status-web-archive/packages/status-communities/src/identity.ts

import { Buffer } from "buffer";

import { keccak256 } from "js-sha3";
import { generatePrivateKey } from "js-waku";
import { utils } from "js-waku";
import * as secp256k1 from "secp256k1";

export class Identity {
  public constructor(public privateKey: Uint8Array) {}

  public static generate(): Identity {
    const privateKey = generatePrivateKey();
    return new Identity(privateKey);
  }

  /**
   * Hashes the payload with SHA3-256 and signs the result using the internal private key.
   */
  public sign(payload: Uint8Array): Uint8Array {
    const hash = keccak256(payload);

    const { signature, recid } = secp256k1.ecdsaSign(
      utils.hexToBuf(hash),
      this.privateKey
    );

    return Buffer.concat([signature, Buffer.from([recid])]);
  }
}