solidity-sha3

web3.sha3 doesn't always match the behavior of sha3 in Solidity. This one does.

• Hashes integers (default size: uint256)
• Hashes tightly-packed arguments
• Supports hex strings and BigNumber instances

Install

$ npm install --save solidity-sha3

Usage

import sha3 from 'solidity-sha3'

sha3('a') // 0x3ac225168df54212a25c1c01fd35bebfea408fdac2e31ddd6f80a4bbf9a5f1cb
sha3('0x0a') // 0x0ef9d8f8804d174666011a394cab7901679a8944d24249fd148a6a36071151f8
sha3(1) // 0xb10e2d527612073b26eecdfd717e6a320cf44b4afac2b0732d9fcbe2b7fa0cf6
sha3(-1) // 0xa9c584056064687e149968cbab758a3376d22aedc6a55823d1b3ecbee81b8fb9
sha3(new BigNumber('100')) // 0x26700e13983fefbd9cf16da2ed70fa5c6798ac55062a4803121a869731e308d2
sha3('a', 1) // 0xb5cafab5b83d18303877bb912b2d66ca18ab7390cfd9be8a2e66cc5096e0ea02

You can also hash a value at a specific size:

import { sha3withsize } from 'solidity-sha3'

// same as sha3(uint32(1)) in Solidity
sha3withsize(1, 32) // 0x51f81bcdfc324a0dff2b5bec9d92e21cbebc4d5e29d3a3d30de3e03fbeab8d7f

// same as sha3(1) in Solidity
sha3withsize(1, 8) // 0x5fe7f977e71dba2ea1a68e21057beebb9be2ac30c6410aa38d4f3fbe41dcffd2

Be aware that strings will be converted into hex by default. You can use sha3num to explicitly pad and hash a string as a number. This is useful for Wei that is not a BigNumber instance:

import { sha3num } from 'solidity-sha3'

// same as sha3(uint(100 ether)) in Solidity
sha3num(web3.toWei(100)) // c7cc234d21c9cfbd4632749fd77669e7ae72f5241ce5895e410c45185a469273

// otherwise, it would convert the value '100000000000000000000' to '0x56bc75e2d63100000' and then hash that
sha3(web3.toWei(100)) // 0x44bc2093d8a26b279e2eecbfdcb9cc0b960c2141b83a29dce25f2a18c2653bfa

License

ISC © Raine Revere