java.security
public abstract class SignatureSpi extends Object
SignatureSpi defines the Service Provider Interface (SPI) for
the {@link Signature} class. The signature class provides an interface to a
digital signature algorithm. Digital signatures are used for authentication
and integrity of data.
Since: 1.2
See Also: Signature
| Field Summary | |
|---|---|
| protected SecureRandom | appRandom Source of randomness. |
| Constructor Summary | |
|---|---|
| SignatureSpi()
Creates a new instance of SignatureSpi. | |
| Method Summary | |
|---|---|
| Object | clone()
Returns a clone of this instance.
|
| protected abstract Object | engineGetParameter(String param)
Returns the value for the specified algorithm parameter.
|
| protected AlgorithmParameters | engineGetParameters()
The default implementaion of this method always throws a
{@link UnsupportedOperationException}. |
| protected abstract void | engineInitSign(PrivateKey privateKey)
Initializes this instance with the private key for signing purposes.
|
| protected void | engineInitSign(PrivateKey privateKey, SecureRandom random)
Initializes this instance with the private key and source of randomness for
signing purposes.
|
| protected abstract void | engineInitVerify(PublicKey publicKey)
Initializes this instance with the public key for verification purposes.
|
| protected abstract void | engineSetParameter(String param, Object value)
Sets the specified algorithm parameter to the specified value.
|
| protected void | engineSetParameter(AlgorithmParameterSpec params)
Sets the signature engine with the specified {@link AlgorithmParameterSpec}.
|
| protected abstract byte[] | engineSign()
Returns the signature bytes of all the data fed to this instance. |
| protected int | engineSign(byte[] outbuf, int offset, int len)
Generates signature bytes of all the data fed to this instance and stores
the result in the designated array. |
| protected abstract void | engineUpdate(byte b)
Updates the data to be signed or verified with the specified byte.
|
| protected abstract void | engineUpdate(byte[] b, int off, int len)
Updates the data to be signed or verified with the specified bytes.
|
| protected void | engineUpdate(ByteBuffer input)
Update this signature with the {@link java.nio.Buffer#remaining()}
bytes of the given buffer.
|
| protected abstract boolean | engineVerify(byte[] sigBytes)
Verifies a designated signature.
|
| protected boolean | engineVerify(byte[] sigBytes, int offset, int length)
Convenience method which calls the method with the same name and one
argument after copying the designated bytes into a temporary byte array.
|
SignatureSpi.Returns: a clone of this instance.
Throws: CloneNotSupportedException if the implementation does not support cloning.
Deprecated: use the other getParameter
Returns the value for the specified algorithm parameter.Parameters: param the parameter name.
Returns: the parameter value.
Throws: InvalidParameterException if the parameter is invalid.
null when that engine does not use
any parameters.
Returns: the parameters used with this signature engine, or
null if it does not use any parameters.
Throws: UnsupportedOperationException always.
Parameters: privateKey the private key to sign with.
Throws: InvalidKeyException if the key is invalid.
This method cannot be abstract for backward compatibility reasons.
Parameters: privateKey the private key to sign with. random the {@link SecureRandom} to use.
Throws: InvalidKeyException if the key is invalid.
Since: 1.2
Parameters: publicKey the public key to verify with.
Throws: InvalidKeyException if the key is invalid.
Deprecated: use the other setParameter.
Sets the specified algorithm parameter to the specified value.Parameters: param the parameter name. value the parameter value.
Throws: InvalidParameterException if the parameter invalid, the parameter is already set and cannot be changed, a security exception occured, etc.
This method cannot be abstract for backward compatibility reasons. By default it always throws {@link UnsupportedOperationException} unless overridden.
Parameters: params the parameters.
Throws: InvalidParameterException if the parameter is invalid, the parameter is already set and cannot be changed, a security exception occured, etc.
Returns: the signature bytes.
Throws: SignatureException if the engine is not properly initialized.
This method cannot be abstract for backward compatibility reasons. After calling this method, the signature is reset to its initial state and can be used to generate additional signatures.
IMPLEMENTATION NOTE:: Neither this method nor the GNU provider
will return partial digests. If len is less than the
signature length, this method will throw a {@link SignatureException}. If
it is greater than or equal then it is ignored.
Parameters: outbuf the array of bytes to store the result in. offset the offset to start at in the array. len the number of the bytes to use in the array.
Returns: the real number of bytes used.
Throws: SignatureException if the engine is not properly initialized.
Since: 1.2
Parameters: b byte to update with.
Throws: SignatureException if the engine is not properly initialized.
Parameters: b the array of bytes to use. off the offset to start at in the array. len the number of the bytes to use from the array.
Throws: SignatureException if the engine is not properly initialized.
Parameters: input The input buffer.
Throws: IllegalStateException if the engine is not properly initialized.
Parameters: sigBytes the signature bytes to verify.
Returns: true if verified, false otherwise.
Throws: SignatureException if the engine is not properly initialized or if it is the wrong signature.
Parameters: sigBytes the array of bytes to use. offset the offset to start from in the array of bytes. length the number of bytes to use, starting at offset.
Returns: true if verified, false otherwise.
Throws: SignatureException if the engine is not properly initialized.