| java.lang.Object
 com.sun.midp.crypto.Cipher
All known Subclasses: com.sun.midp.crypto.RSA, com.sun.midp.crypto.DES, com.sun.midp.crypto.BlockCipherBase, com.sun.midp.crypto.AES, com.sun.midp.crypto.ARC4,
| Cipher | | abstract public class Cipher (Code) | | Implements an abstract class that generalizes all ciphers. It is
modelled after javax.crypto.Cipher.
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| Field Summary | |
| final public static int | DECRYPT_MODE
Used in init to indicate decryption mode. | | final public static int | ENCRYPT_MODE
Used in init to indicate encryption mode. | | final protected static int | MODE_UNINITIALIZED
Flag to indicate the current cipher algorithm is unknown. |
| Constructor Summary | |
| protected | Cipher()
Protected constructor. |
| Method Summary | |
| abstract public int | doFinal(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset)
Encrypts or decrypts data in a single-part operation, or finishes a
multiple-part operation. | | public byte[] | getIV()
Returns the initialization vector (IV) in a new buffer. | | final public static Cipher | getInstance(String transformation)
Generates a Cipher object that implements the specified
transformation.
Parameters:
transformation - the name of the transformation, e.g.,DES/CBC/PKCS5Padding.See Appendix A in theJava Cryptography Extension Reference Guidefor information about standard transformation names. | | public void | init(int opmode, Key key)
Initializes this cipher with a key.
The cipher is initialized for one of the following operations:
encryption, decryption, depending
on the value of opmode.
If this cipher requires any algorithm parameters that cannot be
derived from the given key, the underlying cipher
implementation is supposed to generate the required parameters itself
(using provider-specific default or random values) if it is being
initialized for encryption, and raise an
InvalidKeyException if it is being
initialized for decryption.
Note that when a Cipher object is initialized, it loses all
previously-acquired state. | | abstract public void | init(int opmode, Key key, CryptoParameter params)
Initializes this cipher with a key and a set of algorithm
parameters.
The cipher is initialized for one of the following operations:
encryption or decryption depending
on the value of opmode.
If this cipher requires any algorithm parameters and
params is null, the underlying cipher implementation is
supposed to generate the required parameters itself (using
provider-specific default or random values) if it is being
initialized for encryption, and raise an
InvalidAlgorithmParameterException if it is being
initialized for decryption.
Note that when a Cipher object is initialized, it loses all
previously-acquired state. | | abstract protected void | setChainingModeAndPadding(String mode, String padding)
Called by the factory method to set the mode and padding parameters. | | abstract public int | update(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset)
Continues a multiple-part encryption or decryption operation
(depending on how this cipher was initialized), processing another data
part.
The first inputLen bytes in the input
buffer, starting at inputOffset inclusive, are processed,
and the result is stored in the output buffer, starting at
outputOffset inclusive.
If the output buffer is too small to hold the result,
a ShortBufferException is thrown. |
| DECRYPT_MODE | | final public static int DECRYPT_MODE(Code) | | Used in init to indicate decryption mode.
|
| ENCRYPT_MODE | | final public static int ENCRYPT_MODE(Code) | | Used in init to indicate encryption mode.
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| MODE_UNINITIALIZED | | final protected static int MODE_UNINITIALIZED(Code) | | Flag to indicate the current cipher algorithm is unknown.
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| Cipher | | protected Cipher()(Code) | | Protected constructor.
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| doFinal | | abstract public int doFinal(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset) throws IllegalStateException, ShortBufferException, IllegalBlockSizeException, BadPaddingException(Code) | | Encrypts or decrypts data in a single-part operation, or finishes a
multiple-part operation. The data is encrypted or decrypted,
depending on how this cipher was initialized.
The first inputLen bytes in the input
buffer, starting at inputOffset inclusive, and any input
bytes that may have been buffered during a previous
update operation, are processed, with padding
(if requested) being applied.
The result is stored in the output buffer, starting at
outputOffset inclusive.
If the output buffer is too small to hold the result,
a ShortBufferException is thrown. In this case, repeat this
call with a larger output buffer.
Upon finishing, this method resets this cipher object to the state
it was in when previously initialized via a call to init.
That is, the object is reset and available to encrypt or decrypt
(depending on the operation mode that was specified in the call to
init) more data.
Note: if any exception is thrown, this cipher object may need to
be reset before it can be used again.
Note: this method should be copy-safe, which means the
input and output buffers can reference
the same byte array and no unprocessed input data is overwritten
when the result is copied into the output buffer.
Parameters:
input - the input buffer
Parameters:
inputOffset - the offset in input where the inputstarts
Parameters:
inputLen - the input length
Parameters:
output - the buffer for the result
Parameters:
outputOffset - the offset in output where the resultis stored the number of bytes stored in output
exception:
IllegalStateException - if this cipher is in a wrong state(e.g., has not been initialized)
exception:
IllegalBlockSizeException - if this cipher is a block cipher,no padding has been requested (only in encryption mode), and the totalinput length of the data processed by this cipher is not a multiple ofblock size
exception:
ShortBufferException - if the given output buffer is too smallto hold the result
exception:
BadPaddingException - if this cipher is in decryption mode,and (un)padding has been requested, but the decrypted data is notbounded by the appropriate padding bytes |
| getIV | | public byte[] getIV()(Code) | | Returns the initialization vector (IV) in a new buffer.
This is useful in the case where a random IV was created.
the initialization vector in a new buffer,or null if the underlying algorithm doesnot use an IV, or if the IV has not yet been set. |
| init | | public void init(int opmode, Key key) throws InvalidKeyException(Code) | | Initializes this cipher with a key.
The cipher is initialized for one of the following operations:
encryption, decryption, depending
on the value of opmode.
If this cipher requires any algorithm parameters that cannot be
derived from the given key, the underlying cipher
implementation is supposed to generate the required parameters itself
(using provider-specific default or random values) if it is being
initialized for encryption, and raise an
InvalidKeyException if it is being
initialized for decryption.
Note that when a Cipher object is initialized, it loses all
previously-acquired state. In other words, initializing a Cipher is
equivalent to creating a new instance of that Cipher and initializing
it.
Parameters:
opmode - the operation mode of this cipher (this is one ofthe following:ENCRYPT_MODE or DECRYPT_MODE)
Parameters:
key - the key
exception:
InvalidKeyException - if the given key is inappropriate forinitializing this cipher, or if this cipher is being initialized fordecryption and requires algorithm parameters that cannot bedetermined from the given key, or if the given key has a keysize thatexceeds the maximum allowable keysize. |
| init | | abstract public void init(int opmode, Key key, CryptoParameter params) throws InvalidKeyException, InvalidAlgorithmParameterException(Code) | | Initializes this cipher with a key and a set of algorithm
parameters.
The cipher is initialized for one of the following operations:
encryption or decryption depending
on the value of opmode.
If this cipher requires any algorithm parameters and
params is null, the underlying cipher implementation is
supposed to generate the required parameters itself (using
provider-specific default or random values) if it is being
initialized for encryption, and raise an
InvalidAlgorithmParameterException if it is being
initialized for decryption.
Note that when a Cipher object is initialized, it loses all
previously-acquired state. In other words, initializing a Cipher is
equivalent to creating a new instance of that Cipher and initializing
it.
Parameters:
opmode - the operation mode of this cipher (this is one of thefollowing:ENCRYPT_MODE or DECRYPT_MODE)
Parameters:
key - the encryption key
Parameters:
params - the algorithm parameters
exception:
InvalidKeyException - if the given key is inappropriate forinitializing this cipher, or its keysize exceeds the maximum allowablekeysize.
exception:
InvalidAlgorithmParameterException - if the given algorithmparameters are inappropriate for this cipher,or this cipher is being initialized for decryption and requiresalgorithm parameters and params is null, or the givenalgorithm parameters imply a cryptographic strength that would exceedthe legal limits. |
| setChainingModeAndPadding | | abstract protected void setChainingModeAndPadding(String mode, String padding) throws NoSuchPaddingException(Code) | | Called by the factory method to set the mode and padding parameters.
Need because Class.newInstance does not take args.
Parameters:
mode - the chaining mode parsed from the transformation parameterof getInstance and upper cased
Parameters:
padding - the paddinge parsed from the transformation parameter ofgetInstance and upper cased
exception:
NoSuchPaddingException - if transformationcontains a padding scheme that is not available. |
| update | | abstract public int update(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset) throws IllegalStateException, ShortBufferException(Code) | | Continues a multiple-part encryption or decryption operation
(depending on how this cipher was initialized), processing another data
part.
The first inputLen bytes in the input
buffer, starting at inputOffset inclusive, are processed,
and the result is stored in the output buffer, starting at
outputOffset inclusive.
If the output buffer is too small to hold the result,
a ShortBufferException is thrown. In this case, repeat this
call with a larger output buffer.
If inputLen is zero, this method returns
a length of zero.
Note: this method should be copy-safe, which means the
input and output buffers can reference
the same byte array and no unprocessed input data is overwritten
when the result is copied into the output buffer.
Parameters:
input - the input buffer
Parameters:
inputOffset - the offset in input where the inputstarts
Parameters:
inputLen - the input length
Parameters:
output - the buffer for the result
Parameters:
outputOffset - the offset in output where the resultis stored the number of bytes stored in output
exception:
IllegalStateException - if this cipher is in a wrong state(e.g., has not been initialized)
exception:
ShortBufferException - if the given output buffer is too smallto hold the result |
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