Cryptography (std::crypto)

std::crypto covers unique ID generation and secure randomness. Hash and HMAC functions live in std::hash (next page). Because it depends on operating-system entropy, this module is not available in the WASM sandbox — run the examples with zolo run on the command line.

UUID and NanoID

crypto.uuid() generates a random UUID v4 in the canonical hyphenated format. crypto.nanoid() produces a 21-character URL-safe identifier — more compact than UUID and equally unlikely to collide. It accepts a custom size via nanoid(n).

UUID v4 and NanoID with default and custom sizes.

01-uuid-nanoid.zolo

Playground

// Feature: crypto.uuid / crypto.nanoid — unique IDs
// When to use: primary keys, request IDs, session tokens.

use std::crypto

// UUID v4 (random, 128 bits, canonical hyphenated format).
let id = crypto.uuid()
print(id)  // expected: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx

// nanoid: 21 chars URL-safe — collisions extremely unlikely and more compact than UUID.
let nid = crypto.nanoid()
print(nid.len())  // expected: 21

// nanoid(n) with custom length.
let short = crypto.nanoid(10)
print(short.len())  // expected: 10

Requires the Zolo CLI/host — open in the playground or run locally.

Random bytes and integers

crypto.random_bytes(n) returns an array of n bytes sourced from OS entropy, suitable for salts and tokens. crypto.random_int(min, max) provides a uniformly distributed integer in the inclusive range [min, max].

Generating random bytes and range-bounded integers — useful for salts and simulations.

02-random.zolo

Playground

// Feature: crypto.random_bytes / crypto.random_int — secure randomness
// When to use: salt for hashing, secrets, tokens, crypto simulations.

use std::crypto

// random_bytes(n) -> array of N bytes (0..255).
let bytes = crypto.random_bytes(16)
print(bytes.len())  // expected: 16

// random_int(min, max) -> integer in the range [min, max] (inclusive).
let dice = crypto.random_int(1, 6)
print(dice >= 1 && dice <= 6)  // expected: true

let port = crypto.random_int(1024, 65535)
print(port >= 1024)  // expected: true

Requires the Zolo CLI/host — open in the playground or run locally.

Hashes and HMAC via std::hash

The third file in this folder demonstrates the functions in std::hash (SHA-256, MD5, HMAC-SHA256 and CRC32). Full documentation is in the next section (Hash); the example below serves as a cross-reference.

Quick reference for hash.sha256, hash.hmac and hash.crc32.

03-hash-and-hmac.zolo

Playground

// Feature: cryptographic hashes via the `hash` module
// When to use: integrity, fingerprints, message authentication.
// Note: `crypto` handles randomness/IDs; hashes live in `hash`.

use std::hash

// SHA-256 — deterministic 32-byte fingerprint (64 hex chars).
print(hash.sha256("zolo"))  // expected: 64 hex chars

// SHA-512 / SHA-1 / MD5 also available (legacy: prefer sha256+).
print(hash.sha1("zolo").len())  // expected: 40 (hex of 20 bytes)
print(hash.md5("zolo").len())  // expected: 32 (hex of 16 bytes)

// HMAC-SHA256 — symmetric authentication (message + secret key).
let mac = hash.hmac("sha256", "secret-key", "important message")
print(mac.len())  // expected: 64 hex chars

// CRC32 (non-cryptographic, but useful for cheap checksums).
print(hash.crc32("zolo"))  // expected: int

Requires the Zolo CLI/host — open in the playground or run locally.