Cipher
Related Doc:
package crypto
All Readable stream implementations must provide an implementation of the readable._read() method to fetch data from the underlying resource.
All Readable stream implementations must provide an implementation of the readable._read() method to fetch data from the underlying resource.
When readable._read() is called, if data is available from the resource, the implementation should begin pushing that data into the read queue using the this.push(dataChunk) method. _read() should continue reading from the resource and pushing data until readable.push() returns false. Only when _read() is called again after it has stopped should it resume pushing additional data onto the queue.
the number of bytes to read asynchronously
All Writable stream implementations must provide a writable._write() method to send data to the underlying resource.
All Writable stream implementations must provide a writable._write() method to send data to the underlying resource.
The chunk to be written. Will always be a buffer unless the decodeStrings option was set to false.
Call this function (optionally with an error argument) when processing is complete for the supplied chunk.
All Writable stream implementations must provide a writable._write() method to send data to the underlying resource.
All Writable stream implementations must provide a writable._write() method to send data to the underlying resource.
The chunk to be written. Will always be a buffer unless the decodeStrings option was set to false.
If the chunk is a string, then encoding is the character encoding of that string. If chunk is a Buffer, or if the stream is operating in object mode, encoding may be ignored.
Call this function (optionally with an error argument) when processing is complete for the supplied chunk.
The writable._writev() method may be implemented in addition to writable._write() in stream implementations that are capable of processing multiple chunks of data at once.
The writable._writev() method may be implemented in addition to writable._write() in stream implementations that are capable of processing multiple chunks of data at once. If implemented, the method will be called with all chunks of data currently buffered in the write queue.
The chunks to be written. Each chunk has following format: { chunk: ..., encoding: ... }.
A callback function (optionally with an error argument) to be invoked when processing is complete for the supplied chunks.
Alias for emitter.on(eventName, listener).
Alias for emitter.on(eventName, listener).
emitter.addListener(eventName, listener)
on()
Forces buffering of all writes.
Forces buffering of all writes. Buffered data will be flushed either at stream.uncork() or at stream.end() call.
writable.cork()
Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.
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.
the event name
the event arguments
emitter.emit(name[, arg1][, arg2][, ...])
Call this method when no more data will be written to the stream.
Call this method when no more data will be written to the stream. If supplied, the callback is attached as a listener on the 'finish' event. Calling stream.write() after calling stream.end() will raise an error.
writable.end([chunk][, encoding][, callback])
Call this method when no more data will be written to the stream.
Call this method when no more data will be written to the stream. If supplied, the callback is attached as a listener on the 'finish' event. Calling stream.write() after calling stream.end() will raise an error.
the Callback for when this chunk of data is flushed
writable.end([chunk][, encoding][, callback])
Call this method when no more data will be written to the stream.
Call this method when no more data will be written to the stream. If supplied, the callback is attached as a listener on the 'finish' event. Calling stream.write() after calling stream.end() will raise an error.
The data to write (<String> | <Buffer>)
writable.end([chunk][, encoding][, callback])
Call this method when no more data will be written to the stream.
Call this method when no more data will be written to the stream. If supplied, the callback is attached as a listener on the 'finish' event. Calling stream.write() after calling stream.end() will raise an error.
The data to write (<String> | <Buffer>)
The encoding, if chunk is a String
writable.end([chunk][, encoding][, callback])
Call this method when no more data will be written to the stream.
Call this method when no more data will be written to the stream. If supplied, the callback is attached as a listener on the 'finish' event. Calling stream.write() after calling stream.end() will raise an error.
The data to write (<String> | <Buffer>)
The encoding, if chunk is a String
writable.end([chunk][, encoding][, callback])
Call this method when no more data will be written to the stream.
Call this method when no more data will be written to the stream. If supplied, the callback is attached as a listener on the 'finish' event. Calling stream.write() after calling stream.end() will raise an error.
The data to write (<String> | <Buffer>)
writable.end([chunk][, encoding][, callback])
Call this method when no more data will be written to the stream.
Call this method when no more data will be written to the stream. If supplied, the callback is attached as a listener on the 'finish' event. Calling stream.write() after calling stream.end() will raise an error.
The data to write (<String> | <Buffer>)
the Callback for when this chunk of data is flushed
writable.end([chunk][, encoding][, callback])
Returns any remaining enciphered contents.
Returns any remaining enciphered contents. If output_encoding parameter is one of 'binary', 'base64' or 'hex', a string is returned. If an output_encoding is not provided, a Buffer is returned.
Once the cipher.final() method has been called, the Cipher object can no longer be used to encrypt data. Attempts to call cipher.final() more than once will result in an error being thrown.
cipher.final([output_encoding])
Returns any remaining enciphered contents.
Returns any remaining enciphered contents. If output_encoding parameter is one of 'binary', 'base64' or 'hex', a string is returned. If an output_encoding is not provided, a Buffer is returned.
Once the cipher.final() method has been called, the Cipher object can no longer be used to encrypt data. Attempts to call cipher.final() more than once will result in an error being thrown.
cipher.final([output_encoding])
When using an authenticated encryption mode (only GCM is currently supported), the cipher.getAuthTag() method returns a Buffer containing the authentication tag that has been computed from the given data.
When using an authenticated encryption mode (only GCM is currently supported), the cipher.getAuthTag() method returns a Buffer containing the authentication tag that has been computed from the given data.
The cipher.getAuthTag() method should only be called after encryption has been completed using the cipher.final() method.
cipher.getAuthTag()
Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to EventEmitter.defaultMaxListeners.
Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to EventEmitter.defaultMaxListeners.
emitter.getMaxListeners()
setMaxListeners()
This method returns whether or not the readable has been explicitly paused by client code (using stream.pause() without a corresponding stream.resume()).
This method returns whether or not the readable has been explicitly paused by client code (using stream.pause() without a corresponding stream.resume()).
readable.isPaused()
Returns the number of listeners listening to the event named eventName.
Returns the number of listeners listening to the event named eventName.
emitter.listenerCount(eventName)
Returns a copy of the array of listeners for the event named eventName.
Returns a copy of the array of listeners for the event named eventName.
emitter.listeners(eventName)
Adds the listener function to the end of the listeners array for the event named eventName.
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.
Returns a reference to the EventEmitter so calls can be chained.
emitter.on(eventName, listener)
Adds a one time listener function for the event named eventName.
Adds a one time listener function for the event named eventName. This listener is invoked only the next time eventName is triggered, after which it is removed.
emitter.once(eventName, listener)
This method will cause a stream in flowing mode to stop emitting 'data' events, switching out of flowing mode.
This method will cause a stream in flowing mode to stop emitting 'data' events, switching out of flowing mode. Any data that becomes available will remain in the internal buffer.
readable.pause()
This method pulls all the data out of a readable stream, and writes it to the supplied destination, automatically managing the flow so that the destination is not overwhelmed by a fast readable stream.
This method pulls all the data out of a readable stream, and writes it to the supplied destination, automatically managing the flow so that the destination is not overwhelmed by a fast readable stream. Multiple destinations can be piped to safely.
readable.pipe(destination[, options])
When chunk is a Buffer or string, the chunk of data will be added to the internal queue for users of the stream to consume.
When chunk is a Buffer or string, the chunk of data will be added to the internal queue for users of the stream to consume. Passing chunk as null signals the end of the stream (EOF), after which no more data can be written.
When the Readable is operating in paused mode, the data added with readable.push() can be read out by calling the readable.read() method when the 'readable' event is emitted.
When the Readable is operating in flowing mode, the data added with readable.push() will be delivered by emitting a 'data' event.
the chunk of data to push into the read queue
true if additional chunks of data may continued to be pushed; false otherwise.
When chunk is a Buffer or string, the chunk of data will be added to the internal queue for users of the stream to consume.
When chunk is a Buffer or string, the chunk of data will be added to the internal queue for users of the stream to consume. Passing chunk as null signals the end of the stream (EOF), after which no more data can be written.
When the Readable is operating in paused mode, the data added with readable.push() can be read out by calling the readable.read() method when the 'readable' event is emitted.
When the Readable is operating in flowing mode, the data added with readable.push() will be delivered by emitting a 'data' event.
the chunk of data to push into the read queue
the encoding of String chunks. Must be a valid Buffer encoding, such as 'utf8' or 'ascii'
true if additional chunks of data may continued to be pushed; false otherwise.
The read() method pulls some data out of the internal buffer and returns it.
The read() method pulls some data out of the internal buffer and returns it. If there is no data available, then it will return null.
If you pass in a size argument, then it will return that many bytes. If size bytes are not available, then it will return null, unless we've ended, in which case it will return the data remaining in the buffer.
If you do not specify a size argument, then it will return all the data in the internal buffer.
This method should only be called in paused mode. In flowing mode, this method is called automatically until the internal buffer is drained.
readable.read([size])
Removes all listeners, or those of the specified eventName.
Removes all listeners, or those of the specified eventName.
Note that 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 calls can be chained.
emitter.removeAllListeners([eventName])
Removes all listeners, or those of the specified eventName.
Removes all listeners, or those of the specified eventName.
Note that 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 calls can be chained.
emitter.removeAllListeners([eventName])
Removes the specified listener from the listener array for the event named eventName.
Removes the specified listener from the listener array for the event named eventName. 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.
Note that once an event has been emitted, all listeners attached to it at the time of emitting will be 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 will behave as expected.
emitter.removeListener(eventName, listener)
This method will cause the readable stream to resume emitting 'data' events.
This method will cause the readable stream to resume emitting 'data' events. This method will switch the stream into flowing mode. If you do not want to consume the data from a stream, but you do want to get to its 'end' event, you can call stream.resume() to open the flow of data.
readable.resume()
When using an authenticated encryption mode (only GCM is currently supported), the cipher.setAAD() method sets the value used for the additional authenticated data (AAD) input parameter.
When using an authenticated encryption mode (only GCM is currently supported), the cipher.setAAD() method sets the value used for the additional authenticated data (AAD) input parameter.
cipher.setAAD(buffer)
When using block encryption algorithms, the Cipher class will automatically add padding to the input data to the appropriate block size.
When using block encryption algorithms, the Cipher class will automatically add padding to the input data to the appropriate block size. To disable the default padding call cipher.setAutoPadding(false).
When auto_padding is false, the length of the entire input data must be a multiple of the cipher's block size or cipher.final() will throw an Error. Disabling automatic padding is useful for non-standard padding, for instance using 0x0 instead of PKCS padding.
The cipher.setAutoPadding() method must be called before cipher.final().
cipher.setAutoPadding(auto_padding=true)
Sets the default encoding for a writable stream.
Sets the default encoding for a writable stream.
writable.setDefaultEncoding(encoding)
Call this function to cause the stream to return strings of the specified encoding instead of Buffer objects.
Call this function to cause the stream to return strings of the specified encoding instead of Buffer objects. For example, if you do readable.setEncoding('utf8'), then the output data will be interpreted as UTF-8 data, and returned as strings. If you do readable.setEncoding('hex'), then the data will be encoded in hexadecimal string format.
This properly handles multi-byte characters that would otherwise be potentially mangled if you simply pulled the Buffers directly and called buf.toString(encoding) on them. If you want to read the data as strings, always use this method.
Also you can disable any encoding at all with readable.setEncoding(null). This approach is very useful if you deal with binary data or with large multi-byte strings spread out over multiple chunks.
readable.setEncoding(encoding)
By default EventEmitters will print a warning if more than 10 listeners are added for a particular event.
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. Obviously, not all events should be limited to just 10 listeners. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) for to indicate an unlimited number of listeners.
Returns a reference to the EventEmitter so calls can be chained.
emitter.setMaxListeners(n)
Flush all data, buffered since stream.cork() call.
Flush all data, buffered since stream.cork() call.
writable.uncork()
This method will remove the hooks set up for a previous stream.pipe() call.
This method will remove the hooks set up for a previous stream.pipe() call.
If the destination is not specified, then all pipes are removed.
If the destination is specified, but no pipe is set up for it, then this is a no-op.
readable.unpipe([destination])
This is useful in certain cases where a stream is being consumed by a parser, which needs to "un-consume" some data that it has optimistically pulled out of the source, so that the stream can be passed on to some other party.
This is useful in certain cases where a stream is being consumed by a parser, which needs to "un-consume" some data that it has optimistically pulled out of the source, so that the stream can be passed on to some other party.
Note that stream.unshift(chunk) cannot be called after the 'end' event has been triggered; a runtime error will be raised.
If you find that you must often call stream.unshift(chunk) in your programs, consider implementing a Transform stream instead.
readable.unshift(chunk)
Updates the cipher with data.
Updates the cipher with data. If the input_encoding argument is given, it's value must be one of 'utf8', 'ascii', or 'binary' and the data argument is a string using the specified encoding. If the input_encoding argument is not given, data must be a Buffer. If data is a Buffer then input_encoding is ignored.
The output_encoding specifies the output format of the enciphered data, and can be 'binary', 'base64' or 'hex'. If the output_encoding is specified, a string using the specified encoding is returned. If no output_encoding is provided, a Buffer is returned.
The cipher.update() method can be called multiple times with new data until cipher.final() is called. Calling cipher.update() after cipher.final() will result in an error being thrown.
cipher.update(data[, input_encoding][, output_encoding])
Updates the cipher with data.
Updates the cipher with data. If the input_encoding argument is given, it's value must be one of 'utf8', 'ascii', or 'binary' and the data argument is a string using the specified encoding. If the input_encoding argument is not given, data must be a Buffer. If data is a Buffer then input_encoding is ignored.
The output_encoding specifies the output format of the enciphered data, and can be 'binary', 'base64' or 'hex'. If the output_encoding is specified, a string using the specified encoding is returned. If no output_encoding is provided, a Buffer is returned.
The cipher.update() method can be called multiple times with new data until cipher.final() is called. Calling cipher.update() after cipher.final() will result in an error being thrown.
cipher.update(data[, input_encoding][, output_encoding])
Versions of Node.js prior to v0.10 had streams that did not implement the entire Streams API as it is today.
Versions of Node.js prior to v0.10 had streams that did not implement the entire Streams API as it is today. (See Compatibility for more information.)
If you are using an older Node.js library that emits 'data' events and has a stream.pause() method that is advisory only, then you can use the wrap() method to create a Readable stream that uses the old stream as its data source.
You will very rarely ever need to call this function, but it exists as a convenience for interacting with old Node.js programs and libraries.
readable.wrap(stream)
Flush all data, buffered since stream.cork() call.
Flush all data, buffered since stream.cork() call.
The data to write (<String> | <Buffer>)
The encoding, if chunk is a String
the Callback for when this chunk of data is flushed
true, if the data was handled completely
writable.write(chunk[, encoding][, callback])
Flush all data, buffered since stream.cork() call.
Flush all data, buffered since stream.cork() call.
The data to write (<String> | <Buffer>)
The encoding, if chunk is a String
true, if the data was handled completely
writable.write(chunk[, encoding][, callback])
Flush all data, buffered since stream.cork() call.
Flush all data, buffered since stream.cork() call.
The data to write (<String> | <Buffer>)
the Callback for when this chunk of data is flushed
true, if the data was handled completely
writable.write(chunk[, encoding][, callback])
Instances of the Cipher class are used to encrypt data. The class can be used in one of two ways:
The crypto.createCipher() or crypto.createCipheriv() methods are used to create Cipher instances. Cipher objects are not to be created directly using the new keyword.