VerifySignature

Utility

0xb57c4eff2174...3899886e0f96

FrontierContract #3,532Exact Bytecode MatchEdit this contract

Deployed November 7, 2015 (10 years ago)Block 505,917

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

505,917

Deployment Date

Nov 7, 2015, 10:31 PM

Code Size

1.2 KB

Gas at Deploy

363,641

Deployment Transaction: 0xdaad3885304c0206...3fe0b3482f8cee16

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(1,259 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

Opcodes1,259

Unique Opcodes106

Jump Instructions62

Storage Operations14

Verified Source Available

Source verified through compiler archaeology and exact bytecode matching.

Verified on Etherscan

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;
        return x;
    }

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

    function parseBytes32(string _a) returns (byte[32]) {
        bytes memory tmp = bytes(_a);
        byte[32] memory res;
        uint i = 0;
        for (i=0; i<2*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);
    }

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

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

}

External Links

Etherscan Verified Source (if any)