edu.berkeley.psi.tagged.api
Class DigestFactory

java.lang.Object
  org.acplt.oncrpc.XdrEncodingStream
      edu.berkeley.psi.tagged.api.TaggedEncodingStream
          edu.berkeley.psi.tagged.api.DigestFactory

Direct Known Subclasses:

MD2DigestFactory, MD5DigestFactory, SHA1DigestFactory, SHA256DigestFactory, SHA384DigestFactory, SHA512DigestFactory

public abstract class DigestFactory
extends TaggedEncodingStream

Generates Digests (cryptographic hashes) for Tagged objects. A Digest is computed relative to a digest algorithm. TaggedConst determines how the object classes are rendered as integer tags and the algorithm determines the cryptographic hash function that is used to compute the digest. The object data is rendered using Xdr.

Field Summary

protected java.security.MessageDigest

md

Constructor Summary

DigestFactory()

Method Summary

abstract Digest	digest()
Digest	digest(TaggedIF tobj)
java.lang.String	getAlgorithm()
int	getDigestLength()
static DigestFactory	newFactory()
static DigestFactory	newFactory(java.lang.String alg)
void	reset()
void	update(TaggedIF obj)
void	xdrEncodeInt(int n) Encodes (aka "serializes") a "XDR int" value and writes it down a XDR stream.
void	xdrEncodeOpaque(byte[] buf, int offset, int len) Encodes (aka "serializes") a XDR opaque value, which is represented by a vector of byte values, and starts at offset with a length of length.

Methods inherited from class edu.berkeley.psi.tagged.api.TaggedEncodingStream

put

Methods inherited from class org.acplt.oncrpc.XdrEncodingStream

beginEncoding, close, endEncoding, getCharacterEncoding, setCharacterEncoding, xdrEncodeBoolean, xdrEncodeBooleanFixedVector, xdrEncodeBooleanVector, xdrEncodeByte, xdrEncodeByteFixedVector, xdrEncodeByteVector, xdrEncodeDouble, xdrEncodeDoubleFixedVector, xdrEncodeDoubleVector, xdrEncodeDynamicOpaque, xdrEncodeFloat, xdrEncodeFloatFixedVector, xdrEncodeFloatVector, xdrEncodeIntFixedVector, xdrEncodeIntVector, xdrEncodeLong, xdrEncodeLongFixedVector, xdrEncodeLongVector, xdrEncodeOpaque, xdrEncodeOpaque, xdrEncodeShort, xdrEncodeShortFixedVector, xdrEncodeShortVector, xdrEncodeString, xdrEncodeStringFixedVector, xdrEncodeStringVector

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

md

protected java.security.MessageDigest md

Constructor Detail

DigestFactory

public DigestFactory()

Method Detail

digest

public abstract Digest digest()

newFactory

public static final DigestFactory newFactory()
                                      throws java.security.NoSuchAlgorithmException

Throws:

java.security.NoSuchAlgorithmException

newFactory

public static DigestFactory newFactory(java.lang.String alg)
                                throws java.security.NoSuchAlgorithmException

Throws:

java.security.NoSuchAlgorithmException

update

public final void update(TaggedIF obj)
                  throws OncRpcException,
                         java.io.IOException,
                         TaggedException

Throws:

OncRpcException

java.io.IOException

TaggedException

digest

public final Digest digest(TaggedIF tobj)
                    throws OncRpcException,
                           java.io.IOException,
                           TaggedException

Throws:

OncRpcException

java.io.IOException

TaggedException

getAlgorithm

public final java.lang.String getAlgorithm()

getDigestLength

public final int getDigestLength()

reset

public final void reset()

xdrEncodeInt

public void xdrEncodeInt(int n)
                  throws OncRpcException,
                         java.io.IOException

Description copied from class: XdrEncodingStream

Encodes (aka "serializes") a "XDR int" value and writes it down a XDR stream. A XDR int is 32 bits wide -- the same width Java's "int" data type has. This method is one of the basic methods all other methods can rely on. Because it's so basic, derived classes have to implement it.

Specified by:

xdrEncodeInt in class XdrEncodingStream

Parameters:

n - The int value to be encoded.

Throws:

OncRpcException - if an ONC/RPC error occurs.

java.io.IOException - if an I/O error occurs.

xdrEncodeOpaque

public void xdrEncodeOpaque(byte[] buf,
                            int offset,
                            int len)
                     throws OncRpcException,
                            java.io.IOException

Description copied from class: XdrEncodingStream

Encodes (aka "serializes") a XDR opaque value, which is represented by a vector of byte values, and starts at offset with a length of length. Only the opaque value is encoded, but no length indication is preceeding the opaque value, so the receiver has to know how long the opaque value will be. The encoded data is always padded to be a multiple of four. If the given length is not a multiple of four, zero bytes will be used for padding.

Derived classes must ensure that the proper semantic is maintained.

Specified by:

xdrEncodeOpaque in class XdrEncodingStream

Parameters:

buf - The opaque value to be encoded in the form of a series of bytes.

offset - Start offset in the data.

len - the number of bytes to encode.

Throws:

OncRpcException - if an ONC/RPC error occurs.

java.io.IOException - if an I/O error occurs.