wallet-storage/src/utility/ScriptTemplateSABPPP.ts

BRC100 conforming wallet, wallet storage and wallet signer components

import { HexString, KeyDeriver, KeyDeriverApi, WalletProtocol } from '@bsv/sdk'
import { asBsvSdkPrivateKey, verifyTruthy } from './index.client'
import {
  LockingScript,
  P2PKH,
  PrivateKey,
  Script,
  ScriptTemplate,
  Transaction,
  UnlockingScript
} from '@bsv/sdk'

export interface ScriptTemplateParamsSABPPP {
  derivationPrefix?: string
  derivationSuffix?: string
  keyDeriver: KeyDeriverApi
}

export const brc29ProtocolID: WalletProtocol = [2, '3241645161d8']

export class ScriptTemplateSABPPP implements ScriptTemplate {
  p2pkh: P2PKH

  constructor(public params: ScriptTemplateParamsSABPPP) {
    this.p2pkh = new P2PKH()

    verifyTruthy(params.derivationPrefix)
    verifyTruthy(params.derivationSuffix)
  }

  getKeyID() {
    return `${this.params.derivationPrefix} ${this.params.derivationSuffix}`
  }

  getKeyDeriver(privKey: PrivateKey | HexString): KeyDeriverApi {
    if (typeof privKey === 'string') privKey = PrivateKey.fromHex(privKey)
    if (
      !this.params.keyDeriver ||
      this.params.keyDeriver.rootKey.toHex() !== privKey.toHex()
    )
      return new KeyDeriver(privKey)
    return this.params.keyDeriver
  }

  lock(lockerPrivKey: string, unlockerPubKey: string): LockingScript {
    const address = this.getKeyDeriver(lockerPrivKey)
      .derivePublicKey(brc29ProtocolID, this.getKeyID(), unlockerPubKey, false)
      .toAddress()
    const r = this.p2pkh.lock(address)
    return r
  }

  unlock(
    unlockerPrivKey: string,
    lockerPubKey: string,
    sourceSatoshis?: number,
    lockingScript?: Script
  ): {
    sign: (tx: Transaction, inputIndex: number) => Promise<UnlockingScript>
    estimateLength: (tx?: Transaction, inputIndex?: number) => Promise<number>
  } {
    const derivedPrivateKey = this.getKeyDeriver(unlockerPrivKey)
      .derivePrivateKey(brc29ProtocolID, this.getKeyID(), lockerPubKey)
      .toHex()
    const r = this.p2pkh.unlock(
      asBsvSdkPrivateKey(derivedPrivateKey),
      'all',
      false,
      sourceSatoshis,
      lockingScript
    )
    return r
  }

  /**
   * P2PKH unlock estimateLength is a constant
   */
  unlockLength = 108
}