Sign
The Sign class is a utility for generating signatures. It can be used in one of two ways:
As a writable
stream, where data to be signed is written and thesign.sign()method is used to generate and return the signature, orUsing the
sign.update()andsign.sign()methods to produce the signature.
The {@link createSign} method is used to create Sign instances. The argument is the string name of the hash function to use. Sign objects are not to be created directly using the new keyword.
Example: Using Sign and Verify objects as streams:
const {
generateKeyPairSync,
createSign,
createVerify,
} = await import('node:crypto');
const { privateKey, publicKey } = generateKeyPairSync('ec', {
namedCurve: 'sect239k1',
});
const sign = createSign('SHA256');
sign.write('some data to sign');
sign.end();
const signature = sign.sign(privateKey, 'hex');
const verify = createVerify('SHA256');
verify.write('some data to sign');
verify.end();
console.log(verify.verify(publicKey, signature, 'hex'));
// Prints: trueExample: Using the sign.update() and verify.update() methods:
const {
generateKeyPairSync,
createSign,
createVerify,
} = await import('node:crypto');
const { privateKey, publicKey } = generateKeyPairSync('rsa', {
modulusLength: 2048,
});
const sign = createSign('SHA256');
sign.update('some data to sign');
sign.end();
const signature = sign.sign(privateKey);
const verify = createVerify('SHA256');
verify.update('some data to sign');
verify.end();
console.log(verify.verify(publicKey, signature));
// Prints: trueSince
v0.1.92
Properties
Is true if it is safe to call writable.write(), which means the stream has not been destroyed, errored, or ended.
Number of times writable.uncork() needs to be called in order to fully uncork the stream.
Is true after writable.end() has been called. This property does not indicate whether the data has been flushed, for this use writable.writableFinished instead.
Is set to true immediately before the 'finish' event is emitted.
Return the value of highWaterMark passed when creating this Writable.
This property contains the number of bytes (or objects) in the queue ready to be written. The value provides introspection data regarding the status of the highWaterMark.
Is true if the stream's buffer has been full and stream will emit 'drain'.
Getter for the property objectMode of a given Writable stream.
Functions
Alias for emitter.on(eventName, listener).
Event emitter The defined events on documents including:
Destroy the stream. Optionally emit an 'error' event, and emit a 'close' event (unless emitClose is set to false). After this call, the writable stream has ended and subsequent calls to write() or end() will result in an ERR_STREAM_DESTROYED error. This is a destructive and immediate way to destroy a stream. Previous calls to write() may not have drained, and may trigger an ERR_STREAM_DESTROYED error. Use end() instead of destroy if data should flush before close, or wait for the 'drain' event before destroying the stream.
Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.
Calling the writable.end() method signals that no more data will be written to the Writable. The optional chunk and encoding arguments allow one final additional chunk of data to be written immediately before closing the stream.
Returns an array listing the events for which the emitter has registered listeners. The values in the array are strings or Symbols.
Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to {@link defaultMaxListeners}.
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.
Returns a copy of the array of listeners for the event named eventName.
Alias for emitter.removeListener().
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.
Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.
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.
Adds a one-timelistener 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.
Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).
Removes all listeners, or those of the specified eventName.
Removes the specified listener from the listener array for the event named eventName.
The writable.setDefaultEncoding() method sets the default encoding for a Writable stream.
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.
Calculates the signature on all the data passed through using either sign.update() or sign.write().
Updates the Sign content with the given data, the encoding of which is given in inputEncoding. If encoding is not provided, and the data is a string, an encoding of 'utf8' is enforced. If data is a Buffer, TypedArray, orDataView, then inputEncoding is ignored.
The writable.write() method writes some data to the stream, and calls the supplied callback once the data has been fully handled. If an error occurs, the callback will be called with the error as its first argument. The callback is called asynchronously and before 'error' is emitted.