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SharedAccessKeyAuthenticationProvider class

Package:
azure-iot-device

Provides an AuthenticationProvider object that can be created simply with a connection string and is then used by the device client and transports to authenticate with the Azure IoT hub instance.

The SharedAccessKeyAuthenticationProvider object takes care of creating shared access signature tokens on a regular cadence and emits the newTokenAvailable event for the transports to renew their credentials with the Azure IoT hub instance and stay connected.

Extends

EventEmitter

Properties

type

Methods

fromConnectionString(string, number, number)

Creates a new SharedAccessKeyAuthenticationProvider from a connection string
getDeviceCredentials()
getDeviceCredentials(Callback<TransportConfig>)

This method is used by the transports to gets the most current device credentials in the form of a TransportConfig object.
setTokenRenewalValues(number, number)

This method allows the caller to set new values for the authentication renewal.

This function completes synchronously, BUT, will cause actions to occur asynchronously. If the provider is already doing token renewals, for instance - if a network connection has been make, invoking this function will cause a new renewal to take place on the almost immediately. Depending on the protocol, this could cause a disconnect and reconnect to occur. However, if renewals are NOT currently occurring, we simply save off the new values for use later.
stop()

Stops the timer used to renew to SAS token.

Inherited Methods

addListener<E>(string | symbol, (args: any[]) => void)

Alias for emitter.on(eventName, listener).
emit<E>(string | symbol, any[])

Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

Returns true if the event had listeners, false otherwise.

import { EventEmitter } from 'node:events';
const myEmitter = new EventEmitter();

// First listener
myEmitter.on('event', function firstListener() {
  console.log('Helloooo! first listener');
});
// Second listener
myEmitter.on('event', function secondListener(arg1, arg2) {
  console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
});
// Third listener
myEmitter.on('event', function thirdListener(...args) {
  const parameters = args.join(', ');
  console.log(`event with parameters ${parameters} in third listener`);
});

console.log(myEmitter.listeners('event'));

myEmitter.emit('event', 1, 2, 3, 4, 5);

// Prints:
// [
//   [Function: firstListener],
//   [Function: secondListener],
//   [Function: thirdListener]
// ]
// Helloooo! first listener
// event with parameters 1, 2 in second listener
// event with parameters 1, 2, 3, 4, 5 in third listener
eventNames()

Returns an array listing the events for which the emitter has registered listeners.

import { EventEmitter } from 'node:events';

const myEE = new EventEmitter();
myEE.on('foo', () => {});
myEE.on('bar', () => {});

const sym = Symbol('symbol');
myEE.on(sym, () => {});

console.log(myEE.eventNames());
// Prints: [ 'foo', 'bar', Symbol(symbol) ]
getMaxListeners()

Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to events.defaultMaxListeners.
listenerCount<E>(string | symbol, (args: any[]) => void)

Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.
listeners<E>(string | symbol)

Returns a copy of the array of listeners for the event named eventName.

server.on('connection', (stream) => {
  console.log('someone connected!');
});
console.log(util.inspect(server.listeners('connection')));
// Prints: [ [Function] ]
off<E>(string | symbol, (args: any[]) => void)

Alias for emitter.removeListener().
on<E>(string | symbol, (args: any[]) => void)

Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.on('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.on('foo', () => console.log('a'));
myEE.prependListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a
once<E>(string | symbol, (args: any[]) => void)

Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

server.once('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.once('foo', () => console.log('a'));
myEE.prependOnceListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a
prependListener<E>(string | symbol, (args: any[]) => void)

Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.prependListener('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.
prependOnceListener<E>(string | symbol, (args: any[]) => void)

Adds a one-time listener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

server.prependOnceListener('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.
rawListeners<E>(string | symbol)

Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.once('log', () => console.log('log once'));

// Returns a new Array with a function `onceWrapper` which has a property
// `listener` which contains the original listener bound above
const listeners = emitter.rawListeners('log');
const logFnWrapper = listeners[0];

// Logs "log once" to the console and does not unbind the `once` event
logFnWrapper.listener();

// Logs "log once" to the console and removes the listener
logFnWrapper();

emitter.on('log', () => console.log('log persistently'));
// Will return a new Array with a single function bound by `.on()` above
const newListeners = emitter.rawListeners('log');

// Logs "log persistently" twice
newListeners[0]();
emitter.emit('log');
removeAllListeners<E>(string | symbol)

Removes all listeners, or those of the specified eventName.

It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

Returns a reference to the EventEmitter, so that calls can be chained.
removeListener<E>(string | symbol, (args: any[]) => void)

Removes the specified listener from the listener array for the event named eventName.

const callback = (stream) => {
  console.log('someone connected!');
};
server.on('connection', callback);
// ...
server.removeListener('connection', callback);

removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them from emit() in progress. Subsequent events behave as expected.

import { EventEmitter } from 'node:events';
class MyEmitter extends EventEmitter {}
const myEmitter = new MyEmitter();

const callbackA = () => {
  console.log('A');
  myEmitter.removeListener('event', callbackB);
};

const callbackB = () => {
  console.log('B');
};

myEmitter.on('event', callbackA);

myEmitter.on('event', callbackB);

// callbackA removes listener callbackB but it will still be called.
// Internal listener array at time of emit [callbackA, callbackB]
myEmitter.emit('event');
// Prints:
//   A
//   B

// callbackB is now removed.
// Internal listener array [callbackA]
myEmitter.emit('event');
// Prints:
//   A

Because listeners are managed using an internal array, calling this will change the position indexes of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping') listener is removed:

import { EventEmitter } from 'node:events';
const ee = new EventEmitter();

function pong() {
  console.log('pong');
}

ee.on('ping', pong);
ee.once('ping', pong);
ee.removeListener('ping', pong);

ee.emit('ping');
ee.emit('ping');

Returns a reference to the EventEmitter, so that calls can be chained.
setMaxListeners(number)

By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

Returns a reference to the EventEmitter, so that calls can be chained.
[captureRejectionSymbol](Error, string | symbol, any[])

The Symbol.for('nodejs.rejection') method is called in case a promise rejection happens when emitting an event and captureRejections is enabled on the emitter. It is possible to use events.captureRejectionSymbol in place of Symbol.for('nodejs.rejection').

import { EventEmitter, captureRejectionSymbol } from 'node:events';

class MyClass extends EventEmitter {
  constructor() {
    super({ captureRejections: true });
  }

  [captureRejectionSymbol](err, event, ...args) {
    console.log('rejection happened for', event, 'with', err, ...args);
    this.destroy(err);
  }

  destroy(err) {
    // Tear the resource down here.
  }
}

Property Details

type 

type: AuthenticationType

Property Value

AuthenticationType

Method Details

fromConnectionString(string, number, number)

Creates a new SharedAccessKeyAuthenticationProvider from a connection string

static function fromConnectionString(connectionString: string, tokenValidTimeInSeconds?: number, tokenRenewalMarginInSeconds?: number): SharedAccessKeyAuthenticationProvider

Parameters

connectionString

string

A device connection string containing the required parameters for authentication with the IoT hub.

tokenValidTimeInSeconds

number

[optional] The number of seconds for which a token is supposed to be valid.

tokenRenewalMarginInSeconds

number

[optional] The number of seconds before the end of the validity period during which the SharedAccessKeyAuthenticationProvider should renew the token.

Returns

SharedAccessKeyAuthenticationProvider

getDeviceCredentials() 

function getDeviceCredentials(): Promise<TransportConfig>

Returns

Promise<TransportConfig>

getDeviceCredentials(Callback<TransportConfig>)

This method is used by the transports to gets the most current device credentials in the form of a TransportConfig object.

function getDeviceCredentials(callback?: Callback<TransportConfig>)

Parameters

callback

Callback<TransportConfig>

optional function that will be called with either an error or a set of device credentials that can be used to authenticate with the IoT hub.

setTokenRenewalValues(number, number)

This method allows the caller to set new values for the authentication renewal.

This function completes synchronously, BUT, will cause actions to occur asynchronously. If the provider is already doing token renewals, for instance - if a network connection has been make, invoking this function will cause a new renewal to take place on the almost immediately. Depending on the protocol, this could cause a disconnect and reconnect to occur. However, if renewals are NOT currently occurring, we simply save off the new values for use later.

function setTokenRenewalValues(tokenValidTimeInSeconds: number, tokenRenewalMarginInSeconds: number)

Parameters

tokenValidTimeInSeconds

number

The number of seconds for which a token is supposed to be valid.

tokenRenewalMarginInSeconds

number

The number of seconds before the end of the validity period during which the SharedAccessKeyAuthenticationProvider should renew the token.

stop()

Stops the timer used to renew to SAS token.

function stop()

Inherited Method Details

addListener<E>(string | symbol, (args: any[]) => void)

Alias for emitter.on(eventName, listener).

function addListener<E>(eventName: string | symbol, listener: (args: any[]) => void): SharedAccessKeyAuthenticationProvider

Parameters

eventName

string | symbol

listener

(args: any[]) => void

Returns

SharedAccessKeyAuthenticationProvider

Inherited From EventEmitter.addListener

emit<E>(string | symbol, any[])

Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

Returns true if the event had listeners, false otherwise.

import { EventEmitter } from 'node:events';
const myEmitter = new EventEmitter();

// First listener
myEmitter.on('event', function firstListener() {
  console.log('Helloooo! first listener');
});
// Second listener
myEmitter.on('event', function secondListener(arg1, arg2) {
  console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
});
// Third listener
myEmitter.on('event', function thirdListener(...args) {
  const parameters = args.join(', ');
  console.log(`event with parameters ${parameters} in third listener`);
});

console.log(myEmitter.listeners('event'));

myEmitter.emit('event', 1, 2, 3, 4, 5);

// Prints:
// [
//   [Function: firstListener],
//   [Function: secondListener],
//   [Function: thirdListener]
// ]
// Helloooo! first listener
// event with parameters 1, 2 in second listener
// event with parameters 1, 2, 3, 4, 5 in third listener

function emit<E>(eventName: string | symbol, args: any[]): boolean

Parameters

eventName

string | symbol

args

any[]

Returns

boolean

Inherited From EventEmitter.emit

eventNames()

Returns an array listing the events for which the emitter has registered listeners.

import { EventEmitter } from 'node:events';

const myEE = new EventEmitter();
myEE.on('foo', () => {});
myEE.on('bar', () => {});

const sym = Symbol('symbol');
myEE.on(sym, () => {});

console.log(myEE.eventNames());
// Prints: [ 'foo', 'bar', Symbol(symbol) ]

function eventNames(): (string | symbol)[]

Returns

(string | symbol)[]

Inherited From EventEmitter.eventNames

getMaxListeners()

Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to events.defaultMaxListeners.

function getMaxListeners(): number

Returns

number

Inherited From EventEmitter.getMaxListeners

listenerCount<E>(string | symbol, (args: any[]) => void)

Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

function listenerCount<E>(eventName: string | symbol, listener?: (args: any[]) => void): number

Parameters

eventName

string | symbol

The name of the event being listened for

listener

(args: any[]) => void

The event handler function

Returns

number

Inherited From EventEmitter.listenerCount

listeners<E>(string | symbol)

Returns a copy of the array of listeners for the event named eventName.

server.on('connection', (stream) => {
  console.log('someone connected!');
});
console.log(util.inspect(server.listeners('connection')));
// Prints: [ [Function] ]

function listeners<E>(eventName: string | symbol): (args: any[]) => void[]

Parameters

eventName

string | symbol

Returns

(args: any[]) => void[]

Inherited From EventEmitter.listeners

off<E>(string | symbol, (args: any[]) => void)

Alias for emitter.removeListener().

function off<E>(eventName: string | symbol, listener: (args: any[]) => void): SharedAccessKeyAuthenticationProvider

Parameters

eventName

string | symbol

listener

(args: any[]) => void

Returns

SharedAccessKeyAuthenticationProvider

Inherited From EventEmitter.off

on<E>(string | symbol, (args: any[]) => void)

Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.on('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.on('foo', () => console.log('a'));
myEE.prependListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

function on<E>(eventName: string | symbol, listener: (args: any[]) => void): SharedAccessKeyAuthenticationProvider

Parameters

eventName

string | symbol

The name of the event.

listener

(args: any[]) => void

The callback function

Returns

SharedAccessKeyAuthenticationProvider

Inherited From EventEmitter.on

once<E>(string | symbol, (args: any[]) => void)

Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

server.once('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.once('foo', () => console.log('a'));
myEE.prependOnceListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

function once<E>(eventName: string | symbol, listener: (args: any[]) => void): SharedAccessKeyAuthenticationProvider

Parameters

eventName

string | symbol

The name of the event.

listener

(args: any[]) => void

The callback function

Returns

SharedAccessKeyAuthenticationProvider

Inherited From EventEmitter.once

prependListener<E>(string | symbol, (args: any[]) => void)

Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.prependListener('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

function prependListener<E>(eventName: string | symbol, listener: (args: any[]) => void): SharedAccessKeyAuthenticationProvider

Parameters

eventName

string | symbol

The name of the event.

listener

(args: any[]) => void

The callback function

Returns

SharedAccessKeyAuthenticationProvider

Inherited From EventEmitter.prependListener

prependOnceListener<E>(string | symbol, (args: any[]) => void)

Adds a one-time listener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

server.prependOnceListener('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

function prependOnceListener<E>(eventName: string | symbol, listener: (args: any[]) => void): SharedAccessKeyAuthenticationProvider

Parameters

eventName

string | symbol

The name of the event.

listener

(args: any[]) => void

The callback function

Returns

SharedAccessKeyAuthenticationProvider

Inherited From EventEmitter.prependOnceListener

rawListeners<E>(string | symbol)

Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.once('log', () => console.log('log once'));

// Returns a new Array with a function `onceWrapper` which has a property
// `listener` which contains the original listener bound above
const listeners = emitter.rawListeners('log');
const logFnWrapper = listeners[0];

// Logs "log once" to the console and does not unbind the `once` event
logFnWrapper.listener();

// Logs "log once" to the console and removes the listener
logFnWrapper();

emitter.on('log', () => console.log('log persistently'));
// Will return a new Array with a single function bound by `.on()` above
const newListeners = emitter.rawListeners('log');

// Logs "log persistently" twice
newListeners[0]();
emitter.emit('log');

function rawListeners<E>(eventName: string | symbol): (args: any[]) => void[]

Parameters

eventName

string | symbol

Returns

(args: any[]) => void[]

Inherited From EventEmitter.rawListeners

removeAllListeners<E>(string | symbol)

Removes all listeners, or those of the specified eventName.

It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

Returns a reference to the EventEmitter, so that calls can be chained.

function removeAllListeners<E>(eventName?: string | symbol): SharedAccessKeyAuthenticationProvider

Parameters

eventName

string | symbol

Returns

SharedAccessKeyAuthenticationProvider

Inherited From EventEmitter.removeAllListeners

removeListener<E>(string | symbol, (args: any[]) => void)

Removes the specified listener from the listener array for the event named eventName.

const callback = (stream) => {
  console.log('someone connected!');
};
server.on('connection', callback);
// ...
server.removeListener('connection', callback);

removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them from emit() in progress. Subsequent events behave as expected.

import { EventEmitter } from 'node:events';
class MyEmitter extends EventEmitter {}
const myEmitter = new MyEmitter();

const callbackA = () => {
  console.log('A');
  myEmitter.removeListener('event', callbackB);
};

const callbackB = () => {
  console.log('B');
};

myEmitter.on('event', callbackA);

myEmitter.on('event', callbackB);

// callbackA removes listener callbackB but it will still be called.
// Internal listener array at time of emit [callbackA, callbackB]
myEmitter.emit('event');
// Prints:
//   A
//   B

// callbackB is now removed.
// Internal listener array [callbackA]
myEmitter.emit('event');
// Prints:
//   A

Because listeners are managed using an internal array, calling this will change the position indexes of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping') listener is removed:

import { EventEmitter } from 'node:events';
const ee = new EventEmitter();

function pong() {
  console.log('pong');
}

ee.on('ping', pong);
ee.once('ping', pong);
ee.removeListener('ping', pong);

ee.emit('ping');
ee.emit('ping');

Returns a reference to the EventEmitter, so that calls can be chained.

function removeListener<E>(eventName: string | symbol, listener: (args: any[]) => void): SharedAccessKeyAuthenticationProvider

Parameters

eventName

string | symbol

listener

(args: any[]) => void

Returns

SharedAccessKeyAuthenticationProvider

Inherited From EventEmitter.removeListener

setMaxListeners(number)

By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

Returns a reference to the EventEmitter, so that calls can be chained.

function setMaxListeners(n: number): SharedAccessKeyAuthenticationProvider

Parameters

n

number

Returns

SharedAccessKeyAuthenticationProvider

Inherited From EventEmitter.setMaxListeners

[captureRejectionSymbol](Error, string | symbol, any[])

The Symbol.for('nodejs.rejection') method is called in case a promise rejection happens when emitting an event and captureRejections is enabled on the emitter. It is possible to use events.captureRejectionSymbol in place of Symbol.for('nodejs.rejection').

import { EventEmitter, captureRejectionSymbol } from 'node:events';

class MyClass extends EventEmitter {
  constructor() {
    super({ captureRejections: true });
  }

  [captureRejectionSymbol](err, event, ...args) {
    console.log('rejection happened for', event, 'with', err, ...args);
    this.destroy(err);
  }

  destroy(err) {
    // Tear the resource down here.
  }
}

function [captureRejectionSymbol](error: Error, event: string | symbol, args: any[])

Parameters

error

Error

event

string | symbol

args

any[]

Inherited From EventEmitter.__@captureRejectionSymbol@127