java.lang.Object java.security.MessageDigestSpi
This class defines the Service Provider Interface ( SPI ) for the MessageDigest class, which provides the functionality of a message digest algorithm, such as MD5 or SHA. Message digests are secure one-way hash functions that take arbitrary-sized data and output a fixed-length hash value.
All the abstract methods in this class must be implemented by a cryptographic service provider who wishes to supply the implementation of a particular message digest algorithm.
Implementations are free to implement the Cloneable interface.
Constructor Summary | |
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MessageDigestSpi
() |
Method Summary | |
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Object |
clone
() Returns a clone if the implementation is cloneable. |
protected abstract byte[] |
engineDigest
() Completes the hash computation by performing final operations such as padding. |
protected int |
engineDigest
(byte[] buf, int offset, int len) Completes the hash computation by performing final operations such as padding. |
protected int |
engineGetDigestLength
() Returns the digest length in bytes. |
protected abstract void |
engineReset
() Resets the digest for further use. |
protected abstract void |
engineUpdate
(byte input) Updates the digest using the specified byte. |
protected abstract void |
engineUpdate
(byte[] input, int offset, int len) Updates the digest using the specified array of bytes, starting at the specified offset. |
protected void |
engineUpdate
(
ByteBuffer
Update the digest using the specified ByteBuffer. |
Methods inherited from class java.lang. Object |
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equals , finalize , getClass , hashCode , notify , notifyAll , toString , wait , wait , wait |
Constructor Detail |
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public MessageDigestSpi()
Method Detail |
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protected int engineGetDigestLength()
This concrete method has been added to this previously-defined abstract class. (For backwards compatibility, it cannot be abstract.)
The default behavior is to return 0.
This method may be overridden by a provider to return the digest length.
protected abstract void engineUpdate(byte input)
protected abstract void engineUpdate(byte[] input, int offset, int len)
protected void engineUpdate ( ByteBuffer input)
protected abstract byte[] engineDigest()
protected int engineDigest(byte[] buf, int offset, int len) throws DigestException
protected abstract void engineReset()
public Object clone() throws CloneNotSupportedException