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68 lines
2.1 KiB
68 lines
2.1 KiB
"use strict"; |
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/** |
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* The [Base58 Encoding](link-base58) scheme allows a **numeric** value |
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* to be encoded as a compact string using a radix of 58 using only |
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* alpha-numeric characters. Confusingly similar characters are omitted |
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* (i.e. ``"l0O"``). |
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* |
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* Note that Base58 encodes a **numeric** value, not arbitrary bytes, |
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* since any zero-bytes on the left would get removed. To mitigate this |
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* issue most schemes that use Base58 choose specific high-order values |
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* to ensure non-zero prefixes. |
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* |
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* @_subsection: api/utils:Base58 Encoding [about-base58] |
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*/ |
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Object.defineProperty(exports, "__esModule", { value: true }); |
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exports.decodeBase58 = exports.encodeBase58 = void 0; |
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const data_js_1 = require("./data.js"); |
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const errors_js_1 = require("./errors.js"); |
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const maths_js_1 = require("./maths.js"); |
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const Alphabet = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"; |
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let Lookup = null; |
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function getAlpha(letter) { |
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if (Lookup == null) { |
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Lookup = {}; |
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for (let i = 0; i < Alphabet.length; i++) { |
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Lookup[Alphabet[i]] = BigInt(i); |
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} |
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} |
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const result = Lookup[letter]; |
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(0, errors_js_1.assertArgument)(result != null, `invalid base58 value`, "letter", letter); |
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return result; |
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} |
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const BN_0 = BigInt(0); |
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const BN_58 = BigInt(58); |
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/** |
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* Encode %%value%% as a Base58-encoded string. |
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*/ |
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function encodeBase58(_value) { |
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const bytes = (0, data_js_1.getBytes)(_value); |
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let value = (0, maths_js_1.toBigInt)(bytes); |
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let result = ""; |
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while (value) { |
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result = Alphabet[Number(value % BN_58)] + result; |
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value /= BN_58; |
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} |
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// Account for leading padding zeros |
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for (let i = 0; i < bytes.length; i++) { |
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if (bytes[i]) { |
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break; |
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} |
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result = Alphabet[0] + result; |
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} |
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return result; |
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} |
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exports.encodeBase58 = encodeBase58; |
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/** |
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* Decode the Base58-encoded %%value%%. |
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*/ |
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function decodeBase58(value) { |
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let result = BN_0; |
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for (let i = 0; i < value.length; i++) { |
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result *= BN_58; |
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result += getAlpha(value[i]); |
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} |
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return result; |
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} |
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exports.decodeBase58 = decodeBase58; |
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//# sourceMappingURL=base58.js.map
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