VerifySignature

Utility

0x251c4230387a...2ff7b97c4620

FrontierContract #3,535Exact Bytecode MatchEdit this contract

Deployed November 7, 2015 (10 years ago)Block 505,950

An early experiment in checking a Bitcoin-style signature with ecrecover, using hex-string parsing helpers.

Frontier EraVerified Source

Key Facts

Deployer

0x6f4250...c0af39

Deployment Block

505,950

Deployment Date

Nov 7, 2015, 10:40 PM

Code Size

1.3 KB

Gas at Deploy

378,886

Deployment Transaction: 0xc55fc4be3490b2f0...1760899e9d6075cd

Description

A test contract for verifying a Bitcoin-style ECDSA signature on Ethereum. It holds a message hash, the r, s and v values of a signature over it, and the expected signer, written as hex strings and parsed on chain, then passes them to the ecrecover precompile. The deployer published the final version as verifysignature.sol in the poolicy repository, a project to enforce Bitcoin mining pool policies from Ethereum.

Source Verified

SolidityExact bytecode match(1,323 bytes)

Compiler: v0.1.6+

View verification proof

Exact runtime and creation bytecode match with soljson v0.1.6+commit.d41f8b7c, optimizer on. Source: handwritten reconstruction; parseBytes32 adapted from the Oraclize parseAddr of the period; selector names parse2()/returnBytes(string) and event Log(byte[32]) recovered by dictionary search. Verified on Etherscan. Not submitted to Sourcify: its oldest supported compiler is v0.1.7. Contract name is a stand-in: stand-in: an earlier iteration of the deployer's signature-verification experiment, deployed in the hours before the same author published the final version as VerifySignature in github.com/bertani/poolicy (verifysignature.sol, 2015-11-08), which is byte-exact for 0xee82e544eabcafa92f0bffc2c7131bdd586807ff.

Heuristic Analysis

The following characteristics were detected through bytecode analysis and may not be accurate.

Detected Type: Utility

Contains SELFDESTRUCT opcode

Frontier Era

The initial release of Ethereum. A bare-bones implementation for technical users.

Block span: 0 — 1,149,999

July 30, 2015 — March 14, 2016

Bytecode Overview

Opcodes1,323

Unique Opcodes108

Jump Instructions60

Storage Operations10

Verified Source Available

Source verified through compiler archaeology and exact bytecode matching.

View Verification Proof

Show source code (Solidity)

// Submitted by EthereumHistory (ethereumhistory.com)
contract VerifySignature {
    address owner;

    function VerifySignature() {
        owner = msg.sender;
    }

    function ciao() returns (byte[32]) {
        byte[32] memory x;
        x[0] = 0x14;
        x[1] = 0x20;
        x[2] = 0x20;
        x[3] = 0x84;
        x[4] = 0x84;
        return x;
    }

    function useBytes() returns (bytes) {
        return returnBytes("ciao");
    }

    function returnBytes(string _a) returns (bytes) {
        return bytes(_a);
    }

    function parse2() returns (byte[32]) {
        return parseBytes32("036421f6eca2ef7a43ce0af4a150b933afb3cf0764323b8ff9ebfd4935fd86d436");
    }


    function parseBytes32(string _a) returns (byte[32]) {
        bytes memory tmp = bytes(_a);
        byte[32] memory res;
        uint i = 0;
        for (i=0; i<32; i++){
            uint j = i*2;
            uint8 b1 = uint8(tmp[j]);
            uint8 b2 = uint8(tmp[j+1]);
            if ((b1 >= 97)&&(b1 <= 102)) b1 -= 87;
            else if ((b1 >= 48)&&(b1 <= 57)) b1 -= 48;
            if ((b2 >= 97)&&(b2 <= 102)) b2 -= 87;
            else if ((b2 >= 48)&&(b2 <= 57)) b2 -= 48;
            res[i] = byte(b1*16+b2);
        }
        return res;
    }

    function kill() {
        if (msg.sender == owner) suicide(msg.sender);
    }


}

External Links

Etherscan Verified Source (if any)