📜  Node.js crypto.randomFillSync() 方法

📅  最后修改于: 2022-05-13 01:56:37.299000             🧑  作者: Mango

Node.js crypto.randomFillSync() 方法

crypto.randomFillSync() 方法是加密模块的内置应用程序编程接口,用于返回作为缓冲区参数传递的对象。
句法:

crypto.randomFillSync( buffer, offset, size )

参数:此方法接受三个参数,如上所述,如下所述:

  • buffer该参数保存 Buffer、TypedArray 或 DataView 类型的数据。
  • offset:它是一个数字,默认值为 0。
  • size:它是一个数字,其默认值为(buffer.length – offset)

返回值:返回Buffer、TypedArray或DataView类型的数据。
下面的示例说明了在 Node.js 中使用crypto.randomFillSync() 方法
示例 1:

javascript
// Node.js program to demonstrate the 
// crypto.randomFillSync() method
  
// Including crypto module
const crypto = require('crypto');
  
// Defining buffer
const buffer = Buffer.alloc(15);
  
// Calling randomFillSync method with only 
// one parameter, buffer
console.log(crypto.randomFillSync(buffer).toString('ascii'));
  
// Calling randomFillSync method with 
// two parameters, buffer and offset
crypto.randomFillSync(buffer, 4);
console.log(buffer.toString('base64'));
  
// Calling randomFillSync method with three 
// parameters, buffer, offset and size
crypto.randomFillSync(buffer, 4, 4);
console.log(buffer.toString('base64'));


javascript
// Node.js program to demonstrate the 
// crypto.randomFillSync() method
  
// Including crypto module
const crypto = require('crypto');
  
// Creating TypedArray instance i.e, Int8Array
const x = new Int8Array(5);
  
// Calling randomFillSync with all its parameter
console.log(Buffer.from(crypto.randomFillSync(x).buffer,
         x.byteOffset, x.byteLength).toString('base64'));
  
console.log();
  
// Creating TypedArray instance i.e, BigInt64Array
const y = new BigInt64Array(4);
console.log(Buffer.from(crypto.randomFillSync(y).buffer,
          y.byteOffset, y.byteLength).toString('ascii'));
console.log();
  
// Creating a DataView instance
const z = new DataView(new ArrayBuffer(7));
console.log(Buffer.from(crypto.randomFillSync(z).buffer,
            z.byteOffset, z.byteLength).toString('hex'));


输出:

+~`Ld#%KT&6VF1e
K/7gTBXCFISh30dPoE5o
K/7gTO7iUG+h30dPoE5o

在这里,最后两个值是相同的。
示例 2:

javascript

// Node.js program to demonstrate the 
// crypto.randomFillSync() method
  
// Including crypto module
const crypto = require('crypto');
  
// Creating TypedArray instance i.e, Int8Array
const x = new Int8Array(5);
  
// Calling randomFillSync with all its parameter
console.log(Buffer.from(crypto.randomFillSync(x).buffer,
         x.byteOffset, x.byteLength).toString('base64'));
  
console.log();
  
// Creating TypedArray instance i.e, BigInt64Array
const y = new BigInt64Array(4);
console.log(Buffer.from(crypto.randomFillSync(y).buffer,
          y.byteOffset, y.byteLength).toString('ascii'));
console.log();
  
// Creating a DataView instance
const z = new DataView(new ArrayBuffer(7));
console.log(Buffer.from(crypto.randomFillSync(z).buffer,
            z.byteOffset, z.byteLength).toString('hex'));

输出:

BQrDFc8=

EM4;)N+.qY, o-kp:b:C.

479eb4d9175221

在这里,任何TypedArray 或 DataView实例都作为缓冲区传递。
参考: https://nodejs.org/api/crypto.html#crypto_crypto_randomfillsync_buffer_offset_size