@radixdlt/tx-parser/src/txSignature.ts

Parsing of Radix Engine transactions and instructions

import { combine, Result } from 'neverthrow'
import { TXSig } from './_types'
import { BufferReaderT, Byte } from '@radixdlt/util'
import { UInt256 } from '@radixdlt/uint256'
import { amountToBuffer } from './tokens'

const fromBufferReader = (bufferReader: BufferReaderT): Result<TXSig, Error> =>
	combine([
		bufferReader.readNextBuffer(1),
		bufferReader.readNextBuffer(32),
		bufferReader.readNextBuffer(32),
	])
		.map(resList => {
			const v = resList[0].readUInt8(0) as Byte

			const uint256FromBuffer = (b: unknown): UInt256 => {
				const hex = (b as Buffer).toString('hex')
				return new UInt256(hex, 16)
			}

			const r = uint256FromBuffer(resList[1])
			const s = uint256FromBuffer(resList[2])

			return {
				v,
				r,
				s,
			}
		})
		.map(partial => {
			const buffer = Buffer.concat([
				Buffer.from([partial.v]),
				amountToBuffer(partial.r),
				amountToBuffer(partial.s),
			])
			return {
				...partial,
				toBuffer: () => buffer,
				toString: () =>
					`Signature: { 
						v: ${partial.v}, 
						r: ${partial.r.toString(16)}, 
						s: ${partial.s.toString(16)}
					}`,
			}
		})

export const TxSignature = {
	fromBufferReader,
}