Package org.bouncycastle.crypto.macs
Class SipHash
java.lang.Object
org.bouncycastle.crypto.macs.SipHash
- All Implemented Interfaces:
Mac
- Direct Known Subclasses:
SipHash128
Implementation of SipHash as specified in "SipHash: a fast short-input PRF", by Jean-Philippe
Aumasson and Daniel J. Bernstein (https://131002.net/siphash/siphash.pdf).
"SipHash is a family of PRFs SipHash-c-d where the integer parameters c and d are the number of compression rounds and the number of finalization rounds. A compression round is identical to a finalization round and this round function is called SipRound. Given a 128-bit key k and a (possibly empty) byte string m, SipHash-c-d returns a 64-bit value..."
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Field Summary
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionprotected void
applySipRounds
(int n) long
doFinal()
int
doFinal
(byte[] out, int outOff) Compute the final stage of the MAC writing the output to the out parameter.Return the name of the algorithm the MAC implements.int
Return the block size for this MAC (in bytes).void
init
(CipherParameters params) Initialise the MAC.protected void
void
reset()
Reset the MAC.protected static long
rotateLeft
(long x, int n) void
update
(byte input) add a single byte to the mac for processing.void
update
(byte[] input, int offset, int length)
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Field Details
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Constructor Details
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Method Details
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getAlgorithmName
Description copied from interface:Mac
Return the name of the algorithm the MAC implements.- Specified by:
getAlgorithmName
in interfaceMac
- Returns:
- the name of the algorithm the MAC implements.
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getMacSize
public int getMacSize()Description copied from interface:Mac
Return the block size for this MAC (in bytes).- Specified by:
getMacSize
in interfaceMac
- Returns:
- the block size for this MAC in bytes.
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init
Description copied from interface:Mac
Initialise the MAC.- Specified by:
init
in interfaceMac
- Parameters:
params
- the key and other data required by the MAC.- Throws:
IllegalArgumentException
- if the params argument is inappropriate.
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update
Description copied from interface:Mac
add a single byte to the mac for processing.- Specified by:
update
in interfaceMac
- Parameters:
input
- the byte to be processed.- Throws:
IllegalStateException
- if the MAC is not initialised.
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update
public void update(byte[] input, int offset, int length) throws DataLengthException, IllegalStateException - Specified by:
update
in interfaceMac
- Parameters:
input
- the array containing the input.offset
- the index in the array the data begins at.length
- the length of the input starting at inOff.- Throws:
DataLengthException
- if there isn't enough data in in.IllegalStateException
- if the MAC is not initialised.
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doFinal
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doFinal
Description copied from interface:Mac
Compute the final stage of the MAC writing the output to the out parameter.doFinal leaves the MAC in the same state it was after the last init.
- Specified by:
doFinal
in interfaceMac
- Parameters:
out
- the array the MAC is to be output to.outOff
- the offset into the out buffer the output is to start at.- Throws:
DataLengthException
- if there isn't enough space in out.IllegalStateException
- if the MAC is not initialised.
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reset
public void reset()Description copied from interface:Mac
Reset the MAC. At the end of resetting the MAC should be in the in the same state it was after the last init (if there was one). -
processMessageWord
protected void processMessageWord() -
applySipRounds
protected void applySipRounds(int n) -
rotateLeft
protected static long rotateLeft(long x, int n)
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