From 11d1f60753222e8a281a19688c49fa2a811a0242 Mon Sep 17 00:00:00 2001
From: Mac L <mjladson@pm.me>
Date: Tue, 11 Nov 2025 10:52:46 +0400
Subject: [PATCH] Migrate the `deposit_contract` crate to `alloy` (#8139)

https://github.com/sigp/lighthouse/issues/6022


  Switches the `deposit_contract` crate to use the `alloy` ecosystem and removes the dependency on `ethabi`


Co-Authored-By: Mac L <mjladson@pm.me>
---
 Cargo.lock                                | 300 ++++++----------------
 common/deposit_contract/Cargo.toml        |   5 +-
 common/deposit_contract/src/lib.rs        | 103 +++++---
 common/validator_dir/src/validator_dir.rs |   2 +-
 4 files changed, 148 insertions(+), 262 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 080221e5f2..481fe71df0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -177,6 +177,22 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "alloy-dyn-abi"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3fdff496dd4e98a81f4861e66f7eaf5f2488971848bb42d9c892f871730245c8"
+dependencies = [
+ "alloy-json-abi",
+ "alloy-primitives",
+ "alloy-sol-type-parser",
+ "alloy-sol-types",
+ "itoa",
+ "serde",
+ "serde_json",
+ "winnow",
+]
+
 [[package]]
 name = "alloy-eip2124"
 version = "0.2.0"
@@ -235,6 +251,18 @@ dependencies = [
  "thiserror 2.0.12",
 ]
 
+[[package]]
+name = "alloy-json-abi"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5513d5e6bd1cba6bdcf5373470f559f320c05c8c59493b6e98912fbe6733943f"
+dependencies = [
+ "alloy-primitives",
+ "alloy-sol-type-parser",
+ "serde",
+ "serde_json",
+]
+
 [[package]]
 name = "alloy-network-primitives"
 version = "1.0.42"
@@ -274,7 +302,7 @@ dependencies = [
  "ruint",
  "rustc-hash 2.1.1",
  "serde",
- "sha3 0.10.8",
+ "sha3",
  "tiny-keccak",
 ]
 
@@ -379,14 +407,26 @@ dependencies = [
  "syn-solidity",
 ]
 
+[[package]]
+name = "alloy-sol-type-parser"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "954d1b2533b9b2c7959652df3076954ecb1122a28cc740aa84e7b0a49f6ac0a9"
+dependencies = [
+ "serde",
+ "winnow",
+]
+
 [[package]]
 name = "alloy-sol-types"
 version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "70319350969a3af119da6fb3e9bddb1bce66c9ea933600cb297c8b1850ad2a3c"
 dependencies = [
+ "alloy-json-abi",
  "alloy-primitives",
  "alloy-sol-macro",
+ "serde",
 ]
 
 [[package]]
@@ -1293,28 +1333,16 @@ dependencies = [
  "radium 0.3.0",
 ]
 
-[[package]]
-name = "bitvec"
-version = "0.20.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7774144344a4faa177370406a7ff5f1da24303817368584c6206c8303eb07848"
-dependencies = [
- "funty 1.1.0",
- "radium 0.6.2",
- "tap",
- "wyz 0.2.0",
-]
-
 [[package]]
 name = "bitvec"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1bc2832c24239b0141d5674bb9174f9d68a8b5b3f2753311927c172ca46f7e9c"
 dependencies = [
- "funty 2.0.0",
+ "funty",
  "radium 0.7.0",
  "tap",
- "wyz 0.5.1",
+ "wyz",
 ]
 
 [[package]]
@@ -1332,7 +1360,7 @@ version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c0940dc441f31689269e10ac70eb1002a3a1d3ad1390e030043662eb7fe4688b"
 dependencies = [
- "block-padding 0.1.5",
+ "block-padding",
  "byte-tools",
  "byteorder",
  "generic-array 0.12.4",
@@ -1344,7 +1372,6 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4152116fd6e9dadb291ae18fc1ec3575ed6d84c29642d97890f4b4a3417297e4"
 dependencies = [
- "block-padding 0.2.1",
  "generic-array 0.14.7",
 ]
 
@@ -1366,12 +1393,6 @@ dependencies = [
  "byte-tools",
 ]
 
-[[package]]
-name = "block-padding"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8d696c370c750c948ada61c69a0ee2cbbb9c50b1019ddb86d9317157a99c2cae"
-
 [[package]]
 name = "bls"
 version = "0.2.0"
@@ -1867,7 +1888,7 @@ dependencies = [
  "serde",
  "serde_derive",
  "sha2 0.10.8",
- "sha3 0.10.8",
+ "sha3",
  "thiserror 1.0.69",
 ]
 
@@ -2475,7 +2496,9 @@ dependencies = [
 name = "deposit_contract"
 version = "0.2.0"
 dependencies = [
- "ethabi 16.0.0",
+ "alloy-dyn-abi",
+ "alloy-json-abi",
+ "alloy-primitives",
  "ethereum_ssz",
  "hex",
  "reqwest 0.11.27",
@@ -3029,7 +3052,7 @@ dependencies = [
  "log",
  "rand 0.8.5",
  "serde",
- "sha3 0.10.8",
+ "sha3",
  "zeroize",
 ]
 
@@ -3130,7 +3153,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sha2 0.10.8",
- "sha3 0.10.8",
+ "sha3",
  "thiserror 1.0.69",
  "uuid 0.8.2",
 ]
@@ -3269,51 +3292,23 @@ dependencies = [
  "tempfile",
 ]
 
-[[package]]
-name = "ethabi"
-version = "16.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4c98847055d934070b90e806e12d3936b787d0a115068981c1d8dfd5dfef5a5"
-dependencies = [
- "ethereum-types 0.12.1",
- "hex",
- "serde",
- "serde_json",
- "sha3 0.9.1",
- "thiserror 1.0.69",
- "uint 0.9.5",
-]
-
 [[package]]
 name = "ethabi"
 version = "18.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7413c5f74cc903ea37386a8965a936cbeb334bd270862fdece542c1b2dcbc898"
 dependencies = [
- "ethereum-types 0.14.1",
+ "ethereum-types",
  "hex",
  "once_cell",
  "regex",
  "serde",
  "serde_json",
- "sha3 0.10.8",
+ "sha3",
  "thiserror 1.0.69",
  "uint 0.9.5",
 ]
 
-[[package]]
-name = "ethbloom"
-version = "0.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfb684ac8fa8f6c5759f788862bb22ec6fe3cb392f6bfd08e3c64b603661e3f8"
-dependencies = [
- "crunchy",
- "fixed-hash 0.7.0",
- "impl-rlp",
- "impl-serde 0.3.2",
- "tiny-keccak",
-]
-
 [[package]]
 name = "ethbloom"
 version = "0.13.0"
@@ -3321,40 +3316,26 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c22d4b5885b6aa2fe5e8b9329fb8d232bf739e434e6b87347c63bdd00c120f60"
 dependencies = [
  "crunchy",
- "fixed-hash 0.8.0",
- "impl-codec 0.6.0",
+ "fixed-hash",
+ "impl-codec",
  "impl-rlp",
- "impl-serde 0.4.0",
+ "impl-serde",
  "scale-info",
  "tiny-keccak",
 ]
 
-[[package]]
-name = "ethereum-types"
-version = "0.12.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05136f7057fe789f06e6d41d07b34e6f70d8c86e5693b60f97aaa6553553bdaf"
-dependencies = [
- "ethbloom 0.11.1",
- "fixed-hash 0.7.0",
- "impl-rlp",
- "impl-serde 0.3.2",
- "primitive-types 0.10.1",
- "uint 0.9.5",
-]
-
 [[package]]
 name = "ethereum-types"
 version = "0.14.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "02d215cbf040552efcbe99a38372fe80ab9d00268e20012b79fcd0f073edd8ee"
 dependencies = [
- "ethbloom 0.13.0",
- "fixed-hash 0.8.0",
- "impl-codec 0.6.0",
+ "ethbloom",
+ "fixed-hash",
+ "impl-codec",
  "impl-rlp",
- "impl-serde 0.4.0",
- "primitive-types 0.12.2",
+ "impl-serde",
+ "primitive-types",
  "scale-info",
  "uint 0.9.5",
 ]
@@ -3439,7 +3420,7 @@ dependencies = [
  "chrono",
  "convert_case 0.6.0",
  "elliptic-curve 0.12.3",
- "ethabi 18.0.0",
+ "ethabi",
  "generic-array 0.14.7",
  "hex",
  "k256 0.11.6",
@@ -3775,18 +3756,6 @@ dependencies = [
  "windows-acl",
 ]
 
-[[package]]
-name = "fixed-hash"
-version = "0.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cfcf0ed7fe52a17a03854ec54a9f76d6d84508d1c0e66bc1793301c73fc8493c"
-dependencies = [
- "byteorder",
- "rand 0.8.5",
- "rustc-hex",
- "static_assertions",
-]
-
 [[package]]
 name = "fixed-hash"
 version = "0.8.0"
@@ -3894,12 +3863,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "funty"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fed34cd105917e91daa4da6b3728c47b068749d6a62c59811f06ed2ac71d9da7"
-
 [[package]]
 name = "funty"
 version = "2.0.0"
@@ -4987,22 +4950,13 @@ dependencies = [
  "xmltree",
 ]
 
-[[package]]
-name = "impl-codec"
-version = "0.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "161ebdfec3c8e3b52bf61c4f3550a1eea4f9579d10dc1b936f3171ebdcd6c443"
-dependencies = [
- "parity-scale-codec 2.3.1",
-]
-
 [[package]]
 name = "impl-codec"
 version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ba6a270039626615617f3f36d15fc827041df3b78c439da2cadfa47455a77f2f"
 dependencies = [
- "parity-scale-codec 3.7.4",
+ "parity-scale-codec",
 ]
 
 [[package]]
@@ -5014,15 +4968,6 @@ dependencies = [
  "rlp",
 ]
 
-[[package]]
-name = "impl-serde"
-version = "0.3.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4551f042f3438e64dbd6226b20527fc84a6e1fe65688b58746a2f53623f25f5c"
-dependencies = [
- "serde",
-]
-
 [[package]]
 name = "impl-serde"
 version = "0.4.0"
@@ -5262,7 +5207,7 @@ dependencies = [
  "ecdsa 0.14.8",
  "elliptic-curve 0.12.3",
  "sha2 0.10.8",
- "sha3 0.10.8",
+ "sha3",
 ]
 
 [[package]]
@@ -5305,7 +5250,7 @@ version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4b286e6b663fb926e1eeb68528e69cb70ed46c6d65871a21b2215ae8154c6d3c"
 dependencies = [
- "primitive-types 0.12.2",
+ "primitive-types",
  "tiny-keccak",
 ]
 
@@ -6910,7 +6855,7 @@ dependencies = [
  "arrayvec",
  "auto_impl 1.2.1",
  "bytes",
- "ethereum-types 0.14.1",
+ "ethereum-types",
  "open-fastrlp-derive",
 ]
 
@@ -7094,20 +7039,6 @@ dependencies = [
  "group 0.13.0",
 ]
 
-[[package]]
-name = "parity-scale-codec"
-version = "2.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "373b1a4c1338d9cd3d1fa53b3a11bdab5ab6bd80a20f7f7becd76953ae2be909"
-dependencies = [
- "arrayvec",
- "bitvec 0.20.4",
- "byte-slice-cast",
- "impl-trait-for-tuples",
- "parity-scale-codec-derive 2.3.1",
- "serde",
-]
-
 [[package]]
 name = "parity-scale-codec"
 version = "3.7.4"
@@ -7119,30 +7050,18 @@ dependencies = [
  "byte-slice-cast",
  "const_format",
  "impl-trait-for-tuples",
- "parity-scale-codec-derive 3.7.4",
+ "parity-scale-codec-derive",
  "rustversion",
  "serde",
 ]
 
-[[package]]
-name = "parity-scale-codec-derive"
-version = "2.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1557010476e0595c9b568d16dcfb81b93cdeb157612726f5170d31aa707bed27"
-dependencies = [
- "proc-macro-crate 1.3.1",
- "proc-macro2",
- "quote",
- "syn 1.0.109",
-]
-
 [[package]]
 name = "parity-scale-codec-derive"
 version = "3.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "581c837bb6b9541ce7faa9377c20616e4fb7650f6b0f68bc93c827ee504fb7b3"
 dependencies = [
- "proc-macro-crate 3.3.0",
+ "proc-macro-crate",
  "proc-macro2",
  "quote",
  "syn 2.0.100",
@@ -7472,50 +7391,27 @@ dependencies = [
  "syn 2.0.100",
 ]
 
-[[package]]
-name = "primitive-types"
-version = "0.10.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05e4722c697a58a99d5d06a08c30821d7c082a4632198de1eaa5a6c22ef42373"
-dependencies = [
- "fixed-hash 0.7.0",
- "impl-codec 0.5.1",
- "impl-rlp",
- "impl-serde 0.3.2",
- "uint 0.9.5",
-]
-
 [[package]]
 name = "primitive-types"
 version = "0.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b34d9fd68ae0b74a41b21c03c2f62847aa0ffea044eee893b4c140b37e244e2"
 dependencies = [
- "fixed-hash 0.8.0",
- "impl-codec 0.6.0",
+ "fixed-hash",
+ "impl-codec",
  "impl-rlp",
- "impl-serde 0.4.0",
+ "impl-serde",
  "scale-info",
  "uint 0.9.5",
 ]
 
-[[package]]
-name = "proc-macro-crate"
-version = "1.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f4c021e1093a56626774e81216a4ce732a735e5bad4868a03f3ed65ca0c3919"
-dependencies = [
- "once_cell",
- "toml_edit 0.19.15",
-]
-
 [[package]]
 name = "proc-macro-crate"
 version = "3.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "edce586971a4dfaa28950c6f18ed55e0406c1ab88bbce2c6f6293a7aaba73d35"
 dependencies = [
- "toml_edit 0.22.24",
+ "toml_edit",
 ]
 
 [[package]]
@@ -7858,12 +7754,6 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "def50a86306165861203e7f84ecffbbdfdea79f0e51039b33de1e952358c47ac"
 
-[[package]]
-name = "radium"
-version = "0.6.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "643f8f41a8ebc4c5dc4515c82bb8abd397b527fc20fd681b7c011c2aee5d44fb"
-
 [[package]]
 name = "radium"
 version = "0.7.0"
@@ -8279,8 +8169,8 @@ dependencies = [
  "num-bigint",
  "num-integer",
  "num-traits",
- "parity-scale-codec 3.7.4",
- "primitive-types 0.12.2",
+ "parity-scale-codec",
+ "primitive-types",
  "proptest",
  "rand 0.8.5",
  "rand 0.9.0",
@@ -8608,7 +8498,7 @@ checksum = "346a3b32eba2640d17a9cb5927056b08f3de90f65b72fe09402c2ad07d684d0b"
 dependencies = [
  "cfg-if",
  "derive_more 1.0.0",
- "parity-scale-codec 3.7.4",
+ "parity-scale-codec",
  "scale-info-derive",
 ]
 
@@ -8618,7 +8508,7 @@ version = "2.11.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c6630024bf739e2179b91fb424b28898baf819414262c5d376677dbff1fe7ebf"
 dependencies = [
- "proc-macro-crate 3.3.0",
+ "proc-macro-crate",
  "proc-macro2",
  "quote",
  "syn 2.0.100",
@@ -9005,18 +8895,6 @@ dependencies = [
  "digest 0.10.7",
 ]
 
-[[package]]
-name = "sha3"
-version = "0.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f81199417d4e5de3f04b1e871023acea7389672c4135918f05aa9cbf2f2fa809"
-dependencies = [
- "block-buffer 0.9.0",
- "digest 0.9.0",
- "keccak",
- "opaque-debug 0.3.1",
-]
-
 [[package]]
 name = "sha3"
 version = "0.10.8"
@@ -9956,17 +9834,6 @@ version = "0.6.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0dd7358ecb8fc2f8d014bf86f6f638ce72ba252a2c3a2572f2a795f1d23efb41"
 
-[[package]]
-name = "toml_edit"
-version = "0.19.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1b5bb770da30e5cbfde35a2d7b9b8a2c4b8ef89548a7a6aeab5c9a576e3e7421"
-dependencies = [
- "indexmap 2.8.0",
- "toml_datetime",
- "winnow 0.5.40",
-]
-
 [[package]]
 name = "toml_edit"
 version = "0.22.24"
@@ -9975,7 +9842,7 @@ checksum = "17b4795ff5edd201c7cd6dca065ae59972ce77d1b80fa0a84d94950ece7d1474"
 dependencies = [
  "indexmap 2.8.0",
  "toml_datetime",
- "winnow 0.7.3",
+ "winnow",
 ]
 
 [[package]]
@@ -11424,15 +11291,6 @@ version = "0.53.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"
 
-[[package]]
-name = "winnow"
-version = "0.5.40"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f593a95398737aeed53e489c785df13f3618e41dbcd6718c6addbf1395aa6876"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "winnow"
 version = "0.7.3"
@@ -11500,12 +11358,6 @@ dependencies = [
  "web-sys",
 ]
 
-[[package]]
-name = "wyz"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85e60b0d1b5f99db2556934e21937020776a5d31520bf169e851ac44e6420214"
-
 [[package]]
 name = "wyz"
 version = "0.5.1"
diff --git a/common/deposit_contract/Cargo.toml b/common/deposit_contract/Cargo.toml
index 767f67b853..dfaad43719 100644
--- a/common/deposit_contract/Cargo.toml
+++ b/common/deposit_contract/Cargo.toml
@@ -7,8 +7,11 @@ edition = { workspace = true }
 build = "build.rs"
 
 [dependencies]
-ethabi = "16.0.0"
+alloy-dyn-abi = "1.4"
+alloy-json-abi = "1.4"
+alloy-primitives = { workspace = true }
 ethereum_ssz = { workspace = true }
+serde_json = { workspace = true }
 tree_hash = { workspace = true }
 types = { workspace = true }
 
diff --git a/common/deposit_contract/src/lib.rs b/common/deposit_contract/src/lib.rs
index 7d58240f11..12c3bdaa89 100644
--- a/common/deposit_contract/src/lib.rs
+++ b/common/deposit_contract/src/lib.rs
@@ -1,23 +1,44 @@
-use ethabi::{Contract, Token};
+use alloy_dyn_abi::{DynSolValue, JsonAbiExt};
+use alloy_json_abi::JsonAbi;
+use alloy_primitives::FixedBytes;
 use ssz::{Decode, DecodeError as SszDecodeError, Encode};
 use tree_hash::TreeHash;
 use types::{DepositData, Hash256, PublicKeyBytes, SignatureBytes};
 
-pub use ethabi::Error;
-
 #[derive(Debug)]
-pub enum DecodeError {
-    EthabiError(ethabi::Error),
+pub enum Error {
+    AlloyCoreError(alloy_json_abi::Error),
+    SerdeJsonError(serde_json::Error),
+    DynAbiError(alloy_dyn_abi::Error),
     SszDecodeError(SszDecodeError),
+    FunctionNotFound,
     MissingField,
     UnableToGetBytes,
     MissingToken,
     InadequateBytes,
 }
 
-impl From<ethabi::Error> for DecodeError {
-    fn from(e: ethabi::Error) -> DecodeError {
-        DecodeError::EthabiError(e)
+impl From<alloy_json_abi::Error> for Error {
+    fn from(e: alloy_json_abi::Error) -> Error {
+        Error::AlloyCoreError(e)
+    }
+}
+
+impl From<serde_json::Error> for Error {
+    fn from(e: serde_json::Error) -> Error {
+        Error::SerdeJsonError(e)
+    }
+}
+
+impl From<alloy_dyn_abi::Error> for Error {
+    fn from(e: alloy_dyn_abi::Error) -> Error {
+        Error::DynAbiError(e)
+    }
+}
+
+impl From<SszDecodeError> for Error {
+    fn from(e: SszDecodeError) -> Error {
+        Error::SszDecodeError(e)
     }
 }
 
@@ -36,47 +57,57 @@ pub mod testnet {
 
 pub fn encode_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()),
-        Token::FixedBytes(deposit_data.tree_hash_root().as_ssz_bytes()),
+        DynSolValue::Bytes(deposit_data.pubkey.as_ssz_bytes()),
+        DynSolValue::Bytes(deposit_data.withdrawal_credentials.as_ssz_bytes()),
+        DynSolValue::Bytes(deposit_data.signature.as_ssz_bytes()),
+        DynSolValue::FixedBytes(
+            FixedBytes::<32>::from_slice(&deposit_data.tree_hash_root().as_ssz_bytes()),
+            32,
+        ),
     ];
 
     // Here we make an assumption that the `crate::testnet::ABI` has a superset of the features of
     // the crate::ABI`.
-    let abi = Contract::load(ABI)?;
-    let function = abi.function("deposit")?;
-    function.encode_input(&params)
+    let abi: JsonAbi = serde_json::from_slice(ABI)?;
+    let function = abi
+        .function("deposit")
+        .and_then(|functions| functions.first())
+        .ok_or(Error::FunctionNotFound)?;
+
+    function
+        .abi_encode_input(&params)
+        .map_err(Error::DynAbiError)
 }
 
-pub fn decode_eth1_tx_data(
-    bytes: &[u8],
-    amount: u64,
-) -> Result<(DepositData, Hash256), DecodeError> {
-    let abi = Contract::load(ABI)?;
-    let function = abi.function("deposit")?;
-    let mut tokens = function.decode_input(bytes.get(4..).ok_or(DecodeError::InadequateBytes)?)?;
+pub fn decode_eth1_tx_data(bytes: &[u8], amount: u64) -> Result<(DepositData, Hash256), Error> {
+    let abi: JsonAbi = serde_json::from_slice(ABI)?;
+    let function = abi
+        .function("deposit")
+        .and_then(|functions| functions.first())
+        .ok_or(Error::FunctionNotFound)?;
+
+    let input_data = bytes.get(4..).ok_or(Error::InadequateBytes)?;
+    let mut tokens = function.abi_decode_input(input_data)?;
 
     macro_rules! decode_token {
-        ($type: ty, $to_fn: ident) => {
-            <$type>::from_ssz_bytes(
-                &tokens
-                    .pop()
-                    .ok_or_else(|| DecodeError::MissingToken)?
-                    .$to_fn()
-                    .ok_or_else(|| DecodeError::UnableToGetBytes)?,
-            )
-            .map_err(DecodeError::SszDecodeError)?
-        };
+        ($type: ty) => {{
+            let token = tokens.pop().ok_or(Error::MissingToken)?;
+            let bytes_data = match token {
+                DynSolValue::Bytes(b) => b,
+                DynSolValue::FixedBytes(b, _) => b.to_vec(),
+                _ => return Err(Error::UnableToGetBytes),
+            };
+            <$type>::from_ssz_bytes(&bytes_data)?
+        }};
     }
 
-    let root = decode_token!(Hash256, into_fixed_bytes);
+    let root = decode_token!(Hash256);
 
     let deposit_data = DepositData {
         amount,
-        signature: decode_token!(SignatureBytes, into_bytes),
-        withdrawal_credentials: decode_token!(Hash256, into_bytes),
-        pubkey: decode_token!(PublicKeyBytes, into_bytes),
+        signature: decode_token!(SignatureBytes),
+        withdrawal_credentials: decode_token!(Hash256),
+        pubkey: decode_token!(PublicKeyBytes),
     };
 
     Ok((deposit_data, root))
diff --git a/common/validator_dir/src/validator_dir.rs b/common/validator_dir/src/validator_dir.rs
index 352ede708a..8b50ea6687 100644
--- a/common/validator_dir/src/validator_dir.rs
+++ b/common/validator_dir/src/validator_dir.rs
@@ -32,7 +32,7 @@ pub enum Error {
     UnableToReadDepositAmount(io::Error),
     UnableToParseDepositAmount(std::num::ParseIntError),
     DepositAmountIsNotUtf8(std::string::FromUtf8Error),
-    UnableToParseDepositData(deposit_contract::DecodeError),
+    UnableToParseDepositData(deposit_contract::Error),
     Eth1TxHashExists(PathBuf),
     UnableToWriteEth1TxHash(io::Error),
     /// The deposit root in the deposit data file does not match the one generated locally. This is