Cipher 类

• 继承自: <stream.Transform>

Cipher 类的实例用于加密数据。 可以通过以下两种方式之一使用该类：

• 作为既可读又可写的流，其中写入未加密的纯数据以在可读端生成加密的数据，或
• 使用 cipher.update() 和 cipher.final() 方法生成加密的数据。

crypto.createCipher() 或 crypto.createCipheriv() 方法用于创建 Cipher 实例。 Cipher 对象不能直接使用 new 关键字创建。

示例：使用 Cipher 对象作为流：

const {
  scrypt,
  randomFill,
  createCipheriv
} = await import('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// 首先，将生成密钥。密钥长度取决于算法。
// 在此示例中，用于 aes192，长度是 24 个字节（192 位）。
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // 然后，将生成随机的初始化向量
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    // 一旦有了密钥和 iv，则可以创建和使用加密...
    const cipher = createCipheriv(algorithm, key, iv);

    let encrypted = '';
    cipher.setEncoding('hex');

    cipher.on('data', (chunk) => encrypted += chunk);
    cipher.on('end', () => console.log(encrypted));

    cipher.write('some clear text data');
    cipher.end();
  });
});const {
  scrypt,
  randomFill,
  createCipheriv
} = require('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// 首先，将生成密钥。密钥长度取决于算法。
// 在此示例中，用于 aes192，长度是 24 个字节（192 位）。
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // 然后，将生成随机的初始化向量
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    // 一旦有了密钥和 iv，则可以创建和使用加密...
    const cipher = createCipheriv(algorithm, key, iv);

    let encrypted = '';
    cipher.setEncoding('hex');

    cipher.on('data', (chunk) => encrypted += chunk);
    cipher.on('end', () => console.log(encrypted));

    cipher.write('some clear text data');
    cipher.end();
  });
});

示例：使用 Cipher 和管道流：

import {
  createReadStream,
  createWriteStream,
} from 'fs';

import {
  pipeline
} from 'stream';

const {
  scrypt,
  randomFill,
  createCipheriv
} = await import('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// 首先，将生成密钥。密钥长度取决于算法。
// 在此示例中，用于 aes192，长度是 24 个字节（192 位）。
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // 然后，将生成随机的初始化向量
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    const cipher = createCipheriv(algorithm, key, iv);

    const input = createReadStream('test.js');
    const output = createWriteStream('test.enc');

    pipeline(input, cipher, output, (err) => {
      if (err) throw err;
    });
  });
});const {
  createReadStream,
  createWriteStream,
} = require('node:fs');

const {
  pipeline
} = require('node:stream');

const {
  scrypt,
  randomFill,
  createCipheriv,
} = require('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// 首先，将生成密钥。密钥长度取决于算法。
// 在此示例中，用于 aes192，长度是 24 个字节（192 位）。
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // 然后，将生成随机的初始化向量
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    const cipher = createCipheriv(algorithm, key, iv);

    const input = createReadStream('test.js');
    const output = createWriteStream('test.enc');

    pipeline(input, cipher, output, (err) => {
      if (err) throw err;
    });
  });
});

示例：使用 cipher.update() 和 cipher.final() 方法：

const {
  scrypt,
  randomFill,
  createCipheriv
} = await import('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// 首先，将生成密钥。密钥长度取决于算法。
// 在此示例中，用于 aes192，长度是 24 个字节（192 位）。
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // 然后，将生成随机的初始化向量
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    const cipher = createCipheriv(algorithm, key, iv);

    let encrypted = cipher.update('some clear text data', 'utf8', 'hex');
    encrypted += cipher.final('hex');
    console.log(encrypted);
  });
});const {
  scrypt,
  randomFill,
  createCipheriv,
} = require('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// 首先，将生成密钥。密钥长度取决于算法。
// 在此示例中，用于 aes192，长度是 24 个字节（192 位）。
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // 然后，将生成随机的初始化向量
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    const cipher = createCipheriv(algorithm, key, iv);

    let encrypted = cipher.update('some clear text data', 'utf8', 'hex');
    encrypted += cipher.final('hex');
    console.log(encrypted);
  });
});

• Extends: <stream.Transform>

Instances of the Cipher class are used to encrypt data. The class can be used in one of two ways:

• As a stream that is both readable and writable, where plain unencrypted data is written to produce encrypted data on the readable side, or
• Using the cipher.update() and cipher.final() methods to produce the encrypted data.

The crypto.createCipher() or crypto.createCipheriv() methods are used to create Cipher instances. Cipher objects are not to be created directly using the new keyword.

Example: Using Cipher objects as streams:

const {
  scrypt,
  randomFill,
  createCipheriv
} = await import('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// First, we'll generate the key. The key length is dependent on the algorithm.
// In this case for aes192, it is 24 bytes (192 bits).
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // Then, we'll generate a random initialization vector
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    // Once we have the key and iv, we can create and use the cipher...
    const cipher = createCipheriv(algorithm, key, iv);

    let encrypted = '';
    cipher.setEncoding('hex');

    cipher.on('data', (chunk) => encrypted += chunk);
    cipher.on('end', () => console.log(encrypted));

    cipher.write('some clear text data');
    cipher.end();
  });
});const {
  scrypt,
  randomFill,
  createCipheriv
} = require('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// First, we'll generate the key. The key length is dependent on the algorithm.
// In this case for aes192, it is 24 bytes (192 bits).
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // Then, we'll generate a random initialization vector
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    // Once we have the key and iv, we can create and use the cipher...
    const cipher = createCipheriv(algorithm, key, iv);

    let encrypted = '';
    cipher.setEncoding('hex');

    cipher.on('data', (chunk) => encrypted += chunk);
    cipher.on('end', () => console.log(encrypted));

    cipher.write('some clear text data');
    cipher.end();
  });
});

Example: Using Cipher and piped streams:

import {
  createReadStream,
  createWriteStream,
} from 'fs';

import {
  pipeline
} from 'stream';

const {
  scrypt,
  randomFill,
  createCipheriv
} = await import('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// First, we'll generate the key. The key length is dependent on the algorithm.
// In this case for aes192, it is 24 bytes (192 bits).
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // Then, we'll generate a random initialization vector
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    const cipher = createCipheriv(algorithm, key, iv);

    const input = createReadStream('test.js');
    const output = createWriteStream('test.enc');

    pipeline(input, cipher, output, (err) => {
      if (err) throw err;
    });
  });
});const {
  createReadStream,
  createWriteStream,
} = require('node:fs');

const {
  pipeline
} = require('node:stream');

const {
  scrypt,
  randomFill,
  createCipheriv,
} = require('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// First, we'll generate the key. The key length is dependent on the algorithm.
// In this case for aes192, it is 24 bytes (192 bits).
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // Then, we'll generate a random initialization vector
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    const cipher = createCipheriv(algorithm, key, iv);

    const input = createReadStream('test.js');
    const output = createWriteStream('test.enc');

    pipeline(input, cipher, output, (err) => {
      if (err) throw err;
    });
  });
});

Example: Using the cipher.update() and cipher.final() methods:

const {
  scrypt,
  randomFill,
  createCipheriv
} = await import('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// First, we'll generate the key. The key length is dependent on the algorithm.
// In this case for aes192, it is 24 bytes (192 bits).
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // Then, we'll generate a random initialization vector
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    const cipher = createCipheriv(algorithm, key, iv);

    let encrypted = cipher.update('some clear text data', 'utf8', 'hex');
    encrypted += cipher.final('hex');
    console.log(encrypted);
  });
});const {
  scrypt,
  randomFill,
  createCipheriv,
} = require('node:crypto');

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// First, we'll generate the key. The key length is dependent on the algorithm.
// In this case for aes192, it is 24 bytes (192 bits).
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // Then, we'll generate a random initialization vector
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    const cipher = createCipheriv(algorithm, key, iv);

    let encrypted = cipher.update('some clear text data', 'utf8', 'hex');
    encrypted += cipher.final('hex');
    console.log(encrypted);
  });
});