- Direct Known Subclasses:
NullCipher
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., AES), and may be followed by a feedback mode and padding scheme.
A transformation is of the form:
- "algorithm/mode/padding" or
- "algorithm"
(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("AES/CBC/PKCS5Padding");Using modes such as
CFB
and OFB
, block
ciphers can encrypt data in units smaller than the cipher's actual
block size. When requesting such a mode, you 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 "AES/CFB8/NoPadding
" and
"AES/OFB32/PKCS5Padding
" transformations. If no such
number is specified, a provider-specific default is used.
(See the
JDK Providers Documentation
for the JDK Providers default values.)
Thus, block ciphers can be turned into byte-oriented stream ciphers by
using an 8 bit mode such as CFB8 or OFB8.
Modes such as Authenticated Encryption with Associated Data (AEAD)
provide authenticity assurances for both confidential data and
Additional Associated Data (AAD) that is not encrypted. (Please see
RFC 5116 for more
information on AEAD and AAD algorithms such as GCM/CCM.) Both
confidential and AAD data can be used when calculating the
authentication tag (similar to a Mac
). This tag is appended
to the ciphertext during encryption, and is verified on decryption.
AEAD modes such as GCM/CCM perform all AAD authenticity calculations
before starting the ciphertext authenticity calculations. To avoid
implementations having to internally buffer ciphertext, all AAD data
must be supplied to GCM/CCM implementations (via the updateAAD
methods) before the ciphertext is processed (via
the update
and doFinal
methods).
Note that GCM mode has a uniqueness requirement on IVs used in
encryption with a given key. When IVs are repeated for GCM
encryption, such usages are subject to forgery attacks. Thus, after
each encryption operation using GCM mode, callers should re-initialize
the Cipher
objects with GCM parameters which have a different IV
value.
GCMParameterSpec s = ...; cipher.init(..., s); // If the GCM parameters were generated by the provider, it can // be retrieved by: // cipher.getParameters().getParameterSpec(GCMParameterSpec.class); cipher.updateAAD(...); // AAD cipher.update(...); // Multi-part update cipher.doFinal(...); // conclusion of operation // Use a different IV value for every encryption byte[] newIv = ...; s = new GCMParameterSpec(s.getTLen(), newIv); cipher.init(..., s); ...The ChaCha20 and ChaCha20-Poly1305 algorithms have a similar requirement for unique nonces with a given key. After each encryption or decryption operation, callers should re-initialize their ChaCha20 or ChaCha20-Poly1305 ciphers with parameters that specify a different nonce value. Please see RFC 7539 for more information on the ChaCha20 and ChaCha20-Poly1305 algorithms.
Every implementation of the Java platform is required to support
the following standard Cipher
object transformations with
the keysizes in parentheses:
AES/CBC/NoPadding
(128)AES/CBC/PKCS5Padding
(128)AES/ECB/NoPadding
(128)AES/ECB/PKCS5Padding
(128)AES/GCM/NoPadding
(128)DESede/CBC/NoPadding
(168)DESede/CBC/PKCS5Padding
(168)DESede/ECB/NoPadding
(168)DESede/ECB/PKCS5Padding
(168)RSA/ECB/PKCS1Padding
(1024, 2048)RSA/ECB/OAEPWithSHA-1AndMGF1Padding
(1024, 2048)RSA/ECB/OAEPWithSHA-256AndMGF1Padding
(1024, 2048)
- Since:
- 1.4
- See Also:
-
Field Summary
Modifier and TypeFieldDescriptionstatic final int
Constant used to initialize cipher to decryption mode.static final int
Constant used to initialize cipher to encryption mode.static final int
Constant used to indicate the to-be-unwrapped key is a "private key".static final int
Constant used to indicate the to-be-unwrapped key is a "public key".static final int
Constant used to indicate the to-be-unwrapped key is a "secret key".static final int
Constant used to initialize cipher to key-unwrapping mode.static final int
Constant used to initialize cipher to key-wrapping mode. -
Constructor Summary
-
Method Summary
Modifier and TypeMethodDescriptionfinal byte[]
doFinal()
Finishes a multiple-part encryption or decryption operation, depending on how thisCipher
object was initialized.final byte[]
doFinal
(byte[] input) Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.final int
doFinal
(byte[] output, int outputOffset) Finishes a multiple-part encryption or decryption operation, depending on how thisCipher
object was initialized.final byte[]
doFinal
(byte[] input, int inputOffset, int inputLen) Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.final 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.final 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.final int
doFinal
(ByteBuffer input, ByteBuffer output) Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.final String
Returns the algorithm name of thisCipher
object.final int
Returns the block size (in bytes).final ExemptionMechanism
Returns the exemption mechanism object used with thisCipher
object.static final Cipher
getInstance
(String transformation) Returns aCipher
object that implements the specified transformation.static final Cipher
getInstance
(String transformation, String provider) Returns aCipher
object that implements the specified transformation.static final Cipher
getInstance
(String transformation, Provider provider) Returns aCipher
object that implements the specified transformation.final byte[]
getIV()
Returns the initialization vector (IV) in a new buffer.static final int
getMaxAllowedKeyLength
(String transformation) Returns the maximum key length for the specified transformation according to the installed JCE jurisdiction policy files.static final AlgorithmParameterSpec
getMaxAllowedParameterSpec
(String transformation) Returns an {code AlgorithmParameterSpec} object which contains the maximumCipher
parameter value according to the jurisdiction policy file.final 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 nextupdate
ordoFinal
operation, given the input lengthinputLen
(in bytes).final AlgorithmParameters
Returns the parameters used with thisCipher
object.final Provider
Returns the provider of thisCipher
object.final void
init
(int opmode, Certificate certificate) Initializes thisCipher
object with the public key from the given certificate.final void
init
(int opmode, Certificate certificate, SecureRandom random) Initializes thisCipher
object with the public key from the given certificate and a source of randomness.final void
Initializes thisCipher
object with a key.final void
init
(int opmode, Key key, AlgorithmParameters params) Initializes thisCipher
object with a key and a set of algorithm parameters.final void
init
(int opmode, Key key, AlgorithmParameters params, SecureRandom random) Initializes thisCipher
object with a key, a set of algorithm parameters, and a source of randomness.final void
init
(int opmode, Key key, SecureRandom random) Initializes thisCipher
object with a key and a source of randomness.final void
init
(int opmode, Key key, AlgorithmParameterSpec params) Initializes thisCipher
object with a key and a set of algorithm parameters.final void
init
(int opmode, Key key, AlgorithmParameterSpec params, SecureRandom random) Initializes thisCipher
object with a key, a set of algorithm parameters, and a source of randomness.toString()
Returns aString
representation of thisCipher
object.final Key
Unwrap a previously wrapped key.final byte[]
update
(byte[] input) Continues a multiple-part encryption or decryption operation (depending on how thisCipher
object was initialized), processing another data part.final byte[]
update
(byte[] input, int inputOffset, int inputLen) Continues a multiple-part encryption or decryption operation (depending on how thisCipher
object was initialized), processing another data part.final int
update
(byte[] input, int inputOffset, int inputLen, byte[] output) Continues a multiple-part encryption or decryption operation (depending on how thisCipher
object was initialized), processing another data part.final int
update
(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset) Continues a multiple-part encryption or decryption operation (depending on how thisCipher
object was initialized), processing another data part.final int
update
(ByteBuffer input, ByteBuffer output) Continues a multiple-part encryption or decryption operation (depending on how thisCipher
object was initialized), processing another data part.final void
updateAAD
(byte[] src) Continues a multi-part update of the Additional Authentication Data (AAD).final void
updateAAD
(byte[] src, int offset, int len) Continues a multi-part update of the Additional Authentication Data (AAD), using a subset of the provided buffer.final void
updateAAD
(ByteBuffer src) Continues a multi-part update of the Additional Authentication Data (AAD).final byte[]
Wrap a key.
-
Field Details
-
ENCRYPT_MODE
public static final int ENCRYPT_MODEConstant used to initialize cipher to encryption mode.- See Also:
-
DECRYPT_MODE
public static final int DECRYPT_MODEConstant used to initialize cipher to decryption mode.- See Also:
-
WRAP_MODE
public static final int WRAP_MODEConstant used to initialize cipher to key-wrapping mode.- See Also:
-
UNWRAP_MODE
public static final int UNWRAP_MODEConstant used to initialize cipher to key-unwrapping mode.- See Also:
-
PUBLIC_KEY
public static final int PUBLIC_KEYConstant used to indicate the to-be-unwrapped key is a "public key".- See Also:
-
PRIVATE_KEY
public static final int PRIVATE_KEYConstant used to indicate the to-be-unwrapped key is a "private key".- See Also:
-
SECRET_KEY
public static final int SECRET_KEYConstant used to indicate the to-be-unwrapped key is a "secret key".- See Also:
-
-
Constructor Details
-
Cipher
Creates aCipher
object.- Parameters:
cipherSpi
- the delegateprovider
- the providertransformation
- the transformation- Throws:
NullPointerException
- ifprovider
isnull
IllegalArgumentException
- if the supplied arguments are deemed invalid for constructing theCipher
object
-
-
Method Details
-
getInstance
public static final Cipher getInstance(String transformation) throws NoSuchAlgorithmException, NoSuchPaddingException Returns aCipher
object that implements the specified transformation.This method traverses the list of registered security providers, starting with the most preferred provider. A new
Cipher
object encapsulating theCipherSpi
implementation from the first provider that supports the specified algorithm is returned.Note that the list of registered providers may be retrieved via the
Security.getProviders()
method.- API Note:
- It is recommended to use a transformation that fully specifies the algorithm, mode, and padding. By not doing so, the provider will use a default for the mode and padding which may not meet the security requirements of your application.
- Implementation Note:
- The JDK Reference Implementation additionally uses the
jdk.security.provider.preferred
Security
property to determine the preferred provider order for the specified algorithm. This may be different than the order of providers returned bySecurity.getProviders()
. See also the Cipher Transformations section of the JDK Providers document for information on the transformation defaults used by JDK providers. - Parameters:
transformation
- the name of the transformation, e.g., AES/CBC/PKCS5Padding. See the Cipher section in the Java Security Standard Algorithm Names Specification for information about standard transformation names.- Returns:
- a
Cipher
object that implements the requested transformation - Throws:
NoSuchAlgorithmException
- iftransformation
isnull
, empty, in an invalid format, or if no provider supports aCipherSpi
implementation for the specified algorithmNoSuchPaddingException
- iftransformation
contains a padding scheme that is not available- See Also:
-
getInstance
public static final Cipher getInstance(String transformation, String provider) throws NoSuchAlgorithmException, NoSuchProviderException, NoSuchPaddingException Returns aCipher
object that implements the specified transformation.A new
Cipher
object encapsulating theCipherSpi
implementation from the specified provider is returned. The specified provider must be registered in the security provider list.Note that the list of registered providers may be retrieved via the
Security.getProviders()
method.- API Note:
- It is recommended to use a transformation that fully specifies the algorithm, mode, and padding. By not doing so, the provider will use a default for the mode and padding which may not meet the security requirements of your application.
- Implementation Note:
- See the Cipher Transformations section of the JDK Providers document for information on the transformation defaults used by JDK providers.
- Parameters:
transformation
- the name of the transformation, e.g., AES/CBC/PKCS5Padding. See the Cipher section in the Java Security Standard Algorithm Names Specification for information about standard transformation names.provider
- the name of the provider- Returns:
- a
Cipher
object that implements the requested transformation - Throws:
IllegalArgumentException
- if theprovider
isnull
or emptyNoSuchAlgorithmException
- iftransformation
isnull
, empty, in an invalid format, or if aCipherSpi
implementation for the specified algorithm is not available from the specified providerNoSuchPaddingException
- iftransformation
contains a padding scheme that is not availableNoSuchProviderException
- if the specified provider is not registered in the security provider list- See Also:
-
getInstance
public static final Cipher getInstance(String transformation, Provider provider) throws NoSuchAlgorithmException, NoSuchPaddingException Returns aCipher
object that implements the specified transformation.A new
Cipher
object encapsulating theCipherSpi
implementation from the specifiedprovider
object is returned. Note that the specifiedprovider
object does not have to be registered in the provider list.- API Note:
- It is recommended to use a transformation that fully specifies the algorithm, mode, and padding. By not doing so, the provider will use a default for the mode and padding which may not meet the security requirements of your application.
- Implementation Note:
- See the Cipher Transformations section of the JDK Providers document for information on the transformation defaults used by JDK providers.
- Parameters:
transformation
- the name of the transformation, e.g., AES/CBC/PKCS5Padding. See the Cipher section in the Java Security Standard Algorithm Names Specification for information about standard transformation names.provider
- the provider- Returns:
- a
Cipher
object that implements the requested transformation - Throws:
IllegalArgumentException
- if theprovider
isnull
NoSuchAlgorithmException
- iftransformation
isnull
, empty, in an invalid format, or if aCipherSpi
implementation for the specified algorithm is not available from the specifiedprovider
objectNoSuchPaddingException
- iftransformation
contains a padding scheme that is not available- See Also:
-
getProvider
Returns the provider of thisCipher
object.- Returns:
- the provider of this
Cipher
object
-
getAlgorithm
Returns the algorithm name of thisCipher
object.This is the same name that was specified in one of the
getInstance
calls that created thisCipher
object.- Returns:
- the algorithm name of this
Cipher
object
-
getBlockSize
public final int getBlockSize()Returns the block size (in bytes).- Returns:
- the block size (in bytes), or 0 if this cipher is not a block cipher
-
getOutputSize
public final 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 nextupdate
ordoFinal
operation, given the input lengthinputLen
(in bytes).This call takes into account any unprocessed (buffered) data from a previous
update
call, padding, and AEAD tagging.The actual output length of the next
update
ordoFinal
call may be smaller than the length returned by this method.- Parameters:
inputLen
- the input length (in bytes)- Returns:
- the required output buffer size (in bytes)
- Throws:
IllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not yet been initialized)
-
getIV
public final byte[] getIV()Returns the initialization vector (IV) in a new buffer.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.
- Returns:
- the initialization vector in a new buffer, or
null
if this cipher does not use an IV, or if the IV has not yet been set.
-
getParameters
Returns the parameters used with thisCipher
object.The returned parameters may be the same that were used to initialize this cipher, or may contain additional default or random parameter values used by the underlying cipher implementation. If the required parameters were not supplied and can be generated by the cipher, the generated parameters are returned. Otherwise,
null
is returned.- Returns:
- the parameters used with this cipher, or
null
-
getExemptionMechanism
Returns the exemption mechanism object used with thisCipher
object.- Returns:
- the exemption mechanism object used with this
Cipher
object, ornull
if thisCipher
object does not use any exemption mechanism.
-
init
Initializes thisCipher
object with a key.The
Cipher
object is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value ofopmode
.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 anInvalidKeyException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved usinggetParameters
orgetIV
(if the parameter is an IV).If this cipher requires algorithm parameters that cannot be derived from the input parameters, and there are no reasonable provider-specific default values, initialization will necessarily fail.
If this cipher (including its 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 aCipher
object is equivalent to creating a new instance of thatCipher
object and initializing it.- Parameters:
opmode
- the operation mode of thisCipher
object (this is one of the following:ENCRYPT_MODE
,DECRYPT_MODE
,WRAP_MODE
orUNWRAP_MODE
)key
- the key- Throws:
InvalidKeyException
- if the given key is inappropriate for initializing this cipher, or 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)UnsupportedOperationException
- ifopmode
isWRAP_MODE
orUNWRAP_MODE
but the mode is not implemented by the underlyingCipherSpi
InvalidParameterException
- ifopmode
is not one of the recognized values
-
init
Initializes thisCipher
object with a key and a source of randomness.The
Cipher
object is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value ofopmode
.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 anInvalidKeyException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved usinggetParameters
orgetIV
(if the parameter is an IV).If this cipher requires algorithm parameters that cannot be derived from the input parameters, and there are no reasonable provider-specific default values, initialization will necessarily fail.
If this cipher (including its 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 aCipher
object is equivalent to creating a new instance of thatCipher
object and initializing it.- Parameters:
opmode
- the operation mode of thisCipher
object (this is one of the following:ENCRYPT_MODE
,DECRYPT_MODE
,WRAP_MODE
orUNWRAP_MODE
)key
- the encryption keyrandom
- the source of randomness- Throws:
InvalidKeyException
- if the given key is inappropriate for initializing this cipher, or 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)UnsupportedOperationException
- ifopmode
isWRAP_MODE
orUNWRAP_MODE
but the mode is not implemented by the underlyingCipherSpi
InvalidParameterException
- ifopmode
is not one of the recognized values
-
init
public final void init(int opmode, Key key, AlgorithmParameterSpec params) throws InvalidKeyException, InvalidAlgorithmParameterException Initializes thisCipher
object with a key and a set of algorithm parameters.The
Cipher
object is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value ofopmode
.If this cipher requires any algorithm parameters and
params
isnull
, 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 anInvalidAlgorithmParameterException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved usinggetParameters
orgetIV
(if the parameter is an IV).If this cipher requires algorithm parameters that cannot be derived from the input parameters, and there are no reasonable provider-specific default values, initialization will necessarily fail.
If this cipher (including its 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 aCipher
object is equivalent to creating a new instance of thatCipher
object and initializing it.- Parameters:
opmode
- the operation mode of thisCipher
object (this is one of the following:ENCRYPT_MODE
,DECRYPT_MODE
,WRAP_MODE
orUNWRAP_MODE
)key
- the encryption keyparams
- the algorithm parameters- Throws:
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 requires algorithm parameters andparams
isnull
, or the given algorithm parameters imply a cryptographic strength that would exceed the legal limits (as determined from the configured jurisdiction policy files)UnsupportedOperationException
- ifopmode
isWRAP_MODE
orUNWRAP_MODE
but the mode is not implemented by the underlyingCipherSpi
InvalidParameterException
- ifopmode
is not one of the recognized values
-
init
public final void init(int opmode, Key key, AlgorithmParameterSpec params, SecureRandom random) throws InvalidKeyException, InvalidAlgorithmParameterException Initializes thisCipher
object with a key, a set of algorithm parameters, and a source of randomness.The
Cipher
object is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value ofopmode
.If this cipher requires any algorithm parameters and
params
isnull
, 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 anInvalidAlgorithmParameterException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved usinggetParameters
orgetIV
(if the parameter is an IV).If this cipher requires algorithm parameters that cannot be derived from the input parameters, and there are no reasonable provider-specific default values, initialization will necessarily fail.
If this cipher (including its 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 aCipher
object is equivalent to creating a new instance of thatCipher
object and initializing it.- Parameters:
opmode
- the operation mode of thisCipher
object (this is one of the following:ENCRYPT_MODE
,DECRYPT_MODE
,WRAP_MODE
orUNWRAP_MODE
)key
- the encryption keyparams
- the algorithm parametersrandom
- the source of randomness- Throws:
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 requires algorithm parameters andparams
isnull
, or the given algorithm parameters imply a cryptographic strength that would exceed the legal limits (as determined from the configured jurisdiction policy files)UnsupportedOperationException
- ifopmode
isWRAP_MODE
orUNWRAP_MODE
but the mode is not implemented by the underlyingCipherSpi
InvalidParameterException
- ifopmode
is not one of the recognized values
-
init
public final void init(int opmode, Key key, AlgorithmParameters params) throws InvalidKeyException, InvalidAlgorithmParameterException Initializes thisCipher
object with a key and a set of algorithm parameters.The
Cipher
object is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value ofopmode
.If this cipher requires any algorithm parameters and
params
isnull
, 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 anInvalidAlgorithmParameterException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved usinggetParameters
orgetIV
(if the parameter is an IV).If this cipher requires algorithm parameters that cannot be derived from the input parameters, and there are no reasonable provider-specific default values, initialization will necessarily fail.
If this cipher (including its 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 aCipher
object is equivalent to creating a new instance of thatCipher
object and initializing it.- Parameters:
opmode
- the operation mode of thisCipher
object this is one of the following:ENCRYPT_MODE
,DECRYPT_MODE
,WRAP_MODE
orUNWRAP_MODE
)key
- the encryption keyparams
- the algorithm parameters- Throws:
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 requires algorithm parameters andparams
isnull
, or the given algorithm parameters imply a cryptographic strength that would exceed the legal limits (as determined from the configured jurisdiction policy files)UnsupportedOperationException
- ifopmode
isWRAP_MODE
orUNWRAP_MODE
but the mode is not implemented by the underlyingCipherSpi
InvalidParameterException
- ifopmode
is not one of the recognized values
-
init
public final void init(int opmode, Key key, AlgorithmParameters params, SecureRandom random) throws InvalidKeyException, InvalidAlgorithmParameterException Initializes thisCipher
object with a key, a set of algorithm parameters, and a source of randomness.The
Cipher
object is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value ofopmode
.If this cipher requires any algorithm parameters and
params
isnull
, 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 anInvalidAlgorithmParameterException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved usinggetParameters
orgetIV
(if the parameter is an IV).If this cipher requires algorithm parameters that cannot be derived from the input parameters, and there are no reasonable provider-specific default values, initialization will necessarily fail.
If this cipher (including its 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 aCipher
object is equivalent to creating a new instance of thatCipher
object and initializing it.- Parameters:
opmode
- the operation mode of thisCipher
object (this is one of the following:ENCRYPT_MODE
,DECRYPT_MODE
,WRAP_MODE
orUNWRAP_MODE
)key
- the encryption keyparams
- the algorithm parametersrandom
- the source of randomness- Throws:
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 requires algorithm parameters andparams
isnull
, or the given algorithm parameters imply a cryptographic strength that would exceed the legal limits (as determined from the configured jurisdiction policy files)UnsupportedOperationException
- ifopmode
isWRAP_MODE
orUNWRAP_MODE
but the mode is not implemented by the underlyingCipherSpi
InvalidParameterException
- ifopmode
is not one of the recognized values
-
init
Initializes thisCipher
object with the public key from the given certificate.The
Cipher
object is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value ofopmode
.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
, anInvalidKeyException
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 usinggetParameters
orgetIV
(if the parameter is an IV).If this cipher requires algorithm parameters that cannot be derived from the input parameters, and there are no reasonable provider-specific default values, initialization will necessarily fail.
If this cipher (including its 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 aCipher
object is equivalent to creating a new instance of thatCipher
object and initializing it.- Parameters:
opmode
- the operation mode of thisCipher
object (this is one of the following:ENCRYPT_MODE
,DECRYPT_MODE
,WRAP_MODE
orUNWRAP_MODE
)certificate
- the certificate- Throws:
InvalidKeyException
- if the public key in the given certificate is inappropriate for initializing this cipher, or this cipher 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)UnsupportedOperationException
- ifopmode
isWRAP_MODE
orUNWRAP_MODE
but the mode is not implemented by the underlyingCipherSpi
InvalidParameterException
- ifopmode
is not one of the recognized values
-
init
public final void init(int opmode, Certificate certificate, SecureRandom random) throws InvalidKeyException Initializes thisCipher
object with the public key from the given certificate and a source of randomness.The
Cipher
object is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value ofopmode
.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
, anInvalidKeyException
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 anInvalidKeyException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved usinggetParameters
orgetIV
(if the parameter is an IV).If this cipher requires algorithm parameters that cannot be derived from the input parameters, and there are no reasonable provider-specific default values, initialization will necessarily fail.
If this cipher (including its 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 aCipher
object is equivalent to creating a new instance of thatCipher
object and initializing it.- Parameters:
opmode
- the operation mode of thisCipher
object (this is one of the following:ENCRYPT_MODE
,DECRYPT_MODE
,WRAP_MODE
orUNWRAP_MODE
)certificate
- the certificaterandom
- the source of randomness- Throws:
InvalidKeyException
- if the public key in the given certificate is inappropriate for initializing this cipher, or this cipher 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)UnsupportedOperationException
- ifopmode
isWRAP_MODE
orUNWRAP_MODE
but the mode is not implemented by the underlyingCipherSpi
InvalidParameterException
- ifopmode
is not one of the recognized values
-
update
public final byte[] update(byte[] input) Continues a multiple-part encryption or decryption operation (depending on how thisCipher
object was initialized), processing another data part.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 returnsnull
.- Parameters:
input
- the input buffer- Returns:
- the new buffer with the result, or
null
if this cipher is a block cipher and the input data is too short to result in a new block - Throws:
IllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not been initialized)
-
update
public final byte[] update(byte[] input, int inputOffset, int inputLen) Continues a multiple-part encryption or decryption operation (depending on how thisCipher
object was initialized), processing another data part.The first
inputLen
bytes in theinput
buffer, starting atinputOffset
inclusive, are processed, and the result is stored in a new buffer.If
inputLen
is zero, this method returnsnull
.- Parameters:
input
- the input bufferinputOffset
- the offset ininput
where the input startsinputLen
- the input length- Returns:
- the new buffer with the result, or
null
if this cipher is a block cipher and the input data is too short to result in a new block. - Throws:
IllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not been initialized)
-
update
public final int update(byte[] input, int inputOffset, int inputLen, byte[] output) throws ShortBufferException Continues a multiple-part encryption or decryption operation (depending on how thisCipher
object was initialized), processing another data part.The first
inputLen
bytes in theinput
buffer, starting atinputOffset
inclusive, are processed, and the result is stored in theoutput
buffer.If the
output
buffer is too small to hold the result, aShortBufferException
is thrown. In this case, repeat this call with a larger output buffer. UsegetOutputSize
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
andoutput
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 bufferinputOffset
- the offset ininput
where the input startsinputLen
- the input lengthoutput
- the buffer for the result- Returns:
- the number of bytes stored in
output
- Throws:
IllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not been initialized)ShortBufferException
- if the given output buffer is too small to hold the result
-
update
public final int update(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset) throws ShortBufferException Continues a multiple-part encryption or decryption operation (depending on how thisCipher
object was initialized), processing another data part.The first
inputLen
bytes in theinput
buffer, starting atinputOffset
inclusive, are processed, and the result is stored in theoutput
buffer, starting atoutputOffset
inclusive.If the
output
buffer is too small to hold the result, aShortBufferException
is thrown. In this case, repeat this call with a larger output buffer. UsegetOutputSize
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
andoutput
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 bufferinputOffset
- the offset ininput
where the input startsinputLen
- the input lengthoutput
- the buffer for the resultoutputOffset
- the offset inoutput
where the result is stored- Returns:
- the number of bytes stored in
output
- Throws:
IllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not been initialized)ShortBufferException
- if the given output buffer is too small to hold the result
-
update
Continues a multiple-part encryption or decryption operation (depending on how thisCipher
object was initialized), processing another data part.All
input.remaining()
bytes starting atinput.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, aShortBufferException
is thrown. In this case, repeat this call with a larger output buffer. UsegetOutputSize
to determine how big the output buffer should be.Note: this method should be copy-safe, which means the
input
andoutput
buffers can reference the same block of memory and no unprocessed input data is overwritten when the result is copied into the output buffer.- Parameters:
input
- the input ByteBufferoutput
- the output ByteByffer- Returns:
- the number of bytes stored in
output
- Throws:
IllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not been initialized)IllegalArgumentException
- if input and output are the same objectReadOnlyBufferException
- if the output buffer is read-onlyShortBufferException
- if there is insufficient space in the output buffer- Since:
- 1.5
-
doFinal
Finishes a multiple-part encryption or decryption operation, depending on how thisCipher
object was initialized.Input data that may have been buffered during a previous
update
operation is processed, with padding (if requested) being applied. If an AEAD mode such as GCM/CCM is being used, the authentication tag is appended in the case of encryption, or verified in the case of decryption. 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 toinit
. That is, the object is reset and available to encrypt or decrypt (depending on the operation mode that was specified in the call toinit
) more data.Note: if any exception is thrown, this
Cipher
object may need to be reset before it can be used again.- Returns:
- the new buffer with the result
- Throws:
IllegalStateException
- if thisCipher
object 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 thisCipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if thisCipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated value
-
doFinal
public final int doFinal(byte[] output, int outputOffset) throws IllegalBlockSizeException, ShortBufferException, BadPaddingException Finishes a multiple-part encryption or decryption operation, depending on how thisCipher
object was initialized.Input data that may have been buffered during a previous
update
operation is processed, with padding (if requested) being applied. If an AEAD mode such as GCM/CCM is being used, the authentication tag is appended in the case of encryption, or verified in the case of decryption. The result is stored in theoutput
buffer, starting atoutputOffset
inclusive.If the
output
buffer is too small to hold the result, aShortBufferException
is thrown. In this case, repeat this call with a larger output buffer. UsegetOutputSize
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 toinit
. That is, the object is reset and available to encrypt or decrypt (depending on the operation mode that was specified in the call toinit
) more data.Note: if any exception is thrown, this
Cipher
object may need to be reset before it can be used again.- Parameters:
output
- the buffer for the resultoutputOffset
- the offset inoutput
where the result is stored- Returns:
- the number of bytes stored in
output
- Throws:
IllegalStateException
- if thisCipher
object 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 resultBadPaddingException
- if thisCipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if thisCipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated value
-
doFinal
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how thisCipher
object was initialized.The bytes in the
input
buffer, and any input bytes that may have been buffered during a previousupdate
operation, are processed, with padding (if requested) being applied. If an AEAD mode such as GCM/CCM is being used, the authentication tag is appended in the case of encryption, or verified in the case of decryption. 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 toinit
. That is, the object is reset and available to encrypt or decrypt (depending on the operation mode that was specified in the call toinit
) more data.Note: if any exception is thrown, this
Cipher
object may need to be reset before it can be used again.- Parameters:
input
- the input buffer- Returns:
- the new buffer with the result
- Throws:
IllegalStateException
- if thisCipher
object 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 thisCipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if thisCipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated value
-
doFinal
public final byte[] doFinal(byte[] input, int inputOffset, int inputLen) throws IllegalBlockSizeException, BadPaddingException Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how thisCipher
object was initialized.The first
inputLen
bytes in theinput
buffer, starting atinputOffset
inclusive, and any input bytes that may have been buffered during a previousupdate
operation, are processed, with padding (if requested) being applied. If an AEAD mode such as GCM/CCM is being used, the authentication tag is appended in the case of encryption, or verified in the case of decryption. 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 toinit
. That is, the object is reset and available to encrypt or decrypt (depending on the operation mode that was specified in the call toinit
) more data.Note: if any exception is thrown, this
Cipher
object may need to be reset before it can be used again.- Parameters:
input
- the input bufferinputOffset
- the offset ininput
where the input startsinputLen
- the input length- Returns:
- the new buffer with the result
- Throws:
IllegalStateException
- if thisCipher
object 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 thisCipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if thisCipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated value
-
doFinal
public final int doFinal(byte[] input, int inputOffset, int inputLen, byte[] output) throws ShortBufferException, IllegalBlockSizeException, BadPaddingException Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how thisCipher
object was initialized.The first
inputLen
bytes in theinput
buffer, starting atinputOffset
inclusive, and any input bytes that may have been buffered during a previousupdate
operation, are processed, with padding (if requested) being applied. If an AEAD mode such as GCM/CCM is being used, the authentication tag is appended in the case of encryption, or verified in the case of decryption. The result is stored in theoutput
buffer.If the
output
buffer is too small to hold the result, aShortBufferException
is thrown. In this case, repeat this call with a larger output buffer. UsegetOutputSize
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 toinit
. That is, the object is reset and available to encrypt or decrypt (depending on the operation mode that was specified in the call toinit
) 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
andoutput
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 bufferinputOffset
- the offset ininput
where the input startsinputLen
- the input lengthoutput
- the buffer for the result- Returns:
- the number of bytes stored in
output
- Throws:
IllegalStateException
- if thisCipher
object 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 resultBadPaddingException
- if thisCipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if thisCipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated value
-
doFinal
public final int doFinal(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset) throws ShortBufferException, IllegalBlockSizeException, BadPaddingException Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how thisCipher
object was initialized.The first
inputLen
bytes in theinput
buffer, starting atinputOffset
inclusive, and any input bytes that may have been buffered during a previousupdate
operation, are processed, with padding (if requested) being applied. If an AEAD mode such as GCM/CCM is being used, the authentication tag is appended in the case of encryption, or verified in the case of decryption. The result is stored in theoutput
buffer, starting atoutputOffset
inclusive.If the
output
buffer is too small to hold the result, aShortBufferException
is thrown. In this case, repeat this call with a larger output buffer. UsegetOutputSize
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 toinit
. That is, the object is reset and available to encrypt or decrypt (depending on the operation mode that was specified in the call toinit
) 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
andoutput
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 bufferinputOffset
- the offset ininput
where the input startsinputLen
- the input lengthoutput
- the buffer for the resultoutputOffset
- the offset inoutput
where the result is stored- Returns:
- the number of bytes stored in
output
- Throws:
IllegalStateException
- if thisCipher
object 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 resultBadPaddingException
- if thisCipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if thisCipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated value
-
doFinal
public final int doFinal(ByteBuffer input, ByteBuffer output) throws ShortBufferException, IllegalBlockSizeException, BadPaddingException Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how thisCipher
object was initialized.All
input.remaining()
bytes starting atinput.position()
are processed. If an AEAD mode such as GCM/CCM is being used, the authentication tag is appended in the case of encryption, or verified in the case of decryption. 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, aShortBufferException
is thrown. In this case, repeat this call with a larger output buffer. UsegetOutputSize
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 toinit
. That is, the object is reset and available to encrypt or decrypt (depending on the operation mode that was specified in the call toinit
) 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
andoutput
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 ByteBufferoutput
- the output ByteBuffer- Returns:
- the number of bytes stored in
output
- Throws:
IllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not been initialized)IllegalArgumentException
- if input and output are the same objectReadOnlyBufferException
- if the output buffer is read-onlyIllegalBlockSizeException
- 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 bufferBadPaddingException
- if thisCipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if thisCipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated value- Since:
- 1.5
-
wrap
Wrap a key.- Parameters:
key
- the key to be wrapped- Returns:
- the wrapped key
- Throws:
IllegalStateException
- if thisCipher
object 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 sizeInvalidKeyException
- 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)UnsupportedOperationException
- if the corresponding method in theCipherSpi
is not supported
-
unwrap
public final Key unwrap(byte[] wrappedKey, String wrappedKeyAlgorithm, int wrappedKeyType) throws InvalidKeyException, NoSuchAlgorithmException Unwrap a previously wrapped key.- Parameters:
wrappedKey
- the key to be unwrappedwrappedKeyAlgorithm
- the algorithm associated with the wrapped keywrappedKeyType
- the type of the wrapped key. This must be one ofSECRET_KEY
,PRIVATE_KEY
, orPUBLIC_KEY
- Returns:
- the unwrapped key
- Throws:
IllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not been initialized)NoSuchAlgorithmException
- if no installed providers can create keys of typewrappedKeyType
for thewrappedKeyAlgorithm
InvalidKeyException
- ifwrappedKey
does not represent a wrapped key of typewrappedKeyType
for thewrappedKeyAlgorithm
UnsupportedOperationException
- if the corresponding method in theCipherSpi
is not supported
-
getMaxAllowedKeyLength
public static final int getMaxAllowedKeyLength(String transformation) throws NoSuchAlgorithmException Returns the maximum key length for the specified transformation according to the installed JCE jurisdiction policy files. If JCE unlimited strength jurisdiction policy files are installed,Integer.MAX_VALUE
will be returned. For more information on the default key sizes and the JCE jurisdiction policy files, please see the Cryptographic defaults and limitations in the JDK Providers Documentation.- Parameters:
transformation
- the cipher transformation- Returns:
- the maximum key length in bits or
Integer.MAX_VALUE
- Throws:
NullPointerException
- iftransformation
isnull
NoSuchAlgorithmException
- iftransformation
is not a valid transformation, i.e. in the form of "algorithm" or "algorithm/mode/padding"- Since:
- 1.5
-
getMaxAllowedParameterSpec
public static final AlgorithmParameterSpec getMaxAllowedParameterSpec(String transformation) throws NoSuchAlgorithmException Returns an {code AlgorithmParameterSpec} object which contains the maximumCipher
parameter value according to the jurisdiction policy file. If JCE unlimited strength jurisdiction policy files are installed or there is no maximum limit on the parameters for the specified transformation in the policy file,null
will be returned.- Parameters:
transformation
- the cipher transformation- Returns:
- an {code AlgorithmParameterSpec} object which holds the maximum
value or
null
- Throws:
NullPointerException
- iftransformation
isnull
NoSuchAlgorithmException
- iftransformation
is not a valid transformation, i.e. in the form of "algorithm" or "algorithm/mode/padding"- Since:
- 1.5
-
updateAAD
public final void updateAAD(byte[] src) Continues a multi-part update of the Additional Authentication Data (AAD).Calls to this method provide AAD to the
Cipher
object when operating in modes such as AEAD (GCM/CCM). If thisCipher
object is operating in either GCM or CCM mode, all AAD must be supplied before beginning operations on the ciphertext (via theupdate
anddoFinal
methods).- Parameters:
src
- the buffer containing the Additional Authentication Data- Throws:
IllegalArgumentException
- if thesrc
byte array isnull
IllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not been initialized), does not accept AAD, or if operating in either GCM or CCM mode and one of theupdate
methods has already been called for the active encryption/decryption operationUnsupportedOperationException
- if the corresponding method in theCipherSpi
has not been overridden by an implementation- Since:
- 1.7
-
updateAAD
public final void updateAAD(byte[] src, int offset, int len) Continues a multi-part update of the Additional Authentication Data (AAD), using a subset of the provided buffer.Calls to this method provide AAD to the
Cipher
object when operating in modes such as AEAD (GCM/CCM). If thisCipher
object is operating in either GCM or CCM mode, all AAD must be supplied before beginning operations on the ciphertext (via theupdate
anddoFinal
methods).- Parameters:
src
- the buffer containing the AADoffset
- the offset insrc
where the AAD input startslen
- the number of AAD bytes- Throws:
IllegalArgumentException
- if thesrc
byte array isnull
, or theoffset
orlength
is less than 0, or the sum of theoffset
andlen
is greater than the length of thesrc
byte arrayIllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not been initialized), does not accept AAD, or if operating in either GCM or CCM mode and one of theupdate
methods has already been called for the active encryption/decryption operationUnsupportedOperationException
- if the corresponding method in theCipherSpi
has not been overridden by an implementation- Since:
- 1.7
-
updateAAD
Continues a multi-part update of the Additional Authentication Data (AAD).Calls to this method provide AAD to the
Cipher
object when operating in modes such as AEAD (GCM/CCM). If thisCipher
object is operating in either GCM or CCM mode, all AAD must be supplied before beginning operations on the ciphertext (via theupdate
anddoFinal
methods).All
src.remaining()
bytes starting atsrc.position()
are processed. Upon return, the input buffer's position will be equal to its limit; its limit will not have changed.- Parameters:
src
- the buffer containing the AAD- Throws:
IllegalArgumentException
- if thesrc ByteBuffer
isnull
IllegalStateException
- if thisCipher
object is in a wrong state (e.g., has not been initialized), does not accept AAD, or if operating in either GCM or CCM mode and one of theupdate
methods has already been called for the active encryption/decryption operationUnsupportedOperationException
- if the corresponding method in theCipherSpi
has not been overridden by an implementation- Since:
- 1.7
-
toString
Returns aString
representation of thisCipher
object.
-