Hashes

Four hex-encoded digests: md5, sha1, sha256, sha512. All four take a string and return a lowercase hex string.

Unchanged in v2. They are still synchronous, still need no configuration, and — unlike encrypt/decrypt — need no WebCrypto, so they work in any runtime. If hashes are all you import from this package, the 2.0 upgrade is a no-op for you.

Signatures

md5(text: string):    string  // @deprecated — legacy interop only
sha1(text: string):   string  // @deprecated — legacy interop only
sha256(text: string): string
sha512(text: string): string

Direct passthroughs to CryptoJS.MD5/SHA1/SHA256/SHA512 with .toString().

md5 and sha1 now carry @deprecated JSDoc so an editor strikes them through at the call site. They still work and are not being removed — they exist for legacy interop (old cache keys, gravatar-style identifiers). Do not add new uses; default to sha256.

Test vectors

md5("")          // "d41d8cd98f00b204e9800998ecf8427e"
md5("123456")    // "e10adc3949ba59abbe56e057f20f883e"
sha1("")         // "da39a3ee5e6b4b0d3255bfef95601890afd80709"
sha1("123456")   // "7c4a8d09ca3762af61e59520943dc26494f8941b"
sha256("")       // "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
sha256("123456") // "8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92"
sha512("123456") // "ba3253876aed6bc22d4a6ff53d8406c6ad864195ed144ab5c87621b6c233b548baeae6956df346ec8c17f5ea10f35ee3cbc514797ed7ddd3145464e2a0bab413"

Unicode is encoded as UTF-8 before hashing — outputs match the standard test vectors for that scheme.

Suitable uses

• Content fingerprints — dedup of static assets, build-output integrity (when the threat is wire corruption, not an active attacker).
• ETag-style cache keys — sha256(JSON.stringify(query)) makes a stable key for a complex input.
• Idempotency keys — sha256(payload) collapses retries into one operation.
• Bloom filter / probabilistic structure inputs.

Hash for keys; encrypt for secrecy. Never use a ciphertext as a cache key — encrypt is non-deterministic, so it changes on every call.

Unsuitable uses (use the right tool instead)

Use case	Why hashes here don’t fit	What to use
Password storage	Too fast; no per-record salt; GPU-brute-forceable	bcrypt, scrypt, Argon2id
Message authentication	A plain hash binds no secret	HMAC — crypto-js/hmac-sha256, or crypto.subtle.sign with HMAC
Tamper detection on a payload you also encrypt	Redundant — encrypt already authenticates	encrypt/decrypt from this package (AES-256-GCM)
Signatures over attacker-controlled input	md5 / sha1 are not collision-resistant	sha256 + RSA-PSS / Ed25519, or a JWS library
Constant-time equality of secrets	=== on hex leaks length and timing	crypto.timingSafeEqual (Node)
FIPS / regulatory validation	Pure JS, unvalidated	A vetted library or a KMS

md5 and sha1 are broken — what does that mean?

Both have practical collision attacks:

• An attacker who controls part of the input can construct two messages with the same digest.
• For signatures and integrity over adversarial input, that is fatal.
• For non-adversarial fingerprinting — ETags, deduplicating files you produced yourself, hashing keys into a fixed namespace — it is not: collisions do not appear by chance.

Default to sha256 when unsure. 32 bytes (64 hex chars), fast enough outside a tight loop.

Example: a deterministic cache key

import { sha256 } from "@mongez/encryption";

function cacheKey(query: unknown) {
  // Property order can vary across engines — sort keys for a truly canonical
  // form if the input is built dynamically.
  return `q:${sha256(JSON.stringify(query))}`;
}

Same input → same digest, every time.

Example: HMAC outside this package

The package does not export HMAC. If you need message authentication over data you are not encrypting, use one:

import HmacSHA256 from "crypto-js/hmac-sha256";

const tag = HmacSHA256("the message", "the key").toString();

Compare tags in constant time, not with ===. If you are encrypting the data anyway, you do not need a separate MAC — encrypt is AES-256-GCM and already authenticates the ciphertext and its header.