Signer functionality (#54)

This PR adds a signer crate to handle Signer instantiation.

---------

Co-authored-by: ricomateo <mrico@fi.uba.ar>

Cargo.toml

@@ -19,12 +19,13 @@ members = [
     "crates/types/",
     "crates/metrics/",
     "crates/types/",
+    "crates/signer/",
     "crates/logging/",
     "examples/info-operator-service/",
     "testing/testing-utils/",
     "examples/avsregistry-read",
     "examples/avsregistry-write",
-    "examples/anvil-utils",
+    "examples/anvil-utils"
 ]
 
 resolver = "2"
@@ -88,7 +89,9 @@ thiserror = "1.0"
 tracing = "0.1.40"
 tracing-subscriber = { version = "0.3", features = ["json"] }
 hyper = "0.14.25"
-
+eth-keystore = "0.5.0"
+hex-literal = "0.4.1"
+k256 = "0.13.3"
 
 #misc 
 parking_lot = "0.12"

crates/signer/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "eigen-signer"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+repository.workspace = true
+
+[dependencies]
+alloy-consensus.workspace = true
+alloy-network.workspace = true
+alloy-primitives.workspace = true
+alloy-signer.workspace = true
+alloy-signer-local.workspace = true
+eth-keystore.workspace = true
+hex-literal.workspace = true
+k256.workspace = true
+thiserror.workspace = true

crates/signer/mockdata/dummy.key.json

@@ -0,0 +1,19 @@
+{
+    "crypto": {
+        "cipher": "aes-128-ctr",
+        "cipherparams": {
+            "iv": "6087dab2f9fdbbfaddc31a909735c1e6"
+        },
+        "ciphertext": "5318b4d5bcd28de64ee5559e671353e16f075ecae9f99c7a79a38af5f869aa46",
+        "kdf": "pbkdf2",
+        "kdfparams": {
+            "c": 262144,
+            "dklen": 32,
+            "prf": "hmac-sha256",
+            "salt": "ae3cd4e7013836a3df6bd7241b12db061dbe2c6785853cce422d148a624ce0bd"
+        },
+        "mac": "517ead924a9d0dc3124507e3393d175ce3ff7c1e96529c6c555ce9e51205e9b2"
+    },
+    "id": "3198bc9c-6672-5ab3-d995-4942343ae5b6",
+    "version": 3
+}

crates/signer/src/lib.rs

@@ -0,0 +1,6 @@
+#![doc(
+    html_logo_url = "https://github.com/supernovahs/eigensdk-rs/assets/91280922/bd13caec-3c00-4afc-839a-b83d2890beb5",
+    issue_tracker_base_url = "https://github.com/supernovahs/eigen-rs/issues/"
+)]
+
+pub mod signer;

crates/signer/src/signer.rs

@@ -0,0 +1,116 @@
+use alloy_signer_local::PrivateKeySigner;
+use eth_keystore::decrypt_key;
+use std::path::Path;
+use thiserror::Error;
+
+/// Represents the input params to create a signer
+#[derive(Debug)]
+pub enum Config {
+    /// Hexadecimal private key
+    PrivateKey(String),
+    /// Keystore path and password
+    Keystore(String, String),
+    /// Web3 endpoint and address
+    Web3(String, String),
+}
+
+#[derive(Error, Debug)]
+/// Possible errors raised in signer creation
+pub enum SignerError {
+    #[error("invalid private key")]
+    InvalidPrivateKey,
+    #[error("invalid keystore password")]
+    InvalidPassword,
+}
+
+impl Config {
+    /// Creates a signer from given config.
+    pub fn signer_from_config(c: Config) -> Result<PrivateKeySigner, SignerError> {
+        // TODO: check chain id to select signer
+        match c {
+            Config::PrivateKey(key) => key
+                .parse::<PrivateKeySigner>()
+                .map_err(|_| SignerError::InvalidPrivateKey),
+            Config::Keystore(path, password) => {
+                let keypath = Path::new(&path);
+                let private_key =
+                    decrypt_key(keypath, password).map_err(|_| SignerError::InvalidPassword)?;
+                PrivateKeySigner::from_slice(&private_key)
+                    .map_err(|_| SignerError::InvalidPrivateKey)
+            }
+            Config::Web3(_endpoint, _address) => {
+                todo!() // We are implementing this in a following PR
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::Config;
+    use alloy_consensus::TxLegacy;
+    use alloy_network::TxSignerSync;
+    use alloy_primitives::{bytes, Address, U256};
+    use alloy_signer::Signature;
+    use alloy_signer_local::PrivateKeySigner;
+    use hex_literal::hex;
+    use std::str::FromStr;
+
+    const PRIVATE_KEY: &str = "dcf2cbdd171a21c480aa7f53d77f31bb102282b3ff099c78e3118b37348c72f7";
+    const ADDRESS: [u8; 20] = hex!("d8dA6BF26964aF9D7eEd9e03E53415D37aA96045");
+    const SIGNATURE_R: &str =
+        "99963972037857174861280476053118856715670512199525969754644366601434507134123";
+    const SIGNATURE_S: &str =
+        "54587766196536123534774489028213321677166972433316011091332824361042811624091";
+    const SIGNATURE_Y_PARITY: u64 = 37;
+    const KEYSTORE_PATH: &str = "mockdata/dummy.key.json";
+    const KEYSTORE_PASSWORD: &str = "testpassword";
+
+    #[test]
+    fn sign_transaction_with_private_key() {
+        let config = Config::PrivateKey(PRIVATE_KEY.into());
+        let mut tx = TxLegacy {
+            to: Address::from(ADDRESS).into(),
+            value: U256::from(1_000_000_000),
+            gas_limit: 2_000_000,
+            nonce: 0,
+            gas_price: 21_000_000_000,
+            input: bytes!(),
+            chain_id: Some(1),
+        };
+
+        let signer = Config::signer_from_config(config);
+
+        let signature = signer.unwrap().sign_transaction_sync(&mut tx).unwrap();
+        let expected_signature = Signature::from_rs_and_parity(
+            U256::from_str(SIGNATURE_R).unwrap(),
+            U256::from_str(SIGNATURE_S).unwrap(),
+            SIGNATURE_Y_PARITY,
+        )
+        .unwrap();
+        assert_eq!(signature, expected_signature);
+    }
+
+    #[test]
+    fn sign_transaction_with_keystore() {
+        let config = Config::Keystore(KEYSTORE_PATH.into(), KEYSTORE_PASSWORD.into());
+        let mut tx = TxLegacy {
+            to: Address::from(ADDRESS).into(),
+            value: U256::from(1_000_000_000),
+            gas_limit: 2_000_000,
+            nonce: 0,
+            gas_price: 21_000_000_000,
+            input: bytes!(),
+            chain_id: Some(1),
+        };
+
+        let private_key = hex!("7a28b5ba57c53603b0b07b56bba752f7784bf506fa95edc395f5cf6c7514fe9d");
+        let expected_signer = PrivateKeySigner::from_slice(&private_key).unwrap();
+        let expected_signature = expected_signer.sign_transaction_sync(&mut tx).unwrap();
+
+        let signer = Config::signer_from_config(config);
+        let signature = signer.unwrap().sign_transaction_sync(&mut tx).unwrap();
+
+        assert_eq!(signature, expected_signature);
+    }
+}