bip322-js
Version:
A Javascript library that provides utility functions related to the BIP-322 signature scheme
71 lines • 3.58 kB
JavaScript
;
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
// Import dependencies
const VarInt_1 = __importDefault(require("./VarInt"));
const VarStr_1 = __importDefault(require("./VarStr"));
const BufferUtil_1 = __importDefault(require("./BufferUtil"));
/**
* Class that implement witness data serialization and deserialization.
*/
class Witness {
/**
* Encode array of witness into its base-64 encoded format.
* Follows the encoding scheme found in buidl-python:
* https://github.com/buidl-bitcoin/buidl-python/blob/d79e9808e8ca60975d315be41293cb40d968626d/buidl/witness.py#L35
* @param witnesses Array of witness data
* @returns Base-64 encoded witness data
*/
static serialize(witnesses) {
// The first element to be included is the length of the witness array as VarInt
let witnessStack = VarInt_1.default.encode(witnesses.length);
// Then, for each witness array,
witnesses.forEach((witness) => {
// Append each witness as a VarStr to the witness stack
witnessStack = Buffer.concat([witnessStack, VarStr_1.default.encode(Buffer.from(witness))]);
});
// Return the base-64 encoded witness stack
return witnessStack.toString('base64');
}
/**
* Decode encoded witness data, either as a base-64 encoded string or as a decoded string in a buffer, into an array of witness.
* Follows the decoding scheme found in buidl-python:
* https://github.com/buidl-bitcoin/buidl-python/blob/d79e9808e8ca60975d315be41293cb40d968626d/buidl/witness.py#L62
* @param encodedWitness Base-64 encoded witness data, or encoded witness data that have already been decoded
* @returns Decoded witness data
*/
static deserialize(encodedWitness) {
// Store the decoded witness stack
let witnessDecoded = [];
// Preprocess the encodedWitness if needed
let witnessToDecode;
if (typeof encodedWitness === 'string') {
// Decode the encoded witness if it is a string (assuming it is encoded using base-64)
witnessToDecode = Buffer.from(encodedWitness, 'base64');
}
else {
witnessToDecode = encodedWitness;
}
// Read a VarInt which indicate the number of elements within the original witness array
const witnessCount = VarInt_1.default.decode(witnessToDecode);
// Slice the VarInt in front of the witness buffer before decoding each witness
const varIntLength = VarInt_1.default.encode(witnessCount).byteLength;
witnessToDecode = BufferUtil_1.default.ensureBuffer(witnessToDecode.subarray(varIntLength));
// Loop for each witness encoded
for (let i = 0; i < witnessCount; i++) {
// Read a VarStr from the remaining buffer
const witness = VarStr_1.default.decode(witnessToDecode);
// Append the decoded witness to witnessDecoded
witnessDecoded.push(witness);
// Slice the read witness off witnessToDecode before next iteration
const witnessLength = VarStr_1.default.encode(witness).byteLength;
witnessToDecode = BufferUtil_1.default.ensureBuffer(witnessToDecode.subarray(witnessLength));
}
// Return deserialized witness data
return witnessDecoded;
}
}
exports.default = Witness;
//# sourceMappingURL=Witness.js.map