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
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.
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}.
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.