Implement algorithm switching

This commit implements every algorithm I have played with so far. It also allows for you to switch which algorithm you want to use at runtime.

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

@@ -4,13 +4,13 @@ import * as z from 'zod';
 import { outstandingChallenges } from '~~/server/utils/pow';
 
 const challengeSchema = z.object({
-    challenge: z.string().startsWith("s."),
-    solution: z.string().startsWith("s.")
+    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) => {
-    console.log(await readBody(event));
     const body = await readValidatedBody(event, challengeSchema.safeParse);
 
     if (!body.success) {
@@ -20,9 +20,9 @@ export default defineEventHandler(async (event) => {
         })
     }
 
-    let { challenge, solution } = body.data;
+    let { salt, solution } = body.data;
 
-    const outstanding_challenge = outstandingChallenges.get(challenge);
+    const outstanding_challenge = outstandingChallenges.get(salt);
     if (outstanding_challenge === undefined) {
         throw createError({
             statusCode: 400,
@@ -37,8 +37,8 @@ export default defineEventHandler(async (event) => {
 
     if (challenge_valid) {
         // clear the challenge
-        clearTimeout(outstandingChallenges.get(challenge)!.timeout);
-        outstandingChallenges.delete(challenge);
+        clearTimeout(outstandingChallenges.get(salt)!.timeout);
+        outstandingChallenges.delete(salt);
 
         return {
             message: 'Challenge solved'