- java.lang.Object
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- javax.crypto.ExemptionMechanismSpi
 
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 public abstract class ExemptionMechanismSpi extends Object This class defines the Service Provider Interface (SPI) for theExemptionMechanismclass. All the abstract methods in this class must be implemented by each cryptographic service provider who wishes to supply the implementation of a particular exemption mechanism.- Since:
- 1.4
 
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Constructor SummaryConstructors Constructor Description ExemptionMechanismSpi()
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Method SummaryAll Methods Instance Methods Abstract Methods Modifier and Type Method Description protected abstract byte[]engineGenExemptionBlob()Generates the exemption mechanism key blob.protected abstract intengineGenExemptionBlob(byte[] output, int outputOffset)Generates the exemption mechanism key blob, and stores the result in theoutputbuffer, starting atoutputOffsetinclusive.protected abstract intengineGetOutputSize(int inputLen)Returns the length in bytes that an output buffer would need to be in order to hold the result of the nextengineGenExemptionBloboperation, given the input lengthinputLen(in bytes).protected abstract voidengineInit(Key key)Initializes this exemption mechanism with a key.protected abstract voidengineInit(Key key, AlgorithmParameters params)Initializes this exemption mechanism with a key and a set of algorithm parameters.protected abstract voidengineInit(Key key, AlgorithmParameterSpec params)Initializes this exemption mechanism with a key and a set of algorithm parameters.
 
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Method Detail- 
engineGetOutputSizeprotected abstract int engineGetOutputSize(int inputLen) Returns the length in bytes that an output buffer would need to be in order to hold the result of the nextengineGenExemptionBloboperation, given the input lengthinputLen(in bytes).The actual output length of the next engineGenExemptionBlobcall may be smaller than the length returned by this method.- Parameters:
- inputLen- the input length (in bytes)
- Returns:
- the required output buffer size (in bytes)
 
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engineInitprotected abstract void engineInit(Key key) throws InvalidKeyException, ExemptionMechanismException Initializes this exemption mechanism with a key.If this exemption mechanism requires any algorithm parameters that cannot be derived from the given key, the underlying exemption mechanism implementation is supposed to generate the required parameters itself (using provider-specific default values); in the case that algorithm parameters must be specified by the caller, anInvalidKeyExceptionis raised.- Parameters:
- key- the key for this exemption mechanism
- Throws:
- InvalidKeyException- if the given key is inappropriate for this exemption mechanism.
- ExemptionMechanismException- if problem(s) encountered in the process of initializing.
 
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engineInitprotected abstract void engineInit(Key key, AlgorithmParameterSpec params) throws InvalidKeyException, InvalidAlgorithmParameterException, ExemptionMechanismException Initializes this exemption mechanism with a key and a set of algorithm parameters.If this exemption mechanism requires any algorithm parameters and paramsis null, the underlying exemption mechanism implementation is supposed to generate the required parameters itself (using provider-specific default values); in the case that algorithm parameters must be specified by the caller, anInvalidAlgorithmParameterExceptionis raised.- Parameters:
- key- the key for this exemption mechanism
- params- the algorithm parameters
- Throws:
- InvalidKeyException- if the given key is inappropriate for this exemption mechanism.
- InvalidAlgorithmParameterException- if the given algorithm parameters are inappropriate for this exemption mechanism.
- ExemptionMechanismException- if problem(s) encountered in the process of initializing.
 
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engineInitprotected abstract void engineInit(Key key, AlgorithmParameters params) throws InvalidKeyException, InvalidAlgorithmParameterException, ExemptionMechanismException Initializes this exemption mechanism with a key and a set of algorithm parameters.If this exemption mechanism requires any algorithm parameters and paramsis null, the underlying exemption mechanism implementation is supposed to generate the required parameters itself (using provider-specific default values); in the case that algorithm parameters must be specified by the caller, anInvalidAlgorithmParameterExceptionis raised.- Parameters:
- key- the key for this exemption mechanism
- params- the algorithm parameters
- Throws:
- InvalidKeyException- if the given key is inappropriate for this exemption mechanism.
- InvalidAlgorithmParameterException- if the given algorithm parameters are inappropriate for this exemption mechanism.
- ExemptionMechanismException- if problem(s) encountered in the process of initializing.
 
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engineGenExemptionBlobprotected abstract byte[] engineGenExemptionBlob() throws ExemptionMechanismExceptionGenerates the exemption mechanism key blob.- Returns:
- the new buffer with the result key blob.
- Throws:
- ExemptionMechanismException- if problem(s) encountered in the process of generating.
 
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engineGenExemptionBlobprotected abstract int engineGenExemptionBlob(byte[] output, int outputOffset) throws ShortBufferException, ExemptionMechanismExceptionGenerates the exemption mechanism key blob, and stores the result in theoutputbuffer, starting atoutputOffsetinclusive.If the outputbuffer is too small to hold the result, aShortBufferExceptionis thrown. In this case, repeat this call with a larger output buffer. UseengineGetOutputSizeto determine how big the output buffer should be.- Parameters:
- output- the buffer for the result
- outputOffset- the offset in- outputwhere the result is stored
- Returns:
- the number of bytes stored in output
- Throws:
- ShortBufferException- if the given output buffer is too small to hold the result.
- ExemptionMechanismException- if problem(s) encountered in the process of generating.
 
 
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