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java.lang.Object
|
+--javax.crypto.CipherSpi
|
+--com.ibm.crypto.provider.AESCipher
This class implements the AES algorithm in its various modes
(ECB, CFB, OFB, CBC,
PCBC) and padding schemes (PKCS5Padding,
NoPadding).
AES is a 128-bit block cipher with 128, 192, or 256-bit key.
| Fields inherited from interface com.ibm.crypto.provider.AESConstants |
AES_BLOCK_SIZE |
| Constructor Summary | |
AESCipher()
Creates an instance of AES cipher with default ECB mode and PKCS5Padding. |
|
AESCipher(String mode,
String paddingScheme)
Creates an instance of AES cipher with the requested mode and padding. |
|
| Method Summary | |
protected byte[] |
engineDoFinal(byte[] input,
int inputOffset,
int inputLen)
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. |
protected int |
engineDoFinal(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. |
protected int |
engineGetBlockSize()
Returns the block size (in bytes). |
protected byte[] |
engineGetIV()
Returns the initialization vector (IV) in a new buffer. |
protected int |
engineGetKeySize(Key key)
Returns the key size of the given key object. |
protected int |
engineGetOutputSize(int inputLen)
Returns the length in bytes that an output buffer would need to be in order to hold the result of the next update
or doFinal operation, given the input length
inputLen (in bytes). |
protected AlgorithmParameters |
engineGetParameters()
Returns the parameters used with this cipher. |
protected void |
engineInit(int opmode,
Key key,
AlgorithmParameterSpec params,
SecureRandom random)
Initializes this cipher with a key, a set of algorithm parameters, and a source of randomness. |
protected void |
engineInit(int opmode,
Key key,
AlgorithmParameters params,
SecureRandom random)
Initializes this cipher with a key, a set of algorithm parameters, and a source of randomness. |
protected void |
engineInit(int opmode,
Key key,
SecureRandom random)
Initializes this cipher with a key and a source of randomness. |
protected void |
engineSetMode(String mode)
Sets the mode of this cipher. |
protected void |
engineSetPadding(String paddingScheme)
Sets the padding mechanism of this cipher. |
protected Key |
engineUnwrap(byte[] wrappedKey,
String wrappedKeyAlgorithm,
int wrappedKeyType)
Unwrap a previously wrapped key. |
protected byte[] |
engineUpdate(byte[] input,
int inputOffset,
int inputLen)
Continues a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part. |
protected int |
engineUpdate(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. |
protected byte[] |
engineWrap(Key key)
Wrap a key. |
| Methods inherited from class java.lang.Object |
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait |
| Constructor Detail |
public AESCipher()
public AESCipher(String mode,
String paddingScheme)
throws NoSuchAlgorithmException,
NoSuchPaddingException
mode - the cipher modepaddingScheme - the padding mechanism| Method Detail |
protected void engineSetMode(String mode)
throws NoSuchAlgorithmException
mode - the cipher mode
protected void engineSetPadding(String paddingScheme)
throws NoSuchPaddingException
padding - the padding mechanismprotected int engineGetBlockSize()
protected int engineGetOutputSize(int inputLen)
update
or doFinal operation, given the input length
inputLen (in bytes).
This call takes into account any unprocessed (buffered) data from a
previous update call, and padding.
The actual output length of the next update or
doFinal call may be smaller than the length returned by
this method.
inputLen - the input length (in bytes)protected byte[] engineGetIV()
This is useful in the context of password-based encryption or decryption, where the IV is derived from a user-provided passphrase.
protected AlgorithmParameters engineGetParameters()
The returned parameters may be the same that were used to initialize this cipher, or may contain a combination of default and random parameter values used by the underlying cipher implementation if this cipher requires algorithm parameters but was not initialized with any.
protected void engineInit(int opmode,
Key key,
SecureRandom random)
throws InvalidKeyException
The cipher is initialized for one of the following four operations:
encryption, decryption, key wrapping or key unwrapping, depending on
the value of opmode.
If this cipher requires an initialization vector (IV), it will get
it from random.
This behaviour should only be used in encryption or key wrapping
mode, however.
When initializing a cipher that requires an IV for decryption or
key unwrapping, the IV
(same IV that was used for encryption or key wrapping) must be provided
explicitly as a
parameter, in order to get the correct result.
This method also cleans existing buffer and other related state information.
opmode - the operation mode of this cipher (this is one of
the following:
ENCRYPT_MODE, DECRYPT_MODE,
WRAP_MODE or UNWRAP_MODE)key - the secret keyrandom - the source of randomness
protected void engineInit(int opmode,
Key key,
AlgorithmParameterSpec params,
SecureRandom random)
throws InvalidKeyException,
InvalidAlgorithmParameterException
The cipher is initialized for one of the following four operations:
encryption, decryption, key wrapping or key unwrapping, depending on
the value of opmode.
If this cipher (including its underlying feedback or padding scheme)
requires any random bytes, it will get them from random.
opmode - the operation mode of this cipher (this is one of
the following:
ENCRYPT_MODE, DECRYPT_MODE,
WRAP_MODE or UNWRAP_MODE)key - the encryption keyparams - the algorithm parametersrandom - the source of randomness
protected void engineInit(int opmode,
Key key,
AlgorithmParameters params,
SecureRandom random)
throws InvalidKeyException,
InvalidAlgorithmParameterException
The cipher is initialized for one of the following four operations:
encryption, decryption, key wrapping or key unwrapping, 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 or key wrapping, and raise an
InvalidAlgorithmParameterException if it is being
initialized for decryption or key unwrapping.
The generated parameters can be retrieved using
engineGetParameters or
engineGetIV (if the parameter is an IV).
If this cipher (including its underlying feedback or padding scheme)
requires any random bytes (e.g., for parameter generation), it will get
them from random.
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.
opmode - the operation mode of this cipher (this is one of
the following:
ENCRYPT_MODE, DECRYPT_MODE,
WRAP_MODE or UNWRAP_MODE)key - the encryption keyparams - the algorithm parametersrandom - the source of randomnessparams is null.
protected byte[] engineUpdate(byte[] input,
int inputOffset,
int inputLen)
The first inputLen bytes in the input
buffer, starting at inputOffset, are processed, and the
result is stored in a new buffer.
input - the input bufferinputOffset - the offset in input where the input
startsinputLen - the input length
protected int engineUpdate(byte[] input,
int inputOffset,
int inputLen,
byte[] output,
int outputOffset)
throws ShortBufferException
The first inputLen bytes in the input
buffer, starting at inputOffset, are processed, and the
result is stored in the output buffer, starting at
outputOffset.
input - the input bufferinputOffset - the offset in input where the input
startsinputLen - the input lengthoutput - the buffer for the resultoutputOffset - the offset in output where the result
is storedoutput
protected byte[] engineDoFinal(byte[] input,
int inputOffset,
int inputLen)
throws IllegalBlockSizeException,
BadPaddingException
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 a new buffer.
A call to this method resets this cipher object to the state
it was in when previously initialized via a call to
engineInit.
That is, the object is reset and available to encrypt or decrypt
(depending on the operation mode that was specified in the call to
engineInit) more data.
input - the input bufferinputOffset - the offset in input where the input
startsinputLen - the input length
protected int engineDoFinal(byte[] input,
int inputOffset,
int inputLen,
byte[] output,
int outputOffset)
throws ShortBufferException,
IllegalBlockSizeException,
BadPaddingException
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.
A call to this method resets this cipher object to the state
it was in when previously initialized via a call to
engineInit.
That is, the object is reset and available to encrypt or decrypt
(depending on the operation mode that was specified in the call to
engineInit) more data.
input - the input bufferinputOffset - the offset in input where the input
startsinputLen - the input lengthoutput - the buffer for the resultoutputOffset - the offset in output where the result
is storedoutput
protected byte[] engineWrap(Key key)
throws IllegalBlockSizeException,
InvalidKeyException
key - the key to be wrapped.
protected Key engineUnwrap(byte[] wrappedKey,
String wrappedKeyAlgorithm,
int wrappedKeyType)
throws InvalidKeyException,
NoSuchAlgorithmException
wrappedKey - the key to be unwrapped.wrappedKeyAlgorithm - the algorithm the wrapped key is for.wrappedKeyType - the type of the wrapped key.
This is one of Cipher.SECRET_KEY,
Cipher.PRIVATE_KEY, or Cipher.PUBLIC_KEY.wrappedKey does not
represent a wrapped key, or if the algorithm associated with the
wrapped key is different from wrappedKeyAlgorithm
and/or its key type is different from wrappedKeyType.wrappedKeyAlgorithm.
protected int engineGetKeySize(Key key)
throws InvalidKeyException
This concrete method has been added to this previously-defined
abstract class. It throws an UnsupportedOperationException
if it is not overridden by the provider.
key - the key object.key is invalid.
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