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java.lang.Objectjavax.crypto.Cipher
public class Cipher
This class provides the functionality of a cryptographic cipher for encryption and decryption. It forms the core of the Java Cryptographic Extension (JCE) framework.
In order to create a Cipher object, the application calls the
Cipher's getInstance
method, and passes the
name of the requested transformation to it.
Optionally, the name of a provider may be specified.
A transformation is a string that describes the operation (or set of operations) to be performed on the given input, to produce some output. A transformation always includes the name of a cryptographic algorithm (e.g., DES), and may be followed by a feedback mode and padding scheme.
A transformation is of the form:
(in the latter case, provider-specific default values for the mode and padding scheme are used). For example, the following is a valid transformation:
Cipher c = Cipher.getInstance("DES/CBC/PKCS5Padding");
When requesting a block cipher in stream cipher mode (e.g., DES
in CFB
or OFB
mode), the user may optionally specify the number of bits to be
processed at a time, by appending this number to the mode name as shown
in the "DES/CFB8/NoPadding" and "DES/OFB32/PKCS5Padding"
transformations. If no such number is specified, a provider-specific
default is used. (For example, the "SunJCE" provider uses a default of
64 bits.)
KeyGenerator
,
SecretKey
Field Summary | |
---|---|
static int |
DECRYPT_MODE
Constant used to initialize cipher to decryption mode. |
static int |
ENCRYPT_MODE
Constant used to initialize cipher to encryption mode. |
static int |
PRIVATE_KEY
Constant used to indicate the to-be-unwrapped key is a "private key". |
static int |
PUBLIC_KEY
Constant used to indicate the to-be-unwrapped key is a "public key". |
static int |
SECRET_KEY
Constant used to indicate the to-be-unwrapped key is a "secret key". |
static int |
UNWRAP_MODE
Constant used to initialize cipher to key-unwrapping mode. |
static int |
WRAP_MODE
Constant used to initialize cipher to key-wrapping mode. |
Constructor Summary | |
---|---|
protected |
Cipher(CipherSpi cipherSpi,
Provider provider,
String transformation)
Creates a Cipher object. |
Method Summary | |
---|---|
byte[] |
doFinal()
Finishes a multiple-part encryption or decryption operation, depending on how this cipher was initialized. |
byte[] |
doFinal(byte[] input)
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. |
int |
doFinal(byte[] output,
int outputOffset)
Finishes a multiple-part encryption or decryption operation, depending on how this cipher was initialized. |
byte[] |
doFinal(byte[] input,
int inputOffset, int inputLen)
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. |
int |
doFinal(byte[] input,
int inputOffset, int inputLen, byte[] output)
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. |
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. |
int |
doFinal(java.nio.ByteBuffer input,
java.nio.ByteBuffer output)
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. |
String |
getAlgorithm()
Returns the algorithm name of this Cipher object. |
int |
getBlockSize()
Returns the block size (in bytes). |
ExemptionMechanism |
getExemptionMechanism()
Returns the exemption mechanism object used with this cipher. |
static Cipher |
getInstance(String transformation)
Generates a Cipher object that implements the specified
transformation. |
static Cipher |
getInstance(String transformation,
Provider provider)
Creates a Cipher object that implements the specified
transformation, as supplied by the specified provider. |
static Cipher |
getInstance(String transformation,
String provider)
Creates a Cipher object that implements the specified
transformation, as supplied by the specified provider. |
byte[] |
getIV()
Returns the initialization vector (IV) in a new buffer. |
static int |
getMaxAllowedKeyLength(String transformation)
Returns the maximum key length for the specified transformation according to the installed JCE jurisdiction policy files. |
static AlgorithmParameterSpec |
getMaxAllowedParameterSpec(String transformation)
Returns an AlgorithmParameterSpec object which contains the maximum cipher parameter value according to the jurisdiction policy file. |
int |
getOutputSize(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). |
AlgorithmParameters |
getParameters()
Returns the parameters used with this cipher. |
Provider |
getProvider()
Returns the provider of this Cipher object. |
void |
init(int opmode,
Certificate certificate)
Initializes this cipher with the public key from the given certificate. |
void |
init(int opmode,
Certificate certificate,
SecureRandom random)
Initializes this cipher with the public key from the given certificate and a source of randomness. |
void |
init(int opmode,
Key key)
Initializes this cipher with a key. |
void |
init(int opmode,
Key key,
AlgorithmParameters params)
Initializes this cipher with a key and a set of algorithm parameters. |
void |
init(int opmode,
Key key,
AlgorithmParameterSpec params)
Initializes this cipher with a key and a set of algorithm parameters. |
void |
init(int opmode,
Key key,
AlgorithmParameterSpec params,
SecureRandom random)
Initializes this cipher with a key, a set of algorithm parameters, and a source of randomness. |
void |
init(int opmode,
Key key,
AlgorithmParameters params,
SecureRandom random)
Initializes this cipher with a key, a set of algorithm parameters, and a source of randomness. |
void |
init(int opmode,
Key key,
SecureRandom random)
Initializes this cipher with a key and a source of randomness. |
Key |
unwrap(byte[] wrappedKey,
String wrappedKeyAlgorithm,
int wrappedKeyType)
Unwrap a previously wrapped key. |
byte[] |
update(byte[] input)
Continues a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part. |
byte[] |
update(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. |
int |
update(byte[] input,
int inputOffset, int inputLen, byte[] output)
Continues a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part. |
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. |
int |
update(java.nio.ByteBuffer input,
java.nio.ByteBuffer output)
Continues a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part. |
byte[] |
wrap(Key key)
Wrap a key. |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll,
toString, wait, wait, wait |
Field Detail |
---|
public static final int ENCRYPT_MODE
public static final int DECRYPT_MODE
public static final int WRAP_MODE
public static final int UNWRAP_MODE
public static final int PUBLIC_KEY
public static final int PRIVATE_KEY
public static final int SECRET_KEY
Constructor Detail |
---|
protected Cipher(CipherSpi cipherSpi,
Provider provider,
String transformation)
cipherSpi
- the delegateprovider
- the providertransformation
- the
transformationMethod Detail |
---|
public static final Cipher getInstance(String transformation)
throws NoSuchAlgorithmException,
NoSuchPaddingException
Cipher
object that
implements the specified transformation.
If the default provider package supplies an implementation
of the requested transformation, an instance of Cipher
containing that implementation is returned. If the transformation is
not available in the default provider package, other provider packages
are searched.
transformation
- the name of
the transformation, e.g., DES/CBC/PKCS5Padding. See
Appendix A in the
Java Cryptography Extension Reference Guide for information
about standard transformation names.
NoSuchAlgorithmException
- if transformation
is null, empty, in an
invalid format, or not available from the current installed providers.
NoSuchPaddingException
- if transformation
contains a padding scheme
that is not available.public static final Cipher getInstance(String transformation,
String provider)
throws NoSuchAlgorithmException,
NoSuchProviderException,
NoSuchPaddingException
Cipher
object that
implements the specified transformation, as supplied by the specified
provider.
transformation
- the name of
the transformation, e.g., DES/CBC/PKCS5Padding. See
Appendix A in the
Java Cryptography Extension Reference Guide for information
about standard transformation names.provider
- the name of the
provider
NoSuchAlgorithmException
- if transformation
is null, empty, in an
invalid format, or not available from the specified provider.
NoSuchProviderException
- if the specified provider has not been configured.
NoSuchPaddingException
- if transformation
contains a padding scheme
that is not available.
IllegalArgumentException
- if the provider
is null.public static final Cipher getInstance(String transformation,
Provider provider)
throws NoSuchAlgorithmException,
NoSuchPaddingException
Cipher
object that
implements the specified transformation, as supplied by the specified
provider. Note: the provider
doesn't have to
be registered.
transformation
- the name of
the transformation, e.g., DES/CBC/PKCS5Padding. See
Appendix A in the
Java Cryptography Extension Reference Guide for information
about standard transformation names.provider
- the provider
NoSuchAlgorithmException
- if transformation
is null, empty, in an
invalid format, or not available from the specified provider.
NoSuchPaddingException
- if transformation
contains a padding scheme
that is not available.
IllegalArgumentException
- if the provider
is null.public final Provider getProvider()
Cipher
object.
Cipher
objectpublic final String getAlgorithm()
Cipher
object.
This is the same name that was specified in one of the getInstance
calls that created this Cipher
object..
Cipher
object.public final int getBlockSize()
public final int getOutputSize(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)
IllegalStateException
- if this cipher is in a wrong state (e.g., has not yet been
initialized)public final byte[] getIV()
This is useful in the case where a random IV was created, or in the context of password-based encryption or decryption, where the IV is derived from a user-supplied password.
public final AlgorithmParameters getParameters()
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.
public final ExemptionMechanism getExemptionMechanism()
public final void init(int opmode,
Key key)
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 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 or key wrapping, and raise an InvalidKeyException
if it is being initialized for decryption or key unwrapping. The
generated parameters can be retrieved using getParameters
or getIV
(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 using the
implementation of the highest-priority installed provider as the source
of randomness. (If none of the installed providers supply an
implementation of SecureRandom, a system-provided source of randomness
will be used.) SecureRandom
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 key
InvalidKeyException
- if the given key is inappropriate for initializing this cipher, or if
this cipher is being initialized for decryption and requires algorithm
parameters that cannot be determined from the given key, or if the
given key has a keysize that exceeds the maximum allowable keysize (as
determined from the configured jurisdiction policy files).public final void init(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 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 or key wrapping, and raise an InvalidKeyException
if it is being initialized for decryption or key unwrapping. The
generated parameters can be retrieved using getParameters
or getIV
(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 keyrandom
- the source of
randomness
InvalidKeyException
- if the given key is inappropriate for initializing this cipher, or if
this cipher is being initialized for decryption and requires algorithm
parameters that cannot be determined from the given key, or if the
given key has a keysize that exceeds the maximum allowable keysize (as
determined from the configured jurisdiction policy files).public final void init(int opmode,
Key key,
AlgorithmParameterSpec params)
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 getParameters
or getIV
(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 using the
implementation of the highest-priority installed provider as the source
of randomness. (If none of the installed providers supply an
implementation of SecureRandom, a system-provided source of randomness
will be used.) SecureRandom
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
parameters
InvalidKeyException
- if the given key is inappropriate for initializing this cipher, or
its keysize exceeds the maximum allowable keysize (as determined from
the configured jurisdiction policy files).
InvalidAlgorithmParameterException
- if the given algorithm parameters are inappropriate for this cipher,
or this cipher is being initialized for decryption and requires
algorithm parameters and params
is null, or
the given algorithm parameters imply a cryptographic strength that
would exceed the legal limits (as determined from the configured
jurisdiction policy files).public final void init(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 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 getParameters
or getIV
(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
randomness
InvalidKeyException
- if the given key is inappropriate for initializing this cipher, or
its keysize exceeds the maximum allowable keysize (as determined from
the configured jurisdiction policy files).
InvalidAlgorithmParameterException
- if the given algorithm parameters are inappropriate for this cipher,
or this cipher is being initialized for decryption and requires
algorithm parameters and params
is null, or
the given algorithm parameters imply a cryptographic strength that
would exceed the legal limits (as determined from the configured
jurisdiction policy files).public final void init(int opmode,
Key key,
AlgorithmParameters params)
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 getParameters
or getIV
(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 using the
implementation of the highest-priority installed provider as the source
of randomness. (If none of the installed providers supply an
implementation of SecureRandom, a system-provided source of randomness
will be used.) SecureRandom
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
parameters
InvalidKeyException
- if the given key is inappropriate for initializing this cipher, or
its keysize exceeds the maximum allowable keysize (as determined from
the configured jurisdiction policy files).
InvalidAlgorithmParameterException
- if the given algorithm parameters are inappropriate for this cipher,
or this cipher is being initialized for decryption and requires
algorithm parameters and params
is null, or
the given algorithm parameters imply a cryptographic strength that
would exceed the legal limits (as determined from the configured
jurisdiction policy files).public final void init(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 getParameters
or getIV
(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
randomness
InvalidKeyException
- if the given key is inappropriate for initializing this cipher, or
its keysize exceeds the maximum allowable keysize (as determined from
the configured jurisdiction policy files).
InvalidAlgorithmParameterException
- if the given algorithm parameters are inappropriate for this cipher,
or this cipher is being initialized for decryption and requires
algorithm parameters and params
is null, or
the given algorithm parameters imply a cryptographic strength that
would exceed the legal limits (as determined from the configured
jurisdiction policy files).public final void init(int opmode,
Certificate certificate)
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 the certificate is of type X.509 and has a key
usage extension field marked as critical, and the value of
the key usage extension field implies that the
public key in the certificate and its corresponding private key are not
supposed to be used for the operation represented by the value of opmode
,
an InvalidKeyException
is thrown.
If this cipher requires any algorithm parameters that
cannot be derived from the public key in the given certificate, the
underlying cipher implementation is supposed to generate the required
parameters itself (using provider-specific default or ramdom values) if
it is being initialized for encryption or key wrapping, and raise an
InvalidKeyException
if it is being initialized for
decryption or key unwrapping. The generated parameters can be retrieved
using getParameters
or getIV
(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 using the SecureRandom
implementation of the highest-priority installed provider as the source
of randomness. (If none of the installed providers supply an
implementation of SecureRandom, a system-provided source of randomness
will be used.)
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
)certificate
- the certificate
InvalidKeyException
- if the public key in the given certificate is inappropriate for
initializing this cipher, or this cipher is being initialized for
decryption or unwrapping keys and requires algorithm parameters that
cannot be determined from the public key in the given certificate, or
the keysize of the public key in the given certificate has a keysize
that exceeds the maximum allowable keysize (as determined by the
configured jurisdiction policy files).public final void init(int opmode,
Certificate certificate,
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 the certificate is of type X.509 and has a key
usage extension field marked as critical, and the value of
the key usage extension field implies that the
public key in the certificate and its corresponding private key are not
supposed to be used for the operation represented by the value of opmode
,
an InvalidKeyException
is thrown.
If this cipher requires any algorithm parameters that
cannot be derived from the public key in the given certificate
,
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 InvalidKeyException
if it is being
initialized for decryption or key unwrapping. The generated parameters
can be retrieved using getParameters
or getIV
(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
)certificate
- the certificaterandom
- the source of
randomness
InvalidKeyException
- if the public key in the given certificate is inappropriate for
initializing this cipher, or this cipher is being initialized for
decryption or unwrapping keys and requires algorithm parameters that
cannot be determined from the public key in the given certificate, or
the keysize of the public key in the given certificate has a keysize
that exceeds the maximum allowable keysize (as determined by the
configured jurisdiction policy files).public final byte[] update(byte[] input)
The bytes in the input
buffer
are processed, and the result is stored in a new buffer.
If input
has a length of zero,
this method returns null
.
input
- the input buffer
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)public final byte[] update(byte[] input,
int inputOffset,
int inputLen)
The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive,
are processed, and the result is stored in a new buffer.
If inputLen
is zero, this method
returns null
.
input
- the input bufferinputOffset
- the offset in input
where the input startsinputLen
- the input length
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)public final int update(byte[] input,
int inputOffset,
int inputLen,
byte[] output)
throws ShortBufferException
The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive,
are processed, and the result is stored in the output
buffer.
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.
Use getOutputSize
to determine how big the output buffer should be.
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.
input
- the input bufferinputOffset
- the offset in input
where the input startsinputLen
- the input lengthoutput
- the buffer for the
result
output
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)
ShortBufferException
- if the given output buffer is too small to hold the resultpublic final int update(byte[] input,
int inputOffset,
int inputLen,
byte[] output,
int outputOffset)
throws ShortBufferException
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.
Use getOutputSize
to determine how big the output buffer should be.
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.
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 stored
output
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)
ShortBufferException
- if the given output buffer is too small to hold the resultpublic final int update(java.nio.ByteBuffer input,
java.nio.ByteBuffer output)
throws ShortBufferException
All input.remaining()
bytes
starting at input.position()
are processed.
The result is stored in the output buffer. Upon return, the input
buffer's position will be equal to its limit; its limit will not have
changed. The output buffer's position will have advanced by n, where n
is the value returned by this method; the output buffer's limit will
not have changed.
If output.remaining()
bytes are
insufficient to hold the result, a ShortBufferException
is thrown. In this case, repeat this call with a larger output buffer.
Use getOutputSize
to determine how big the output buffer should be.
Note: this method should be copy-safe, which means the input
and output
buffers can reference the same
block of memory and no unprocessed input data is overwritten when the
result is copied into the output buffer.
input
- the input ByteBufferoutput
- the output ByteByffer
output
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)
IllegalArgumentException
- if input and output are the same object
java.nio.ReadOnlyBufferException
- if the output buffer is read-only
ShortBufferException
- if there is insufficient space in the output bufferpublic final byte[] doFinal()
throws IllegalBlockSizeException,
BadPaddingException
Input data that may have been buffered during a previous update
operation is processed, with padding (if requested) being applied. The
result is stored in a new 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.
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)
IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested (only
in encryption mode), and the total input length of the data processed
by this cipher is not a multiple of block size; or if this encryption
algorithm is unable to process the input data provided.
BadPaddingException
- if this cipher is in decryption mode, and (un)padding has been
requested, but the decrypted data is not bounded by the appropriate
padding bytespublic final int doFinal(byte[] output,
int outputOffset)
throws IllegalBlockSizeException,
ShortBufferException,
BadPaddingException
Input data that may have been buffered during a previous update
operation is 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.
Use getOutputSize
to determine how big the output buffer should be.
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.
output
- the buffer for the
resultoutputOffset
- the offset in output
where the result is stored
output
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)
IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested (only
in encryption mode), and the total input length of the data processed
by this cipher is not a multiple of block size; or if this encryption
algorithm is unable to process the input data provided.
ShortBufferException
- if the given output buffer is too small to hold the result
BadPaddingException
- if this cipher is in decryption mode, and (un)padding has been
requested, but the decrypted data is not bounded by the appropriate
padding bytespublic final byte[] doFinal(byte[] input)
throws IllegalBlockSizeException,
BadPaddingException
The bytes in the input
buffer,
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.
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.
input
- the input buffer
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)
IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested (only
in encryption mode), and the total input length of the data processed
by this cipher is not a multiple of block size; or if this encryption
algorithm is unable to process the input data provided.
BadPaddingException
- if this cipher is in decryption mode, and (un)padding has been
requested, but the decrypted data is not bounded by the appropriate
padding bytespublic final byte[] doFinal(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.
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.
input
- the input bufferinputOffset
- the offset in input
where the input startsinputLen
- the input length
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)
IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested (only
in encryption mode), and the total input length of the data processed
by this cipher is not a multiple of block size; or if this encryption
algorithm is unable to process the input data provided.
BadPaddingException
- if this cipher is in decryption mode, and (un)padding has been
requested, but the decrypted data is not bounded by the appropriate
padding bytespublic final int doFinal(byte[] input,
int inputOffset,
int inputLen,
byte[] output)
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.
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.
Use getOutputSize
to determine how big the output buffer should be.
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.
input
- the input bufferinputOffset
- the offset in input
where the input startsinputLen
- the input lengthoutput
- the buffer for the
result
output
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)
IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested (only
in encryption mode), and the total input length of the data processed
by this cipher is not a multiple of block size; or if this encryption
algorithm is unable to process the input data provided.
ShortBufferException
- if the given output buffer is too small to hold the result
BadPaddingException
- if this cipher is in decryption mode, and (un)padding has been
requested, but the decrypted data is not bounded by the appropriate
padding bytespublic final int doFinal(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. In this case, repeat this call with a larger output buffer.
Use getOutputSize
to determine how big the output buffer should be.
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.
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 stored
output
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)
IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested (only
in encryption mode), and the total input length of the data processed
by this cipher is not a multiple of block size; or if this encryption
algorithm is unable to process the input data provided.
ShortBufferException
- if the given output buffer is too small to hold the result
BadPaddingException
- if this cipher is in decryption mode, and (un)padding has been
requested, but the decrypted data is not bounded by the appropriate
padding bytespublic final int doFinal(java.nio.ByteBuffer input,
java.nio.ByteBuffer output)
throws ShortBufferException,
IllegalBlockSizeException,
BadPaddingException
All input.remaining()
bytes
starting at input.position()
are processed.
The result is stored in the output buffer. Upon return, the input
buffer's position will be equal to its limit; its limit will not have
changed. The output buffer's position will have advanced by n, where n
is the value returned by this method; the output buffer's limit will
not have changed.
If output.remaining()
bytes are
insufficient to hold the result, a ShortBufferException
is thrown. In this case, repeat this call with a larger output buffer.
Use getOutputSize
to determine how big the output buffer should be.
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.
input
- the input ByteBufferoutput
- the output ByteBuffer
output
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)
IllegalArgumentException
- if input and output are the same object
java.nio.ReadOnlyBufferException
- if the output buffer is read-only
IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested (only
in encryption mode), and the total input length of the data processed
by this cipher is not a multiple of block size; or if this encryption
algorithm is unable to process the input data provided.
ShortBufferException
- if there is insufficient space in the output buffer
BadPaddingException
- if this cipher is in decryption mode, and (un)padding has been
requested, but the decrypted data is not bounded by the appropriate
padding bytespublic final byte[] wrap(Key key)
throws IllegalBlockSizeException,
InvalidKeyException
key
- the key to be wrapped.
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized).
IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested, and
the length of the encoding of the key to be wrapped is not a multiple
of the block size.
InvalidKeyException
- if it is impossible or unsafe to wrap the key with this cipher (e.g.,
a hardware protected key is being passed to a software-only cipher).public final Key unwrap(byte[] wrappedKey,
String wrappedKeyAlgorithm,
int wrappedKeyType)
throws InvalidKeyException,
NoSuchAlgorithmException
wrappedKey
- the key to be
unwrapped.wrappedKeyAlgorithm
- the
algorithm associated with the wrapped key.wrappedKeyType
- the type of
the wrapped key. This must be one of SECRET_KEY
,
PRIVATE_KEY
, or PUBLIC_KEY
.
IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized).
NoSuchAlgorithmException
- if no installed providers can create keys of type wrappedKeyType
for the wrappedKeyAlgorithm
.
InvalidKeyException
- if wrappedKey
does not represent a wrapped
key of type wrappedKeyType
for the wrappedKeyAlgorithm
.public static final int getMaxAllowedKeyLength(String transformation)
throws NoSuchAlgorithmException
transformation
- the cipher
transformation.
NullPointerException
- if transformation
is null.
NoSuchAlgorithmException
- if transformation
is not a valid
transformation, i.e. in the form of "algorithm" or
"algorithm/mode/padding".public static final AlgorithmParameterSpec getMaxAllowedParameterSpec(String transformation)
throws NoSuchAlgorithmException
transformation
- the cipher
transformation.
NullPointerException
- if transformation
is null.
NoSuchAlgorithmException
- if transformation
is not a valid
transformation, i.e. in the form of "algorithm" or
"algorithm/mode/padding".
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