impost/example-app/server/api/pow/challenge.post.ts

import { defineEventHandler } from 'h3'
import { validate_challenge } from '@impost/lib/validator';
import * as z from 'zod';
import { outstandingChallenges } from '~~/server/utils/pow';

const challengeSchema = z.object({
    salt: z.string(),
    // either a string if the algorithm is kCTF, or a number if the algorithm is Argon2id or SHA256
    solution: z.string().or(z.number()),
})

// post handler that takes in the challenge, and the nonce
export default defineEventHandler(async (event) => {
    const body = await readValidatedBody(event, challengeSchema.safeParse);

    if (!body.success) {
        throw createError({
            statusCode: 400,
            statusMessage: 'Validation failed'
        })
    }

    let { salt, solution } = body.data;

    const outstanding_challenge = outstandingChallenges.get(salt);
    if (outstanding_challenge === undefined) {
        throw createError({
            statusCode: 400,
            statusMessage: 'Challenge not found'
        })
    }

    // check if the challenge is valid
    const challenge_valid = await validate_challenge(outstanding_challenge.challenge, solution);

    console.log("CHALLENGE VALID", challenge_valid);

    if (challenge_valid) {
        // clear the challenge
        clearTimeout(outstandingChallenges.get(salt)!.timeout);
        outstandingChallenges.delete(salt);

        return {
            message: 'Challenge solved'
        };
    }

    throw createError({
        statusCode: 400,
        statusMessage: 'Challenge is not valid'
    })
})