@signumjs/crypto/out/random.js

Cryptographic functions for building Signum Network apps.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.DefaultAlphabet = void 0;
exports.getRandomBytes = getRandomBytes;
exports.getRandomWords = getRandomWords;
exports.getRandomString = getRandomString;
const base_1 = require("./base");
function getRandomBytes(length) {
    return base_1.Crypto.adapter.getRandomValues(new Uint8Array(length));
}
function getRandomWords(count, dictionary) {
    if (count > dictionary.length) {
        throw new Error('Too few words in dictionary');
    }
    if (dictionary.length > 2 ** 32) {
        throw new Error('Dictionary must have less than 65536 words');
    }
    const indices = new Set();
    const mask = 2 ** 32 - (2 ** 32 % dictionary.length);
    const randomBytes = new Uint8Array(4);
    const cp = base_1.Crypto.adapter;
    while (indices.size < count) {
        cp.getRandomValues(randomBytes);
        const randomUint32 = ((randomBytes[0] << 24) | (randomBytes[1] << 16) | (randomBytes[2] << 8) | randomBytes[3]) >>> 0;
        const randomIndex = randomUint32 % dictionary.length;
        if (randomUint32 < mask) {
            indices.add(randomUint32 % dictionary.length);
        }
    }
    return Array.from(indices).map(index => dictionary[index]);
}
exports.DefaultAlphabet = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
function getRandomString(length, alphabet = exports.DefaultAlphabet) {
    if (alphabet.length === 0) {
        throw new Error('Alphabet must not be empty.');
    }
    const MaxLength = 65536;
    if (alphabet.length >= MaxLength) {
        throw new Error(`Alphabet is too large. Alphabet must be less than ${MaxLength} characters long.`);
    }
    const maxNonBiasedValue = Math.floor(MaxLength / alphabet.length) * alphabet.length;
    const indices = base_1.Crypto.adapter.getRandomValues(new Uint8Array(length * 2));
    const uint16View = new Uint16Array(indices.buffer);
    let result = '';
    for (let i = 0; i < length; i++) {
        let value = uint16View[i];
        while (value >= maxNonBiasedValue) {
            const newBytes = base_1.Crypto.adapter.getRandomValues(new Uint8Array(2));
            value = new Uint16Array(newBytes.buffer)[0];
        }
        result += alphabet[value % alphabet.length];
    }
    return result;
}
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