public class TMMH16 extends BaseMac
TMMH is a universal hash function suitable for message authentication in the Wegman-Carter paradigm, as in the Stream Cipher Security Transform. It is simple, quick, and especially appropriate for Digital Signal Processors and other processors with a fast multiply operation, though a straightforward implementation requires storage equal in length to the largest message to be hashed.
TMMH is a simple hash function which maps a key and a message to a hash value. There are two versions of TMMH: TMMH/16 and TMMH/32. TMMH can be used as a message authentication code, as described in Section 5 (see References).
The key, message, and hash value are all octet strings, and the lengths of
these quantities are denoted as KEY_LENGTH,
MESSAGE_LENGTH, and TAG_LENGTH, respectively. The
values of KEY_LENGTH and TAG_LENGTH
MUST be fixed for any particular fixed value of the key, and
must obey the alignment restrictions described below.
The parameter MAX_HASH_LENGTH, which denotes the maximum
value which MESSAGE_LENGTH may take, is equal to
KEY_LENGTH - TAG_LENGTH.
References:
| Modifier and Type | Field and Description |
|---|---|
static java.lang.String |
KEYSTREAM |
static java.lang.String |
PREFIX |
static java.lang.String |
TAG_LENGTH |
name, truncatedSize, underlyingHashMAC_KEY_MATERIAL, TRUNCATED_SIZE| Constructor and Description |
|---|
TMMH16()
Trivial 0-arguments constructor.
|
| Modifier and Type | Method and Description |
|---|---|
java.lang.Object |
clone()
Returns a clone copy of this instance.
|
byte[] |
digest()
Completes the MAC by performing final operations such as
padding and resetting the instance.
|
byte[] |
digest(tr.gov.tubitak.uekae.esya.api.common.crypto.IRandom prng)
Similar to the same method with no arguments, but uses the designated
random number generator to compute needed keying material.
|
void |
init(java.util.Map attributes)
Initialises the algorithm with designated attributes.
|
int |
macSize()
Returns the output length in bytes of this MAC algorithm.
|
void |
reset()
Resets the algorithm instance for re-initialisation and use with other
characteristics.
|
boolean |
selfTest()
A basic test.
|
void |
update(byte b)
Continues a MAC operation using the input byte.
|
void |
update(byte[] b,
int offset,
int len)
Continues a MAC operation, by filling the buffer, processing
data in the algorithm's MAC_SIZE-bit block(s), updating the context and
count, and buffering the remaining bytes in buffer for the next
operation.
|
void |
update(byte[] b,
int offset,
int len,
tr.gov.tubitak.uekae.esya.api.common.crypto.IRandom prng)
Similar to the same method with three arguments, but uses the
designated random number generator to compute needed keying material.
|
void |
update(byte b,
tr.gov.tubitak.uekae.esya.api.common.crypto.IRandom prng)
Similar to the same method with one argument, but uses the designated
random number generator to compute needed keying material.
|
public static final java.lang.String TAG_LENGTH
public static final java.lang.String KEYSTREAM
public static final java.lang.String PREFIX
public java.lang.Object clone()
IMacReturns a clone copy of this instance.
public int macSize()
IMacReturns the output length in bytes of this MAC algorithm.
public void init(java.util.Map attributes)
throws java.security.InvalidKeyException,
java.lang.IllegalStateException
IMacInitialises the algorithm with designated attributes. Permissible names and values are described in the class documentation above.
init in interface IMacinit in class BaseMacattributes - a set of name-value pairs that describe the desired
future instance behaviour.java.security.InvalidKeyException - if the key data is invalid.java.lang.IllegalStateException - if the instance is already initialised.IMac.MAC_KEY_MATERIALpublic void update(byte b)
IMacContinues a MAC operation using the input byte.
public void update(byte[] b,
int offset,
int len)
IMacContinues a MAC operation, by filling the buffer, processing data in the algorithm's MAC_SIZE-bit block(s), updating the context and count, and buffering the remaining bytes in buffer for the next operation.
public byte[] digest()
IMacCompletes the MAC by performing final operations such as padding and resetting the instance.
public void reset()
IMacResets the algorithm instance for re-initialisation and use with other characteristics. This method always succeeds.
public boolean selfTest()
IMacA basic test. Ensures that the MAC of a pre-determined message is equal to a known pre-computed value.
public void update(byte b,
tr.gov.tubitak.uekae.esya.api.common.crypto.IRandom prng)
Similar to the same method with one argument, but uses the designated random number generator to compute needed keying material.
b - the byte to process.prng - the source of randomness to use.public void update(byte[] b,
int offset,
int len,
tr.gov.tubitak.uekae.esya.api.common.crypto.IRandom prng)
Similar to the same method with three arguments, but uses the designated random number generator to compute needed keying material.
b - the byte array to process.offset - the starting offset in b to start considering
the bytes to process.len - the number of bytes in b starting from
offset to process.prng - the source of randomness to use.public byte[] digest(tr.gov.tubitak.uekae.esya.api.common.crypto.IRandom prng)
Similar to the same method with no arguments, but uses the designated random number generator to compute needed keying material.
prng - the source of randomness to use.Copyright © 2025. All rights reserved.