ChainProof SmartContract

code:ChainProof.sol

pragma solidity ^0.5.7;

contract ChainProof {

struct Proof {

bytes32 messageHash;

uint256 timestamp;

}

mapping (address => Proof) public proofs;

event ProofCreated(address signer);

constructor () public {

}

function registerProof(bytes32 messageHash, bytes memory signature)

public

returns (bool)

{

bytes32 r;

bytes32 s;

uint8 v;

assembly {

r := mload(add(signature, 32))

s := mload(add(signature, 64))

v := byte(0, mload(add(signature, 96)))

}

address signer = ecrecover(messageHash, v, r, s);

require(signer != address(0));

require(proofssigner.timestamp == 0);

Proof storage proof = proofssigner;

proof.messageHash = messageHash;

proof.timestamp = now;

emit ProofCreated(signer);

return true;

}

function getProof(address _address)

public

view

returns (bytes32, uint256) {

Proof memory proof = proofs_address;

return (proof.messageHash, proof.timestamp);

}