Node.js v8.x 中文文档


目录

tls (安全传输层)#

稳定性: 2 - 稳定的

tls 模块是对安全传输层(TLS)及安全套接层(SSL)协议的实现,建立在OpenSSL的基础上。 按如下方式引用此模块:

const tls = require('tls');

TLS/SSL 概念#

TLS/SSL是public/private key infrastructure (PKI).大部分情况下,每个服务器和客户端都应该有一个私钥

私钥能有多种生成方式,下面举一个例子。 用OpenSSL的命令行来生成一个2048位的RSA私钥:

openssl genrsa -out ryans-key.pem 2048

通过TLS/SSL,所有的服务器(和一些客户端)必须要一个证书。 证书是相似于私钥的公钥,它由CA或者私钥拥有者数字签名,特别地,私钥拥有者所签名的被称为自签名。 获取证书的第一步是生成一个证书申请文件(CSR)

用OpenSSL能生成一个私钥的CSR文件:

openssl req -new -sha256 -key ryans-key.pem -out ryans-csr.pem

CSR文件被生成以后,它既能被CA签名也能被用户自签名。 用OpenSSL生成一个自签名证书的命令如下:

openssl x509 -req -in ryans-csr.pem -signkey ryans-key.pem -out ryans-cert.pem

证书被生成以后,它又能用来生成一个.pfx或者.p12文件:

openssl pkcs12 -export -in ryans-cert.pem -inkey ryans-key.pem \
      -certfile ca-cert.pem -out ryans.pfx

命令行参数:

  • in: 被签名的证书
  • inkey: 有关的私钥
  • certfile: 签入文件的证书串,比如: cat ca1-cert.pem ca2-cert.pem > ca-cert.pem

Perfect Forward Secrecy#

术语“前向保密”或“[完全前向保密]”是一种密钥协商(或称做密钥交换)方法. 通过这种方法,客户端与服务端在当前会话中,协商一个临时生成的密钥进行对称加密的密钥交换. 这意味着即使服务器端私钥发生泄漏,窃密者与攻击者也无法解密通信内容,除非他们能得到当前会话的临时密钥.

TLS/SSL 握手时,使用完全前向即每次会话都会随机生成一个临时密钥对用于对称加密密钥协商(区别于每次会话都是用相同的密钥). 实现这个技术的密钥交换算法都带有一个E,即ephemeral.

当前最常用的两种实现完全前向保密的算法(注意算法结尾的"E"):

  • [DHE] - 使用临时密钥的Diffie Hellman密钥交换算法.
  • [ECDHE] - 使用临时密钥的椭圆曲线Diffie Hellman密钥交换算法.

使用临时密钥会带来性能损失,因为密钥生成的过程十分消耗CPU计算性能.

如需使用完全前向加密,例如使用tls模块的DHE算法,使用之前需要生成一个Diffie-Hellman 参数并将其用dhparam声明在[tls.createSecureContext()][]中.如下例子展示了如何使用 OpenSSL命令生成参数:

openssl dhparam -outform PEM -out dhparam.pem 2048

如需使用ECDHE算法,则不需要生成Diffie-Hellman参数,因为可以使用默认的ECDHE曲线. 在创建TLS Server时,可使用ecdhCurve属性声明服务器支持的曲线名词.详请参考[tls.createServer()].

ALPN, NPN, and SNI#

ALPN (Application-Layer Protocol Negotiation Extension,应用层协议协商), NPN (Next Protocol Negotiation,下一代协议协商) , SNI (Server Name Indication,服务器名称指示)是三个TLS拓展:

  • ALPN/NPN - 允许一个TLS服务器使用多个版本的HTTP协议 (HTTP, SPDY, HTTP/2).
  • SNI - 允许一个TLS服务器支持多个主机名以及证书.

注意: 应优先使用ALPN而非NPN,因为NPN拓展从未正式定义或记录,一般不建议使用.

Client-initiated renegotiation attack mitigation#

TLS协议允许客户端在TLS会话中进行重协商,用于安全因素的考量. 不幸的是,会话重协商需要消耗大量的服务器端资源,这将导致服务器存在潜在的被DDoS攻击的可能.

为了减轻这个风险,node限制每十分钟只能使用三次重协商,超过这个限制将会在[tls.TLSSocket][]实例中产生一个error事件. 这个限制是可配置的:

  • tls.CLIENT_RENEG_LIMIT <number> 指定重协商请求的次数限制,默认为3.
  • tls.CLIENT_RENEG_WINDOW <number> 指定限制次数的生效时间段,默认是600(十分钟).

注意: 不应在未充分理解其含义与影响的情况下修改上述参数.

如果要测试服务端重协商限制,请使用OpenSSL命令行客户端(openssl s_client -connect address:port)连接服务器,并输入 R<CR> (即输入R字符后紧跟回车) 多次,如在默认配置下连接服务器并输入三次R加回车后,服务器断开了连接,则表示限制生效.

Modifying the Default TLS Cipher suite#

Node.js is built with a default suite of enabled and disabled TLS ciphers. Currently, the default cipher suite is:

ECDHE-RSA-AES128-GCM-SHA256:
ECDHE-ECDSA-AES128-GCM-SHA256:
ECDHE-RSA-AES256-GCM-SHA384:
ECDHE-ECDSA-AES256-GCM-SHA384:
DHE-RSA-AES128-GCM-SHA256:
ECDHE-RSA-AES128-SHA256:
DHE-RSA-AES128-SHA256:
ECDHE-RSA-AES256-SHA384:
DHE-RSA-AES256-SHA384:
ECDHE-RSA-AES256-SHA256:
DHE-RSA-AES256-SHA256:
HIGH:
!aNULL:
!eNULL:
!EXPORT:
!DES:
!RC4:
!MD5:
!PSK:
!SRP:
!CAMELLIA

This default can be replaced entirely using the --tls-cipher-list command line switch. For instance, the following makes ECDHE-RSA-AES128-GCM-SHA256:!RC4 the default TLS cipher suite:

node --tls-cipher-list="ECDHE-RSA-AES128-GCM-SHA256:!RC4"

The default can also be replaced on a per client or server basis using the ciphers option from [tls.createSecureContext()][], which is also available in [tls.createServer()], [tls.connect()], and when creating new [tls.TLSSocket]s.

Consult [OpenSSL cipher list format documentation][] for details on the format.

Note: The default cipher suite included within Node.js has been carefully selected to reflect current security best practices and risk mitigation. Changing the default cipher suite can have a significant impact on the security of an application. The --tls-cipher-list switch and ciphers option should by used only if absolutely necessary.

The default cipher suite prefers GCM ciphers for [Chrome's 'modern cryptography' setting] and also prefers ECDHE and DHE ciphers for Perfect Forward Secrecy, while offering some backward compatibility.

128 bit AES is preferred over 192 and 256 bit AES in light of [specific attacks affecting larger AES key sizes].

Old clients that rely on insecure and deprecated RC4 or DES-based ciphers (like Internet Explorer 6) cannot complete the handshaking process with the default configuration. If these clients must be supported, the [TLS recommendations] may offer a compatible cipher suite. For more details on the format, see the [OpenSSL cipher list format documentation].

Class: tls.Server#

The tls.Server class is a subclass of net.Server that accepts encrypted connections using TLS or SSL.

Event: 'newSession'#

The 'newSession' event is emitted upon creation of a new TLS session. This may be used to store sessions in external storage. The listener callback is passed three arguments when called:

  • sessionId - The TLS session identifier
  • sessionData - The TLS session data
  • callback <Function> A callback function taking no arguments that must be invoked in order for data to be sent or received over the secure connection.

Note: Listening for this event will have an effect only on connections established after the addition of the event listener.

Event: 'OCSPRequest'#

The 'OCSPRequest' event is emitted when the client sends a certificate status request. The listener callback is passed three arguments when called:

  • certificate <Buffer> The server certificate
  • issuer <Buffer> The issuer's certificate
  • callback <Function> A callback function that must be invoked to provide the results of the OCSP request.

The server's current certificate can be parsed to obtain the OCSP URL and certificate ID; after obtaining an OCSP response, callback(null, resp) is then invoked, where resp is a Buffer instance containing the OCSP response. Both certificate and issuer are Buffer DER-representations of the primary and issuer's certificates. These can be used to obtain the OCSP certificate ID and OCSP endpoint URL.

Alternatively, callback(null, null) may be called, indicating that there was no OCSP response.

Calling callback(err) will result in a socket.destroy(err) call.

The typical flow of an OCSP Request is as follows:

  1. Client connects to the server and sends an 'OCSPRequest' (via the status info extension in ClientHello).
  2. Server receives the request and emits the 'OCSPRequest' event, calling the listener if registered.
  3. Server extracts the OCSP URL from either the certificate or issuer and performs an [OCSP request] to the CA.
  4. Server receives OCSPResponse from the CA and sends it back to the client via the callback argument
  5. Client validates the response and either destroys the socket or performs a handshake.

Note: The issuer can be null if the certificate is either self-signed or the issuer is not in the root certificates list. (An issuer may be provided via the ca option when establishing the TLS connection.)

Note: Listening for this event will have an effect only on connections established after the addition of the event listener.

Note: An npm module like [asn1.js] may be used to parse the certificates.

Event: 'resumeSession'#

The 'resumeSession' event is emitted when the client requests to resume a previous TLS session. The listener callback is passed two arguments when called:

  • sessionId - The TLS/SSL session identifier
  • callback <Function> A callback function to be called when the prior session has been recovered.

When called, the event listener may perform a lookup in external storage using the given sessionId and invoke callback(null, sessionData) once finished. If the session cannot be resumed (i.e., doesn't exist in storage) the callback may be invoked as callback(null, null). Calling callback(err) will terminate the incoming connection and destroy the socket.

Note: Listening for this event will have an effect only on connections established after the addition of the event listener.

The following illustrates resuming a TLS session:

const tlsSessionStore = {};
server.on('newSession', (id, data, cb) => {
  tlsSessionStore[id.toString('hex')] = data;
  cb();
});
server.on('resumeSession', (id, cb) => {
  cb(null, tlsSessionStore[id.toString('hex')] || null);
});

Event: 'secureConnection'#

The 'secureConnection' event is emitted after the handshaking process for a new connection has successfully completed. The listener callback is passed a single argument when called:

The tlsSocket.authorized property is a boolean indicating whether the client has been verified by one of the supplied Certificate Authorities for the server. If tlsSocket.authorized is false, then socket.authorizationError is set to describe how authorization failed. Note that depending on the settings of the TLS server, unauthorized connections may still be accepted.

The tlsSocket.npnProtocol and tlsSocket.alpnProtocol properties are strings that contain the selected NPN and ALPN protocols, respectively. When both NPN and ALPN extensions are received, ALPN takes precedence over NPN and the next protocol is selected by ALPN.

When ALPN has no selected protocol, tlsSocket.alpnProtocol returns false.

The tlsSocket.servername property is a string containing the server name requested via SNI.

Event: 'tlsClientError'#

The 'tlsClientError' event is emitted when an error occurs before a secure connection is established. The listener callback is passed two arguments when called:

  • exception <Error> The Error object describing the error
  • tlsSocket <tls.TLSSocket> The tls.TLSSocket instance from which the error originated.

server.addContext(hostname, context)#

  • hostname <string> A SNI hostname or wildcard (e.g. '*')
  • context <Object> An object containing any of the possible properties from the [tls.createSecureContext()][] options arguments (e.g. key, cert, ca, etc).

The server.addContext() method adds a secure context that will be used if the client request's SNI hostname matches the supplied hostname (or wildcard).

server.address()#

Returns the bound address, the address family name, and port of the server as reported by the operating system. See [net.Server.address()][] for more information.

server.close([callback])#

  • callback <Function> An optional listener callback that will be registered to listen for the server instance's 'close' event.

The server.close() method stops the server from accepting new connections.

This function operates asynchronously. The 'close' event will be emitted when the server has no more open connections.

server.connections#

Stability: 0 - Deprecated: Use [server.getConnections()][] instead.

Returns the current number of concurrent connections on the server.

server.getTicketKeys()#

Returns a Buffer instance holding the keys currently used for encryption/decryption of the [TLS Session Tickets][]

server.listen()#

Starts the server listening for encrypted connections. This method is identical to [server.listen()][] from [net.Server][].

server.setTicketKeys(keys)#

  • keys <Buffer> The keys used for encryption/decryption of the [TLS Session Tickets][].

Updates the keys for encryption/decryption of the [TLS Session Tickets][].

Note: The key's Buffer should be 48 bytes long. See ticketKeys option in tls.createServer for more information on how it is used.

Note: Changes to the ticket keys are effective only for future server connections. Existing or currently pending server connections will use the previous keys.

Class: tls.TLSSocket#

The tls.TLSSocket is a subclass of [net.Socket][] that performs transparent encryption of written data and all required TLS negotiation.

Instances of tls.TLSSocket implement the duplex [Stream][] interface.

Note: Methods that return TLS connection metadata (e.g. [tls.TLSSocket.getPeerCertificate()][] will only return data while the connection is open.

new tls.TLSSocket(socket[, options])#

  • socket <net.Socket> | <stream.Duplex> On the server side, any Duplex stream. On the client side, any instance of [net.Socket][] (for generic Duplex stream support on the client side, [tls.connect()][] must be used).
  • options <Object>
    • isServer: The SSL/TLS protocol is asymmetrical, TLSSockets must know if they are to behave as a server or a client. If true the TLS socket will be instantiated as a server. Defaults to false.
    • server <net.Server> An optional [net.Server][] instance.
    • requestCert: Whether to authenticate the remote peer by requesting a certificate. Clients always request a server certificate. Servers (isServer is true) may optionally set requestCert to true to request a client certificate.
    • rejectUnauthorized: Optional, see [tls.createServer()][]
    • NPNProtocols: Optional, see [tls.createServer()][]
    • ALPNProtocols: Optional, see [tls.createServer()][]
    • SNICallback: Optional, see [tls.createServer()][]
    • session <Buffer> An optional Buffer instance containing a TLS session.
    • requestOCSP <boolean> If true, specifies that the OCSP status request extension will be added to the client hello and an 'OCSPResponse' event will be emitted on the socket before establishing a secure communication
    • secureContext: Optional TLS context object created with [tls.createSecureContext()][]. If a secureContext is not provided, one will be created by passing the entire options object to tls.createSecureContext().
    • ...: Optional [tls.createSecureContext()][] options that are used if the secureContext option is missing, otherwise they are ignored.

Construct a new tls.TLSSocket object from an existing TCP socket.

Event: 'OCSPResponse'#

The 'OCSPResponse' event is emitted if the requestOCSP option was set when the tls.TLSSocket was created and an OCSP response has been received. The listener callback is passed a single argument when called:

  • response <Buffer> The server's OCSP response

Typically, the response is a digitally signed object from the server's CA that contains information about server's certificate revocation status.

Event: 'secureConnect'#

The 'secureConnect' event is emitted after the handshaking process for a new connection has successfully completed. The listener callback will be called regardless of whether or not the server's certificate has been authorized. It is the client's responsibility to check the tlsSocket.authorized property to determine if the server certificate was signed by one of the specified CAs. If tlsSocket.authorized === false, then the error can be found by examining the tlsSocket.authorizationError property. If either ALPN or NPN was used, the tlsSocket.alpnProtocol or tlsSocket.npnProtocol properties can be checked to determine the negotiated protocol.

tlsSocket.address()#

Returns the bound address, the address family name, and port of the underlying socket as reported by the operating system. Returns an object with three properties, e.g. { port: 12346, family: 'IPv4', address: '127.0.0.1' }

tlsSocket.authorizationError#

Returns the reason why the peer's certificate was not been verified. This property is set only when tlsSocket.authorized === false.

tlsSocket.authorized#

Returns true if the peer certificate was signed by one of the CAs specified when creating the tls.TLSSocket instance, otherwise false.

tlsSocket.disableRenegotiation()#

Disables TLS renegotiation for this TLSSocket instance. Once called, attempts to renegotiate will trigger an 'error' event on the TLSSocket.

tlsSocket.encrypted#

Always returns true. This may be used to distinguish TLS sockets from regular net.Socket instances.

tlsSocket.getCipher()#

Returns an object representing the cipher name. The version key is a legacy field which always contains the value 'TLSv1/SSLv3'.

For example: { name: 'AES256-SHA', version: 'TLSv1/SSLv3' }

See SSL_CIPHER_get_name() in https://www.openssl.org/docs/man1.0.2/ssl/SSL_CIPHER_get_name.html for more information.

tlsSocket.getEphemeralKeyInfo()#

Returns an object representing the type, name, and size of parameter of an ephemeral key exchange in [Perfect Forward Secrecy][] on a client connection. It returns an empty object when the key exchange is not ephemeral. As this is only supported on a client socket; null is returned if called on a server socket. The supported types are 'DH' and 'ECDH'. The name property is available only when type is 'ECDH'.

For Example: { type: 'ECDH', name: 'prime256v1', size: 256 }

tlsSocket.getPeerCertificate([detailed])#

  • detailed <boolean> Include the full certificate chain if true, otherwise include just the peer's certificate.

Returns an object representing the peer's certificate. The returned object has some properties corresponding to the fields of the certificate.

If the full certificate chain was requested, each certificate will include a issuerCertificate property containing an object representing its issuer's certificate.

For example:

{ subject:
   { C: 'UK',
     ST: 'Acknack Ltd',
     L: 'Rhys Jones',
     O: 'node.js',
     OU: 'Test TLS Certificate',
     CN: 'localhost' },
  issuer:
   { C: 'UK',
     ST: 'Acknack Ltd',
     L: 'Rhys Jones',
     O: 'node.js',
     OU: 'Test TLS Certificate',
     CN: 'localhost' },
  issuerCertificate:
   { ... another certificate, possibly with a .issuerCertificate ... },
  raw: < RAW DER buffer >,
  valid_from: 'Nov 11 09:52:22 2009 GMT',
  valid_to: 'Nov  6 09:52:22 2029 GMT',
  fingerprint: '2A:7A:C2:DD:E5:F9:CC:53:72:35:99:7A:02:5A:71:38:52:EC:8A:DF',
  serialNumber: 'B9B0D332A1AA5635' }

If the peer does not provide a certificate, an empty object will be returned.

tlsSocket.getProtocol()#

Returns a string containing the negotiated SSL/TLS protocol version of the current connection. The value 'unknown' will be returned for connected sockets that have not completed the handshaking process. The value null will be returned for server sockets or disconnected client sockets.

Example responses include:

  • SSLv3
  • TLSv1
  • TLSv1.1
  • TLSv1.2
  • unknown

See https://www.openssl.org/docs/man1.0.2/ssl/SSL_get_version.html for more information.

tlsSocket.getSession()#

Returns the ASN.1 encoded TLS session or undefined if no session was negotiated. Can be used to speed up handshake establishment when reconnecting to the server.

tlsSocket.getTLSTicket()#

Returns the TLS session ticket or undefined if no session was negotiated.

Note: This only works with client TLS sockets. Useful only for debugging, for session reuse provide session option to [tls.connect()][].

tlsSocket.localAddress#

Returns the string representation of the local IP address.

tlsSocket.localPort#

Returns the numeric representation of the local port.

tlsSocket.remoteAddress#

Returns the string representation of the remote IP address. For example, '74.125.127.100' or '2001:4860:a005::68'.

tlsSocket.remoteFamily#

Returns the string representation of the remote IP family. 'IPv4' or 'IPv6'.

tlsSocket.remotePort#

Returns the numeric representation of the remote port. For example, 443.

tlsSocket.renegotiate(options, callback)#

  • options <Object>
    • rejectUnauthorized <boolean> If not false, the server certificate is verified against the list of supplied CAs. An 'error' event is emitted if verification fails; err.code contains the OpenSSL error code. Defaults to true.
    • requestCert
  • callback <Function> A function that will be called when the renegotiation request has been completed.

The tlsSocket.renegotiate() method initiates a TLS renegotiation process. Upon completion, the callback function will be passed a single argument that is either an Error (if the request failed) or null.

Note: This method can be used to request a peer's certificate after the secure connection has been established.

Note: When running as the server, the socket will be destroyed with an error after handshakeTimeout timeout.

tlsSocket.setMaxSendFragment(size)#

  • size <number> The maximum TLS fragment size. Defaults to 16384. The maximum value is 16384.

The tlsSocket.setMaxSendFragment() method sets the maximum TLS fragment size. Returns true if setting the limit succeeded; false otherwise.

Smaller fragment sizes decrease the buffering latency on the client: larger fragments are buffered by the TLS layer until the entire fragment is received and its integrity is verified; large fragments can span multiple roundtrips and their processing can be delayed due to packet loss or reordering. However, smaller fragments add extra TLS framing bytes and CPU overhead, which may decrease overall server throughput.

tls.checkServerIdentity(host, cert)#

  • host <string> The hostname to verify the certificate against
  • cert <Object> An object representing the peer's certificate. The returned object has some properties corresponding to the fields of the certificate.

Verifies the certificate cert is issued to host host.

Returns <Error> object, populating it with the reason, host, and cert on failure. On success, returns <undefined>.

Note: This function can be overwritten by providing alternative function as part of the options.checkServerIdentity option passed to tls.connect(). The overwriting function can call tls.checkServerIdentity() of course, to augment the checks done with additional verification.

Note: This function is only called if the certificate passed all other checks, such as being issued by trusted CA (options.ca).

The cert object contains the parsed certificate and will have a structure similar to:

{ subject:
   { OU: [ 'Domain Control Validated', 'PositiveSSL Wildcard' ],
     CN: '*.nodejs.org' },
  issuer:
   { C: 'GB',
     ST: 'Greater Manchester',
     L: 'Salford',
     O: 'COMODO CA Limited',
     CN: 'COMODO RSA Domain Validation Secure Server CA' },
  subjectaltname: 'DNS:*.nodejs.org, DNS:nodejs.org',
  infoAccess:
   { 'CA Issuers - URI':
      [ 'http://crt.comodoca.com/COMODORSADomainValidationSecureServerCA.crt' ],
     'OCSP - URI': [ 'http://ocsp.comodoca.com' ] },
  modulus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
  exponent: '0x10001',
  valid_from: 'Aug 14 00:00:00 2017 GMT',
  valid_to: 'Nov 20 23:59:59 2019 GMT',
  fingerprint: '01:02:59:D9:C3:D2:0D:08:F7:82:4E:44:A4:B4:53:C5:E2:3A:87:4D',
  ext_key_usage: [ '1.3.6.1.5.5.7.3.1', '1.3.6.1.5.5.7.3.2' ],
  serialNumber: '66593D57F20CBC573E433381B5FEC280',
  raw: <Buffer ....> }

tls.connect(options[, callback])#

  • options <Object>
    • host <string> Host the client should connect to, defaults to 'localhost'.
    • port <number> Port the client should connect to.
    • path <string> Creates unix socket connection to path. If this option is specified, host and port are ignored.
    • socket <stream.Duplex> Establish secure connection on a given socket rather than creating a new socket. Typically, this is an instance of [net.Socket][], but any Duplex stream is allowed. If this option is specified, path, host and port are ignored, except for certificate validation. Usually, a socket is already connected when passed to tls.connect(), but it can be connected later. Note that connection/disconnection/destruction of socket is the user's responsibility, calling tls.connect() will not cause net.connect() to be called.
    • rejectUnauthorized <boolean> If not false, the server certificate is verified against the list of supplied CAs. An 'error' event is emitted if verification fails; err.code contains the OpenSSL error code. Defaults to true.
    • NPNProtocols <string[]> | <Buffer[]> | <Uint8Array[]> | <Buffer> | <Uint8Array> An array of strings, Buffers or Uint8Arrays, or a single Buffer or Uint8Array containing supported NPN protocols. Buffers should have the format [len][name][len][name]... e.g. 0x05hello0x05world, where the first byte is the length of the next protocol name. Passing an array is usually much simpler, e.g. ['hello', 'world'].
    • ALPNProtocols: <string[]> | <Buffer[]> | <Uint8Array[]> | <Buffer> | <Uint8Array> An array of strings, Buffers or Uint8Arrays, or a single Buffer or Uint8Array containing the supported ALPN protocols. Buffers should have the format [len][name][len][name]... e.g. 0x05hello0x05world, where the first byte is the length of the next protocol name. Passing an array is usually much simpler, e.g. ['hello', 'world'].
    • servername: <string> Server name for the SNI (Server Name Indication) TLS extension.
    • checkServerIdentity(servername, cert) <Function> A callback function to be used (instead of the builtin tls.checkServerIdentity() function) when checking the server's hostname (or the provided servername when explicitly set) against the certificate. This should return an <Error> if verification fails. The method should return undefined if the servername and cert are verified.
    • session <Buffer> A Buffer instance, containing TLS session.
    • minDHSize <number> Minimum size of the DH parameter in bits to accept a TLS connection. When a server offers a DH parameter with a size less than minDHSize, the TLS connection is destroyed and an error is thrown. Defaults to 1024.
    • secureContext: Optional TLS context object created with [tls.createSecureContext()][]. If a secureContext is not provided, one will be created by passing the entire options object to tls.createSecureContext().
    • lookup: <Function> Custom lookup function. Defaults to [dns.lookup()][].
    • ...: Optional [tls.createSecureContext()][] options that are used if the secureContext option is missing, otherwise they are ignored.
  • callback <Function>

The callback function, if specified, will be added as a listener for the ['secureConnect'][] event.

tls.connect() returns a [tls.TLSSocket][] object.

The following implements a simple "echo server" example:

const tls = require('tls');
const fs = require('fs');

const options = {
  // Necessary only if using the client certificate authentication
  key: fs.readFileSync('client-key.pem'),
  cert: fs.readFileSync('client-cert.pem'),

  // Necessary only if the server uses the self-signed certificate
  ca: [ fs.readFileSync('server-cert.pem') ]
};

const socket = tls.connect(8000, options, () => {
  console.log('client connected',
              socket.authorized ? 'authorized' : 'unauthorized');
  process.stdin.pipe(socket);
  process.stdin.resume();
});
socket.setEncoding('utf8');
socket.on('data', (data) => {
  console.log(data);
});
socket.on('end', () => {
  server.close();
});

Or

const tls = require('tls');
const fs = require('fs');

const options = {
  pfx: fs.readFileSync('client.pfx')
};

const socket = tls.connect(8000, options, () => {
  console.log('client connected',
              socket.authorized ? 'authorized' : 'unauthorized');
  process.stdin.pipe(socket);
  process.stdin.resume();
});
socket.setEncoding('utf8');
socket.on('data', (data) => {
  console.log(data);
});
socket.on('end', () => {
  server.close();
});

tls.connect(path[, options][, callback])#

  • path <string> Default value for options.path.
  • options <Object> See [tls.connect()][].
  • callback <Function> See [tls.connect()][].

Same as [tls.connect()][] except that path can be provided as an argument instead of an option.

Note: A path option, if specified, will take precedence over the path argument.

tls.connect(port[, host][, options][, callback])#

  • port <number> Default value for options.port.
  • host <string> Optional default value for options.host.
  • options <Object> See [tls.connect()][].
  • callback <Function> See [tls.connect()][].

Same as [tls.connect()][] except that port and host can be provided as arguments instead of options.

Note: A port or host option, if specified, will take precedence over any port or host argument.

tls.createSecureContext(options)#

  • options <Object>
    • pfx <string> | <string[]> | <Buffer> | <Buffer[]> | <Object[]> Optional PFX or PKCS12 encoded private key and certificate chain. pfx is an alternative to providing key and cert individually. PFX is usually encrypted, if it is, passphrase will be used to decrypt it. Multiple PFX can be provided either as an array of unencrypted PFX buffers, or an array of objects in the form {buf: <string|buffer>[, passphrase: <string>]}. The object form can only occur in an array. object.passphrase is optional. Encrypted PFX will be decrypted with object.passphrase if provided, or options.passphrase if it is not.
    • key <string> | <string[]> | <Buffer> | <Buffer[]> | <Object[]> Optional private keys in PEM format. PEM allows the option of private keys being encrypted. Encrypted keys will be decrypted with options.passphrase. Multiple keys using different algorithms can be provided either as an array of unencrypted key strings or buffers, or an array of objects in the form {pem: <string|buffer>[, passphrase: <string>]}. The object form can only occur in an array. object.passphrase is optional. Encrypted keys will be decrypted with object.passphrase if provided, or options.passphrase if it is not.
    • passphrase <string> Optional shared passphrase used for a single private key and/or a PFX.
    • cert <string> | <string[]> | <Buffer> | <Buffer[]> Optional cert chains in PEM format. One cert chain should be provided per private key. Each cert chain should consist of the PEM formatted certificate for a provided private key, followed by the PEM formatted intermediate certificates (if any), in order, and not including the root CA (the root CA must be pre-known to the peer, see ca). When providing multiple cert chains, they do not have to be in the same order as their private keys in key. If the intermediate certificates are not provided, the peer will not be able to validate the certificate, and the handshake will fail.
    • ca <string> | <string[]> | <Buffer> | <Buffer[]> Optionally override the trusted CA certificates. Default is to trust the well-known CAs curated by Mozilla. Mozilla's CAs are completely replaced when CAs are explicitly specified using this option. The value can be a string or Buffer, or an Array of strings and/or Buffers. Any string or Buffer can contain multiple PEM CAs concatenated together. The peer's certificate must be chainable to a CA trusted by the server for the connection to be authenticated. When using certificates that are not chainable to a well-known CA, the certificate's CA must be explicitly specified as a trusted or the connection will fail to authenticate. If the peer uses a certificate that doesn't match or chain to one of the default CAs, use the ca option to provide a CA certificate that the peer's certificate can match or chain to. For self-signed certificates, the certificate is its own CA, and must be provided.
    • crl <string> | <string[]> | <Buffer> | <Buffer[]> Optional PEM formatted CRLs (Certificate Revocation Lists).
    • ciphers <string> Optional cipher suite specification, replacing the default. For more information, see [modifying the default cipher suite][].
    • honorCipherOrder <boolean> Attempt to use the server's cipher suite preferences instead of the client's. When true, causes SSL_OP_CIPHER_SERVER_PREFERENCE to be set in secureOptions, see [OpenSSL Options][] for more information.
    • ecdhCurve <string> A string describing a named curve or a colon separated list of curve NIDs or names, for example P-521:P-384:P-256, to use for ECDH key agreement, or false to disable ECDH. Set to auto to select the curve automatically. Defaults to [tls.DEFAULT_ECDH_CURVE]. Use [crypto.getCurves()][] to obtain a list of available curve names. On recent releases, openssl ecparam -list_curves will also display the name and description of each available elliptic curve.
    • dhparam <string> | <Buffer> Diffie Hellman parameters, required for [Perfect Forward Secrecy][]. Use openssl dhparam to create the parameters. The key length must be greater than or equal to 1024 bits, otherwise an error will be thrown. It is strongly recommended to use 2048 bits or larger for stronger security. If omitted or invalid, the parameters are silently discarded and DHE ciphers will not be available.
    • secureProtocol <string> Optional SSL method to use, default is "SSLv23_method". The possible values are listed as [SSL_METHODS][], use the function names as strings. For example, "SSLv3_method" to force SSL version 3.
    • secureOptions <number> Optionally affect the OpenSSL protocol behavior, which is not usually necessary. This should be used carefully if at all! Value is a numeric bitmask of the SSL_OP_* options from [OpenSSL Options][].
    • sessionIdContext <string> Optional opaque identifier used by servers to ensure session state is not shared between applications. Unused by clients.

Note:

  • [tls.createServer()][] sets the default value of the honorCipherOrder option to true, other APIs that create secure contexts leave it unset.

  • [tls.createServer()][] uses a 128 bit truncated SHA1 hash value generated from process.argv as the default value of the sessionIdContext option, other APIs that create secure contexts have no default value.

The tls.createSecureContext() method creates a credentials object.

A key is required for ciphers that make use of certificates. Either key or pfx can be used to provide it.

If the 'ca' option is not given, then Node.js will use the default publicly trusted list of CAs as given in https://hg.mozilla.org/mozilla-central/raw-file/tip/security/nss/lib/ckfw/builtins/certdata.txt.

tls.createServer([options][, secureConnectionListener])#

  • options <Object>
    • handshakeTimeout <number> Abort the connection if the SSL/TLS handshake does not finish in the specified number of milliseconds. Defaults to 120 seconds. A 'tlsClientError' is emitted on the tls.Server object whenever a handshake times out.
    • requestCert <boolean> If true the server will request a certificate from clients that connect and attempt to verify that certificate. Defaults to false.
    • rejectUnauthorized <boolean> If not false the server will reject any connection which is not authorized with the list of supplied CAs. This option only has an effect if requestCert is true. Defaults to true.
    • NPNProtocols <string[]> | <Buffer[]> | <Uint8Array[]> | <Buffer> | <Uint8Array> An array of strings, Buffers or Uint8Arrays, or a single Buffer or Uint8Array containing supported NPN protocols. Buffers should have the format [len][name][len][name]... e.g. 0x05hello0x05world, where the first byte is the length of the next protocol name. Passing an array is usually much simpler, e.g. ['hello', 'world']. (Protocols should be ordered by their priority.)
    • ALPNProtocols: <string[]> | <Buffer[]> | <Uint8Array[]> | <Buffer> | <Uint8Array> An array of strings, Buffers or Uint8Arrays, or a single Buffer or Uint8Array containing the supported ALPN protocols. Buffers should have the format [len][name][len][name]... e.g. 0x05hello0x05world, where the first byte is the length of the next protocol name. Passing an array is usually much simpler, e.g. ['hello', 'world']. (Protocols should be ordered by their priority.) When the server receives both NPN and ALPN extensions from the client, ALPN takes precedence over NPN and the server does not send an NPN extension to the client.
    • SNICallback(servername, cb) <Function> A function that will be called if the client supports SNI TLS extension. Two arguments will be passed when called: servername and cb. SNICallback should invoke cb(null, ctx), where ctx is a SecureContext instance. (tls.createSecureContext(...) can be used to get a proper SecureContext.) If SNICallback wasn't provided the default callback with high-level API will be used (see below).
    • sessionTimeout <number> An integer specifying the number of seconds after which the TLS session identifiers and TLS session tickets created by the server will time out. See [SSL_CTX_set_timeout] for more details.
    • ticketKeys: A 48-byte Buffer instance consisting of a 16-byte prefix, a 16-byte HMAC key, and a 16-byte AES key. This can be used to accept TLS session tickets on multiple instances of the TLS server.
    • ...: Any [tls.createSecureContext()][] options can be provided. For servers, the identity options (pfx or key/cert) are usually required.
  • secureConnectionListener <Function>

Creates a new [tls.Server][]. The secureConnectionListener, if provided, is automatically set as a listener for the ['secureConnection'][] event.

Note: The ticketKeys options is automatically shared between cluster module workers.

The following illustrates a simple echo server:

const tls = require('tls');
const fs = require('fs');

const options = {
  key: fs.readFileSync('server-key.pem'),
  cert: fs.readFileSync('server-cert.pem'),

  // This is necessary only if using the client certificate authentication.
  requestCert: true,

  // This is necessary only if the client uses the self-signed certificate.
  ca: [ fs.readFileSync('client-cert.pem') ]
};

const server = tls.createServer(options, (socket) => {
  console.log('server connected',
              socket.authorized ? 'authorized' : 'unauthorized');
  socket.write('welcome!\n');
  socket.setEncoding('utf8');
  socket.pipe(socket);
});
server.listen(8000, () => {
  console.log('server bound');
});

Or

const tls = require('tls');
const fs = require('fs');

const options = {
  pfx: fs.readFileSync('server.pfx'),

  // This is necessary only if using the client certificate authentication.
  requestCert: true,

};

const server = tls.createServer(options, (socket) => {
  console.log('server connected',
              socket.authorized ? 'authorized' : 'unauthorized');
  socket.write('welcome!\n');
  socket.setEncoding('utf8');
  socket.pipe(socket);
});
server.listen(8000, () => {
  console.log('server bound');
});

This server can be tested by connecting to it using openssl s_client:

openssl s_client -connect 127.0.0.1:8000

tls.getCiphers()#

Returns an array with the names of the supported SSL ciphers.

For example:

console.log(tls.getCiphers()); // ['AES128-SHA', 'AES256-SHA', ...]

tls.DEFAULT_ECDH_CURVE#

The default curve name to use for ECDH key agreement in a tls server. The default value is 'prime256v1' (NIST P-256). Consult [RFC 4492] and [FIPS.186-4] for more details.

Deprecated APIs#

Class: CryptoStream#

Stability: 0 - Deprecated: Use [tls.TLSSocket][] instead.

The tls.CryptoStream class represents a stream of encrypted data. This class has been deprecated and should no longer be used.

cryptoStream.bytesWritten#

The cryptoStream.bytesWritten property returns the total number of bytes written to the underlying socket including the bytes required for the implementation of the TLS protocol.

Class: SecurePair#

Stability: 0 - Deprecated: Use [tls.TLSSocket][] instead.

Returned by [tls.createSecurePair()][].

Event: 'secure'#

The 'secure' event is emitted by the SecurePair object once a secure connection has been established.

As with checking for the server secureConnection event, pair.cleartext.authorized should be inspected to confirm whether the certificate used is properly authorized.

tls.createSecurePair([context][, isServer][, requestCert][, rejectUnauthorized][, options])#

Stability: 0 - Deprecated: Use [tls.TLSSocket][] instead.
  • context <Object> A secure context object as returned by tls.createSecureContext()
  • isServer <boolean> true to specify that this TLS connection should be opened as a server.
  • requestCert <boolean> true to specify whether a server should request a certificate from a connecting client. Only applies when isServer is true.
  • rejectUnauthorized <boolean> If not false a server automatically reject clients with invalid certificates. Only applies when isServer is true.
  • options
    • secureContext: An optional TLS context object from [tls.createSecureContext()][]
    • isServer: If true the TLS socket will be instantiated in server-mode. Defaults to false.
    • server <net.Server> An optional [net.Server][] instance
    • requestCert: Optional, see [tls.createServer()][]
    • rejectUnauthorized: Optional, see [tls.createServer()][]
    • NPNProtocols: Optional, see [tls.createServer()][]
    • ALPNProtocols: Optional, see [tls.createServer()][]
    • SNICallback: Optional, see [tls.createServer()][]
    • session <Buffer> An optional Buffer instance containing a TLS session.
    • requestOCSP <boolean> If true, specifies that the OCSP status request extension will be added to the client hello and an 'OCSPResponse' event will be emitted on the socket before establishing a secure communication

Creates a new secure pair object with two streams, one of which reads and writes the encrypted data and the other of which reads and writes the cleartext data. Generally, the encrypted stream is piped to/from an incoming encrypted data stream and the cleartext one is used as a replacement for the initial encrypted stream.

tls.createSecurePair() returns a tls.SecurePair object with cleartext and encrypted stream properties.

Note: cleartext has the same API as [tls.TLSSocket][].

Note: The tls.createSecurePair() method is now deprecated in favor of tls.TLSSocket(). For example, the code:

pair = tls.createSecurePair(/* ... */);
pair.encrypted.pipe(socket);
socket.pipe(pair.encrypted);

can be replaced by:

secure_socket = tls.TLSSocket(socket, options);

where secure_socket has the same API as pair.cleartext. ['secureConnect']: #tls_event_secureconnect ['secureConnection']: #tls_event_secureconnection [crypto.getCurves()]: crypto.html#crypto_crypto_getcurves [net.Server.address()]: net.html#net_server_address [net.Server]: net.html#net_class_net_server [net.Socket]: net.html#net_class_net_socket [server.getConnections()]: net.html#net_server_getconnections_callback [server.listen()]: net.html#net_server_listen [tls.DEFAULT_ECDH_CURVE]: #tls_tls_default_ecdh_curve [tls.TLSSocket.getPeerCertificate()]: #tls_tlssocket_getpeercertificate_detailed [tls.TLSSocket]: #tls_class_tls_tlssocket [tls.connect()]: #tls_tls_connect_options_callback [tls.createSecureContext()]: #tls_tls_createsecurecontext_options [tls.createSecurePair()]: #tls_tls_createsecurepair_context_isserver_requestcert_rejectunauthorized_options [tls.createServer()]: #tls_tls_createserver_options_secureconnectionlistener [Chrome's 'modern cryptography' setting]: https://www.chromium.org/Home/chromium-security/education/tls#TOC-Cipher-Suites [DHE]: https://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange [ECDHE]: https://en.wikipedia.org/wiki/Elliptic_curve_Diffie%E2%80%93Hellman [FIPS.186-4]: http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf [Forward secrecy]: https://en.wikipedia.org/wiki/Perfect_forward_secrecy [OCSP request]: https://en.wikipedia.org/wiki/OCSP_stapling [OpenSSL Options]: crypto.html#crypto_openssl_options [OpenSSL cipher list format documentation]: https://www.openssl.org/docs/man1.0.2/apps/ciphers.html#CIPHER-LIST-FORMAT [Perfect Forward Secrecy]: #tls_perfect_forward_secrecy [完全前向保密]: #tls_perfect_forward_secrecy [RFC 4492]: https://www.rfc-editor.org/rfc/rfc4492.txt [SSL_CTX_set_timeout]: https://www.openssl.org/docs/man1.0.2/ssl/SSL_CTX_set_timeout.html [SSL_METHODS]: https://www.openssl.org/docs/man1.0.2/ssl/ssl.html#DEALING-WITH-PROTOCOL-METHODS [Stream]: stream.html#stream_stream [TLS Session Tickets]: https://www.ietf.org/rfc/rfc5077.txt [TLS recommendations]: https://wiki.mozilla.org/Security/Server_Side_TLS [asn1.js]: https://npmjs.org/package/asn1.js [modifying the default cipher suite]: #tls_modifying_the_default_tls_cipher_suite [specific attacks affecting larger AES key sizes]: https://www.schneier.com/blog/archives/2009/07/another_new_aes.html [tls.Server]: #tls_class_tls_server [dns.lookup()]: dns.html#dns_dns_lookup_hostname_options_callback