micro-base58/index.js

Fast and beautiful base58 encoder without dependencies.

'use strict';
Object.defineProperty(exports, "__esModule", { value: true });
exports.decode = exports.encode = void 0;
function bytesToHex(uint8a) {
    let hex = '';
    for (let i = 0; i < uint8a.length; i++) {
        hex += uint8a[i].toString(16).padStart(2, '0');
    }
    return hex;
}
const COMMON_B58_ALPHABET = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz';
const alphabet = {
    ipfs: COMMON_B58_ALPHABET,
    btc: COMMON_B58_ALPHABET,
    xmr: COMMON_B58_ALPHABET,
    flickr: '123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ',
    xrp: 'rpshnaf39wBUDNEGHJKLM4PQRST7VWXYZ2bcdeCg65jkm8oFqi1tuvAxyz'
};
function encode(source, type = 'ipfs') {
    if (source.length === 0)
        return '';
    if (typeof source === 'string') {
        if (typeof TextEncoder !== 'undefined') {
            source = new TextEncoder().encode(source);
        }
        else {
            source = new Uint8Array(source.split('').map(c => c.charCodeAt(0)));
        }
    }
    type = type.toLowerCase();
    if (type === 'xmr') {
        let res = '';
        for (let i = 0; i < source.length + 3; i += 8) {
            const slice = source.slice(i, i + 8);
            res += encode(slice).padStart(slice.length === 8 ? 11 : 7, '1');
        }
        return res;
    }
    if (!alphabet.hasOwnProperty(type))
        throw new Error('invalid type');
    const letters = alphabet[type];
    let x = BigInt('0x' + bytesToHex(source));
    let output = [];
    while (x > 0) {
        const mod = Number(x % 58n);
        x = x / 58n;
        output.push(letters[mod]);
    }
    for (let i = 0; source[i] === 0; i++) {
        output.push(letters[0]);
    }
    return output.reverse().join('');
}
exports.encode = encode;
function decode(output, type = 'ipfs') {
    if (output.length === 0)
        return new Uint8Array([]);
    const letters = alphabet[type];
    const bytes = [0];
    for (let i = 0; i < output.length; i++) {
        const char = output[i];
        const value = letters.indexOf(char);
        if (value === undefined) {
            throw new Error(`base58.decode received invalid input. Character '${char}' is not in the base58 alphabet.`);
        }
        for (let j = 0; j < bytes.length; j++) {
            bytes[j] *= 58;
        }
        bytes[0] += value;
        let carry = 0;
        for (let j = 0; j < bytes.length; j++) {
            bytes[j] += carry;
            carry = bytes[j] >> 8;
            bytes[j] &= 0xff;
        }
        while (carry > 0) {
            bytes.push(carry & 0xff);
            carry >>= 8;
        }
    }
    for (let i = 0; i < output.length && output[i] === '1'; i++) {
        bytes.push(0);
    }
    return new Uint8Array(bytes.reverse());
}
exports.decode = decode;
exports.default = encode;