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base58.ts
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base58.ts
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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
// This module is browser compatible.
import { validateBinaryLike } from "./_util.ts";
/**
* {@linkcode encodeBase58} and {@linkcode decodeBase58} for
* [base58](https://en.wikipedia.org/wiki/Binary-to-text_encoding#Base58) encoding.
*
* This module is browser compatible.
*
* @module
*/
// deno-fmt-ignore
const mapBase58: Record<string, number> = {
"1": 0, "2": 1, "3": 2, "4": 3, "5": 4, "6": 5, "7": 6, "8": 7, "9": 8, A: 9,
B: 10, C: 11, D: 12, E: 13, F: 14, G: 15, H: 16, J: 17, K: 18, L: 19, M: 20,
N: 21, P: 22, Q: 23, R: 24, S: 25, T: 26, U: 27, V: 28, W: 29, X: 30, Y: 31,
Z: 32, a: 33, b: 34, c: 35, d: 36, e: 37, f: 38, g: 39, h: 40, i: 41, j: 42,
k: 43, m: 44, n: 45, o: 46, p: 47, q: 48, r: 49, s: 50, t: 51, u: 52, v: 53,
w: 54, x: 55, y: 56, z: 57
};
const base58alphabet =
"123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz".split("");
/**
* @deprecated (will be removed in 0.210.0) Use {@linkcode encodeBase58} instead.
*
* Encodes a given Uint8Array, ArrayBuffer or string into draft-mspotny-base58-03 RFC base58 representation:
* https://tools.ietf.org/id/draft-msporny-base58-01.html#rfc.section.1
*
* @param data
*
* @returns Encoded value
*/
export const encode = encodeBase58;
/**
* @deprecated (will be removed in 0.210.0) Use {@linkcode decodeBase58} instead.
*
* Decodes a given b58 string according to draft-mspotny-base58-03 RFC base58 representation:
* https://tools.ietf.org/id/draft-msporny-base58-01.html#rfc.section.1
*
* @param b58
*
* @returns Decoded value
*/
export const decode = decodeBase58;
/**
* Encodes a given Uint8Array, ArrayBuffer or string into draft-mspotny-base58-03 RFC base58 representation:
* https://tools.ietf.org/id/draft-msporny-base58-01.html#rfc.section.1
*/
export function encodeBase58(data: ArrayBuffer | Uint8Array | string): string {
const uint8tData = validateBinaryLike(data);
let length = 0;
let zeroes = 0;
// Counting leading zeroes
let index = 0;
while (uint8tData[index] === 0) {
zeroes++;
index++;
}
const notZeroUint8Data = uint8tData.slice(index);
const size = Math.round((uint8tData.length * 138) / 100 + 1);
const b58Encoding: number[] = [];
notZeroUint8Data.forEach((byte) => {
let i = 0;
let carry = byte;
for (
let reverse_iterator = size - 1;
(carry > 0 || i < length) && reverse_iterator !== -1;
reverse_iterator--, i++
) {
carry += (b58Encoding[reverse_iterator] || 0) * 256;
b58Encoding[reverse_iterator] = Math.round(carry % 58);
carry = Math.floor(carry / 58);
}
length = i;
});
const strResult: string[] = Array.from({
length: b58Encoding.length + zeroes,
});
if (zeroes > 0) {
strResult.fill("1", 0, zeroes);
}
b58Encoding.forEach((byteValue) => strResult.push(base58alphabet[byteValue]));
return strResult.join("");
}
/**
* Decodes a given b58 string according to draft-mspotny-base58-03 RFC base58 representation:
* https://tools.ietf.org/id/draft-msporny-base58-01.html#rfc.section.1
*/
export function decodeBase58(b58: string): Uint8Array {
const splitInput = b58.trim().split("");
let length = 0;
let ones = 0;
// Counting leading ones
let index = 0;
while (splitInput[index] === "1") {
ones++;
index++;
}
const notZeroData = splitInput.slice(index);
const size = Math.round((b58.length * 733) / 1000 + 1);
const output: number[] = [];
notZeroData.forEach((char, idx) => {
let carry = mapBase58[char];
let i = 0;
if (carry === undefined) {
throw new Error(`Invalid base58 char at index ${idx} with value ${char}`);
}
for (
let reverse_iterator = size - 1;
(carry > 0 || i < length) && reverse_iterator !== -1;
reverse_iterator--, i++
) {
carry += 58 * (output[reverse_iterator] || 0);
output[reverse_iterator] = Math.round(carry % 256);
carry = Math.floor(carry / 256);
}
length = i;
});
const validOutput = output.filter((item) => item !== undefined);
if (ones > 0) {
const onesResult = Array.from({ length: ones }).fill(0, 0, ones);
return new Uint8Array([...onesResult, ...validOutput] as number[]);
}
return new Uint8Array(validOutput);
}