Node.js v8.x 中文文档

crypto (加密)#

crypto 模块提供了加密功能，包含对 OpenSSL 的哈希、HMAC、加密、解密、签名、以及验证功能的一整套封装。

使用 require('crypto') 来访问该模块。

const crypto = require('crypto');

const secret = 'abcdefg';
const hash = crypto.createHmac('sha256', secret)
                   .update('I love cupcakes')
                   .digest('hex');
console.log(hash);
// Prints:
//   c0fa1bc00531bd78ef38c628449c5102aeabd49b5dc3a2a516ea6ea959d6658e

Determining if crypto support is unavailable#

可以在不包括支持 crypto 模块的情况下构建 Node.js, 这时, 调用 require('crypto') 将导致抛出异常.

let crypto;
try {
  crypto = require('crypto');
} catch (err) {
  console.log('不支持 crypto!');
}

Class: Certificate#

新增于: v0.11.8

SPKAC 最初是由 Netscape 实现的一种证书签名请求机制, 现在正式成为 HTML5's keygen element 的一部分.

crypto 模块提供 Certificate 类用于处理 SPKAC 数据. 最普遍的用法是处理 HTML5 keygen 元素产生的输出. Node.js 内部使用 OpenSSL's SPKAC implementation 处理.

new crypto.Certificate()#

可以使用 new 关键字或者调用 crypto.Certificate() 方法创建 Certificate 类的实例:

const crypto = require('crypto');

const cert1 = new crypto.Certificate();
const cert2 = crypto.Certificate();

certificate.exportChallenge(spkac)#

新增于: v0.11.8

spkac <string> | <Buffer> | <TypedArray> | <DataView>
返回 <Buffer> 返回 spkac 数据结构的 challenge 部分，spkac 包含一个公钥和一个 challange。

const cert = require('crypto').Certificate();
const spkac = getSpkacSomehow();
const challenge = cert.exportChallenge(spkac);
console.log(challenge.toString('utf8'));
// Prints: the challenge as a UTF8 string

certificate.exportPublicKey(spkac)#

新增于: v0.11.8

spkac <string> | <Buffer> | <TypedArray> | <DataView>
返回 <Buffer> 数据结构的公钥部分，spkac 包含一个公钥和一个 challange。

const cert = require('crypto').Certificate();
const spkac = getSpkacSomehow();
const publicKey = cert.exportPublicKey(spkac);
console.log(publicKey);
// Prints: the public key as <Buffer ...>

certificate.verifySpkac(spkac)#

新增于: v0.11.8

spkac <Buffer> | <TypedArray> | <DataView>
返回 <boolean> 如果 spkac 数据结构是有效的返回 true，否则返回 false。

const cert = require('crypto').Certificate();
const spkac = getSpkacSomehow();
console.log(cert.verifySpkac(Buffer.from(spkac)));
// Prints: true 或者 false

Class: Cipher#

新增于: v0.1.94

Cipher类的实例用于加密数据。这个类可以用在以下两种方法中的一种:

作为stream，既可读又可写，未加密数据的编写是为了在可读的方面生成加密的数据，或者
使用cipher.update()和cipher.final()方法产生加密的数据。

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 crypto = require('crypto');
const cipher = crypto.createCipher('aes192', 'a password');

let encrypted = '';
cipher.on('readable', () => {
  const data = cipher.read();
  if (data)
    encrypted += data.toString('hex');
});
cipher.on('end', () => {
  console.log(encrypted);
  // Prints: ca981be48e90867604588e75d04feabb63cc007a8f8ad89b10616ed84d815504
});

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

示例:使用Cipher和管道流:

const crypto = require('crypto');
const fs = require('fs');
const cipher = crypto.createCipher('aes192', 'a password');

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

input.pipe(cipher).pipe(output);

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

const crypto = require('crypto');
const cipher = crypto.createCipher('aes192', 'a password');

let encrypted = cipher.update('some clear text data', 'utf8', 'hex');
encrypted += cipher.final('hex');
console.log(encrypted);
// Prints: ca981be48e90867604588e75d04feabb63cc007a8f8ad89b10616ed84d815504

cipher.final([outputEncoding])#

新增于: v0.1.94

outputEncoding <string>

返回任何加密的内容。如果 outputEncoding 参数是'latin1', 'base64' 或者 'hex'，返回字符串。如果没有提供 outputEncoding，则返回Buffer。

一旦cipher.final()方法已被调用，Cipher 对象就不能再用于加密数据。如果试图再次调用cipher.final()，将会抛出一个错误。

cipher.setAAD(buffer)#

新增于: v1.0.0

buffer <Buffer>
返回<Cipher>方法链。

当使用经过验证的加密模式(目前只支持GCM)时，cipher.setAAD()方法设置用于additional authenticated data(附加验证的data(AAD))输入参数的值。

cipher.setAAD()法必须在cipher.update()之前调用。

cipher.getAuthTag()#

新增于: v1.0.0

当使用经验证的加密模式时(目前只有GCM支持),cipher.getAuthTag()方法返回一个Buffer，此Buffer包含已从给定数据计算后的authentication tag。 cipher.getAuthTag()方法只能在使用cipher.final()方法完全加密后调用。

cipher.setAutoPadding([autoPadding])#

新增于: v0.7.1

autoPadding <boolean> 默认为 true.
返回<Cipher>方法链。

当使用块加密算法时，Cipher类会自动添加padding到输入数据中，来适配相应块大小。可调用cipher.setAutoPadding(false)禁用默认padding。

当autoPadding是false时，整个输入数据的长度必须是cipher块大小的倍数，否则cipher.final()将抛出一个错误。禁用自动填充对于非标准填充是有用的，例如使用0x0代替PKCS填充。

cipher.setAutoPadding()必须在cipher.final()之前被调用。

cipher.update(data[, inputEncoding][, outputEncoding])#

版本历史

版本	变更
v6.0.0	默认`inputEncoding`由`binary` 变为 `utf8`
v0.1.94	新增于: v0.1.94

data <string> | <Buffer> | <TypedArray> | <DataView>
inputEncoding <string>
outputEncoding <string>

用data更新密码。如果给出了inputEncoding的论证，它的值必须是'utf8', 'ascii', 或者'latin1'，而data参数是使用指定编码的字符串。如果不给出inputEncoding的参数，则data必须是Buffer，TypedArray，或者DataView。如果data是一个Buffer，TypedArray，或者 DataView，那么inputEncoding就被忽略了。

outputEncoding指定了加密数据的输出格式，可以是'latin1'， 'base64' 或者 'hex'。如果指定了outputEncoding，则返回使用指定编码的字符串。如果没有outputEncoding被提供，会返回Buffer。

cipher.update()方法可以用新数据多次调用，直到cipher.final()被调用。 [' cipher.final()'][]。在cipher.final()之后调用cipher.update()将抛出错误。

Class: Decipher#

新增于: v0.1.94

Decipher类的实例用于解密数据。这个类可以用在以下两种方法中的一种:

作为stream，既可读，又可写，加密数据的编写是为了在可读的方面生成未加密的数据
使用decipher.update()和decipher.final()方法产生未加密的数据。

crypto.createDecipher()或crypto.createDecipheriv()的方法用于创建Decipher实例。Decipher对象不能直接使用new关键字创建。

示例:使用Decipher对象作为流:

const crypto = require('crypto');
const decipher = crypto.createDecipher('aes192', 'a password');

let decrypted = '';
decipher.on('readable', () => {
  const data = decipher.read();
  if (data)
    decrypted += data.toString('utf8');
});
decipher.on('end', () => {
  console.log(decrypted);
  // Prints: some clear text data
});

const encrypted =
    'ca981be48e90867604588e75d04feabb63cc007a8f8ad89b10616ed84d815504';
decipher.write(encrypted, 'hex');
decipher.end();

示例:使用Decipher和管道流:

const crypto = require('crypto');
const fs = require('fs');
const decipher = crypto.createDecipher('aes192', 'a password');

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

input.pipe(decipher).pipe(output);

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

const crypto = require('crypto');
const decipher = crypto.createDecipher('aes192', 'a password');

const encrypted =
    'ca981be48e90867604588e75d04feabb63cc007a8f8ad89b10616ed84d815504';
let decrypted = decipher.update(encrypted, 'hex', 'utf8');
decrypted += decipher.final('utf8');
console.log(decrypted);
// Prints: some clear text data

decipher.final([outputEncoding])#

新增于: v0.1.94

outputEncoding <string>

返回任何剩余的解密内容。如果outputEncoding参数是'latin1'，'ascii'或'utf8'之一，则返回一个字符串。如果未提供输出编码，则返回Buffer。

一旦调用了decipher.final()方法，Decipher对象就不能再用于解密数据。试图不止一次调用decipher.final()会导致错误被抛出。

decipher.setAAD(buffer)#

版本历史

版本	变更
v7.2.0	This method now returns a reference to `decipher`.
v1.0.0	新增于: v1.0.0

buffer <Buffer> | <TypedArray> | <DataView>
返回<cipher>的一个方法链。

当使用经过验证的加密模式（当前仅支持GCM）时，decipher.setAAD()方法会设置用于附加验证数据(AAD)输入参数的值。

decipher.setAAD() 必须在decipher.update()之前被调用。

decipher.setAuthTag(buffer)#

版本历史

版本	变更
v7.2.0	This method now returns a reference to `decipher`.
v1.0.0	新增于: v1.0.0

buffer <Buffer> | <TypedArray> | <DataView>
Returns the <Cipher> for method chaining.

When using an authenticated encryption mode (only GCM is currently supported), the decipher.setAuthTag() method is used to pass in the received authentication tag. If no tag is provided, or if the cipher text has been tampered with, decipher.final() will throw, indicating that the cipher text should be discarded due to failed authentication.

The decipher.setAuthTag() method must be called before decipher.final().

decipher.setAutoPadding([autoPadding])#

新增于: v0.7.1

autoPadding <boolean> Defaults to true.
Returns the <Cipher> for method chaining.

When data has been encrypted without standard block padding, calling decipher.setAutoPadding(false) will disable automatic padding to prevent decipher.final() from checking for and removing padding.

Turning auto padding off will only work if the input data's length is a multiple of the ciphers block size.

The decipher.setAutoPadding() method must be called before decipher.final().

decipher.update(data[, inputEncoding][, outputEncoding])#

版本历史

版本	变更
v6.0.0	The default `inputEncoding` changed from `binary` to `utf8`.
v0.1.94	新增于: v0.1.94

data <string> | <Buffer> | <TypedArray> | <DataView>
inputEncoding <string>
outputEncoding <string>

使用新数据更新解密。如果给出inputEncoding参数，它的值必须是'latin1', 'base64'或'hex'中的一个，data参数是使用指定编码的字符串。如果未给出inputEncoding参数，则data必须是Buffer。如果data是Buffer，则忽略inputEncoding。

outputEncoding指定加密数据的输出格式，可以是'latin1', 'ascii'或'utf8'。如果指定了outputEncoding，则返回使用指定编码的字符串。如果未提供outputEncoding，则返回Buffer。

可以使用新数据多次调用decipher.update()方法，直到调用decipher.final()。在decipher.final()之后调用decipher.update()会导致抛出错误。

Class: DiffieHellman#

新增于: v0.5.0

DiffieHellman类是一个用来创建Diffie-Hellman键交换的工具。 DiffieHellman类的实例可以使用crypto.createDiffieHellman()方法。

const crypto = require('crypto');
const assert = require('assert');

// Generate Alice's keys...
const alice = crypto.createDiffieHellman(2048);
const aliceKey = alice.generateKeys();

// Generate Bob's keys...
const bob = crypto.createDiffieHellman(alice.getPrime(), alice.getGenerator());
const bobKey = bob.generateKeys();

// Exchange and generate the secret...
const aliceSecret = alice.computeSecret(bobKey);
const bobSecret = bob.computeSecret(aliceKey);

// OK
assert.strictEqual(aliceSecret.toString('hex'), bobSecret.toString('hex'));

diffieHellman.computeSecret(otherPublicKey[, inputEncoding][, outputEncoding])#

新增于: v0.5.0

otherPublicKey <string> | <Buffer> | <TypedArray> | <DataView>
inputEncoding <string>
outputEncoding <string>

Computes the shared secret using otherPublicKey as the other party's public key and returns the computed shared secret. The supplied key is interpreted using the specified inputEncoding, and secret is encoded using specified outputEncoding. Encodings can be 'latin1', 'hex', or 'base64'. If the inputEncoding is not provided, otherPublicKey is expected to be a Buffer, TypedArray, or DataView.

If outputEncoding is given a string is returned; otherwise, a Buffer is returned.

diffieHellman.generateKeys([encoding])#

新增于: v0.5.0

encoding <string>

Generates private and public Diffie-Hellman key values, and returns the public key in the specified encoding. This key should be transferred to the other party. Encoding can be 'latin1', 'hex', or 'base64'. If encoding is provided a string is returned; otherwise a Buffer is returned.

diffieHellman.getGenerator([encoding])#

新增于: v0.5.0

encoding <string>

Returns the Diffie-Hellman generator in the specified encoding, which can be 'latin1', 'hex', or 'base64'. If encoding is provided a string is returned; otherwise a Buffer is returned.

diffieHellman.getPrime([encoding])#

新增于: v0.5.0

encoding <string>

Returns the Diffie-Hellman prime in the specified encoding, which can be 'latin1', 'hex', or 'base64'. If encoding is provided a string is returned; otherwise a Buffer is returned.

diffieHellman.getPrivateKey([encoding])#

新增于: v0.5.0

encoding <string>

Returns the Diffie-Hellman private key in the specified encoding, which can be 'latin1', 'hex', or 'base64'. If encoding is provided a string is returned; otherwise a Buffer is returned.

diffieHellman.getPublicKey([encoding])#

新增于: v0.5.0

encoding <string>

Returns the Diffie-Hellman public key in the specified encoding, which can be 'latin1', 'hex', or 'base64'. If encoding is provided a string is returned; otherwise a Buffer is returned.

diffieHellman.setPrivateKey(privateKey[, encoding])#

新增于: v0.5.0

privateKey <string> | <Buffer> | <TypedArray> | <DataView>
encoding <string>

Sets the Diffie-Hellman private key. If the encoding argument is provided and is either 'latin1', 'hex', or 'base64', privateKey is expected to be a string. If no encoding is provided, privateKey is expected to be a Buffer, TypedArray, or DataView.

diffieHellman.setPublicKey(publicKey[, encoding])#

新增于: v0.5.0

publicKey <string> | <Buffer> | <TypedArray> | <DataView>
encoding <string>

Sets the Diffie-Hellman public key. If the encoding argument is provided and is either 'latin1', 'hex' or 'base64', publicKey is expected to be a string. If no encoding is provided, publicKey is expected to be a Buffer, TypedArray, or DataView.

diffieHellman.verifyError#

新增于: v0.11.12

A bit field containing any warnings and/or errors resulting from a check performed during initialization of the DiffieHellman object.

The following values are valid for this property (as defined in constants module):

DH_CHECK_P_NOT_SAFE_PRIME
DH_CHECK_P_NOT_PRIME
DH_UNABLE_TO_CHECK_GENERATOR
DH_NOT_SUITABLE_GENERATOR

Class: ECDH#

新增于: v0.11.14

ECDH类是创建椭圆曲线Diffie-Hellman（Elliptic Curve Diffie-Hellman (ECDH)）键交换的实用工具。 ECDH类的实例可以使用crypto.createECDH()方法。

const crypto = require('crypto');
const assert = require('assert');

// Generate Alice's keys...
const alice = crypto.createECDH('secp521r1');
const aliceKey = alice.generateKeys();

// Generate Bob's keys...
const bob = crypto.createECDH('secp521r1');
const bobKey = bob.generateKeys();

// Exchange and generate the secret...
const aliceSecret = alice.computeSecret(bobKey);
const bobSecret = bob.computeSecret(aliceKey);

assert.strictEqual(aliceSecret.toString('hex'), bobSecret.toString('hex'));
// OK

ecdh.computeSecret(otherPublicKey[, inputEncoding][, outputEncoding])#

版本历史

版本	变更
v6.0.0	The default `inputEncoding` changed from `binary` to `utf8`.
v0.11.14	新增于: v0.11.14

otherPublicKey <string> | <Buffer> | <TypedArray> | <DataView>
inputEncoding <string>
outputEncoding <string>

Computes the shared secret using otherPublicKey as the other party's public key and returns the computed shared secret. The supplied key is interpreted using specified inputEncoding, and the returned secret is encoded using the specified outputEncoding. Encodings can be 'latin1', 'hex', or 'base64'. If the inputEncoding is not provided, otherPublicKey is expected to be a Buffer, TypedArray, or DataView.

If outputEncoding is given a string will be returned; otherwise a Buffer is returned.

ecdh.generateKeys([encoding[, format]])#

新增于: v0.11.14

encoding <string>
format <string> Defaults to uncompressed.

Generates private and public EC Diffie-Hellman key values, and returns the public key in the specified format and encoding. This key should be transferred to the other party.

The format argument specifies point encoding and can be 'compressed' or 'uncompressed'. If format is not specified, the point will be returned in 'uncompressed' format.

The encoding argument can be 'latin1', 'hex', or 'base64'. If encoding is provided a string is returned; otherwise a Buffer is returned.

ecdh.getPrivateKey([encoding])#

新增于: v0.11.14

encoding <string>

Returns the EC Diffie-Hellman private key in the specified encoding, which can be 'latin1', 'hex', or 'base64'. If encoding is provided a string is returned; otherwise a Buffer is returned.

ecdh.getPublicKey([encoding][, format])#

新增于: v0.11.14

encoding <string>
format <string> Defaults to uncompressed.

Returns the EC Diffie-Hellman public key in the specified encoding and format.

The format argument specifies point encoding and can be 'compressed' or 'uncompressed'. If format is not specified the point will be returned in 'uncompressed' format.

The encoding argument can be 'latin1', 'hex', or 'base64'. If encoding is specified, a string is returned; otherwise a Buffer is returned.

ecdh.setPrivateKey(privateKey[, encoding])#

新增于: v0.11.14

privateKey <string> | <Buffer> | <TypedArray> | <DataView>
encoding <string>

Sets the EC Diffie-Hellman private key. The encoding can be 'latin1', 'hex' or 'base64'. If encoding is provided, privateKey is expected to be a string; otherwise privateKey is expected to be a Buffer, TypedArray, or DataView.

If privateKey is not valid for the curve specified when the ECDH object was created, an error is thrown. Upon setting the private key, the associated public point (key) is also generated and set in the ECDH object.

ecdh.setPublicKey(publicKey[, encoding])#

新增于: v0.11.14废弃于: v5.2.0

Stability: 0 - Deprecated

publicKey <string> | <Buffer> | <TypedArray> | <DataView>
encoding <string>

Sets the EC Diffie-Hellman public key. Key encoding can be 'latin1', 'hex' or 'base64'. If encoding is provided publicKey is expected to be a string; otherwise a Buffer, TypedArray, or DataView is expected.

Note that there is not normally a reason to call this method because ECDH only requires a private key and the other party's public key to compute the shared secret. Typically either ecdh.generateKeys() or ecdh.setPrivateKey() will be called. The ecdh.setPrivateKey() method attempts to generate the public point/key associated with the private key being set.

Example (obtaining a shared secret):

const crypto = require('crypto');
const alice = crypto.createECDH('secp256k1');
const bob = crypto.createECDH('secp256k1');

// Note: This is a shortcut way to specify one of Alice's previous private
// keys. It would be unwise to use such a predictable private key in a real
// application.
alice.setPrivateKey(
  crypto.createHash('sha256').update('alice', 'utf8').digest()
);

// Bob uses a newly generated cryptographically strong
// pseudorandom key pair
bob.generateKeys();

const aliceSecret = alice.computeSecret(bob.getPublicKey(), null, 'hex');
const bobSecret = bob.computeSecret(alice.getPublicKey(), null, 'hex');

// aliceSecret and bobSecret should be the same shared secret value
console.log(aliceSecret === bobSecret);

Class: Hash#

新增于: v0.1.92

Hash类是用于创建数据哈希值的工具类。它能用以下方法使用：

作为一个stream，它既可读又可写，数据被写入要在可读的方面生成一个计算散列摘要
使用hash.update()和hash.digest()方法产生计算后的哈希。

crypto.createHash()方法用于创建Hash实例。Hash不能直接使用new关键字创建对象。

示例: 使用Hash对象作为流:

const crypto = require('crypto');
const hash = crypto.createHash('sha256');

hash.on('readable', () => {
  const data = hash.read();
  if (data) {
    console.log(data.toString('hex'));
    // Prints:
    //   6a2da20943931e9834fc12cfe5bb47bbd9ae43489a30726962b576f4e3993e50
  }
});

hash.write('some data to hash');
hash.end();

示例:使用 Hash 和管道流

const crypto = require('crypto');
const fs = require('fs');
const hash = crypto.createHash('sha256');

const input = fs.createReadStream('test.js');
input.pipe(hash).pipe(process.stdout);

示例:使用hash.update()和hash.digest()

const crypto = require('crypto');
const hash = crypto.createHash('sha256');

hash.update('some data to hash');
console.log(hash.digest('hex'));
// Prints:
//   6a2da20943931e9834fc12cfe5bb47bbd9ae43489a30726962b576f4e3993e50

hash.digest([encoding])#

新增于: v0.1.92

encoding <string>

Calculates the digest of all of the data passed to be hashed (using the hash.update() method). The encoding can be 'hex', 'latin1' or 'base64'. If encoding is provided a string will be returned; otherwise a Buffer is returned.

The Hash object can not be used again after hash.digest() method has been called. Multiple calls will cause an error to be thrown.

hash.update(data[, inputEncoding])#

版本历史

版本	变更
v6.0.0	The default `inputEncoding` changed from `binary` to `utf8`.
v0.1.92	新增于: v0.1.92

data <string> | <Buffer> | <TypedArray> | <DataView>
inputEncoding <string>

Updates the hash content with the given data, the encoding of which is given in inputEncoding and can be 'utf8', 'ascii' or 'latin1'. If encoding is not provided, and the data is a string, an encoding of 'utf8' is enforced. If data is a Buffer, TypedArray, or DataView, then inputEncoding is ignored.

This can be called many times with new data as it is streamed.

Class: Hmac#

新增于: v0.1.94

Hmac类是用于创建加密Hmac摘要的工具。它可以有两种用法:

作为stream,它既可读又可写，数据被写入要在可读的方面生成一个经过计算的HMAC摘要。
使用hmac.update()和hmac.digest()方法产生计算后的HMAC摘要。

crypto.createHmac()方法用来创建Hmac实例。Hmac不能直接使用new关键字创建对象。

示例:使用Hmac对象作为流:

const crypto = require('crypto');
const hmac = crypto.createHmac('sha256', 'a secret');

hmac.on('readable', () => {
  const data = hmac.read();
  if (data) {
    console.log(data.toString('hex'));
    // Prints:
    //   7fd04df92f636fd450bc841c9418e5825c17f33ad9c87c518115a45971f7f77e
  }
});

hmac.write('some data to hash');
hmac.end();

示例：使用Hmac和管道流

const crypto = require('crypto');
const fs = require('fs');
const hmac = crypto.createHmac('sha256', 'a secret');

const input = fs.createReadStream('test.js');
input.pipe(hmac).pipe(process.stdout);

示例：使用hmac.update()和hmac.digest()方法

const crypto = require('crypto');
const hmac = crypto.createHmac('sha256', 'a secret');

hmac.update('some data to hash');
console.log(hmac.digest('hex'));
// Prints:
//   7fd04df92f636fd450bc841c9418e5825c17f33ad9c87c518115a45971f7f77e

hmac.digest([encoding])#

新增于: v0.1.94

encoding <string>

Calculates the HMAC digest of all of the data passed using hmac.update(). The encoding can be 'hex', 'latin1' or 'base64'. If encoding is provided a string is returned; otherwise a Buffer is returned;

The Hmac object can not be used again after hmac.digest() has been called. Multiple calls to hmac.digest() will result in an error being thrown.

hmac.update(data[, inputEncoding])#

版本历史

版本	变更
v6.0.0	The default `inputEncoding` changed from `binary` to `utf8`.
v0.1.94	新增于: v0.1.94

data <string> | <Buffer> | <TypedArray> | <DataView>
inputEncoding <string>

Updates the Hmac content with the given data, the encoding of which is given in inputEncoding and can be 'utf8', 'ascii' or 'latin1'. If encoding is not provided, and the data is a string, an encoding of 'utf8' is enforced. If data is a Buffer, TypedArray, or DataView, then inputEncoding is ignored.

This can be called many times with new data as it is streamed.

Class: Sign#

新增于: v0.1.92

“Sign”类是生成签名的实用工具。它有两种使用方式:

作为一个可写的stream，在这里，要签署的数据是写出来的，sign.sign()方法用于生成并返回签名
使用sign.update()和sign.sign()方法生产签名。

crypto.createSign()方法用于创建Sign实例。Sign实例不能直接使用new关键字创建。

示例:使用“符号”对象作为流:

const crypto = require('crypto');
const sign = crypto.createSign('SHA256');

sign.write('some data to sign');
sign.end();

const privateKey = getPrivateKeySomehow();
console.log(sign.sign(privateKey, 'hex'));
// Prints: the calculated signature using the specified private key and
// SHA-256. For RSA keys, the algorithm is RSASSA-PKCS1-v1_5 (see padding
// parameter below for RSASSA-PSS). For EC keys, the algorithm is ECDSA.

示例：使用sign.update()和sign.sign()方法：

const crypto = require('crypto');
const sign = crypto.createSign('SHA256');

sign.update('some data to sign');

const privateKey = getPrivateKeySomehow();
console.log(sign.sign(privateKey, 'hex'));
// Prints: the calculated signature

一个Sign实例也可以通过仅仅通过摘要来创建算法名称，在这种情况下，OpenSSL将会从PEM-formatted私钥的类型推断出完整的签名算法，包括不直接暴露姓名常数的算法。比如'ecdsa-with-SHA256'。

示例:使用ECDSA与SHA256进行签名

const crypto = require('crypto');
const sign = crypto.createSign('RSA-SHA256');

sign.update('some data to sign');

const privateKey = getPrivateKeySomehow();
console.log(sign.sign(privateKey, 'hex'));
// Prints: the calculated signature

sign.sign(privateKey[, outputFormat])#

版本历史

版本	变更
v8.0.0	Support for RSASSA-PSS and additional options was added.
v0.1.92	新增于: v0.1.92

privateKey <string> | <Object>
- key <string>
- passphrase <string>
outputFormat <string>

Calculates the signature on all the data passed through using either sign.update() or sign.write().

The privateKey argument can be an object or a string. If privateKey is a string, it is treated as a raw key with no passphrase. If privateKey is an object, it must contain one or more of the following properties:

key: <string> - PEM encoded private key (required)
passphrase: <string> - passphrase for the private key
padding: <integer> - Optional padding value for RSA, one of the following:
- crypto.constants.RSA_PKCS1_PADDING (default)
- crypto.constants.RSA_PKCS1_PSS_PADDING
Note that RSA_PKCS1_PSS_PADDING will use MGF1 with the same hash function used to sign the message as specified in section 3.1 of RFC 4055.
saltLength: <integer> - salt length for when padding is RSA_PKCS1_PSS_PADDING. The special value crypto.constants.RSA_PSS_SALTLEN_DIGEST sets the salt length to the digest size, crypto.constants.RSA_PSS_SALTLEN_MAX_SIGN (default) sets it to the maximum permissible value.

The outputFormat can specify one of 'latin1', 'hex' or 'base64'. If outputFormat is provided a string is returned; otherwise a Buffer is returned.

The Sign object can not be again used after sign.sign() method has been called. Multiple calls to sign.sign() will result in an error being thrown.

sign.update(data[, inputEncoding])#

版本历史

版本	变更
v6.0.0	The default `inputEncoding` changed from `binary` to `utf8`.
v0.1.92	新增于: v0.1.92

data <string> | <Buffer> | <TypedArray> | <DataView>
inputEncoding <string>

Updates the Sign content with the given data, the encoding of which is given in inputEncoding and can be 'utf8', 'ascii' or 'latin1'. If encoding is not provided, and the data is a string, an encoding of 'utf8' is enforced. If data is a Buffer, TypedArray, or DataView, then inputEncoding is ignored.

This can be called many times with new data as it is streamed.

Class: Verify#

新增于: v0.1.92

Verify类是验证签名的工具。它可以两种方式使用:

作为可写的stream，使用书面数据来验证提供的签名
使用verify.update()和verify.verify()的方法来验证签名。

crypto.createVerify()方法用于创建Verify实例。 Verify对象不能直接使用new关键字创建。

示例:使用“验证”对象作为流:

const crypto = require('crypto');
const verify = crypto.createVerify('SHA256');

verify.write('some data to sign');
verify.end();

const publicKey = getPublicKeySomehow();
const signature = getSignatureToVerify();
console.log(verify.verify(publicKey, signature));
// Prints: true or false

示例：使用verify.update()和verify.verify()方法

const crypto = require('crypto');
const verify = crypto.createVerify('SHA256');

verify.update('some data to sign');

const publicKey = getPublicKeySomehow();
const signature = getSignatureToVerify();
console.log(verify.verify(publicKey, signature));
// Prints: true or false

verify.update(data[, inputEncoding])#

版本历史

版本	变更
v6.0.0	The default `inputEncoding` changed from `binary` to `utf8`.
v0.1.92	新增于: v0.1.92

data <string> | <Buffer> | <TypedArray> | <DataView>
inputEncoding <string>

Updates the Verify content with the given data, the encoding of which is given in inputEncoding and can be 'utf8', 'ascii' or 'latin1'. If encoding is not provided, and the data is a string, an encoding of 'utf8' is enforced. If data is a Buffer, TypedArray, or DataView, then inputEncoding is ignored.

This can be called many times with new data as it is streamed.

verify.verify(object, signature[, signatureFormat])#

版本历史

版本	变更
v8.0.0	Support for RSASSA-PSS and additional options was added.
v0.1.92	新增于: v0.1.92

object <string> | <Object>
signature <string> | <Buffer> | <TypedArray> | <DataView>
signatureFormat <string>

Verifies the provided data using the given object and signature. The object argument can be either a string containing a PEM encoded object, which can be an RSA public key, a DSA public key, or an X.509 certificate, or an object with one or more of the following properties:

key: <string> - PEM encoded public key (required)
padding: <integer> - Optional padding value for RSA, one of the following:
- crypto.constants.RSA_PKCS1_PADDING (default)
- crypto.constants.RSA_PKCS1_PSS_PADDING
Note that RSA_PKCS1_PSS_PADDING will use MGF1 with the same hash function used to verify the message as specified in section 3.1 of RFC 4055.
saltLength: <integer> - salt length for when padding is RSA_PKCS1_PSS_PADDING. The special value crypto.constants.RSA_PSS_SALTLEN_DIGEST sets the salt length to the digest size, crypto.constants.RSA_PSS_SALTLEN_AUTO (default) causes it to be determined automatically.

The signature argument is the previously calculated signature for the data, in the signatureFormat which can be 'latin1', 'hex' or 'base64'. If a signatureFormat is specified, the signature is expected to be a string; otherwise signature is expected to be a Buffer, TypedArray, or DataView.

Returns true or false depending on the validity of the signature for the data and public key.

The verify object can not be used again after verify.verify() has been called. Multiple calls to verify.verify() will result in an error being thrown.

`crypto` module methods and properties#

crypto.constants#

新增于: v6.3.0

Returns an object containing commonly used constants for crypto and security related operations. The specific constants currently defined are described in Crypto Constants.

crypto.DEFAULT_ENCODING#

新增于: v0.9.3

The default encoding to use for functions that can take either strings or buffers. The default value is 'buffer', which makes methods default to Buffer objects.

The crypto.DEFAULT_ENCODING mechanism is provided for backwards compatibility with legacy programs that expect 'latin1' to be the default encoding.

New applications should expect the default to be 'buffer'. This property may become deprecated in a future Node.js release.

crypto.fips#

新增于: v6.0.0

Property for checking and controlling whether a FIPS compliant crypto provider is currently in use. Setting to true requires a FIPS build of Node.js.

crypto.createCipher(algorithm, password[, options])#

新增于: v0.1.94

algorithm <string>
password <string> | <Buffer> | <TypedArray> | <DataView>
options <Object> stream.transform options

Creates and returns a Cipher object that uses the given algorithm and password. Optional options argument controls stream behavior.

The algorithm is dependent on OpenSSL, examples are 'aes192', etc. On recent OpenSSL releases, openssl list-cipher-algorithms will display the available cipher algorithms.

The password is used to derive the cipher key and initialization vector (IV). The value must be either a 'latin1' encoded string, a Buffer, a TypedArray, or a DataView.

The implementation of crypto.createCipher() derives keys using the OpenSSL function EVP_BytesToKey with the digest algorithm set to MD5, one iteration, and no salt. The lack of salt allows dictionary attacks as the same password always creates the same key. The low iteration count and non-cryptographically secure hash algorithm allow passwords to be tested very rapidly.

In line with OpenSSL's recommendation to use PBKDF2 instead of EVP_BytesToKey it is recommended that developers derive a key and IV on their own using crypto.pbkdf2() and to use crypto.createCipheriv() to create the Cipher object. Users should not use ciphers with counter mode (e.g. CTR, GCM, or CCM) in crypto.createCipher(). A warning is emitted when they are used in order to avoid the risk of IV reuse that causes vulnerabilities. For the case when IV is reused in GCM, see Nonce-Disrespecting Adversaries for details.

crypto.createCipheriv(algorithm, key, iv[, options])#

algorithm <string>
key <string> | <Buffer> | <TypedArray> | <DataView>
iv <string> | <Buffer> | <TypedArray> | <DataView>
options <Object> stream.transform options

Creates and returns a Cipher object, with the given algorithm, key and initialization vector (iv). Optional options argument controls stream behavior.

The algorithm is dependent on OpenSSL, examples are 'aes192', etc. On recent OpenSSL releases, openssl list-cipher-algorithms will display the available cipher algorithms.

The key is the raw key used by the algorithm and iv is an initialization vector. Both arguments must be 'utf8' encoded strings, Buffers, TypedArray, or DataViews.

crypto.createCredentials(details)#

新增于: v0.1.92废弃于: v0.11.13

Stability: 0 - Deprecated: Use tls.createSecureContext() instead.

details <Object> Identical to tls.createSecureContext().

The crypto.createCredentials() method is a deprecated function for creating and returning a tls.SecureContext. It should not be used. Replace it with tls.createSecureContext() which has the exact same arguments and return value.

Returns a tls.SecureContext, as-if tls.createSecureContext() had been called.

crypto.createDecipher(algorithm, password[, options])#

新增于: v0.1.94

algorithm <string>
password <string> | <Buffer> | <TypedArray> | <DataView>
options <Object> stream.transform options

Creates and returns a Decipher object that uses the given algorithm and password (key). Optional options argument controls stream behavior.

The implementation of crypto.createDecipher() derives keys using the OpenSSL function EVP_BytesToKey with the digest algorithm set to MD5, one iteration, and no salt. The lack of salt allows dictionary attacks as the same password always creates the same key. The low iteration count and non-cryptographically secure hash algorithm allow passwords to be tested very rapidly.

crypto.createDecipheriv(algorithm, key, iv[, options])#

新增于: v0.1.94

algorithm <string>
key <string> | <Buffer> | <TypedArray> | <DataView>
iv <string> | <Buffer> | <TypedArray> | <DataView>
options <Object> stream.transform options

Creates and returns a Decipher object that uses the given algorithm, key and initialization vector (iv). Optional options argument controls stream behavior.

The algorithm is dependent on OpenSSL, examples are 'aes192', etc. On recent OpenSSL releases, openssl list-cipher-algorithms will display the available cipher algorithms.

The key is the raw key used by the algorithm and iv is an initialization vector. Both arguments must be 'utf8' encoded strings or buffers.

crypto.createDiffieHellman(prime[, primeEncoding][, generator][, generatorEncoding])#

版本历史

版本	变更
v8.0.0	The `prime` argument can be any `TypedArray` or `DataView` now.
v8.0.0	The `prime` argument can be a `Uint8Array` now.
v6.0.0	The default for the encoding parameters changed from `binary` to `utf8`.
v0.11.12	新增于: v0.11.12

prime <string> | <Buffer> | <TypedArray> | <DataView>
primeEncoding <string>
generator <number> | <string> | <Buffer> | <TypedArray> | <DataView> Defaults to 2.
generatorEncoding <string>

Creates a DiffieHellman key exchange object using the supplied prime and an optional specific generator.

The generator argument can be a number, string, or Buffer. If generator is not specified, the value 2 is used.

The primeEncoding and generatorEncoding arguments can be 'latin1', 'hex', or 'base64'.

If primeEncoding is specified, prime is expected to be a string; otherwise a Buffer, TypedArray, or DataView is expected.

If generatorEncoding is specified, generator is expected to be a string; otherwise a number, Buffer, TypedArray, or DataView is expected.

crypto.createDiffieHellman(primeLength[, generator])#

新增于: v0.5.0

primeLength <number>
generator <number> | <string> | <Buffer> | <TypedArray> | <DataView> Defaults to 2.

Creates a DiffieHellman key exchange object and generates a prime of primeLength bits using an optional specific numeric generator. If generator is not specified, the value 2 is used.

crypto.createECDH(curveName)#

新增于: v0.11.14

curveName <string>

Creates an Elliptic Curve Diffie-Hellman (ECDH) key exchange object using a predefined curve specified by the curveName string. Use crypto.getCurves() to obtain a list of available curve names. On recent OpenSSL releases, openssl ecparam -list_curves will also display the name and description of each available elliptic curve.

crypto.createHash(algorithm[, options])#

新增于: v0.1.92

algorithm <string>
options <Object> stream.transform options

Creates and returns a Hash object that can be used to generate hash digests using the given algorithm. Optional options argument controls stream behavior.

The algorithm is dependent on the available algorithms supported by the version of OpenSSL on the platform. Examples are 'sha256', 'sha512', etc. On recent releases of OpenSSL, openssl list-message-digest-algorithms will display the available digest algorithms.

Example: generating the sha256 sum of a file

const filename = process.argv[2];
const crypto = require('crypto');
const fs = require('fs');

const hash = crypto.createHash('sha256');

const input = fs.createReadStream(filename);
input.on('readable', () => {
  const data = input.read();
  if (data)
    hash.update(data);
  else {
    console.log(`${hash.digest('hex')} ${filename}`);
  }
});

crypto.createHmac(algorithm, key[, options])#

新增于: v0.1.94

algorithm <string>
key <string> | <Buffer> | <TypedArray> | <DataView>
options <Object> stream.transform options

Creates and returns an Hmac object that uses the given algorithm and key. Optional options argument controls stream behavior.

The key is the HMAC key used to generate the cryptographic HMAC hash.

Example: generating the sha256 HMAC of a file

const filename = process.argv[2];
const crypto = require('crypto');
const fs = require('fs');

const hmac = crypto.createHmac('sha256', 'a secret');

const input = fs.createReadStream(filename);
input.on('readable', () => {
  const data = input.read();
  if (data)
    hmac.update(data);
  else {
    console.log(`${hmac.digest('hex')} ${filename}`);
  }
});

crypto.createSign(algorithm[, options])#

新增于: v0.1.92

algorithm <string>
options <Object> stream.Writable options

Creates and returns a Sign object that uses the given algorithm. Use crypto.getHashes() to obtain an array of names of the available signing algorithms. Optional options argument controls the stream.Writable behavior.

crypto.createVerify(algorithm[, options])#

新增于: v0.1.92

algorithm <string>
options <Object> stream.Writable options

Creates and returns a Verify object that uses the given algorithm. Use crypto.getHashes() to obtain an array of names of the available signing algorithms. Optional options argument controls the stream.Writable behavior.

crypto.getCiphers()#

新增于: v0.9.3

Returns an array with the names of the supported cipher algorithms.

Example:

const ciphers = crypto.getCiphers();
console.log(ciphers); // ['aes-128-cbc', 'aes-128-ccm', ...]

crypto.getCurves()#

新增于: v2.3.0

Returns an array with the names of the supported elliptic curves.

Example:

const curves = crypto.getCurves();
console.log(curves); // ['Oakley-EC2N-3', 'Oakley-EC2N-4', ...]

crypto.getDiffieHellman(groupName)#

新增于: v0.7.5

groupName <string>

Creates a predefined DiffieHellman key exchange object. The supported groups are: 'modp1', 'modp2', 'modp5' (defined in RFC 2412, but see Caveats) and 'modp14', 'modp15', 'modp16', 'modp17', 'modp18' (defined in RFC 3526). The returned object mimics the interface of objects created by crypto.createDiffieHellman(), but will not allow changing the keys (with diffieHellman.setPublicKey() for example). The advantage of using this method is that the parties do not have to generate nor exchange a group modulus beforehand, saving both processor and communication time.

Example (obtaining a shared secret):

const crypto = require('crypto');
const alice = crypto.getDiffieHellman('modp14');
const bob = crypto.getDiffieHellman('modp14');

alice.generateKeys();
bob.generateKeys();

const aliceSecret = alice.computeSecret(bob.getPublicKey(), null, 'hex');
const bobSecret = bob.computeSecret(alice.getPublicKey(), null, 'hex');

/* aliceSecret and bobSecret should be the same */
console.log(aliceSecret === bobSecret);

crypto.getHashes()#

新增于: v0.9.3

Returns an array of the names of the supported hash algorithms, such as RSA-SHA256.

Example:

const hashes = crypto.getHashes();
console.log(hashes); // ['DSA', 'DSA-SHA', 'DSA-SHA1', ...]

crypto.pbkdf2(password, salt, iterations, keylen, digest, callback)#

版本历史

版本	变更
v8.0.0	The `digest` parameter is always required now.
v6.0.0	Calling this function without passing the `digest` parameter is deprecated now and will emit a warning.
v6.0.0	The default encoding for `password` if it is a string changed from `binary` to `utf8`.
v0.5.5	新增于: v0.5.5

password <string>
salt <string>
iterations <number>
keylen <number>
digest <string>
callback <Function>
- err <Error>
- derivedKey <Buffer>

Provides an asynchronous Password-Based Key Derivation Function 2 (PBKDF2) implementation. A selected HMAC digest algorithm specified by digest is applied to derive a key of the requested byte length (keylen) from the password, salt and iterations.

The supplied callback function is called with two arguments: err and derivedKey. If an error occurs, err will be set; otherwise err will be null. The successfully generated derivedKey will be passed as a Buffer.

The iterations argument must be a number set as high as possible. The higher the number of iterations, the more secure the derived key will be, but will take a longer amount of time to complete.

The salt should also be as unique as possible. It is recommended that the salts are random and their lengths are at least 16 bytes. See NIST SP 800-132 for details.

Example:

const crypto = require('crypto');
crypto.pbkdf2('secret', 'salt', 100000, 64, 'sha512', (err, derivedKey) => {
  if (err) throw err;
  console.log(derivedKey.toString('hex'));  // '3745e48...08d59ae'
});

An array of supported digest functions can be retrieved using crypto.getHashes().

Note that this API uses libuv's threadpool, which can have surprising and negative performance implications for some applications, see the UV_THREADPOOL_SIZE documentation for more information.

crypto.pbkdf2Sync(password, salt, iterations, keylen, digest)#

版本历史

版本	变更
v6.0.0	Calling this function without passing the `digest` parameter is deprecated now and will emit a warning.
v6.0.0	The default encoding for `password` if it is a string changed from `binary` to `utf8`.
v0.9.3	新增于: v0.9.3

password <string>
salt <string>
iterations <number>
keylen <number>
digest <string>

Provides a synchronous Password-Based Key Derivation Function 2 (PBKDF2) implementation. A selected HMAC digest algorithm specified by digest is applied to derive a key of the requested byte length (keylen) from the password, salt and iterations.

If an error occurs an Error will be thrown, otherwise the derived key will be returned as a Buffer.

The iterations argument must be a number set as high as possible. The higher the number of iterations, the more secure the derived key will be, but will take a longer amount of time to complete.

The salt should also be as unique as possible. It is recommended that the salts are random and their lengths are at least 16 bytes. See NIST SP 800-132 for details.

Example:

const crypto = require('crypto');
const key = crypto.pbkdf2Sync('secret', 'salt', 100000, 64, 'sha512');
console.log(key.toString('hex'));  // '3745e48...08d59ae'

An array of supported digest functions can be retrieved using crypto.getHashes().

crypto.privateDecrypt(privateKey, buffer)#

新增于: v0.11.14

privateKey <Object> | <string>
- key <string> A PEM encoded private key.
- passphrase <string> An optional passphrase for the private key.
- padding <crypto.constants> An optional padding value defined in crypto.constants, which may be: crypto.constants.RSA_NO_PADDING, RSA_PKCS1_PADDING, or crypto.constants.RSA_PKCS1_OAEP_PADDING.
buffer <Buffer> | <TypedArray> | <DataView>
Returns: <Buffer> A new Buffer with the decrypted content.

Decrypts buffer with privateKey.

privateKey can be an object or a string. If privateKey is a string, it is treated as the key with no passphrase and will use RSA_PKCS1_OAEP_PADDING.

crypto.privateEncrypt(privateKey, buffer)#

新增于: v1.1.0

privateKey <Object> | <string>
- key <string> A PEM encoded private key.
- passphrase <string> An optional passphrase for the private key.
- padding <crypto.constants> An optional padding value defined in crypto.constants, which may be: crypto.constants.RSA_NO_PADDING or RSA_PKCS1_PADDING.
buffer <Buffer> | <TypedArray> | <DataView>
Returns: <Buffer> A new Buffer with the encrypted content.

Encrypts buffer with privateKey.

privateKey can be an object or a string. If privateKey is a string, it is treated as the key with no passphrase and will use RSA_PKCS1_PADDING.

crypto.publicDecrypt(key, buffer)#

新增于: v1.1.0

key <Object> | <string>
- key <string> A PEM encoded public or private key.
- passphrase <string> An optional passphrase for the private key.
- padding <crypto.constants> An optional padding value defined in crypto.constants, which may be: crypto.constants.RSA_NO_PADDING or RSA_PKCS1_PADDING.
buffer <Buffer> | <TypedArray> | <DataView>
Returns: <Buffer> A new Buffer with the decrypted content.

Decrypts buffer with key.

key can be an object or a string. If key is a string, it is treated as the key with no passphrase and will use RSA_PKCS1_PADDING.

Because RSA public keys can be derived from private keys, a private key may be passed instead of a public key.

crypto.publicEncrypt(key, buffer)#

新增于: v0.11.14

key <Object> | <string>
- key <string> A PEM encoded public or private key.
- passphrase <string> An optional passphrase for the private key.
- padding <crypto.constants> An optional padding value defined in crypto.constants, which may be: crypto.constants.RSA_NO_PADDING, RSA_PKCS1_PADDING, or crypto.constants.RSA_PKCS1_OAEP_PADDING.
buffer <Buffer> | <TypedArray> | <DataView>
Returns: <Buffer> A new Buffer with the encrypted content.

Encrypts the content of buffer with key and returns a new Buffer with encrypted content.

key can be an object or a string. If key is a string, it is treated as the key with no passphrase and will use RSA_PKCS1_OAEP_PADDING.

Because RSA public keys can be derived from private keys, a private key may be passed instead of a public key.

crypto.randomBytes(size[, callback])#

新增于: v0.5.8

size <number>
callback <Function>
- err <Error>
- buf <Buffer>

生成加密强伪随机数据. size参数是指示要生成的字节数的数值。

如果提供 callback回调函数 ,这些字节是异步生成的并且使用两个参数调用callback函数：err和buf。如果发生错误, err是一个Error对象；否则为null。buf参数是包含生成字节的Buffer。

// Asynchronous
const crypto = require('crypto');
crypto.randomBytes(256, (err, buf) => {
  if (err) throw err;
  console.log(`${buf.length} bytes of random data: ${buf.toString('hex')}`);
});

如果未提供 callback回调函数, 则同步地生成随机字节并返回为Buffer。如果生成字节遇到问题，将会抛出一个错误。

// Synchronous
const buf = crypto.randomBytes(256);
console.log(
  `${buf.length} bytes of random data: ${buf.toString('hex')}`);

crypto.randomBytes()方法将在获得足够的熵之后完成。这通常不会超过几毫秒。只有在刚开机时才可能会阻塞更久，因为此时整个系统的熵不多。

注意这个API使用libuv的线程池，所以在某些时候可能会产生意外的性能问题，查看UV_THREADPOOL_SIZE的文档以了解更多信息。

Note: The asynchronous version of crypto.randomBytes() is carried out in a single threadpool request. To minimize threadpool task length variation, partition large randomBytes requests when doing so as part of fulfilling a client request.

crypto.randomFillSync(buffer[, offset][, size])#

新增于: v7.10.0

buffer <Buffer> | <Uint8Array> Must be supplied.
offset <number> Defaults to 0.
size <number> Defaults to buffer.length - offset.

Synchronous version of crypto.randomFill().

Returns buffer

const buf = Buffer.alloc(10);
console.log(crypto.randomFillSync(buf).toString('hex'));

crypto.randomFillSync(buf, 5);
console.log(buf.toString('hex'));

// The above is equivalent to the following:
crypto.randomFillSync(buf, 5, 5);
console.log(buf.toString('hex'));

crypto.randomFill(buffer[, offset][, size], callback)#

新增于: v7.10.0

buffer <Buffer> | <Uint8Array>必须被支持.
offset <number> Defaults to 0.
size <number> Defaults to buffer.length - offset.
callback <Function> function(err, buf) {}.

This function is similar to crypto.randomBytes() but requires the first argument to be a Buffer that will be filled. It also requires that a callback is passed in.

If the callback function is not provided, an error will be thrown.

const buf = Buffer.alloc(10);
crypto.randomFill(buf, (err, buf) => {
  if (err) throw err;
  console.log(buf.toString('hex'));
});

crypto.randomFill(buf, 5, (err, buf) => {
  if (err) throw err;
  console.log(buf.toString('hex'));
});

// The above is equivalent to the following:
crypto.randomFill(buf, 5, 5, (err, buf) => {
  if (err) throw err;
  console.log(buf.toString('hex'));
});

Note that this API uses libuv's threadpool, which can have surprising and negative performance implications for some applications, see the UV_THREADPOOL_SIZE documentation for more information.

Note: The asynchronous version of crypto.randomFill() is carried out in a single threadpool request. To minimize threadpool task length variation, partition large randomFill requests when doing so as part of fulfilling a client request.

crypto.setEngine(engine[, flags])#

新增于: v0.11.11

engine <string>
flags <crypto.constants> Defaults to crypto.constants.ENGINE_METHOD_ALL.

Load and set the engine for some or all OpenSSL functions (selected by flags).

engine could be either an id or a path to the engine's shared library.

The optional flags argument uses ENGINE_METHOD_ALL by default. The flags is a bit field taking one of or a mix of the following flags (defined in crypto.constants):

crypto.constants.ENGINE_METHOD_RSA
crypto.constants.ENGINE_METHOD_DSA
crypto.constants.ENGINE_METHOD_DH
crypto.constants.ENGINE_METHOD_RAND
crypto.constants.ENGINE_METHOD_ECDH
crypto.constants.ENGINE_METHOD_ECDSA
crypto.constants.ENGINE_METHOD_CIPHERS
crypto.constants.ENGINE_METHOD_DIGESTS
crypto.constants.ENGINE_METHOD_STORE
crypto.constants.ENGINE_METHOD_PKEY_METHS
crypto.constants.ENGINE_METHOD_PKEY_ASN1_METHS
crypto.constants.ENGINE_METHOD_ALL
crypto.constants.ENGINE_METHOD_NONE

crypto.timingSafeEqual(a, b)#

新增于: v6.6.0

a <Buffer> | <TypedArray> | <DataView>
b <Buffer> | <TypedArray> | <DataView>

This function is based on a constant-time algorithm. Returns true if a is equal to b, without leaking timing information that would allow an attacker to guess one of the values. This is suitable for comparing HMAC digests or secret values like authentication cookies or capability urls.

a and b must both be Buffers, TypedArrays, or DataViews, and they must have the same length.

Note: Use of crypto.timingSafeEqual does not guarantee that the surrounding code is timing-safe. Care should be taken to ensure that the surrounding code does not introduce timing vulnerabilities.

Notes#

Legacy Streams API (pre Node.js v0.10)#

The Crypto module was added to Node.js before there was the concept of a unified Stream API, and before there were Buffer objects for handling binary data. As such, the many of the crypto defined classes have methods not typically found on other Node.js classes that implement the streams API (e.g. update(), final(), or digest()). Also, many methods accepted and returned 'latin1' encoded strings by default rather than Buffers. This default was changed after Node.js v0.8 to use Buffer objects by default instead.

Recent ECDH Changes#

Usage of ECDH with non-dynamically generated key pairs has been simplified. Now, ecdh.setPrivateKey() can be called with a preselected private key and the associated public point (key) will be computed and stored in the object. This allows code to only store and provide the private part of the EC key pair. ecdh.setPrivateKey() now also validates that the private key is valid for the selected curve.

The ecdh.setPublicKey() method is now deprecated as its inclusion in the API is not useful. Either a previously stored private key should be set, which automatically generates the associated public key, or ecdh.generateKeys() should be called. The main drawback of using ecdh.setPublicKey() is that it can be used to put the ECDH key pair into an inconsistent state.

Support for weak or compromised algorithms#

The crypto module still supports some algorithms which are already compromised and are not currently recommended for use. The API also allows the use of ciphers and hashes with a small key size that are considered to be too weak for safe use.

Users should take full responsibility for selecting the crypto algorithm and key size according to their security requirements.

Based on the recommendations of NIST SP 800-131A:

MD5 and SHA-1 are no longer acceptable where collision resistance is required such as digital signatures.
The key used with RSA, DSA, and DH algorithms is recommended to have at least 2048 bits and that of the curve of ECDSA and ECDH at least 224 bits, to be safe to use for several years.
The DH groups of modp1, modp2 and modp5 have a key size smaller than 2048 bits and are not recommended.

See the reference for other recommendations and details.

Crypto Constants#

The following constants exported by crypto.constants apply to various uses of the crypto, tls, and https modules and are generally specific to OpenSSL.

OpenSSL Options#

Constant	Description
`SSL_OP_ALL`	Applies multiple bug workarounds within OpenSSL. See https://www.openssl.org/docs/man1.0.2/ssl/SSL_CTX_set_options.html for detail.
`SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION`	Allows legacy insecure renegotiation between OpenSSL and unpatched clients or servers. See https://www.openssl.org/docs/man1.0.2/ssl/SSL_CTX_set_options.html.
`SSL_OP_CIPHER_SERVER_PREFERENCE`	Attempts to use the server's preferences instead of the client's when selecting a cipher. Behavior depends on protocol version. See https://www.openssl.org/docs/man1.0.2/ssl/SSL_CTX_set_options.html.
`SSL_OP_CISCO_ANYCONNECT`	Instructs OpenSSL to use Cisco's "speshul" version of DTLS_BAD_VER.
`SSL_OP_COOKIE_EXCHANGE`	Instructs OpenSSL to turn on cookie exchange.
`SSL_OP_CRYPTOPRO_TLSEXT_BUG`	Instructs OpenSSL to add server-hello extension from an early version of the cryptopro draft.
`SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS`	Instructs OpenSSL to disable a SSL 3.0/TLS 1.0 vulnerability workaround added in OpenSSL 0.9.6d.
`SSL_OP_EPHEMERAL_RSA`	Instructs OpenSSL to always use the tmp_rsa key when performing RSA operations.
`SSL_OP_LEGACY_SERVER_CONNECT`	Allows initial connection to servers that do not support RI.
`SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER`
`SSL_OP_MICROSOFT_SESS_ID_BUG`
`SSL_OP_MSIE_SSLV2_RSA_PADDING`	Instructs OpenSSL to disable the workaround for a man-in-the-middle protocol-version vulnerability in the SSL 2.0 server implementation.
`SSL_OP_NETSCAPE_CA_DN_BUG`
`SSL_OP_NETSCAPE_CHALLENGE_BUG`
`SSL_OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG`
`SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG`
`SSL_OP_NO_COMPRESSION`	Instructs OpenSSL to disable support for SSL/TLS compression.
`SSL_OP_NO_QUERY_MTU`
`SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION`	Instructs OpenSSL to always start a new session when performing renegotiation.
`SSL_OP_NO_SSLv2`	Instructs OpenSSL to turn off SSL v2
`SSL_OP_NO_SSLv3`	Instructs OpenSSL to turn off SSL v3
`SSL_OP_NO_TICKET`	Instructs OpenSSL to disable use of RFC4507bis tickets.
`SSL_OP_NO_TLSv1`	Instructs OpenSSL to turn off TLS v1
`SSL_OP_NO_TLSv1_1`	Instructs OpenSSL to turn off TLS v1.1
`SSL_OP_NO_TLSv1_2`	Instructs OpenSSL to turn off TLS v1.2
`SSL_OP_PKCS1_CHECK_1`
`SSL_OP_PKCS1_CHECK_2`
`SSL_OP_SINGLE_DH_USE`	Instructs OpenSSL to always create a new key when using temporary/ephemeral DH parameters.
`SSL_OP_SINGLE_ECDH_USE`	Instructs OpenSSL to always create a new key when using temporary/ephemeral ECDH parameters.
`SSL_OP_SSLEAY_080_CLIENT_DH_BUG`
`SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG`
`SSL_OP_TLS_BLOCK_PADDING_BUG`
`SSL_OP_TLS_D5_BUG`
`SSL_OP_TLS_ROLLBACK_BUG`	Instructs OpenSSL to disable version rollback attack detection.

OpenSSL Engine Constants#

Constant	Description
`ENGINE_METHOD_RSA`	Limit engine usage to RSA
`ENGINE_METHOD_DSA`	Limit engine usage to DSA
`ENGINE_METHOD_DH`	Limit engine usage to DH
`ENGINE_METHOD_RAND`	Limit engine usage to RAND
`ENGINE_METHOD_ECDH`	Limit engine usage to ECDH
`ENGINE_METHOD_ECDSA`	Limit engine usage to ECDSA
`ENGINE_METHOD_CIPHERS`	Limit engine usage to CIPHERS
`ENGINE_METHOD_DIGESTS`	Limit engine usage to DIGESTS
`ENGINE_METHOD_STORE`	Limit engine usage to STORE
`ENGINE_METHOD_PKEY_METHS`	Limit engine usage to PKEY_METHDS
`ENGINE_METHOD_PKEY_ASN1_METHS`	Limit engine usage to PKEY_ASN1_METHS
`ENGINE_METHOD_ALL`
`ENGINE_METHOD_NONE`

Other OpenSSL Constants#

Constant	Description
`DH_CHECK_P_NOT_SAFE_PRIME`
`DH_CHECK_P_NOT_PRIME`
`DH_UNABLE_TO_CHECK_GENERATOR`
`DH_NOT_SUITABLE_GENERATOR`
`NPN_ENABLED`
`ALPN_ENABLED`
`RSA_PKCS1_PADDING`
`RSA_SSLV23_PADDING`
`RSA_NO_PADDING`
`RSA_PKCS1_OAEP_PADDING`
`RSA_X931_PADDING`
`RSA_PKCS1_PSS_PADDING`
`RSA_PSS_SALTLEN_DIGEST`	Sets the salt length for `RSA_PKCS1_PSS_PADDING` to the digest size when signing or verifying.
`RSA_PSS_SALTLEN_MAX_SIGN`	Sets the salt length for `RSA_PKCS1_PSS_PADDING` to the maximum permissible value when signing data.
`RSA_PSS_SALTLEN_AUTO`	Causes the salt length for `RSA_PKCS1_PSS_PADDING` to be determined automatically when verifying a signature.
`POINT_CONVERSION_COMPRESSED`
`POINT_CONVERSION_UNCOMPRESSED`
`POINT_CONVERSION_HYBRID`

Node.js Crypto Constants#

Constant	Description
`defaultCoreCipherList`	Specifies the built-in default cipher list used by Node.js.
`defaultCipherList`	Specifies the active default cipher list used by the current Node.js process.

Node.js 中文文档 | Node.js 中文网

目录

crypto (加密)#

Determining if crypto support is unavailable#

Class: Certificate#

new crypto.Certificate()#

certificate.exportChallenge(spkac)#

certificate.exportPublicKey(spkac)#

certificate.verifySpkac(spkac)#

Class: Cipher#

cipher.final([outputEncoding])#

cipher.setAAD(buffer)#

cipher.getAuthTag()#

cipher.setAutoPadding([autoPadding])#

cipher.update(data[, inputEncoding][, outputEncoding])#

Class: Decipher#

decipher.final([outputEncoding])#

decipher.setAAD(buffer)#

decipher.setAuthTag(buffer)#

decipher.setAutoPadding([autoPadding])#

decipher.update(data[, inputEncoding][, outputEncoding])#

Class: DiffieHellman#

diffieHellman.computeSecret(otherPublicKey[, inputEncoding][, outputEncoding])#

diffieHellman.generateKeys([encoding])#

diffieHellman.getGenerator([encoding])#

diffieHellman.getPrime([encoding])#

diffieHellman.getPrivateKey([encoding])#

diffieHellman.getPublicKey([encoding])#

diffieHellman.setPrivateKey(privateKey[, encoding])#

diffieHellman.setPublicKey(publicKey[, encoding])#

diffieHellman.verifyError#

Class: ECDH#

ecdh.computeSecret(otherPublicKey[, inputEncoding][, outputEncoding])#

ecdh.generateKeys([encoding[, format]])#

ecdh.getPrivateKey([encoding])#

ecdh.getPublicKey([encoding][, format])#

ecdh.setPrivateKey(privateKey[, encoding])#

ecdh.setPublicKey(publicKey[, encoding])#

Class: Hash#

hash.digest([encoding])#

hash.update(data[, inputEncoding])#

Class: Hmac#

hmac.digest([encoding])#

hmac.update(data[, inputEncoding])#

Class: Sign#

sign.sign(privateKey[, outputFormat])#

sign.update(data[, inputEncoding])#

Class: Verify#

verify.update(data[, inputEncoding])#

verify.verify(object, signature[, signatureFormat])#

crypto module methods and properties#

crypto.constants#

crypto.DEFAULT_ENCODING#

crypto.fips#

crypto.createCipher(algorithm, password[, options])#

crypto.createCipheriv(algorithm, key, iv[, options])#

crypto.createCredentials(details)#

crypto.createDecipher(algorithm, password[, options])#

crypto.createDecipheriv(algorithm, key, iv[, options])#

crypto.createDiffieHellman(prime[, primeEncoding][, generator][, generatorEncoding])#

crypto.createDiffieHellman(primeLength[, generator])#

crypto.createECDH(curveName)#

crypto.createHash(algorithm[, options])#

crypto.createHmac(algorithm, key[, options])#

crypto.createSign(algorithm[, options])#

crypto.createVerify(algorithm[, options])#

crypto.getCiphers()#

crypto.getCurves()#

crypto.getDiffieHellman(groupName)#

crypto.getHashes()#

crypto.pbkdf2(password, salt, iterations, keylen, digest, callback)#

crypto.pbkdf2Sync(password, salt, iterations, keylen, digest)#

crypto.privateDecrypt(privateKey, buffer)#

crypto.privateEncrypt(privateKey, buffer)#

crypto.publicDecrypt(key, buffer)#

crypto.publicEncrypt(key, buffer)#

crypto.randomBytes(size[, callback])#

crypto.randomFillSync(buffer[, offset][, size])#

crypto.randomFill(buffer[, offset][, size], callback)#

crypto.setEngine(engine[, flags])#

crypto.timingSafeEqual(a, b)#

`crypto` module methods and properties#