public class Cipher extends Object
This class provides the functionality of a cryptographic cipher for encryption and decryption. It forms the core of the Java Cryptographic Extension (JCE) framework.
In order to create a Cipher object, the application calls the Cipher's getInstance
method, and passes the name of the requested transformation to it. Optionally, the name of a provider may be specified.
A transformation is a string that describes the operation (or set of operations) to be performed on the given input, to produce some output. A transformation always includes the name of a cryptographic algorithm (e.g., DES), and may be followed by a feedback mode and padding scheme.
A transformation is of the form:
(in the latter case, provider-specific default values for the mode and padding scheme are used). For example, the following is a valid transformation:
Cipher c = Cipher.getInstance("DES/CBC/PKCS5Padding");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 "DES/CFB8/NoPadding
" and "DES/OFB32/PKCS5Padding
" transformations. If no such number is specified, a provider-specific default is used. (For example, the SunJCE provider uses a default of 64 bits for DES.) 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 AEAD 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 has 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); ...Every implementation of the Java platform is required to support the following standard
Cipher
transformations with the keysizes in parentheses: AES/CBC/NoPadding
(128)AES/CBC/PKCS5Padding
(128)AES/ECB/NoPadding
(128)AES/ECB/PKCS5Padding
(128)DES/CBC/NoPadding
(56)DES/CBC/PKCS5Padding
(56)DES/ECB/NoPadding
(56)DES/ECB/PKCS5Padding
(56)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)KeyGenerator
, SecretKey
public static final int ENCRYPT_MODE
Constant used to initialize cipher to encryption mode.
public static final int DECRYPT_MODE
Constant used to initialize cipher to decryption mode.
public static final int WRAP_MODE
Constant used to initialize cipher to key-wrapping mode.
public static final int UNWRAP_MODE
Constant used to initialize cipher to key-unwrapping mode.
public static final int PUBLIC_KEY
Constant used to indicate the to-be-unwrapped key is a "public key".
public static final int PRIVATE_KEY
Constant used to indicate the to-be-unwrapped key is a "private key".
public static final int SECRET_KEY
Constant used to indicate the to-be-unwrapped key is a "secret key".
protected Cipher(CipherSpi cipherSpi, Provider provider, String transformation)
Creates a Cipher object.
cipherSpi
- the delegateprovider
- the providertransformation
- the transformationpublic static final Cipher getInstance(String transformation) throws NoSuchAlgorithmException, NoSuchPaddingException
Returns a 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.
transformation
- the name of the transformation, e.g., DES/CBC/PKCS5Padding. See the Cipher section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard transformation names.NoSuchAlgorithmException
- if transformation
is null, empty, in an invalid format, or if no Provider supports a CipherSpi implementation for the specified algorithm.NoSuchPaddingException
- if transformation
contains a padding scheme that is not available.Provider
public static final Cipher getInstance(String transformation, String provider) throws NoSuchAlgorithmException, NoSuchProviderException, NoSuchPaddingException
Returns a 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., DES/CBC/PKCS5Padding. See the Cipher section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard transformation names.provider
- the name of the provider.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.NoSuchProviderException
- if the specified provider is not registered in the security provider list.NoSuchPaddingException
- if transformation
contains a padding scheme that is not available.IllegalArgumentException
- if the provider
is null or empty.Provider
public static final Cipher getInstance(String transformation, Provider provider) throws NoSuchAlgorithmException, NoSuchPaddingException
Returns a 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., DES/CBC/PKCS5Padding. See the Cipher section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard transformation names.provider
- the provider.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 object.NoSuchPaddingException
- if transformation
contains a padding scheme that is not available.IllegalArgumentException
- if the provider
is null.Provider
public final Provider getProvider()
Returns the provider of this Cipher
object.
Cipher
objectpublic final String getAlgorithm()
Returns the algorithm name of this Cipher
object.
This is the same name that was specified in one of the getInstance
calls that created this Cipher
object..
Cipher
object.public final int getBlockSize()
Returns the block size (in bytes).
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 next 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 is in a wrong state (e.g., has not yet been initialized)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.
public final AlgorithmParameters getParameters()
Returns the parameters used with this cipher.
The returned parameters may be the same that were used to initialize this cipher, or may contain a combination of default and random parameter values used by the underlying cipher implementation if this cipher requires algorithm parameters but was not initialized with any.
public final ExemptionMechanism getExemptionMechanism()
Returns the exemption mechanism object used with this cipher.
public final void init(int opmode, Key key) throws InvalidKeyException
Initializes this cipher with a key.
The cipher is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value of opmode
.
If this cipher requires any algorithm parameters that cannot be derived from the given key
, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption or key wrapping, and raise an InvalidKeyException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved using getParameters
or getIV
(if the parameter is an IV).
If this cipher 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 underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them using the SecureRandom
implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation of SecureRandom, a system-provided source of randomness will be used.)
Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.
opmode
- the operation mode of this cipher (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)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 (@code opmode} is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
.public final void init(int opmode, Key key, SecureRandom random) throws InvalidKeyException
Initializes this cipher with a key and a source of randomness.
The cipher is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value of opmode
.
If this cipher requires any algorithm parameters that cannot be derived from the given key
, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption or key wrapping, and raise an InvalidKeyException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved using getParameters
or getIV
(if the parameter is an IV).
If this cipher 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 underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them from random
.
Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.
opmode
- the operation mode of this cipher (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)key
- the encryption keyrandom
- the source of 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 (@code opmode} is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
.public final void init(int opmode, Key key, AlgorithmParameterSpec params) throws InvalidKeyException, InvalidAlgorithmParameterException
Initializes this cipher with a key and a set of algorithm parameters.
The cipher is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value of opmode
.
If this cipher requires any algorithm parameters and params
is null, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption or key wrapping, and raise an InvalidAlgorithmParameterException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved using getParameters
or getIV
(if the parameter is an IV).
If this cipher 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 underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them using the SecureRandom
implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation of SecureRandom, a system-provided source of randomness will be used.)
Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.
opmode
- the operation mode of this cipher (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)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 (@code opmode} is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
.public final void init(int opmode, Key key, AlgorithmParameterSpec params, SecureRandom random) throws InvalidKeyException, InvalidAlgorithmParameterException
Initializes this cipher with a key, a set of algorithm parameters, and a source of randomness.
The cipher is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value of opmode
.
If this cipher requires any algorithm parameters and params
is null, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption or key wrapping, and raise an InvalidAlgorithmParameterException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved using getParameters
or getIV
(if the parameter is an IV).
If this cipher 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 underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them from random
.
Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.
opmode
- the operation mode of this cipher (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)key
- the encryption keyparams
- the algorithm parametersrandom
- the source of 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 (@code opmode} is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
.public final void init(int opmode, Key key, AlgorithmParameters params) throws InvalidKeyException, InvalidAlgorithmParameterException
Initializes this cipher with a key and a set of algorithm parameters.
The cipher is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value of opmode
.
If this cipher requires any algorithm parameters and params
is null, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption or key wrapping, and raise an InvalidAlgorithmParameterException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved using getParameters
or getIV
(if the parameter is an IV).
If this cipher 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 underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them using the SecureRandom
implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation of SecureRandom, a system-provided source of randomness will be used.)
Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.
opmode
- the operation mode of this cipher (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)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 (@code opmode} is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
.public final void init(int opmode, Key key, AlgorithmParameters params, SecureRandom random) throws InvalidKeyException, InvalidAlgorithmParameterException
Initializes this cipher with a key, a set of algorithm parameters, and a source of randomness.
The cipher is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value of opmode
.
If this cipher requires any algorithm parameters and params
is null, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption or key wrapping, and raise an InvalidAlgorithmParameterException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved using getParameters
or getIV
(if the parameter is an IV).
If this cipher 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 underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them from random
.
Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.
opmode
- the operation mode of this cipher (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)key
- the encryption keyparams
- the algorithm parametersrandom
- the source of 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 (@code opmode} is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
.public final void init(int opmode, Certificate certificate) throws InvalidKeyException
Initializes this cipher with the public key from the given certificate.
The cipher is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value of opmode
.
If the certificate is of type X.509 and has a key usage extension field marked as critical, and the value of the key usage extension field implies that the public key in the certificate and its corresponding private key are not supposed to be used for the operation represented by the value of opmode
, an InvalidKeyException
is thrown.
If this cipher requires any algorithm parameters that cannot be derived from the public key in the given certificate, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption or key wrapping, and raise an
InvalidKeyException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved using getParameters
or getIV
(if the parameter is an IV).
If this cipher 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 underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them using the SecureRandom
implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation of SecureRandom, a system-provided source of randomness will be used.)
Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.
opmode
- the operation mode of this cipher (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)certificate
- the 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 (@code opmode} is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
.public final void init(int opmode, Certificate certificate, SecureRandom random) throws InvalidKeyException
Initializes this cipher with the public key from the given certificate and a source of randomness.
The cipher is initialized for one of the following four operations: encryption, decryption, key wrapping or key unwrapping, depending on the value of opmode
.
If the certificate is of type X.509 and has a key usage extension field marked as critical, and the value of the key usage extension field implies that the public key in the certificate and its corresponding private key are not supposed to be used for the operation represented by the value of opmode
, an InvalidKeyException
is thrown.
If this cipher requires any algorithm parameters that cannot be derived from the public key in the given certificate
, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption or key wrapping, and raise an InvalidKeyException
if it is being initialized for decryption or key unwrapping. The generated parameters can be retrieved using getParameters
or getIV
(if the parameter is an IV).
If this cipher 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 underlying feedback or padding scheme) requires any random bytes (e.g., for parameter generation), it will get them from random
.
Note that when a Cipher object is initialized, it loses all previously-acquired state. In other words, initializing a Cipher is equivalent to creating a new instance of that Cipher and initializing it.
opmode
- the operation mode of this cipher (this is one of the following: ENCRYPT_MODE
, DECRYPT_MODE
, WRAP_MODE
or UNWRAP_MODE
)certificate
- the certificaterandom
- the source of 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 (@code opmode} is WRAP_MODE
or UNWRAP_MODE
but the mode is not implemented by the underlying CipherSpi
.public final byte[] update(byte[] input)
Continues a multiple-part encryption or decryption operation (depending on how this cipher 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 bufferIllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)public final byte[] update(byte[] input, int inputOffset, int inputLen)
Continues a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part.
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 lengthIllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized)public final int update(byte[] input, int inputOffset, int inputLen, byte[] output) throws ShortBufferException
Continues a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part.
The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, are processed, and the result is stored in the output
buffer.
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 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
Continues a multiple-part encryption or decryption operation (depending on how this cipher was initialized), processing another data part.
The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, are processed, and the result is stored in the output
buffer, starting at outputOffset
inclusive.
If the output
buffer is too small to hold the result, a ShortBufferException
is thrown. In this case, repeat this call with a larger output buffer. 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 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
Continues a multiple-part encryption or decryption operation (depending on how this cipher 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 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
Finishes a multiple-part encryption or decryption operation, depending on how this cipher 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 is in a wrong state (e.g., has not been initialized)IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size; or if this encryption algorithm is unable to process the input data provided.BadPaddingException
- if this cipher is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if this cipher 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
Finishes a multiple-part encryption or decryption operation, depending on how this cipher 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 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 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 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
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how this cipher was initialized.
The 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 is in a wrong state (e.g., has not been initialized)IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size; or if this encryption algorithm is unable to process the input data provided.BadPaddingException
- if this cipher is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if this cipher 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
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how this cipher was initialized.
The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, and any input bytes that may have been buffered during a previous update
operation, are processed, with padding (if requested) being applied. 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 is in a wrong state (e.g., has not been initialized)IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size; or if this encryption algorithm is unable to process the input data provided.BadPaddingException
- if this cipher is in decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytesAEADBadTagException
- if this cipher 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
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how this cipher was initialized.
The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, and any input bytes that may have been buffered during a previous update
operation, are processed, with padding (if requested) being applied. 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 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 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 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
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how this cipher was initialized.
The first inputLen
bytes in the input
buffer, starting at inputOffset
inclusive, and any input bytes that may have been buffered during a previous update
operation, are processed, with padding (if requested) being applied. 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 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 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 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
Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how this cipher was initialized.
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 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 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 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
Wrap a key.
key
- the key to be wrapped.IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized).IllegalBlockSizeException
- if this cipher is a block cipher, no padding has been requested, and the length of the encoding of the key to be wrapped is not a multiple of the block size.InvalidKeyException
- if it is impossible or unsafe to wrap the key with this cipher (e.g., a hardware protected key is being passed to a software-only cipher).UnsupportedOperationException
- if the corresponding method in the CipherSpi
is not supported.public final Key unwrap(byte[] wrappedKey, String wrappedKeyAlgorithm, int wrappedKeyType) throws InvalidKeyException, NoSuchAlgorithmException
Unwrap a previously wrapped key.
wrappedKey
- the key to be unwrapped.wrappedKeyAlgorithm
- the algorithm associated with the wrapped key.wrappedKeyType
- the type of the wrapped key. This must be one of SECRET_KEY
, PRIVATE_KEY
, or PUBLIC_KEY
.IllegalStateException
- if this cipher is in a wrong state (e.g., has not been initialized).NoSuchAlgorithmException
- if no installed providers can create keys of type wrappedKeyType
for the wrappedKeyAlgorithm
.InvalidKeyException
- if wrappedKey
does not represent a wrapped key of type wrappedKeyType
for the wrappedKeyAlgorithm
.UnsupportedOperationException
- if the corresponding method in the CipherSpi
is not supported.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 default key size in JCE jurisdiction policy files, please see Appendix E in the Java Cryptography Architecture Reference Guide.
transformation
- the cipher transformation.NullPointerException
- if transformation
is null.NoSuchAlgorithmException
- if transformation
is not a valid transformation, i.e. in the form of "algorithm" or "algorithm/mode/padding".public static final AlgorithmParameterSpec getMaxAllowedParameterSpec(String transformation) throws NoSuchAlgorithmException
Returns an AlgorithmParameterSpec object which contains the maximum 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 transformation.NullPointerException
- if transformation
is null.NoSuchAlgorithmException
- if transformation
is not a valid transformation, i.e. in the form of "algorithm" or "algorithm/mode/padding".public 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 when operating in modes such as AEAD (GCM/CCM). If this cipher 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 nullIllegalStateException
- if this cipher 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)
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 when operating in modes such as AEAD (GCM/CCM). If this cipher 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 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)
Continues a multi-part update of the Additional Authentication Data (AAD).
Calls to this method provide AAD to the cipher when operating in modes such as AEAD (GCM/CCM). If this cipher 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 nullIllegalStateException
- if this cipher 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 implementation
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