VerifySignature

Utility

0xca8eb2465bc1...cd79331090ef

FrontierContract #3,524Exact Bytecode MatchEdit this contract

Deployed November 7, 2015 (10 years ago)Block 505,762

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

505,762

Deployment Date

Nov 7, 2015, 09:49 PM

Code Size

969.0 B

Gas at Deploy

288,938

Deployment Transaction: 0xf64faa56a3457c2e...2814bbe2735b8b6c

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(969 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; parseBytes adapted from the Oraclize parseAddr of the period; returnBytes(string) 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

Opcodes969

Unique Opcodes92

Jump Instructions49

Storage Operations14

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

    function log() returns (bytes) {
        bytes memory b = parseBytes("0336");
        return b;
    }

    function parseBytes(string _a) returns (bytes) {
        bytes memory tmp = bytes(_a);
        bytes memory res;
        for (uint i=0; i<tmp.length; 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 returnBytes(string _a) returns (bytes) {
        return bytes(_a);
    }

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

}

External Links

Etherscan Verified Source (if any)