public Class SignatureSpi

Implements abstract java.security.SignatureSpi.engineGetParameter.

Doc from java.security.SignatureSpi.engineGetParameter.

Gets the value of the specified algorithm parameter. This method supplies a general-purpose mechanism through which it is possible to get the various parameters of this object. A parameter may be any settable parameter for the algorithm, such as a parameter size, or a source of random bits for signature generation (if appropriate), or an indication of whether to perform a specific but optional computation. A uniform algorithm-specific naming scheme for each parameter is desirable but left unspecified at this time.

Parameters

param:String

the string name of the parameter.

Returns:Object

the object that represents the parameter value, or null if there is none.

Overrides java.security.SignatureSpi.engineGetParameters.

Doc from java.security.SignatureSpi.engineGetParameters.

Returns the parameters used with this Signature object.

The returned parameters may be the same that were used to initialize this Signature object, or may contain additional default or random parameter values used by the underlying signature scheme. If the required parameters were not supplied and can be generated by the Signature object, the generated parameters are returned; otherwise null is returned.

However, if the signature scheme does not support returning the parameters as AlgorithmParameters, null is always returned.

Returns:AlgorithmParameters

the parameters used with this Signature object, or null

Implements abstract java.security.SignatureSpi.engineInitSign.

Doc from java.security.SignatureSpi.engineInitSign.

Initializes this Signature object with the specified private key for signing operations.

Parameters

privateKey:PrivateKey

the private key of the identity whose signature will be generated.

Exceptions

InvalidKeyException:

if the key is improperly encoded, parameters are missing, and so on.

Implements abstract java.security.SignatureSpi.engineInitVerify.

Doc from java.security.SignatureSpi.engineInitVerify.

Initializes this Signature object with the specified public key for verification operations.

Parameters

publicKey:PublicKey

the public key of the identity whose signature is going to be verified.

Exceptions

InvalidKeyException:

if the key is improperly encoded, parameters are missing, and so on.

Overrides java.security.SignatureSpi.engineSetParameter.

Doc from java.security.SignatureSpi.engineSetParameter.

Initializes this Signature object with the specified parameter values.

Parameters

params:AlgorithmParameterSpec

the parameters

Implements abstract java.security.SignatureSpi.engineSetParameter.

Doc from java.security.SignatureSpi.engineSetParameter.

Sets the specified algorithm parameter to the specified value. This method supplies a general-purpose mechanism through which it is possible to set the various parameters of this object. A parameter may be any settable parameter for the algorithm, such as a parameter size, or a source of random bits for signature generation (if appropriate), or an indication of whether to perform a specific but optional computation. A uniform algorithm-specific naming scheme for each parameter is desirable but left unspecified at this time.

Parameters

param:String

the string identifier of the parameter.

value:Object

the parameter value.

Implements abstract java.security.SignatureSpi.engineSign.

Doc from java.security.SignatureSpi.engineSign.

Returns the signature bytes of all the data updated so far. The format of the signature depends on the underlying signature scheme.

Returns:byte[]

the signature bytes of the signing operation's result.

Exceptions

SignatureException:

if the engine is not initialized properly or if this signature algorithm is unable to process the input data provided.

Implements abstract java.security.SignatureSpi.engineUpdate.

Doc from java.security.SignatureSpi.engineUpdate.

Updates the data to be signed or verified using the specified byte.

Parameters

b:byte

the byte to use for the update.

Exceptions

SignatureException:

if the engine is not initialized properly.

Implements abstract java.security.SignatureSpi.engineUpdate.

Doc from java.security.SignatureSpi.engineUpdate.

Updates the data to be signed or verified, using the specified array of bytes, starting at the specified offset.

Parameters

b:byte[]

the array of bytes

off:int

the offset to start from in the array of bytes

len:int

the number of bytes to use, starting at offset

Exceptions

SignatureException:

if the engine is not initialized properly

Implements abstract java.security.SignatureSpi.engineVerify.

Doc from java.security.SignatureSpi.engineVerify.

Verifies the passed-in signature.

Parameters

sigBytes:byte[]

the signature bytes to be verified.

Returns:boolean

true if the signature was verified, false if not.

Exceptions

SignatureException:

if the engine is not initialized properly, the passed-in signature is improperly encoded or of the wrong type, if this signature algorithm is unable to process the input data provided, etc.