crypto.getRandomValues must be defined

[windswrold]

使用 solana/web3.js ,开发uni app， 但是提示 crypto.getRandomValues must be defined

[xu-zhipeng]

可以试试我的这个解决办法，通过打补丁的方式，我参考的是之前的uni-app源码的提交记录，但是他们新版又给去除了。只能支持crypto.getRandomValues和crypto.randomBytes方法,如果你的第三方库用到crypto其他方法，那只能自己去实现了。
web3 的这些sdk底层都要获取随机数，应该都用了这一套，所以其他币也是同样解决办法。

提交记录参考：feat(app-plus): add crypto

crypto.ts 文件内容：

const lookup = [
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 62, 0, 62, 0, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 0, 0, 0,
  0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
  24, 25, 0, 0, 0, 0, 63, 0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,
  44, 45, 46, 47, 48, 49, 50, 51,
]

function base64Decode(source: string, target: Uint8Array) {
  const sourceLength = source.length
  const paddingLength =
    source[sourceLength - 2] === '=' ? 2 : source[sourceLength - 1] === '=' ? 1 : 0

  let tmp
  let byteIndex = 0
  const baseLength = (sourceLength - paddingLength) & 0xfffffffc

  for (var i = 0; i < baseLength; i += 4) {
    tmp =
      (lookup[source.charCodeAt(i)] << 18) |
      (lookup[source.charCodeAt(i + 1)] << 12) |
      (lookup[source.charCodeAt(i + 2)] << 6) |
      lookup[source.charCodeAt(i + 3)]

    target[byteIndex++] = (tmp >> 16) & 0xff
    target[byteIndex++] = (tmp >> 8) & 0xff
    target[byteIndex++] = tmp & 0xff
  }

  if (paddingLength === 1) {
    tmp =
      (lookup[source.charCodeAt(i)] << 10) |
      (lookup[source.charCodeAt(i + 1)] << 4) |
      (lookup[source.charCodeAt(i + 2)] >> 2)

    target[byteIndex++] = (tmp >> 8) & 0xff
    target[byteIndex++] = tmp & 0xff
  }

  if (paddingLength === 2) {
    tmp = (lookup[source.charCodeAt(i)] << 2) | (lookup[source.charCodeAt(i + 1)] >> 4)

    target[byteIndex++] = tmp & 0xff
  }
}

export default {
  getRandomValues(arr: {
    byteLength: number | undefined
    buffer: ArrayBufferLike
    byteOffset: number | undefined
  }) {
    if (
      !(
        arr instanceof Int8Array ||
        arr instanceof Uint8Array ||
        arr instanceof Int16Array ||
        arr instanceof Uint16Array ||
        arr instanceof Int32Array ||
        arr instanceof Uint32Array ||
        arr instanceof Uint8ClampedArray
      )
    ) {
      throw new Error('Expected an integer array')
    }
    if (arr.byteLength > 65536) {
      throw new Error('Can only request a maximum of 65536 bytes')
    }
    var crypto = uni.requireNativePlugin('DCloud-Crypto')
    base64Decode(
      crypto.getRandomValues(arr.byteLength),
      new Uint8Array(arr.buffer, arr.byteOffset, arr.byteLength),
    )
    return arr
  },
  randomBytes(arrSize: number) {
    if (arrSize > 65536) {
      throw new Error('Can only request a maximum of 65536 bytes')
    }
    var crypto = uni.requireNativePlugin('DCloud-Crypto')
    var arr = new Uint8Array(arrSize)
    base64Decode(
      crypto.getRandomValues(arr.byteLength),
      new Uint8Array(arr.buffer, arr.byteOffset, arr.byteLength),
    )
    return arr
  },
}

index.ts 文件内容

import crypto from "./crypto";

/**
 * 全局内置类型替换
 */
(function (scope) {
  'use strict';

  if(!(scope as any).crypto){
    (scope as any).crypto = crypto
    console.log('crypto不存在, 使用自定义crypto进行替换')
  }
})(typeof globalThis !== 'undefined'? globalThis : typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : this)

console.log('crypto polyfill loaded for App environment.')