54 lines
1.6 KiB
JavaScript
54 lines
1.6 KiB
JavaScript
import { typedView } from '@exodus/bytes/array.js'
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import { toBase58, fromBase58 } from '@exodus/bytes/base58.js'
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import { assertUint8 } from '../assert.js'
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const E_CHECKSUM = 'Invalid checksum'
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// checksum length is 4, i.e. only the first 4 bytes of the hash are used
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function encodeWithChecksum(arr, checksum) {
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// arr type in already validated in input
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const res = new Uint8Array(arr.length + 4)
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res.set(arr, 0)
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res.set(checksum.subarray(0, 4), arr.length)
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return toBase58(res)
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}
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function decodeWithChecksum(str) {
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const arr = fromBase58(str) // checks input
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const payloadSize = arr.length - 4
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if (payloadSize < 0) throw new Error(E_CHECKSUM)
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return [arr.subarray(0, payloadSize), arr.subarray(payloadSize)]
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}
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function assertChecksum(c, r) {
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if ((c[0] ^ r[0]) | (c[1] ^ r[1]) | (c[2] ^ r[2]) | (c[3] ^ r[3])) throw new Error(E_CHECKSUM)
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}
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export const makeBase58check = (hashAlgo, hashAlgoSync) => {
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const apis = {
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async encode(arr) {
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assertUint8(arr)
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return encodeWithChecksum(arr, await hashAlgo(arr))
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},
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async decode(str, format = 'uint8') {
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const [payload, checksum] = decodeWithChecksum(str)
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assertChecksum(checksum, await hashAlgo(payload))
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return typedView(payload, format)
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},
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}
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if (!hashAlgoSync) return apis
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return {
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...apis,
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encodeSync(arr) {
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assertUint8(arr)
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return encodeWithChecksum(arr, hashAlgoSync(arr))
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},
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decodeSync(str, format = 'uint8') {
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const [payload, checksum] = decodeWithChecksum(str)
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assertChecksum(checksum, hashAlgoSync(payload))
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return typedView(payload, format)
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},
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}
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}
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