Function validateNip44Payload

src/utils/nip44.ts:158–180

(payload: string)

const BASE64_RE = /^[A-Za-z0-9+/]*={0,2}$/

export function validateNip44Payload(payload: string): string | undefined {
  if (!payload || payload[0] === '#') {
    return 'unsupported encryption version'
  }
  if (payload.length < 132 || payload.length > 87472) {
    return 'invalid payload size'
  }

  if (payload.length % 4 !== 0 || !BASE64_RE.test(payload)) {
    return 'payload is not valid base64'
  }

  const data = Buffer.from(payload, 'base64')

  if (data.length < 99 || data.length > 65603) {
    return 'invalid decoded payload size'
  }
  if (data[0] !== 2) {
    return `unsupported encryption version ${data[0]}`
  }

  return undefined
}