public class Poly1305 extends Object implements Mac
Poly1305 computes a 128-bit (16 bytes) authenticator, using a 128 bit nonce and a 256 bit key consisting of a 128 bit key applied to an underlying cipher, and a 128 bit key (with 106 effective key bits) used in the authenticator.
The polynomial calculation in this implementation is adapted from the public domain poly1305-donna-unrolled C implementation by Andrew M (@floodyberry).
Poly1305KeyGenerator
Constructor and Description |
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Poly1305()
Constructs a Poly1305 MAC, where the key passed to init() will be used directly.
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Poly1305(BlockCipher cipher)
Constructs a Poly1305 MAC, using a 128 bit block cipher.
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Modifier and Type | Method and Description |
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int |
doFinal(byte[] out,
int outOff)
Compute the final stage of the MAC writing the output to the out
parameter.
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String |
getAlgorithmName()
Return the name of the algorithm the MAC implements.
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int |
getMacSize()
Return the block size for this MAC (in bytes).
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void |
init(CipherParameters params)
Initialises the Poly1305 MAC.
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void |
reset()
Reset the MAC.
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void |
update(byte in)
add a single byte to the mac for processing.
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void |
update(byte[] in,
int inOff,
int len) |
public Poly1305()
public Poly1305(BlockCipher cipher)
public void init(CipherParameters params) throws IllegalArgumentException
init
in interface Mac
params
- if used with a block cipher, then a ParametersWithIV
containing a 128 bit
nonce and a KeyParameter
with a 256 bit key complying to the
Poly1305 key format
, otherwise just the
KeyParameter
.IllegalArgumentException
- if the params argument is
inappropriate.public String getAlgorithmName()
Mac
getAlgorithmName
in interface Mac
public int getMacSize()
Mac
getMacSize
in interface Mac
public void update(byte in) throws IllegalStateException
Mac
update
in interface Mac
in
- the byte to be processed.IllegalStateException
- if the MAC is not initialised.public void update(byte[] in, int inOff, int len) throws DataLengthException, IllegalStateException
update
in interface Mac
in
- the array containing the input.inOff
- the index in the array the data begins at.len
- the length of the input starting at inOff.DataLengthException
- if there isn't enough data in in.IllegalStateException
- if the MAC is not initialised.public int doFinal(byte[] out, int outOff) throws DataLengthException, IllegalStateException
Mac
doFinal leaves the MAC in the same state it was after the last init.
doFinal
in interface Mac
out
- the array the MAC is to be output to.outOff
- the offset into the out buffer the output is to start at.DataLengthException
- if there isn't enough space in out.IllegalStateException
- if the MAC is not initialised.Copyright © 2021 BouncyCastle.org. All rights reserved.