Node.js decipher.update() 方法

decipher.update()方法是加密模块中 Decipher 类的内置应用程序编程接口，用于根据给定的编码格式用数据更新解密。

句法：

const dicipher.update(data[, inputEncoding][, outputEncoding])

参数：此方法采用以下参数：

• 数据：用于通过新内容更新解密。
• inputEncoding：输入编码格式。
• outputEncoding：输出编码格式。

返回值：此方法不返回任何值。

示例 1：文件名：index.js

Javascript

// Node.js program to demonstrate the
// decipher.update() method
 
// importing crypto module
const crypto = require('crypto');
 
// Creating and initializing algorithm and password
const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';
 
// Getting key for the decipher object
const key = crypto.scryptSync(password, 'salt', 24);
 
// Creating and initializing the static iv
const iv = Buffer.alloc(16, 0);
 
// Creating and initializing the decipher object
const decipher = crypto.createDecipheriv(algorithm, key, iv);
 
// Encrypted using same algorithm, key and iv.
const encrypted =
'e5f79c5915c02171eec6b212d5520d44480993d7d622a7c4c2da32f6efda0ffa';
 
// Updating the data into decipher object
let decrypted = decipher.update(encrypted, 'hex', 'utf8');
 
// Getting decrypted data
decrypted += decipher.final('utf8');
 
// Display the result
console.log("buffer :- " + decrypted);

输出：

buffer :- some clear text data

示例 2：文件名：index.js

Javascript

// Node.js program to demonstrate the
// decipher.update() method
 
// Importing crypto module
const crypto = require('crypto');
 
// Creating and initializing algorithm and password
const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';
 
// Getting key for cipher object
crypto.scrypt(password, 'salt', 24,
 
    { N: 512 }, (err, key) => {
 
        if (err) throw err;
 
        // Creating and initializing the static iv
        const iv = Buffer.alloc(16, 0);
 
        // Creating and initializing the decipher object
        const decipher = crypto
            .createDecipheriv(algorithm, key, iv);
 
 
        // Encrypted using same algorithm, key and iv.
        const encrypted =
'e5f79c5915c02171eec6b212d5520d44480993d7d622a7c4c2da32f6efda0ffa';
 
        // updating the data into decipher object
        const decrypted = decipher.update(encrypted, 'hex', 'utf8');
 
        console.log("buffer :- " + decipher);
    });

输出：

buffer :- [object Object]

使用以下命令运行 index.js 文件：

node index.js

参考： https://nodejs.org/dist/latest-v12.x/docs/api/crypto.html#crypto_decipher_update_data_inputencoding_outputencoding