NullCipher
public class Cipher extends Object
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:
(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)Modifier and Type | Field | Description |
---|---|---|
static final int |
DECRYPT_MODE |
Constant used to initialize cipher to decryption mode. |
static final int |
ENCRYPT_MODE |
Constant used to initialize cipher to encryption mode. |
static final int |
PRIVATE_KEY |
Constant used to indicate the to-be-unwrapped key is a "private key". |
static final int |
PUBLIC_KEY |
Constant used to indicate the to-be-unwrapped key is a "public key". |
static final int |
SECRET_KEY |
Constant used to indicate the to-be-unwrapped key is a "secret key". |
static final int |
UNWRAP_MODE |
Constant used to initialize cipher to key-unwrapping mode. |
static final int |
WRAP_MODE |
Constant used to initialize cipher to key-wrapping mode. |
Modifier | Constructor | Description |
---|---|---|
protected |
Creates a Cipher object. |
Modifier and Type | Method | Description |
---|---|---|
final byte[] |
doFinal() |
Finishes a multiple-part encryption or decryption operation, depending on how this Cipher object was initialized. |
final byte[] |
doFinal |
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. |
final int |
doFinal |
Finishes a multiple-part encryption or decryption operation, depending on how this Cipher object was initialized. |
final byte[] |
doFinal |
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. |
final int |
doFinal |
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. |
final int |
doFinal |
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. |
final int |
doFinal |
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. |
final String |
getAlgorithm() |
Returns the algorithm name of this Cipher object. |
final int |
getBlockSize() |
Returns the block size (in bytes). |
final ExemptionMechanism |
getExemptionMechanism() |
Returns the exemption mechanism object used with this Cipher object. |
static final Cipher |
getInstance |
Returns a Cipher object that implements the specified transformation. |
static final Cipher |
getInstance |
Returns a Cipher object that implements the specified transformation. |
static final Cipher |
getInstance |
Returns a Cipher object that implements the specified transformation. |
final byte[] |
getIV() |
Returns the initialization vector (IV) in a new buffer. |
static final int |
getMaxAllowedKeyLength |
Returns the maximum key length for the specified transformation according to the installed JCE jurisdiction policy files. |
static final AlgorithmParameterSpec |
getMaxAllowedParameterSpec |
Returns an {code AlgorithmParameterSpec} object which contains the maximum Cipher parameter value according to the jurisdiction policy file. |
final int |
getOutputSize |
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). |
final AlgorithmParameters |
getParameters() |
Returns the parameters used with this Cipher object. |
final Provider |
getProvider() |
Returns the provider of this Cipher object. |
final void |
init |
Initializes this Cipher object with the public key from the given certificate. |
final void |
init |
Initializes this Cipher object with the public key from the given certificate and a source of randomness. |
final void |
init |
Initializes this Cipher object with a key. |
final void |
init |
Initializes this Cipher object with a key and a set of algorithm parameters. |
final void |
init |
Initializes this Cipher object with a key, a set of algorithm parameters, and a source of randomness. |
final void |
init |
Initializes this Cipher object with a key and a source of randomness. |
final void |
init |
Initializes this Cipher object with a key and a set of algorithm parameters. |
final void |
init |
Initializes this Cipher object with a key, a set of algorithm parameters, and a source of randomness. |
String |
toString() |
Returns a String representation of this Cipher object. |
final Key |
unwrap |
Unwrap a previously wrapped key. |
final byte[] |
update |
Continues a multiple-part encryption or decryption operation (depending on how this Cipher object was initialized), processing another data part. |
final byte[] |
update |
Continues a multiple-part encryption or decryption operation (depending on how this Cipher object was initialized), processing another data part. |
final int |
update |
Continues a multiple-part encryption or decryption operation (depending on how this Cipher object was initialized), processing another data part. |
final int |
update |
Continues a multiple-part encryption or decryption operation (depending on how this Cipher object was initialized), processing another data part. |
final int |
update |
Continues a multiple-part encryption or decryption operation (depending on how this Cipher object was initialized), processing another data part. |
final void |
updateAAD |
Continues a multi-part update of the Additional Authentication Data (AAD). |
final void |
updateAAD |
Continues a multi-part update of the Additional Authentication Data (AAD), using a subset of the provided buffer. |
final void |
updateAAD |
Continues a multi-part update of the Additional Authentication Data (AAD). |
final byte[] |
wrap |
Wrap a key. |
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
protected Cipher(CipherSpi cipherSpi, Provider provider, String transformation)
Cipher
object.cipherSpi
- the delegateprovider
- the providertransformation
- the transformationNullPointerException
- if provider
is null
IllegalArgumentException
- if the supplied arguments are deemed invalid for constructing the Cipher
objectpublic static final Cipher getInstance(String transformation) throws NoSuchAlgorithmException, NoSuchPaddingException
Cipher
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 the CipherSpi
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.
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 by Security.getProviders()
. See also the Cipher Transformations section of the JDK Providers document for information on the transformation defaults used by JDK providers.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.Cipher
object that implements the requested transformationNoSuchAlgorithmException
- if transformation
is null
, empty, in an invalid format, or if no provider supports a CipherSpi
implementation for the specified algorithmNoSuchPaddingException
- if transformation
contains a padding scheme that is not availablepublic static final Cipher getInstance(String transformation, String provider) throws NoSuchAlgorithmException, NoSuchProviderException, NoSuchPaddingException
Cipher
object that implements the specified transformation. A new Cipher
object encapsulating the CipherSpi
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.
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 providerCipher
object that implements the requested transformationIllegalArgumentException
- if the provider
is null
or emptyNoSuchAlgorithmException
- if transformation
is null
, empty, in an invalid format, or if a CipherSpi
implementation for the specified algorithm is not available from the specified providerNoSuchPaddingException
- if transformation
contains a padding scheme that is not availableNoSuchProviderException
- if the specified provider is not registered in the security provider listpublic static final Cipher getInstance(String transformation, Provider provider) throws NoSuchAlgorithmException, NoSuchPaddingException
Cipher
object that implements the specified transformation. A new Cipher
object encapsulating the CipherSpi
implementation from the specified provider
object is returned. Note that the specified provider
object does not have to be registered in the provider list.
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 providerCipher
object that implements the requested transformationIllegalArgumentException
- if the provider
is null
NoSuchAlgorithmException
- if transformation
is null
, empty, in an invalid format, or if a CipherSpi
implementation for the specified algorithm is not available from the specified provider
objectNoSuchPaddingException
- if transformation
contains a padding scheme that is not availablepublic 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
objectpublic 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, padding, and AEAD tagging.
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
object 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.
null
if this cipher does not use an IV, or if the IV has not yet been set.public final AlgorithmParameters getParameters()
Cipher
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.
null
public final ExemptionMechanism getExemptionMechanism()
Cipher
object.Cipher
object, or null
if this Cipher
object does not use any exemption mechanism.public final void init(int opmode, Key key) throws InvalidKeyException
Cipher
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 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 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 a Cipher
object is equivalent to creating a new instance of that Cipher
object and initializing it.
opmode
- the operation mode of this Cipher
object (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)key
- the keyInvalidKeyException
- 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
- if opmode
is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
InvalidParameterException
- if opmode
is not one of the recognized valuespublic final void init(int opmode, Key key, SecureRandom random) throws InvalidKeyException
Cipher
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 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 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 a Cipher
object is equivalent to creating a new instance of that Cipher
object and initializing it.
opmode
- the operation mode of this Cipher
object (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)key
- the encryption keyrandom
- the source of randomnessInvalidKeyException
- 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
- if opmode
is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
InvalidParameterException
- if opmode
is not one of the recognized valuespublic final void init(int opmode, Key key, AlgorithmParameterSpec params) throws InvalidKeyException, InvalidAlgorithmParameterException
Cipher
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 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 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 a Cipher
object is equivalent to creating a new instance of that Cipher
object and initializing it.
opmode
- the operation mode of this Cipher
object (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)key
- the encryption keyparams
- the algorithm parametersInvalidKeyException
- 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 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)UnsupportedOperationException
- if opmode
is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
InvalidParameterException
- if opmode
is not one of the recognized valuespublic final void init(int opmode, Key key, AlgorithmParameterSpec params, SecureRandom random) throws InvalidKeyException, InvalidAlgorithmParameterException
Cipher
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 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 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 a Cipher
object is equivalent to creating a new instance of that Cipher
object and initializing it.
opmode
- the operation mode of this Cipher
object (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 randomnessInvalidKeyException
- 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 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)UnsupportedOperationException
- if opmode
is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
InvalidParameterException
- if opmode
is not one of the recognized valuespublic final void init(int opmode, Key key, AlgorithmParameters params) throws InvalidKeyException, InvalidAlgorithmParameterException
Cipher
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 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 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 a Cipher
object is equivalent to creating a new instance of that Cipher
object and initializing it.
opmode
- the operation mode of this Cipher
object this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)key
- the encryption keyparams
- the algorithm parametersInvalidKeyException
- 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 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)UnsupportedOperationException
- if opmode
is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
InvalidParameterException
- if opmode
is not one of the recognized valuespublic final void init(int opmode, Key key, AlgorithmParameters params, SecureRandom random) throws InvalidKeyException, InvalidAlgorithmParameterException
Cipher
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 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 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 a Cipher
object is equivalent to creating a new instance of that Cipher
object and initializing it.
opmode
- the operation mode of this Cipher
object (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 randomnessInvalidKeyException
- 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 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)UnsupportedOperationException
- if opmode
is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
InvalidParameterException
- if opmode
is not one of the recognized valuespublic final void init(int opmode, Certificate certificate) throws InvalidKeyException
Cipher
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 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 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 a Cipher
object is equivalent to creating a new instance of that Cipher
object and initializing it.
opmode
- the operation mode of this Cipher
object (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)certificate
- the certificateInvalidKeyException
- 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
- if opmode
is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
InvalidParameterException
- if opmode
is not one of the recognized valuespublic final void init(int opmode, Certificate certificate, SecureRandom random) throws InvalidKeyException
Cipher
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 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 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 a Cipher
object is equivalent to creating a new instance of that Cipher
object and initializing it.
opmode
- the operation mode of this Cipher
object (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)certificate
- the certificaterandom
- the source of randomnessInvalidKeyException
- 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
- if opmode
is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
InvalidParameterException
- if opmode
is not one of the recognized valuespublic final byte[] update(byte[] input)
Cipher
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 returns null
.
input
- the input buffernull
if this cipher is a block cipher and the input data is too short to result in a new blockIllegalStateException
- if this Cipher
object is in a wrong state (e.g., has not been initialized)public final byte[] update(byte[] input, int inputOffset, int inputLen)
Cipher
object was initialized), processing another data part. The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, are processed, and the result is stored in 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 lengthnull
if this cipher is a block cipher and the input data is too short to result in a new block.IllegalStateException
- if this Cipher
object 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
Cipher
object was initialized), processing another data part. The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, are processed, and the result is stored in the output
buffer.
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 resultoutput
IllegalStateException
- if this Cipher
object 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
Cipher
object was initialized), processing another data part. The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, are processed, and the result is stored in the output
buffer, starting at outputOffset
inclusive.
If the output
buffer is too small to hold the result, a ShortBufferException
is thrown. In this case, repeat this call with a larger output buffer. 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 storedoutput
IllegalStateException
- if this Cipher
object 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(ByteBuffer input, ByteBuffer output) throws ShortBufferException
Cipher
object was initialized), processing another data part. 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 ByteByfferoutput
IllegalStateException
- if this Cipher
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 bufferpublic final byte[] doFinal() throws IllegalBlockSizeException, BadPaddingException
Cipher
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 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
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 this Cipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if this Cipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated valuepublic final int doFinal(byte[] output, int outputOffset) throws IllegalBlockSizeException, ShortBufferException, BadPaddingException
Cipher
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 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 storedoutput
IllegalStateException
- if this Cipher
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 this Cipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if this Cipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated valuepublic final byte[] doFinal(byte[] input) throws IllegalBlockSizeException, BadPaddingException
Cipher
object was initialized. 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. 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 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 bufferIllegalStateException
- if this Cipher
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 this Cipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if this Cipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated valuepublic final byte[] doFinal(byte[] input, int inputOffset, int inputLen) throws IllegalBlockSizeException, BadPaddingException
Cipher
object was initialized. The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, and any input bytes that may have been buffered during a previous update
operation, are processed, with padding (if requested) being applied. 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 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 lengthIllegalStateException
- if this Cipher
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 this Cipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if this Cipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated valuepublic final int doFinal(byte[] input, int inputOffset, int inputLen, byte[] output) throws ShortBufferException, IllegalBlockSizeException, BadPaddingException
Cipher
object was initialized. The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, and any input bytes that may have been buffered during a previous update
operation, are processed, with padding (if requested) being applied. 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.
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 resultoutput
IllegalStateException
- if this Cipher
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 this Cipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if this Cipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated valuepublic final int doFinal(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset) throws ShortBufferException, IllegalBlockSizeException, BadPaddingException
Cipher
object was initialized. The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, and any input bytes that may have been buffered during a previous update
operation, are processed, with padding (if requested) being applied. 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, 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 storedoutput
IllegalStateException
- if this Cipher
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 this Cipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if this Cipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated valuepublic final int doFinal(ByteBuffer input, ByteBuffer output) throws ShortBufferException, IllegalBlockSizeException, BadPaddingException
Cipher
object was initialized. All input.remaining()
bytes starting at input.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, 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 ByteBufferoutput
IllegalStateException
- if this Cipher
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 this Cipher
object is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if this Cipher
object is decrypting in an AEAD mode (such as GCM/CCM), and the received authentication tag does not match the calculated valuepublic final byte[] wrap(Key key) throws IllegalBlockSizeException, InvalidKeyException
key
- the key to be wrappedIllegalStateException
- if this Cipher
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 the CipherSpi
is not supportedpublic final Key unwrap(byte[] wrappedKey, String wrappedKeyAlgorithm, int wrappedKeyType) throws InvalidKeyException, NoSuchAlgorithmException
wrappedKey
- the key to be unwrappedwrappedKeyAlgorithm
- the algorithm associated with the wrapped keywrappedKeyType
- the type of the wrapped key. This must be one of SECRET_KEY
, PRIVATE_KEY
, or PUBLIC_KEY
IllegalStateException
- if this Cipher
object 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
UnsupportedOperationException
- if the corresponding method in the CipherSpi
is not supportedpublic static final int getMaxAllowedKeyLength(String transformation) throws NoSuchAlgorithmException
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.transformation
- the cipher transformationInteger.MAX_VALUE
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
Cipher
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.transformation
- the cipher transformationnull
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 final void updateAAD(byte[] src)
Calls to this method provide AAD to the Cipher
object when operating in modes such as AEAD (GCM/CCM). If this Cipher
object is operating in either GCM or CCM mode, all AAD must be supplied before beginning operations on the ciphertext (via the update
and doFinal
methods).
src
- the buffer containing the Additional Authentication DataIllegalArgumentException
- if the src
byte array is null
IllegalStateException
- if this Cipher
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 the update
methods has already been called for the active encryption/decryption operationUnsupportedOperationException
- if the corresponding method in the CipherSpi
has not been overridden by an implementationpublic final void updateAAD(byte[] src, int offset, int len)
Calls to this method provide AAD to the Cipher
object when operating in modes such as AEAD (GCM/CCM). If this Cipher
object is operating in either GCM or CCM mode, all AAD must be supplied before beginning operations on the ciphertext (via the update
and doFinal
methods).
src
- the buffer containing the AADoffset
- the offset in src
where the AAD input startslen
- the number of AAD bytesIllegalArgumentException
- if the src
byte array is null
, or the offset
or length
is less than 0, or the sum of the offset
and len
is greater than the length of the src
byte arrayIllegalStateException
- if this Cipher
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 the update
methods has already been called for the active encryption/decryption operationUnsupportedOperationException
- if the corresponding method in the CipherSpi
has not been overridden by an implementationpublic final void updateAAD(ByteBuffer src)
Calls to this method provide AAD to the Cipher
object when operating in modes such as AEAD (GCM/CCM). If this Cipher
object is operating in either GCM or CCM mode, all AAD must be supplied before beginning operations on the ciphertext (via the update
and doFinal
methods).
All src.remaining()
bytes starting at src.position()
are processed. Upon return, the input buffer's position will be equal to its limit; its limit will not have changed.
src
- the buffer containing the AADIllegalArgumentException
- if the src ByteBuffer
is null
IllegalStateException
- if this Cipher
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 the update
methods has already been called for the active encryption/decryption operationUnsupportedOperationException
- if the corresponding method in the CipherSpi
has not been overridden by an implementationpublic String toString()
String
representation of this Cipher
object.
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/javax/crypto/Cipher.html