chain_id` for the authorization.
+    ///
+    /// # Note
+    ///
+    /// Implementers should check that this matches the current `chain_id` *or* is 0.
+    pub const fn chain_id(&self) -> ChainId {
+        self.chain_id
+    }
+
+    /// Get the `address` for the authorization.
+    pub const fn address(&self) -> &Address {
+        &self.address
+    }
+
+    /// Get the `nonce` for the authorization.
+    ///
+    /// # Note
+    ///
+    /// If this is `Some`, implementers should check that the nonce of the authority is equal to
+    /// this nonce.
+    pub fn nonce(&self) -> Option<u64> {
+        *self.nonce
+    }
+
+    /// Computes the signature hash used to sign the authorization, or recover the authority from a
+    /// signed authorization list item.
+    ///
+    /// The signature hash is `keccak(MAGIC || rlp([chain_id, [nonce], address]))`
+    #[inline]
+    pub fn signature_hash(&self) -> B256 {
+        use super::constants::MAGIC;
+
+        #[derive(RlpEncodable)]
+        struct Auth {
+            chain_id: ChainId,
+            nonce: OptionalNonce,
+            address: Address,
+        }
+
+        let mut buf = Vec::new();
+        buf.put_u8(MAGIC);
+
+        Auth { chain_id: self.chain_id, nonce: self.nonce, address: self.address }.encode(&mut buf);
+
+        keccak256(buf)
+    }
+
+    /// Convert to a signed authorization by adding a signature.
+    pub const fn into_signed<S>(self, signature: S) -> SignedAuthorization<S> {
+        SignedAuthorization { inner: self, signature }
+    }
+}
+
+/// A signed EIP-7702 authorization.
+#[derive(Debug, Clone, RlpEncodable, RlpDecodable)]
+pub struct SignedAuthorization<S> {
+    inner: Authorization,
+    signature: S,
+}
+
+impl<S> SignedAuthorization<S> {
+    /// Get the `signature` for the authorization.
+    pub const fn signature(&self) -> &S {
+        &self.signature
+    }
+}
+
+#[cfg(feature = "k256")]
+impl SignedAuthorization<Signature> {
+    /// Recover the authority for the authorization.
+    ///
+    /// # Note
+    ///
+    /// Implementers should check that the authority has no code.
+    pub fn recover_authority(&self) -> Result<Address, SignatureError> {
+        self.signature.recover_address_from_prehash(&self.inner.signature_hash())
+    }
+}
+
+impl<S> Deref for SignedAuthorization<S> {
+    type Target = Authorization;
+
+    fn deref(&self) -> &Self::Target {
+        &self.inner
+    }
+}
+
+/// An internal wrapper around an `Option<u64>` for optional nonces.
+///
+/// In EIP-7702 the nonce is encoded as a list of either 0 or 1 items, where 0 items means that no
+/// nonce was specified (i.e. `None`). If there is 1 item, this is the same as `Some`.
+///
+/// The wrapper type is used for RLP encoding and decoding.
+#[derive(Debug, Copy, Clone)]
+struct OptionalNonce(Option<u64>);
+
+impl Encodable for OptionalNonce {
+    fn encode(&self, out: &mut dyn BufMut) {
+        match self.0 {
+            Some(nonce) => {
+                Header { list: true, payload_length: nonce.length() }.encode(out);
+                nonce.encode(out);
+            }
+            None => Header { list: true, payload_length: 0 }.encode(out),
+        }
+    }
+}
+
+impl Decodable for OptionalNonce {
+    fn decode(buf: &mut &[u8]) -> alloy_rlp::Result<Self> {
+        let list: Vec<u64> = Vec::decode(buf)?;
+        Ok(Self(list.first().copied()))
+    }
+}
+
+impl Deref for OptionalNonce {
+    type Target = Option<u64>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}

crates/eips/src/eip7702/constants.rs

@@ -0,0 +1,18 @@
+//! [EIP-7702] constants.
+//!
+//! [EIP-7702]: https://eips.ethereum.org/EIPS/eip-7702
+
+/// Identifier for EIP7702's set code transaction.
+///
+/// See also [EIP-7702](https://eips.ethereum.org/EIPS/eip-7702).
+pub const EIP7702_TX_TYPE_ID: u8 = 4;
+
+/// Magic number used to calculate an EIP7702 authority.
+///
+/// See also [EIP-7702](https://eips.ethereum.org/EIPS/eip-7702).
+pub const MAGIC: u8 = 0x05;
+
+/// An additional gas cost per EIP7702 authorization list item.
+///
+/// See also [EIP-7702](https://eips.ethereum.org/EIPS/eip-7702).
+pub const PER_AUTH_BASE_COST: u64 = 2500;

crates/eips/src/eip7702/mod.rs

@@ -0,0 +1,8 @@
+//! [EIP-7702] constants, helpers, and types.
+//!
+//! [EIP-7702]: https://eips.ethereum.org/EIPS/eip-7702
+
+mod auth_list;
+pub use auth_list::*;
+
+pub mod constants;

crates/eips/src/lib.rs

@@ -27,11 +27,11 @@ pub mod eip2935;
 
 pub mod eip4788;
 
-pub mod eip4895;
-
 pub mod eip4844;
 pub use eip4844::{calc_blob_gasprice, calc_excess_blob_gas};
 
+pub mod eip4895;
+
 pub mod eip6110;
 pub mod merge;
 
@@ -40,3 +40,5 @@ pub mod eip7002;
 pub mod eip7251;
 
 pub mod eip7685;
+
+pub mod eip7702;

crates/rpc-types-eth/Cargo.toml

@@ -66,4 +66,4 @@ arbitrary = [
 ]
 jsonrpsee-types = ["dep:jsonrpsee-types"]
 ssz = ["alloy-primitives/ssz", "alloy-eips/ssz"]
-k256 = ["alloy-consensus/k256"]
+k256 = ["alloy-consensus/k256", "alloy-eips/k256"]