namehash

package.json

@@ -34,6 +34,7 @@
     "@hazae41/base64url": "^1.0.4",
     "@hazae41/berith": "^1.2.4",
     "@hazae41/binary": "^1.3.1",
+    "@hazae41/box": "^1.0.3",
     "@hazae41/bytes": "^1.2.2",
     "@hazae41/cadenas": "^0.2.42",
     "@hazae41/cascade": "^1.1.27",
@@ -65,6 +66,7 @@
     "@scure/bip32": "^1.3.2",
     "@scure/bip39": "^1.2.1",
     "ethers": "^6.7.1",
+    "idna-uts46-hx": "^5.1.0",
     "next": "13.5.4",
     "react": "18.2.0",
     "react-dom": "18.2.0",

src/libs/ethereum/mods/ens/ens.ts

@@ -0,0 +1,42 @@
+import { Base16 } from "@hazae41/base16"
+import { Box } from "@hazae41/box"
+import { Bytes } from "@hazae41/bytes"
+import { ZeroHexString } from "@hazae41/cubane"
+import { Copiable, Copied, Keccak256 } from "@hazae41/keccak256"
+import * as Uts46 from "idna-uts46-hx"
+
+export class Slot<T extends Disposable> implements Disposable {
+
+  constructor(
+    public inner: T
+  ) { }
+
+  [Symbol.dispose]() {
+    this.inner[Symbol.dispose]()
+  }
+
+}
+
+export namespace Ens {
+
+  export function namehash(name: string): ZeroHexString {
+    if (name.length === 0)
+      return "0x".padEnd(2 + 32, "0") as ZeroHexString
+
+    const uts46 = Uts46.toUnicode(name, { useStd3ASCII: true })
+    const labels = uts46.split('.').reverse()
+
+    using node: Slot<Box<Copiable>> = new Slot(new Box(new Copied(new Uint8Array(32))))
+
+    for (const label of labels) {
+      using previous = node.inner.unwrap()
+      using hashed = Keccak256.get().tryHash(Bytes.fromUtf8(label)).unwrap()
+
+      const concat = Bytes.concat([previous.bytes, hashed.bytes])
+      node.inner = new Box(Keccak256.get().tryHash(concat).unwrap())
+    }
+
+    return "0x" + Base16.get().tryEncode(node.inner.unwrap().bytes).unwrap() as ZeroHexString
+  }
+
+}