EVM Constructor Decoder

Decode Solidity constructor arguments directly from contract creation bytecode.

Useful for:

• Smart contract auditing
• Reverse engineering deployed contracts
• CTFs
• On-chain security research
• Recovering constructor secrets

---

Installation

From GitHub:

pip install "git+https://github.com/touchmeangel/evm_decode_constructor.git"

Docker:

docker pull touchmeangel/evm_decode_constructor

---

Usage

CLI:

evm_decode_constructor "<creation_input>" "<constructor_types>"

Docker:

docker run --rm touchmeangel/evm_decode_constructor \
    "<creation_input>" \
    "<constructor_types>"

---

Examples

Single parameter:

evm_decode_constructor "0x6080604052..." "bytes32"

Multiple parameters:

evm_decode_constructor "0x6080604052..." "address,uint256,bool"

---

Example Output

======================================================================
DECODED CONSTRUCTOR ARGUMENTS
======================================================================
Parameter 1 (bytes32):
b'A very strong secret password :)'
======================================================================

---

Getting the Creation Input

On Etherscan:

1. Open the contract.
2. Select the Contract tab.
3. Open Contract Creation Code.
4. Copy the complete creation input.

The copied creation input is the value passed to the decoder.

---

Supported ABI Types

Examples include:

• address
• bool
• string
• bytes
• bytes32
• uint256
• int256
• address[]
• uint256[]
• tuples
• nested ABI-compatible types

---

Notes

• The constructor types must exactly match the deployed constructor.
• Input must be the complete contract creation bytecode.
• Uses standard Solidity ABI decoding.

---

License

Apache-2.0