@ctrl/ts-base32/dist/src/index.js

Base32 encoder/decoder with support for multiple variants

const RFC4648 = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
const RFC4648_HEX = '0123456789ABCDEFGHIJKLMNOPQRSTUV';
const CROCKFORD = '0123456789ABCDEFGHJKMNPQRSTVWXYZ';
export function base32Encode(input, variant = 'RFC4648', options = {}) {
    let alphabet;
    let defaultPadding;
    switch (variant) {
        case 'RFC3548':
        case 'RFC4648':
            alphabet = RFC4648;
            defaultPadding = true;
            break;
        case 'RFC4648-HEX':
            alphabet = RFC4648_HEX;
            defaultPadding = true;
            break;
        case 'Crockford':
            alphabet = CROCKFORD;
            defaultPadding = false;
            break;
        // eslint-disable-next-line @typescript-eslint/switch-exhaustiveness-check
        default:
            throw new Error(`Unknown base32 variant: ${variant}`);
    }
    const padding = options.padding ?? defaultPadding;
    const length = input.byteLength;
    const view = new Uint8Array(input);
    let bits = 0;
    let value = 0;
    let output = '';
    for (let i = 0; i < length; i++) {
        value = (value << 8) | view[i];
        bits += 8;
        while (bits >= 5) {
            output += alphabet[(value >>> (bits - 5)) & 31];
            bits -= 5;
        }
    }
    if (bits > 0) {
        output += alphabet[(value << (5 - bits)) & 31];
    }
    if (padding) {
        while (output.length % 8 !== 0) {
            output += '=';
        }
    }
    return output;
}
function readChar(alphabet, char) {
    const idx = alphabet.indexOf(char);
    if (idx === -1) {
        throw new Error('Invalid character found: ' + char);
    }
    return idx;
}
export function base32Decode(input, variant = 'RFC4648') {
    let alphabet;
    let cleanedInput;
    switch (variant) {
        case 'RFC3548':
        case 'RFC4648':
            alphabet = RFC4648;
            cleanedInput = input.toUpperCase().replace(/=+$/, '');
            break;
        case 'RFC4648-HEX':
            alphabet = RFC4648_HEX;
            cleanedInput = input.toUpperCase().replace(/=+$/, '');
            break;
        case 'Crockford':
            alphabet = CROCKFORD;
            cleanedInput = input.toUpperCase().replace(/O/g, '0').replace(/[IL]/g, '1');
            break;
        // eslint-disable-next-line @typescript-eslint/switch-exhaustiveness-check
        default:
            throw new Error(`Unknown base32 variant: ${variant}`);
    }
    const { length } = cleanedInput;
    let bits = 0;
    let value = 0;
    let index = 0;
    const output = new Uint8Array(((length * 5) / 8) | 0);
    for (let i = 0; i < length; i++) {
        value = (value << 5) | readChar(alphabet, cleanedInput[i]);
        bits += 5;
        if (bits >= 8) {
            output[index++] = (value >>> (bits - 8)) & 255;
            bits -= 8;
        }
    }
    return output;
}
/**
 * Turn a string of hexadecimal characters into an Uint8Array
 */
export function hexToUint8Array(hex) {
    if (hex.length % 2 !== 0) {
        throw new RangeError('Expected string to be an even number of characters');
    }
    const view = new Uint8Array(hex.length / 2);
    for (let i = 0; i < hex.length; i += 2) {
        view[i / 2] = parseInt(hex.substring(i, i + 2), 16);
    }
    return view;
}