public class CipherInputStream extends FilterInputStream
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, the
skip 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.
InputStream,
FilterInputStream,
Cipher,
CipherOutputStreamin| Modifier | Constructor and 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.
|
| Modifier and Type | Method and 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. |
mark, resetpublic CipherInputStream(InputStream is, Cipher c)
is - the to-be-processed input streamc - an initialized Cipher objectprotected CipherInputStream(InputStream is)
is - the to-be-processed input streampublic int read()
throws IOException
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.
read in class FilterInputStream-1 if the end of the
stream is reached.IOException - if an I/O error occurs.FilterInputStream.inpublic int read(byte[] b)
throws IOException
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.
read in class FilterInputStreamb - the buffer into which the data is read.-1 is there is no more data because the end of
the stream has been reached.IOException - if an I/O error occurs.InputStream.read(byte[], int, int)public int read(byte[] b,
int off,
int len)
throws IOException
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.read in class FilterInputStreamb - the buffer into which the data is read.off - the start offset in the destination array
buflen - the maximum number of bytes read.-1 if there is no more data because the end of
the stream has been reached.IOException - if an I/O error occurs.InputStream.read()public long skip(long n)
throws IOException
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,
whichever is smaller.
If n is less than zero, no bytes are skipped.
The actual number of bytes skipped is returned.
skip in class FilterInputStreamn - the number of bytes to be skipped.IOException - if an I/O error occurs.public int available()
throws IOException
available method of
InputStream returns 0. This method
should be overridden by subclasses.available in class FilterInputStreamIOException - if an I/O error occurs.public void close()
throws IOException
The close method of CipherInputStream
calls the close method of its underlying input
stream.
close in interface Closeableclose in interface AutoCloseableclose in class FilterInputStreamIOException - if an I/O error occurs.FilterInputStream.inpublic boolean markSupported()
mark
and reset methods, which it does not.markSupported in class FilterInputStreamfalse, since this class does not support the
mark and reset methods.InputStream.mark(int),
InputStream.reset() Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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