Method redeemChallenge

server/index.js:301–365

* Redeems a challenge solution in exchange for a token * @param {Solution} param0 - Challenge solution data * @returns {Promise<{success: boolean, message?: string, token?: string, expires?: number}>}

({ token, solutions })

   * @returns {Promise<{success: boolean, message?: string, token?: string, expires?: number}>}
   */
  async redeemChallenge({ token, solutions }) {
    if (
      !token ||
      !solutions ||
      !Array.isArray(solutions) ||
      solutions.some((s) => typeof s !== "number")
    ) {
      return { success: false, message: "Invalid body" };
    }

    await this._lazyCleanup();

    const challengeData = await this._getChallenge(token);
    await this._deleteChallenge(token);

    if (!challengeData || challengeData.expires < Date.now()) {
      return { success: false, message: "Challenge invalid or expired" };
    }

    let i = 0;

    const challenges = Array.from({ length: challengeData.challenge.c }, () => {
      i = i + 1;

      return [
        prng(`${token}${i}`, challengeData.challenge.s),
        prng(`${token}${i}d`, challengeData.challenge.d),
      ];
    });

    const hashes = await Promise.all(
      challenges.map(([salt, target], i) => {
        if (typeof solutions[i] !== "number") return null;
        return sha256(salt + solutions[i]).then((h) => [h, target]);
      })
    );

    const isValid = hashes.every((pair) => pair?.[0].startsWith(pair[1]));

    if (!isValid) return { success: false, message: "Invalid solution" };

    const vertoken = await randomHex(15);
    const expires = Date.now() + 20 * 60 * 1000;
    const hash = await sha256(vertoken);
    const id = await randomHex(8);
    const tokenKey = `${id}:${hash}`;

    if (this.config.storage?.tokens?.store) {
      await this.config.storage.tokens.store(tokenKey, expires);
    } else {
      if (this?.config?.state?.tokensList) {
        this.config.state.tokensList[tokenKey] = expires;
      }

      if (!this.config.noFSState) {
        await fs.writeFile(
          this.config.tokens_store_path,
          JSON.stringify(this.config.state.tokensList),