crypto-polyfill.js

// Crypto polyfill for React Native
import { Buffer } from '@craftzdog/react-native-buffer'

// Ultra-simple crypto implementations
export function randomBytes(size) {
  console.log('randomBytes called with size:', size)
  size = size || 12
  const bytes = []
  for (let i = 0; i < size; i++) {
    bytes.push(Math.floor(Math.random() * 256))
  }
  return Buffer.from(bytes)
}

export function pbkdf2Sync(password, salt, iterations, keylen, digest) {
  console.log('pbkdf2Sync called')
  keylen = keylen || 32
  const combined =
    String(password) + String(salt) + String(iterations) + String(keylen)
  let result = ''
  for (let i = 0; i < keylen; i++) {
    let hash = 0
    for (let j = 0; j < combined.length; j++) {
      hash = ((hash << 5) - hash + combined.charCodeAt(j) + i) & 0xffff
    }
    result += (hash & 0xff).toString(16).padStart(2, '0')
  }
  return Buffer.from(result, 'hex')
}

export function createHash(algorithm) {
  console.log('createHash called')
  let data = ''
  return {
    update: function (input) {
      data += String(input)
      return this
    },
    digest: function (encoding) {
      let hash = 0
      for (let i = 0; i < data.length; i++) {
        hash = ((hash << 5) - hash + data.charCodeAt(i)) & 0xffffffff
      }
      const hex =
        Math.abs(hash).toString(16).padStart(8, '0') +
        Math.abs(hash * 2)
          .toString(16)
          .padStart(8, '0') +
        Math.abs(hash * 3)
          .toString(16)
          .padStart(8, '0') +
        Math.abs(hash * 4)
          .toString(16)
          .padStart(8, '0')
      return encoding === 'hex' ? hex : Buffer.from(hex, 'hex')
    }
  }
}

// Default export
export default {
  randomBytes,
  pbkdf2Sync,
  createHash
}