a7e91856f3
* Update to ganache-cli v6.1.0 and truffle v4.1.0 * Update to stable version of ganache-cli * fix: update event emission warning - Fix event emission warnings for solidity 4.21 after truffle has been updated to use this version * fix pr review comments * update to truffle v4.1.5 * update package-lock * add additional emit keywords * update solidity-coverage to 0.4.15 * update to solium 1.1.6 * fix MerkleProof coverage analysis by testing through wrapper * change version pragma to ^0.4.21 * fix solium linting errors
55 lines
1.4 KiB
Solidity
55 lines
1.4 KiB
Solidity
pragma solidity ^0.4.21;
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/**
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* @title Eliptic curve signature operations
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*
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* @dev Based on https://gist.github.com/axic/5b33912c6f61ae6fd96d6c4a47afde6d
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*
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* TODO Remove this library once solidity supports passing a signature to ecrecover.
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* See https://github.com/ethereum/solidity/issues/864
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*
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*/
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library ECRecovery {
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/**
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* @dev Recover signer address from a message by using their signature
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* @param hash bytes32 message, the hash is the signed message. What is recovered is the signer address.
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* @param sig bytes signature, the signature is generated using web3.eth.sign()
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*/
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function recover(bytes32 hash, bytes sig) internal pure returns (address) {
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bytes32 r;
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bytes32 s;
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uint8 v;
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//Check the signature length
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if (sig.length != 65) {
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return (address(0));
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}
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// Divide the signature in r, s and v variables
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// ecrecover takes the signature parameters, and the only way to get them
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// currently is to use assembly.
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// solium-disable-next-line security/no-inline-assembly
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assembly {
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r := mload(add(sig, 32))
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s := mload(add(sig, 64))
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v := byte(0, mload(add(sig, 96)))
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}
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// Version of signature should be 27 or 28, but 0 and 1 are also possible versions
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if (v < 27) {
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v += 27;
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}
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// If the version is correct return the signer address
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if (v != 27 && v != 28) {
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return (address(0));
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} else {
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return ecrecover(hash, v, r, s);
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}
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}
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}
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