PBKDF2 key derivation

Derive a cryptographic key from a password using PBKDF2 (RFC 8018). Returns the hex-encoded derived key along with all parameters used, so you can store or verify them later. Supports sha1, sha256, sha384, sha512 digests.

Input

Field	Type	Description
password *	string	Password or passphrase to derive from
salt *	string	Salt string (should be unique per password)
iterations	integer	Iteration count (default 100000, max 1000000)
keyLength	integer	Desired key length in bytes (default 32, max 128)
digest	string	Hash algorithm: sha1, sha256, sha384, sha512 (default sha256)

Example output

{
  "derivedKey": "a1b2c3d4e5f6...",
  "algorithm": "pbkdf2",
  "digest": "sha256",
  "iterations": 100000,
  "keyLength": 32,
  "saltUsed": "random-salt-value"
}

Try it — see the 402 challenge (free)

curl -i -X POST https://agent402.tools/api/pbkdf2 \
  -H "Content-Type: application/json" \
  -d '{"password":"hunter2","salt":"random-salt-value","iterations":100000,"keyLength":32,"digest":"sha256"}'

The response is HTTP 402 Payment Required with exact payment requirements. Any x402 v2 client pays automatically and retries:

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/pbkdf2", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "password": "hunter2",
    "salt": "random-salt-value",
    "iterations": 100000,
    "keyLength": 32,
    "digest": "sha256"
  }),
});

No wallet? Pay with compute

This is a pure-CPU tool, so an agent without a wallet can pay with proof-of-work instead of USDC: fetch a challenge, solve the sha256 puzzle (16 leading zero bits — a fraction of a second of CPU, no money, no AI tokens), and resend with the X-Pow-Solution header.

import { createHash } from "node:crypto";
const lz = (b) => { let t = 0; for (const x of b) { if (!x) { t += 8; continue; } t += Math.clz32(x) - 24; break; } return t; };
const c = await (await fetch("https://agent402.tools/api/pow/challenge?slug=pbkdf2")).json();
let n = 0;
while (lz(createHash("sha256").update(c.challenge + ":" + n).digest()) < c.difficulty) n++;
await fetch("https://agent402.tools/api/pbkdf2", { method: "POST", headers: { "X-Pow-Solution": c.token + ":" + n, "Content-Type": "application/json" }, body: JSON.stringify({"password":"hunter2","salt":"random-salt-value","iterations":100000,"keyLength":32,"digest":"sha256"}) });

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