sign-prng

🔧 A module for generating and validating hexadecimal signatures, creating pseudo-random numbers, and computing hashes based on deterministic signatures.

Installation

npm install sign-prng

Usage

import sign from 'sign-prng'

API

sign.generate(bytesLength?: number): string

Generates a random signature as a hexadecimal string.

Parameters:

• bytesLength - Length in bytes (default: 16)

Returns: Hexadecimal string (32 chars for 16 bytes)

Example:

const signature = sign.generate()
// => "a1ace80f9fabed1bc4b2d28bd5081afc"

const longSignature = sign.generate(32)
// => "a1b2c3...64 chars"

sign.check(signature: string): boolean

Validates if a string is a valid hexadecimal signature.

Parameters:

• signature - String to validate

Returns: true if valid, false otherwise

Example:

sign.check('a1ace80f9fabed1bc4b2d28bd5081afc') // => true
sign.check('invalid') // => false

sign.getMatRandomFn(signature: string): () => number

Returns a deterministic pseudo-random number generator (0-1) based on signature.

Parameters:

• signature - Source signature for seeding

Returns: Function that returns numbers between 0 and 1

Example:

const random = sign.getMatRandomFn('a1ace80f9fabed1bc4b2d28bd5081afc')

random() // => 0.7336...
random() // => 0.5182...

// Same signature produces same sequence
const random2 = sign.getMatRandomFn('a1ace80f9fabed1bc4b2d28bd5081afc')
random2() // => 0.7336... (same as first call)

sign.getIntFn(signature: string, max?: number): () => number

Returns a deterministic integer generator (0 to max) based on signature.

Parameters:

• signature - Source signature for seeding
• max - Maximum value (default: 1)

Returns: Function that returns integers from 0 to max

Example:

const getInt = sign.getIntFn('a1ace80f9fabed1bc4b2d28bd5081afc', 100)

getInt() // => 42
getInt() // => 71
getInt() // => 61

sign.getMod(signature: string, max: number): number

Calculates modulo of signature by max value.

Parameters:

• signature - Hexadecimal signature
• max - Maximum value for modulo operation

Returns: Integer from 0 to max

Example:

sign.getMod('a1ace80f9fabed1bc4b2d28bd5081afc', 100)
// => 42 (always the same for this signature)

sign.sha(str: string): string

Computes a simple hash of a string.

Parameters:

• str - Input string to hash

Returns: Hexadecimal hash string

Example:

sign.sha('hello') // => "5d41402abc..."
sign.sha('world') // => "7c211433f0..."

Use Cases

• Deterministic randomness: Use signatures as seeds for reproducible random sequences
• ID generation: Create random hex identifiers
• Reproducible states: Generate consistent states from seed values (games, simulations, testing)

License

ISC