Add deposit_contract crate

eth2/utils/deposit_contract/src/lib.rs

@@ -0,0 +1,56 @@
+use ethabi::{Contract, Token};
+use ssz::Encode;
+use types::{ChainSpec, DepositData, SecretKey};
+
+pub use ethabi::Error;
+
+pub const CONTRACT_DEPLOY_GAS: usize = 4_000_000;
+pub const DEPOSIT_GAS: usize = 4_000_000;
+pub const ABI: &[u8] = include_bytes!("../contract/v0.8.3_validator_registration.json");
+pub const BYTECODE: &[u8] = include_bytes!("../contract/v0.8.3_validator_registration.bytecode");
+
+pub fn eth1_tx_data(deposit_data: &DepositData) -> Result<Vec<u8>, Error> {
+    let params = vec![
+        Token::Bytes(deposit_data.pubkey.as_ssz_bytes()),
+        Token::Bytes(deposit_data.withdrawal_credentials.as_ssz_bytes()),
+        Token::Bytes(deposit_data.signature.as_ssz_bytes()),
+    ];
+
+    let abi = Contract::load(ABI)?;
+    let function = abi.function("deposit")?;
+    function.encode_input(&params)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use types::{
+        test_utils::generate_deterministic_keypair, EthSpec, Hash256, Keypair, MinimalEthSpec,
+        Signature,
+    };
+
+    type E = MinimalEthSpec;
+
+    fn get_deposit(keypair: Keypair, spec: &ChainSpec) -> DepositData {
+        let mut deposit_data = DepositData {
+            pubkey: keypair.pk.into(),
+            withdrawal_credentials: Hash256::from_slice(&[42; 32]),
+            amount: u64::max_value(),
+            signature: Signature::empty_signature().into(),
+        };
+        deposit_data.signature = deposit_data.create_signature(&keypair.sk, spec);
+        deposit_data
+    }
+
+    #[test]
+    fn basic() {
+        let spec = &E::default_spec();
+
+        let keypair = generate_deterministic_keypair(42);
+        let deposit = get_deposit(keypair.clone(), spec);
+
+        let data = eth1_tx_data(&deposit).expect("should produce tx data");
+
+        assert_eq!(data.len(), 388, "bytes should be correct length");
+    }
+}