/** * The [Base58 Encoding](link-base58) scheme allows a **numeric** value * to be encoded as a compact string using a radix of 58 using only * alpha-numeric characters. Confusingly similar characters are omitted * (i.e. ``"l0O"``). * * Note that Base58 encodes a **numeric** value, not arbitrary bytes, * since any zero-bytes on the left would get removed. To mitigate this * issue most schemes that use Base58 choose specific high-order values * to ensure non-zero prefixes. * * @_subsection: api/utils:Base58 Encoding [about-base58] */ import { getBytes } from "./data.js"; import { assertArgument } from "./errors.js"; import { toBigInt } from "./maths.js"; const Alphabet = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"; let Lookup = null; function getAlpha(letter) { if (Lookup == null) { Lookup = {}; for (let i = 0; i < Alphabet.length; i++) { Lookup[Alphabet[i]] = BigInt(i); } } const result = Lookup[letter]; assertArgument(result != null, `invalid base58 value`, "letter", letter); return result; } const BN_0 = BigInt(0); const BN_58 = BigInt(58); /** * Encode %%value%% as a Base58-encoded string. */ export function encodeBase58(_value) { const bytes = getBytes(_value); let value = toBigInt(bytes); let result = ""; while (value) { result = Alphabet[Number(value % BN_58)] + result; value /= BN_58; } // Account for leading padding zeros for (let i = 0; i < bytes.length; i++) { if (bytes[i]) { break; } result = Alphabet[0] + result; } return result; } /** * Decode the Base58-encoded %%value%%. */ export function decodeBase58(value) { let result = BN_0; for (let i = 0; i < value.length; i++) { result *= BN_58; result += getAlpha(value[i]); } return result; } //# sourceMappingURL=base58.js.map