CipherInputStream (Java SE 11 & JDK 11 ) (original) (raw)

java.lang.Object
- java.io.InputStream
- - java.io.FilterInputStream
    - - javax.crypto.CipherInputStream
All Implemented Interfaces:
[Closeable](../../java/io/Closeable.html "interface in java.io"), [AutoCloseable](../../java/lang/AutoCloseable.html "interface in java.lang")

public class CipherInputStream
extends FilterInputStream
A CipherInputStream is composed of an InputStream and a Cipher so that read() methods return data that are read in from the underlying InputStream but have been additionally processed by the Cipher. The Cipher must be fully initialized before being used by a CipherInputStream.
For example, if the Cipher is initialized for decryption, the CipherInputStream will attempt to read in data and decrypt them, before returning the decrypted data.
This class adheres strictly to the semantics, especially the failure semantics, of its ancestor classes java.io.FilterInputStream and java.io.InputStream. This class has exactly those methods specified in its ancestor classes, and overrides them all. Moreover, this class catches all exceptions that are not thrown by its ancestor classes. In particular, theskip method skips, and the available method counts only data that have been processed by the encapsulated Cipher. This class may catch BadPaddingException and other exceptions thrown by failed integrity checks during decryption. These exceptions are not re-thrown, so the client may not be informed that integrity checks failed. Because of this behavior, this class may not be suitable for use with decryption in an authenticated mode of operation (e.g. GCM). Applications that require authenticated encryption can use the Cipher API directly as an alternative to using this class.
It is crucial for a programmer using this class not to use methods that are not defined or overriden in this class (such as a new method or constructor that is later added to one of the super classes), because the design and implementation of those methods are unlikely to have considered security impact with regard to CipherInputStream.
Since:
1.4
See Also:
InputStream, FilterInputStream, Cipher, CipherOutputStream

Field Summary

 * ### Fields declared in class java.io.[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")  
 `[in](../../java/io/FilterInputStream.html#in)`

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CipherInputStream(InputStream is)	Constructs a CipherInputStream from an InputStream without specifying a Cipher.
	CipherInputStream(InputStream is,Cipher c)	Constructs a CipherInputStream from an InputStream and a Cipher.

Method Summary

All Methods Instance Methods Concrete Methods

Modifier and Type	Method	Description
int	available()	Returns the number of bytes that can be read from this input stream without blocking.
void	close()	Closes this input stream and releases any system resources associated with the stream.
boolean	markSupported()	Tests if this input stream supports the mark and reset methods, which it does not.
int	read()	Reads the next byte of data from this input stream.
int	read(byte[] b)	Reads up to b.length bytes of data from this input stream into an array of bytes.
int	read(byte[] b, int off, int len)	Reads up to len bytes of data from this input stream into an array of bytes.
long	skip(long n)	Skips n bytes of input from the bytes that can be read from this input stream without blocking.

   * ### Methods declared in class java.io.[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")  
   `[mark](../../java/io/FilterInputStream.html#mark%28int%29), [reset](../../java/io/FilterInputStream.html#reset%28%29)`  
   * ### Methods declared in class java.io.[InputStream](../../java/io/InputStream.html "class in java.io")  
   `[nullInputStream](../../java/io/InputStream.html#nullInputStream%28%29), [readAllBytes](../../java/io/InputStream.html#readAllBytes%28%29), [readNBytes](../../java/io/InputStream.html#readNBytes%28byte%5B%5D,int,int%29), [readNBytes](../../java/io/InputStream.html#readNBytes%28int%29), [transferTo](../../java/io/InputStream.html#transferTo%28java.io.OutputStream%29)`  
   * ### Methods declared in class java.lang.[Object](../../java/lang/Object.html "class in java.lang")  
   `[clone](../../java/lang/Object.html#clone%28%29), [equals](../../java/lang/Object.html#equals%28java.lang.Object%29), [finalize](../../java/lang/Object.html#finalize%28%29), [getClass](../../java/lang/Object.html#getClass%28%29), [hashCode](../../java/lang/Object.html#hashCode%28%29), [notify](../../java/lang/Object.html#notify%28%29), [notifyAll](../../java/lang/Object.html#notifyAll%28%29), [toString](../../java/lang/Object.html#toString%28%29), [wait](../../java/lang/Object.html#wait%28%29), [wait](../../java/lang/Object.html#wait%28long%29), [wait](../../java/lang/Object.html#wait%28long,int%29)`

Constructor Detail

 * #### CipherInputStream  
 public CipherInputStream([InputStream](../../java/io/InputStream.html "class in java.io") is,  
                          [Cipher](Cipher.html "class in javax.crypto") c)  
 Constructs a CipherInputStream from an InputStream and a Cipher.  
 Note: if the specified input stream or cipher is null, a NullPointerException may be thrown later when they are used.  
 Parameters:  
 `is` \- the to-be-processed input stream  
 `c` \- an initialized Cipher object  
 * #### CipherInputStream  
 protected CipherInputStream([InputStream](../../java/io/InputStream.html "class in java.io") is)  
 Constructs a CipherInputStream from an InputStream without specifying a Cipher. This has the effect of constructing a CipherInputStream using a NullCipher.  
 Note: if the specified input stream is null, a NullPointerException may be thrown later when it is used.  
 Parameters:  
 `is` \- the to-be-processed input stream

Method Detail

* #### read  
public int read()  
         throws [IOException](../../java/io/IOException.html "class in java.io")  
Reads the next byte of data from this input stream. The value byte is returned as an `int` in the range`0` to `255`. If no byte is available because the end of the stream has been reached, the value`-1` is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.  
Overrides:  
`[read](../../java/io/FilterInputStream.html#read%28%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Returns:  
the next byte of data, or `-1` if the end of the stream is reached.  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs.  
See Also:  
[FilterInputStream.in](../../java/io/FilterInputStream.html#in)  
* #### read  
public int read(byte[] b)  
         throws [IOException](../../java/io/IOException.html "class in java.io")  
Reads up to `b.length` bytes of data from this input stream into an array of bytes.  
 The `read` method of `InputStream` calls the `read` method of three arguments with the arguments`b`, `0`, and `b.length`.  
Overrides:  
`[read](../../java/io/FilterInputStream.html#read%28byte%5B%5D%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Parameters:  
`b` \- the buffer into which the data is read.  
Returns:  
the total number of bytes read into the buffer, or`-1` is there is no more data because the end of the stream has been reached.  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs.  
See Also:  
[InputStream.read(byte\[\], int, int)](../../java/io/InputStream.html#read%28byte%5B%5D,int,int%29)  
* #### read  
public int read(byte[] b,  
                int off,  
                int len)  
         throws [IOException](../../java/io/IOException.html "class in java.io")  
Reads up to `len` bytes of data from this input stream into an array of bytes. This method blocks until some input is available. If the first argument is `null,` up to`len` bytes are read and discarded.  
Overrides:  
`[read](../../java/io/FilterInputStream.html#read%28byte%5B%5D,int,int%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Parameters:  
`b` \- the buffer into which the data is read.  
`off` \- the start offset in the destination array`buf`  
`len` \- the maximum number of bytes read.  
Returns:  
the total number of bytes read into the buffer, or`-1` if there is no more data because the end of the stream has been reached.  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs.  
See Also:  
[InputStream.read()](../../java/io/InputStream.html#read%28%29)  
* #### skip  
public long skip(long n)  
          throws [IOException](../../java/io/IOException.html "class in java.io")  
Skips `n` bytes of input from the bytes that can be read from this input stream without blocking.  
Fewer bytes than requested might be skipped. The actual number of bytes skipped is equal to `n` or the result of a call to[available](#available%28%29), whichever is smaller. If `n` is less than zero, no bytes are skipped.  
The actual number of bytes skipped is returned.  
Overrides:  
`[skip](../../java/io/FilterInputStream.html#skip%28long%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Parameters:  
`n` \- the number of bytes to be skipped.  
Returns:  
the actual number of bytes skipped.  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs.  
* #### available  
public int available()  
              throws [IOException](../../java/io/IOException.html "class in java.io")  
Returns the number of bytes that can be read from this input stream without blocking. The `available` method of`InputStream` returns `0`. This method**should** be overridden by subclasses.  
Overrides:  
`[available](../../java/io/FilterInputStream.html#available%28%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Returns:  
the number of bytes that can be read from this input stream without blocking.  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs.  
* #### close  
public void close()  
           throws [IOException](../../java/io/IOException.html "class in java.io")  
Closes this input stream and releases any system resources associated with the stream.  
 The `close` method of `CipherInputStream` calls the `close` method of its underlying input stream.  
Specified by:  
`[close](../../java/lang/AutoCloseable.html#close%28%29)` in interface `[AutoCloseable](../../java/lang/AutoCloseable.html "interface in java.lang")`  
Specified by:  
`[close](../../java/io/Closeable.html#close%28%29)` in interface `[Closeable](../../java/io/Closeable.html "interface in java.io")`  
Overrides:  
`[close](../../java/io/FilterInputStream.html#close%28%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs.  
See Also:  
[FilterInputStream.in](../../java/io/FilterInputStream.html#in)  
* #### markSupported  
public boolean markSupported()  
Tests if this input stream supports the `mark` and `reset` methods, which it does not.  
Overrides:  
`[markSupported](../../java/io/FilterInputStream.html#markSupported%28%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Returns:  
`false`, since this class does not support the`mark` and `reset` methods.  
See Also:  
[InputStream.mark(int)](../../java/io/InputStream.html#mark%28int%29), [InputStream.reset()](../../java/io/InputStream.html#reset%28%29)

Report a bug or suggest an enhancement
For further API reference and developer documentation see the Java SE Documentation, which contains more detailed, developer-targeted descriptions with conceptual overviews, definitions of terms, workarounds, and working code examples.
Java is a trademark or registered trademark of Oracle and/or its affiliates in the US and other countries.
Copyright © 1993, 2025, Oracle and/or its affiliates, 500 Oracle Parkway, Redwood Shores, CA 94065 USA.
All rights reserved. Use is subject to license terms and the documentation redistribution policy.

CipherInputStream (Java SE 11 & JDK 11 ) (original) (raw)

Field Summary

Constructor Summary

Method Summary

Constructor Detail

Method Detail