RopstenCtf is an easy tool to interact with the ethereum ropsten network for ctf purpose and more.

⚠️Disclaimer: don't modify this tools for usage on ethereum blockchain or use at your own risk, I'm not responsible if you lose your cryptocurrencies. This tools is for educational purpose on Ropsten test network only.

RopstenCtf

The inspiration for this tool comes from my laziness creating more and more script to interact with blockchain during ctfs.
I hope this project will facilitate access to web3 for everyone specialy during ctf.

I used the awesome Capture the ether platform made by smarx to test this tool.

💡 You will need some $rETH to send transaction, claim $rETH using this faucet: https://faucet.egorfine.com/

Supported features:

• Ethereum wallet manager
• Deployment and compilation of smart contract
• Interaction with on chain smart contract
• Inspection of transactions and blocks
• Some Ethereum cryptography utils

Prerequisites

Solc (for smart contract deployment and compilation features only)

You need the solc binary to use somes features, follow the official documentation here for installation. I highly recommand to directly download the binary from release rename it solc and add binary to path.

⚠️ If you encounter issues installing solc check the troubleshooting section at the bottom of this page.

Python dependencies

python3 -m pip install -r requirements.txt

Infura api key

To interact with ethereum blockchain you need an api key, you can use the Infura provider to generate your key. Check the documentation here.

Usage

Wallet

Import the provider key

Now import the project-id from infura, by running:

./RopstenCtf.py wallet --provider-key project-id-from-infura

Setup your wallet

Generate a new wallet

./RopstenCtf.py wallet --generate

If you want to import the generated private key in metamask follow the documentation here.

Or import an existing wallet

If you want to import an existing wallet with private key follow the metamask documentation here.

./RopstenCtf.py wallet --import-key your-private-key

Check information about your wallet

./RopstenCtf wallet --info
[+] Connected to ropsten network
[+] Public adress: 0x84dAAB1265344F9227fa1Df63906CEa27109F1a8
[INFO] Checkout your public informations here:
https://ropsten.etherscan.io/address/0x84dAAB1265344F9227fa1Df63906CEa27109F1a8
[INFO] You can claim $rETH unsing this faucet: https://faucet.egorfine.com/
[+] Balance: 9.994406372074854 $rETH

💡 Calling all these parameters at once is possible.

Inspecting transaction and block

Inspecting transaction

./RopstenCtf.py transaction --txn 0x9c5629ad19808d0f9edf291a616196f149e5e95ad434d678ce3650f81c2dc6b2
[+] Connected to ropsten network
╭───────── Transaction 0x9c5629ad19808d0f9edf291a616196f149e5e95ad434d678ce3650f81c2dc6b2 ──────────╮
│        blockHash = HexBytes('0xa7f4ca4998002f01b54fdde12f3cf3af8e3a6cf2ca86b22708e0ff88d7813cf7') │
│      blockNumber = 12295069                                                                       │
│             from = '0x84dAAB1265344F9227fa1Df63906CEa27109F1a8'                                   │
│              gas = 2000000                                                                        │
│         gasPrice = 40000000000                                                                    │
│             hash = HexBytes('0x9c5629ad19808d0f9edf291a616196f149e5e95ad434d678ce3650f81c2dc6b2') │
│            input = '0xa3c8e393'                                                                   │
│            nonce = 1                                                                              │
│                r = HexBytes('0x44edf6088964fb5987fa08349a335335530ddab70740a4951ed579d824f301fc') │
│                s = HexBytes('0x09b6fa6b7142068c7e2e3651a1ec1bbc6b957b41f78ede8814a42bc2e4824250') │
│               to = '0x19EF59B45a65ab0850cFCB17a66478d80C319fc6'                                   │
│ transactionIndex = 2                                                                              │
│             type = '0x0'                                                                          │
│                v = 41                                                                             │
│            value = 0                                                                              │
╰───────────────────────────────────────────────────────────────────────────────────────────────────╯

Inspecting block

with block number

./RopstenCtf.py transaction --block-id 12295069
[+] Connected to ropsten network
╭─────────────────────────────────────────────────── Block 12295069 ───────────────────────────────────────────────────╮
│    baseFeePerGas = 2243528846                                                                                        │
│       difficulty = 10178556523                                                                                       │
│        extraData = HexBytes('0x')                                                                                    │
│         gasLimit = 8000000                                                                                           │
│          gasUsed = 5471822                                                                                           │
│             hash = HexBytes('0xa7f4ca4998002f01b54fdde12f3cf3af8e3a6cf2ca86b22708e0ff88d7813cf7')                    │
│        logsBloom = HexBytes('0x000000000000000000000800002000244002000004008800408081000008000121100000000200800004… │
│            miner = '0x0FB988FeC207162a1a0060533fBcb7aF9aDacf52'                                                      │
│          mixHash = HexBytes('0x0f45161cc9a365be62e058abbf9ab659557edd0538e2ceec6f4523befb3d6d1e')                    │
│            nonce = HexBytes('0x00007a86c02ebf0a')                                                                    │
│           number = 12295069                                                                                          │
│       parentHash = HexBytes('0x18e646c3d8e2c69bf41b82ba81f10f57d6b639c7029b44c6c62acb349f94dea5')                    │
│     receiptsRoot = HexBytes('0x462fa2ae6c03e6fb4e41a3b652a0ed002df0c0ea4725dccd30ff74af087791c0')                    │
│       sha3Uncles = HexBytes('0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347')                    │
│             size = 20655                                                                                             │
│        stateRoot = HexBytes('0x5221c766169d948e3f0408215edd4f1319d44903283f769c2d49c7e67f12107d')                    │
│        timestamp = 1653418694                                                                                        │
│  totalDifficulty = 42066043784994543                                                                                 │
│     transactions = ['...']                                                                                           │
│ transactionsRoot = HexBytes('0x4a45e19ef76496d3908391f7b89fecb7e88fe4c6243d0182049fbe2bb12eaa83')                    │
│           uncles = []                                                                                                │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯

💡 Add --all to see transactions in block information

with transaction hash

./RopstenCtf.py transaction --txn 0x9c5629ad19808d0f9edf291a616196f149e5e95ad434d678ce3650f81c2dc6b2 --block-info

Deal with smart contract

Interact with smart contract

Retrieve available function of a smart contract

./RopstenCtf.py contract --address 0x19EF59B45a65ab0850cFCB17a66478d80C319fc6 --info
[+] Connected to ropsten network
[INFO] Inspect contract at https://ropsten.etherscan.io/address/0x19EF59B45a65ab0850cFCB17a66478d80C319fc6
[INFO] Fetching abi done
[+] List of functions:
        [*] callme()
        [*] isComplete()

View smart contract return method or variable

./RopstenCtf.py contract --address 0x19EF59B45a65ab0850cFCB17a66478d80C319fc6 --view -fc isComplete
[+] Connected to ropsten network
[INFO] Inspect contract at https://ropsten.etherscan.io/address/0x19EF59B45a65ab0850cFCB17a66478d80C319fc6
[INFO] Fetching abi done
[INFO] Calling function done
[+] Reponse isComplete(): False

💡 No transaction will be created here.

Call smart contract function

This action send a transaction to the network.

./RopstenCtf.py contract --address 0x19EF59B45a65ab0850cFCB17a66478d80C319fc6 --call -fc callme
[+] Connected to ropsten network
[INFO] Inspect contract at https://ropsten.etherscan.io/address/0x19EF59B45a65ab0850cFCB17a66478d80C319fc6
[INFO] Fetching abi done
[INFO] Inspect transaction here:
https://ropsten.etherscan.io/tx/0x9c5629ad19808d0f9edf291a616196f149e5e95ad434d678ce3650f81c2dc6b2
[INFO] Transaction done
[+] Reponse callme():
        [*] Transaction status: success

⚠️This action can take times and will timeout after 120s, you can still see the transaction status on ropsten etherscan. If transaction takes a lot of time, try to increase the gas price with --gas-price (default is 4000 gwei).

Call smart contract function with parameters

./RopstenCtf.py contract --address 0x7F5d37E8645d4A8C1CD08ea712C0508e8470F9BF --call -fc guess -p 42 --ether 1
[+] Connected to ropsten network
[INFO] Inspect contract at https://ropsten.etherscan.io/address/0x7F5d37E8645d4A8C1CD08ea712C0508e8470F9BF
[INFO] Fetching abi done
[INFO] Inspect transaction here:
https://ropsten.etherscan.io/tx/0xfa778b121d7f3881159eef6812a3c240979543c063dc3b0310019295bfdb2fa7
[INFO] Transaction done
[+] Reponse guess(42):
        [*] Transaction status: success

💡 Multiple parameters is supported, usage: -p parameter1,parameter2,...
No need to worry about parameters types, they are handled automatically.

⚠️Notice the -e/--ether that send 1 $rETH, this parameter is optional it depends on the smart contract.

Compiling, deploying smart contract

⚠️The solc binary is needed for these features.

Compiling smart_contract.sol

./RopstenCtf.py contract --compile -f NickName.sol
[+] Connected to ropsten network
--> NickName.sol

[+] abi and bin files generated on directory:
        [*] ./NickName/CaptureTheEther.abi
        [*] ./NickName/CaptureTheEther.bin

Deploying contract:

./RopstenCtf.py contract --deploy -f NickName.sol
[+] Connected to ropsten network
--> NickName.sol

[+] abi and bin files generated on directory:
        [*] ./NickName/NickName.abi
        [*] ./NickName/NickName.bin
[INFO] Inspect transaction here: https://ropsten.etherscan.io/tx/0xea3a3349d7284e7a7bd2dbc94ebcc20a7ffac6b96f3726251b369744ddc8c16c
[INFO] Transaction done
[+] Reponse deploying contract NickName:
        [*] Transaction status: success

⚠️This step compile and after deploy the contract on chain.

Troubleshouting

Error: No such file or directory: 'solc'

"FileNotFoundError: [Errno 2] No such file or directory: 'solc'"  

You need to install solc binary

Error: Contract source code not verified

./RopstenCtf.py contract --address 0x21Ac7a18A8e04A712EcEe9f5FB9aa25Dc2f568B4 --info
[+] Connected to ropsten network
[INFO] Inspect contract at https://ropsten.etherscan.io/address/0x21Ac7a18A8e04A712EcEe9f5FB9aa25Dc2f568B4
[ERROR] Contract source code not verified, try again specifying the abi file with --abi (you can compile the
smart_contract.sol with --compile if you don't have the abi file)

If the source code is not verified, try to compile the smart_contract.sol and specified the smart_contract.abi:

./RopstenCtf.py contract --address 0x21Ac7a18A8e04A712EcEe9f5FB9aa25Dc2f568B4 --abi NickName/NickName.abi --info
[+] Connected to ropsten network
[INFO] Inspect contract at https://ropsten.etherscan.io/address/0x21Ac7a18A8e04A712EcEe9f5FB9aa25Dc2f568B4
[+] List of functions:
        [*] nicknameOf(:address)
        [*] setNickname(nickname:bytes32)