Paano kayo hash passwords kuma crypto module?

Question

Accepted Answer

Node's kasar **`crypto`** module yana ba da ayyuka na cryptographic: hashing, encryption, random values, da HMAC. Mafitacciyar aikin amfani - **password hashing** - yana da mahimmin iyakoki: mai ba bugi sake amfani da sauri, gaba jiya abilumi (MD5/SHA-256) don sirrce.

## Password hashing: amfani da jajere, salty algorithm

```js
import { scrypt, randomBytes, timingSafeEqual } from "crypto";
import { promisify } from "util";
const scryptAsync = promisify(scrypt);

// HASH a password (on signup)
async function hashPassword(password) {
  const salt = randomBytes(16).toString("hex");          // unique random salt per user
  const derived = await scryptAsync(password, salt, 64); // slow, salted derivation
  return `${salt}:${derived.toString("hex")}`;            // store salt + hash together
}

// VERIFY a password (on login)
async function verify(password, stored) {
  const [salt, hash] = stored.split(":");
  const derived = await scryptAsync(password, salt, 64);
  const hashBuf = Buffer.from(hash, "hex");
  return timingSafeEqual(hashBuf, derived); // constant-time compare (avoid timing attacks)
}
```

Mafitacciyar abubuwa: **`scrypt`** (ko bcrypt/argon2) *jajere take* don shayar da brute-force; **na musamman salty ga ko password** sanye rainbow tables; da **`timingSafeEqual`** yana bada daidaita hash a lokacin daidaita don hana lokaci sulke.

## Yake ba MD5/SHA-256 don passwords

```js
// ❌ NEVER do this — SHA/MD5 are FAST, so attackers can guess billions/sec
crypto.createHash("sha256").update(password).digest("hex");
```

Sauri hash sun dace ga file checksums amma abin bala'i don passwords — sauri yana daidai abin da ya sa su brute-forceable. (A aiki, mabukoki kamar **bcrypt** ko **argon2** sukayi sanyi ga raw scrypt saboda ergonomics.)

## Sauran crypto amfani

```js
import crypto from "crypto";

crypto.randomBytes(32).toString("hex");        // secure random tokens (session ids, CSRF)
crypto.randomUUID();                            // a secure UUID v4

// HMAC — verify integrity/authenticity (e.g. webhook signatures)
crypto.createHmac("sha256", secret).update(payload).digest("hex");

// hashing for NON-secret integrity (file checksums) — SHA is fine here
crypto.createHash("sha256").update(fileBuffer).digest("hex");
```

## Yake ya sa yana mahimmi

Gina storing password daidai ne hujja mahimmin saurin gida, kuma yana kasua, hadari kurakira amfani da sauri hash ko tsine salty.

`crypto` module (ko mataas-mataas bcrypt/argon2) yana ba da daidai primitives: jajere salty hashing don passwords, daidai-lokaci bada daidaita, amince random generat don tokens, da HMAC don tabbatar da honesty (kamar webhook signatures).

Gani *yake* passwords bugun daidai, salty, daidai-lokaci jiyya - kuma sauri hash ne kabyar ga sirrce checksums - muhimmi ne gina gida amfani da ba amince ba.