ethers.js/utils/namehash.js
2017-05-03 20:24:07 -04:00

39 lines
1.2 KiB
JavaScript

'use strict';
var convert = require('./convert');
var utf8 = require('./utf8');
var keccak256 = require('./keccak256');
var Zeros = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
var Partition = new RegExp("^((.*)\\.)?([^.]+)$");
var UseSTD3ASCIIRules = new RegExp("^[a-z0-9.-]*$");
function namehash(name, depth) {
name = name.toLowerCase();
// Supporting the full UTF-8 space requires additional (and large)
// libraries, so for now we simply do not support them.
// It should be fairly easy in the future to support systems with
// String.normalize, but that is future work.
if (!name.match(UseSTD3ASCIIRules)) {
throw new Error('contains invalid UseSTD3ASCIIRules characters');
}
var result = Zeros;
var processed = 0;
while (name.length && (!depth || processed < depth)) {
var partition = name.match(Partition);
var label = utf8.toUtf8Bytes(partition[3]);
result = keccak256(convert.concat([result, keccak256(label)]));
name = partition[2] || '';
processed++;
}
return convert.hexlify(result);
}
module.exports = namehash;