freenet.crypt

Class MessageAuthCode

java.lang.Object

freenet.crypt.MessageAuthCode

public final class MessageAuthCode
extends java.lang.Object

The MessageAuthCode class will generate the Message Authentication Code of a given set of bytes using a secret key. It can also verify

Constructor Summary

Constructors

Constructor and Description
MessageAuthCode(MACType type) Creates an instance of MessageAuthCode that will use the specified algorithm and will generate a key (and an IV if necessary).
MessageAuthCode(MACType type, byte[] cryptoKey) Creates an instance of MessageAuthCode that will use the specified algorithm and key which is converted from a byte[] to a SecretKey.
MessageAuthCode(MACType type, byte[] key, javax.crypto.spec.IvParameterSpec iv) Creates an instance of MessageAuthCode that will use the specified algorithm with the specified key and iv.
MessageAuthCode(MACType type, java.nio.ByteBuffer cryptoKey) Creates an instance of MessageAuthCode that will use the specified algorithm and key which is converted from a ByteBuffer to a SecretKey.
MessageAuthCode(MACType type, javax.crypto.SecretKey cryptoKey) Creates an instance of MessageAuthCode that will use the specified algorithm and key.
MessageAuthCode(MACType type, javax.crypto.SecretKey key, javax.crypto.spec.IvParameterSpec iv) Creates an instance of MessageAuthCode that will use the specified algorithm with the specified key and iv.

Method Summary

Modifier and Type	Method and Description
void	addByte(byte input) Adds the specified byte to the buffer of bytes to be used for MAC generation
void	addBytes(byte[]... input) Adds the specified byte arrays to the buffer of bytes to be used for MAC generation
void	addBytes(byte[] input, int offset, int len) Adds the specified portion of the byte[] passed in to the buffer of bytes to be used for MAC generation
void	addBytes(java.nio.ByteBuffer input) Adds the remaining bytes from a ByteBuffer to the buffer of bytes to be used for MAC generation.
javax.crypto.spec.IvParameterSpec	genIV() Generates a new IV to be used.
java.nio.ByteBuffer	genMac() Generates the MAC of all the bytes in the buffer added with the addBytes methods.
java.nio.ByteBuffer	genMac(byte[]... input) Generates the MAC of only the specified bytes.
java.nio.ByteBuffer	genMac(java.nio.ByteBuffer input) Generates the MAC of only the specified bytes.
javax.crypto.spec.IvParameterSpec	getIv() Gets the IV being used.
javax.crypto.SecretKey	getKey() Gets the key being used
void	setIV(javax.crypto.spec.IvParameterSpec iv) Changes the current iv to the provided iv.
static boolean	verify(byte[] mac1, byte[] mac2) Verifies that the two MAC addresses passed are equivalent.
static boolean	verify(java.nio.ByteBuffer mac1, java.nio.ByteBuffer mac2) Verifies that the two MAC addresses passed are equivalent.
boolean	verifyData(byte[] otherMac, byte[]... data) Generates the MAC of the byte arrays provided and checks to see if that MAC is the same as the one passed in.
boolean	verifyData(java.nio.ByteBuffer otherMac, java.nio.ByteBuffer data) Generates the MAC of the byte arrays provided and checks to see if that MAC is the same as the one passed in.

Methods inherited from class java.lang.Object

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

Constructor Detail

MessageAuthCode

public MessageAuthCode(MACType type,
                       javax.crypto.SecretKey cryptoKey)
                throws java.security.InvalidKeyException

Creates an instance of MessageAuthCode that will use the specified algorithm and key. Must not be used on algorithms that require an IV, as a specified key but a random IV is probably not useful for an HMAC.

Parameters:

type - The MAC algorithm to use

cryptoKey - The key to use

Throws:

java.security.InvalidKeyException

MessageAuthCode

public MessageAuthCode(MACType type,
                       byte[] cryptoKey)
                throws java.security.InvalidKeyException

Creates an instance of MessageAuthCode that will use the specified algorithm and key which is converted from a byte[] to a SecretKey. Must not be used on algorithms that require an IV, as a specified key but a random IV is probably not useful for an HMAC.

Parameters:

type - The MAC algorithm to use

cryptoKey - The key to use

Throws:

java.security.InvalidKeyException

MessageAuthCode

public MessageAuthCode(MACType type,
                       java.nio.ByteBuffer cryptoKey)
                throws java.security.InvalidKeyException

Creates an instance of MessageAuthCode that will use the specified algorithm and key which is converted from a ByteBuffer to a SecretKey. If that algorithms requires an IV it will generate one.

Parameters:

type - The MAC algorithm to use

cryptoKey - The key to use

Throws:

java.security.InvalidKeyException

MessageAuthCode

public MessageAuthCode(MACType type)
                throws java.security.InvalidKeyException

Creates an instance of MessageAuthCode that will use the specified algorithm and will generate a key (and an IV if necessary).

Parameters:

type - The MAC algorithm to

Throws:

java.security.InvalidKeyException

MessageAuthCode

public MessageAuthCode(MACType type,
                       javax.crypto.SecretKey key,
                       javax.crypto.spec.IvParameterSpec iv)
                throws java.security.InvalidKeyException,
                       java.security.InvalidAlgorithmParameterException

Creates an instance of MessageAuthCode that will use the specified algorithm with the specified key and iv. The specified algorithm must require an iv.

Parameters:

key - They key to be used

iv - The iv to be used

Throws:

java.security.InvalidKeyException

java.security.InvalidAlgorithmParameterException

MessageAuthCode

public MessageAuthCode(MACType type,
                       byte[] key,
                       javax.crypto.spec.IvParameterSpec iv)
                throws java.security.InvalidKeyException,
                       java.security.InvalidAlgorithmParameterException

Creates an instance of MessageAuthCode that will use the specified algorithm with the specified key and iv. The specified algorithm must require an iv.

Parameters:

key - They key to be used as a byte[]

iv - The iv to be used

Throws:

java.security.InvalidKeyException

java.security.InvalidAlgorithmParameterException

Method Detail

addByte

public final void addByte(byte input)

Adds the specified byte to the buffer of bytes to be used for MAC generation

Parameters:

input - The byte to add

addBytes

public final void addBytes(byte[]... input)

Adds the specified byte arrays to the buffer of bytes to be used for MAC generation

Parameters:

input - The byte[]s to add

addBytes

public final void addBytes(java.nio.ByteBuffer input)

Adds the remaining bytes from a ByteBuffer to the buffer of bytes to be used for MAC generation. The bytes read from the ByteBuffer will be from input.position() to input.remaining(). Upon return, the ByteBuffer's .position() will be equal to .remaining() and .remaining() will stay unchanged.

Parameters:

input - The ByteBuffer to be added

addBytes

public final void addBytes(byte[] input,
                           int offset,
                           int len)

Adds the specified portion of the byte[] passed in to the buffer of bytes to be used for MAC generation

Parameters:

input - The byte to add

offset - What byte to start at

len - How many bytes after offset to add to buffer

genMac

public final java.nio.ByteBuffer genMac()

Generates the MAC of all the bytes in the buffer added with the addBytes methods. The buffer is then cleared after the MAC has been generated.

Returns:

The Message Authentication Code. Will have a backing array and array offset 0, so you can call array() on it if you really must.

genMac

public final java.nio.ByteBuffer genMac(byte[]... input)

Generates the MAC of only the specified bytes. The buffer is cleared before processing the input to ensure that no extra data is included. Once the MAC has been generated, the buffer is cleared again.

Parameters:

input -

Returns:

The Message Authentication Code

genMac

public final java.nio.ByteBuffer genMac(java.nio.ByteBuffer input)

Generates the MAC of only the specified bytes. The buffer is cleared before processing the input to ensure that no extra data is included. Once the MAC has been generated, the buffer is cleared again.

Parameters:

input -

Returns:

The Message Authentication Code

verify

public static final boolean verify(byte[] mac1,
                                   byte[] mac2)

Verifies that the two MAC addresses passed are equivalent.

Parameters:

mac1 - First MAC to be verified

mac2 - Second MAC to be verified

Returns:

Returns true if the MACs match, otherwise false.

verify

public static final boolean verify(java.nio.ByteBuffer mac1,
                                   java.nio.ByteBuffer mac2)

Verifies that the two MAC addresses passed are equivalent. The two ByteBuffer's will both be emptied.

Parameters:

mac1 - First MAC to be verified

mac2 - Second MAC to be verified

Returns:

Returns true if the MACs match, otherwise false.

verifyData

public final boolean verifyData(byte[] otherMac,
                                byte[]... data)

Generates the MAC of the byte arrays provided and checks to see if that MAC is the same as the one passed in. The buffer is cleared before processing the input to ensure that no extra data is included. Once the MAC has been generated, the buffer is cleared again.

Parameters:

otherMac - The MAC to check

data - The data to check the MAC against

Returns:

Returns true if it is a match, otherwise false.

verifyData

public final boolean verifyData(java.nio.ByteBuffer otherMac,
                                java.nio.ByteBuffer data)

Generates the MAC of the byte arrays provided and checks to see if that MAC is the same as the one passed in. The buffer is cleared before processing the input to ensure that no extra data is included. Once the MAC has been generated, the buffer is cleared again.

Parameters:

otherMac - The MAC to check

data - The data to check the MAC against

Returns:

Returns true if it is a match, otherwise false.

getKey

public final javax.crypto.SecretKey getKey()

Gets the key being used

Returns:

Returns the key as a SecretKey

getIv

public final javax.crypto.spec.IvParameterSpec getIv()

Gets the IV being used. Only works with algorithms that support IVs.

Returns:

Returns the iv as a IvParameterSpec

setIV

public final void setIV(javax.crypto.spec.IvParameterSpec iv)
                 throws java.security.InvalidAlgorithmParameterException

Changes the current iv to the provided iv. Only works with algorithms that support IVs.

Parameters:

iv - The new iv to use as IvParameterSpec

Throws:

java.security.InvalidAlgorithmParameterException

genIV

public final javax.crypto.spec.IvParameterSpec genIV()

Generates a new IV to be used. Only works with algorithms that support IVs.

Returns:

The generated IV