ethers.js/lib.esm/hash/namehash.js
2023-10-10 22:41:46 -04:00

85 lines
2.6 KiB
JavaScript

import { keccak256 } from "../crypto/index.js";
import { concat, hexlify, assertArgument, toUtf8Bytes } from "../utils/index.js";
import { ens_normalize } from "@adraffy/ens-normalize";
const Zeros = new Uint8Array(32);
Zeros.fill(0);
function checkComponent(comp) {
assertArgument(comp.length !== 0, "invalid ENS name; empty component", "comp", comp);
return comp;
}
function ensNameSplit(name) {
const bytes = toUtf8Bytes(ensNormalize(name));
const comps = [];
if (name.length === 0) {
return comps;
}
let last = 0;
for (let i = 0; i < bytes.length; i++) {
const d = bytes[i];
// A separator (i.e. "."); copy this component
if (d === 0x2e) {
comps.push(checkComponent(bytes.slice(last, i)));
last = i + 1;
}
}
// There was a stray separator at the end of the name
assertArgument(last < bytes.length, "invalid ENS name; empty component", "name", name);
comps.push(checkComponent(bytes.slice(last)));
return comps;
}
/**
* Returns the ENS %%name%% normalized.
*/
export function ensNormalize(name) {
try {
if (name.length === 0) {
throw new Error("empty label");
}
return ens_normalize(name);
}
catch (error) {
assertArgument(false, `invalid ENS name (${error.message})`, "name", name);
}
}
/**
* Returns ``true`` if %%name%% is a valid ENS name.
*/
export function isValidName(name) {
try {
return (ensNameSplit(name).length !== 0);
}
catch (error) { }
return false;
}
/**
* Returns the [[link-namehash]] for %%name%%.
*/
export function namehash(name) {
assertArgument(typeof (name) === "string", "invalid ENS name; not a string", "name", name);
assertArgument(name.length, `invalid ENS name (empty label)`, "name", name);
let result = Zeros;
const comps = ensNameSplit(name);
while (comps.length) {
result = keccak256(concat([result, keccak256((comps.pop()))]));
}
return hexlify(result);
}
/**
* Returns the DNS encoded %%name%%.
*
* This is used for various parts of ENS name resolution, such
* as the wildcard resolution.
*/
export function dnsEncode(name) {
return hexlify(concat(ensNameSplit(name).map((comp) => {
// DNS does not allow components over 63 bytes in length
if (comp.length > 63) {
throw new Error("invalid DNS encoded entry; length exceeds 63 bytes");
}
const bytes = new Uint8Array(comp.length + 1);
bytes.set(comp, 1);
bytes[0] = bytes.length - 1;
return bytes;
}))) + "00";
}
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