iaik.me.utils
Class CryptoUtils

java.lang.Object
  |
  +--iaik.me.utils.CryptoUtils

public class CryptoUtils

extends Object

Method Summary

static void	copyBlock(byte[] src, byte[] dst) Copies one byte block to another.
static void	copyBlock(byte[] src, int srcOff, byte[] dst, int dstOff, int len) Copies the specified byte sequence of the given source array to the specified destination array.
static void	copyBlock(int[] src, int[] dst) Copies one int block to another.
static void	copyBlock(int[] src, int srcOff, int[] dst, int dstOff, int len) Copies the specified int sequence of the given source array to the specified destination array.
static boolean	equalsBlock(byte[] a, byte[] b) Checks two byte blocks for equality.
static boolean	equalsBlock(byte[] a, int aOff, byte[] b, int bOff, int len) Check the specified sub-sequences of the given byte arrays for equality.
static void	spreadIntsToBytes(int[] inInts, int inOff, byte[] outBytes, int outOff, int intLen)
static void	spreadIntsToBytesLE(int[] inInts, int inOff, byte[] outBytes, int outOff, int intLen) Spreads ints into bytes in little endian bytes ordering.
static void	spreadShortsToBytesBE(int[] inShorts, int inOff, byte[] outBytes, int outOff, int shortLen)
static void	spreadShortsToBytesLE(int[] inShorts, int inOff, byte[] outBytes, int outOff, int shortLen) Spreads shorts ints into bytes in little endian bytes ordering.
static void	squashBytesToInts(byte[] inBytes, int inOff, int[] outInts, int outOff, int intLen)
static void	squashBytesToIntsLE(byte[] inBytes, int inOff, int[] outInts, int outOff, int intLen)
static void	squashBytesToShortsBE(byte[] inBytes, int inOff, int[] outShorts, int outOff, int shortLen)
static void	squashBytesToShortsLE(byte[] inBytes, int inOff, int[] outShorts, int outOff, int shortLen)
static void	zeroBlock(byte[] block) Fills the given byte array with zeros.
static void	zeroBlock(byte[] block, int off, int len) Fills the specified sub-array of the given byte array with zeros.
static void	zeroBlock(int[] block) Fill an integer array with zeros.
static void	zeroBlock(int[] block, int off, int len) Fill part of an integer array with zeros.

Methods inherited from class java.lang.Object

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

Method Detail

zeroBlock

public static void zeroBlock(byte[] block,
                             int off,
                             int len)

Fills the specified sub-array of the given byte array with zeros.

Starting at the given off position, len bytes of the given array are set to zero. To, for instance, set three bytes to zero, starting at position 2, use:

 byte[] block = ...;
 CryptoUtils.zeroBlock(block, 2, 3);
 

Parameters:

block - the byte array of which some bytes have to be set to zero

off - the offset indicating the start position within the byte array; the following len bytes are set to zero

len - the number of bytes to be set to zero, starting at off

zeroBlock

public static void zeroBlock(int[] block,
                             int off,
                             int len)

Fill part of an integer array with zeros.

Parameters:

int - array

offset - within the block

length - how far to fill with zeros

zeroBlock

public static void zeroBlock(byte[] block)

Fills the given byte array with zeros.

Parameters:

block - the byte array to be filled with zeros

zeroBlock

public static void zeroBlock(int[] block)

Fill an integer array with zeros.

Parameters:

block - the int array to be filled with zeros

copyBlock

public static void copyBlock(byte[] src,
                             int srcOff,
                             byte[] dst,
                             int dstOff,
                             int len)

Copies the specified byte sequence of the given source array to the specified destination array.

Beginning at the specified srcOff position, len bytes of the source array are copied to the given destination array, starting at dstOff.

Parameters:

src - the source byte array

srcOff - the offset indicating the start position within the first byte array; the following len bytes will be copied to the destination array

dst - the destination array to which to copy the bytes

dstOff - the offset indicating the start position within the destination byte array, to which the bytes shall be copied

len - the number of bytes to be copied

copyBlock

public static void copyBlock(byte[] src,
                             byte[] dst)

Copies one byte block to another.

Parameters:

src - the source byte array

dst - the destination array to which to copy the bytes

copyBlock

public static void copyBlock(int[] src,
                             int srcOff,
                             int[] dst,
                             int dstOff,
                             int len)

Copies the specified int sequence of the given source array to the specified destination array.

Beginning at the specified srcOff position, len ints of the source array are copied to the given destination array, starting at dstOff.

Parameters:

src - the source int array

srcOff - the offset indicating the start position within the first int array; the following len ints will be copied to the destination array

dst - the destination array to which to copy the ints

dstOff - the offset indicating the start position within the destination int array, to which the ints shall be copied

len - the number of ints to be copied

copyBlock

public static void copyBlock(int[] src,
                             int[] dst)

Copies one int block to another.

Parameters:

src - the source int array

dst - the destination array to which to copy the ints

equalsBlock

public static boolean equalsBlock(byte[] a,
                                  int aOff,
                                  byte[] b,
                                  int bOff,
                                  int len)

Check the specified sub-sequences of the given byte arrays for equality.

Parameters:

a - the first byte array

aOff - the offset indicating the start position within the first byte array; the following len bytes are compared with the corresponding number of bytes of the second byte array

b - the second byte array

bOff - the offset indicating the start position within the second byte array; the following len bytes are compared with the corresponding number of bytes of the first byte array

len - the number of bytes to be compared

Returns:

true if the two sub-arrays have the same contents, false if not

equalsBlock

public static boolean equalsBlock(byte[] a,
                                  byte[] b)

Checks two byte blocks for equality.

Parameters:

a - the first byte array to be compared with the second byte array

b - the second byte array to be compared with the first byte array

Returns:

true if the two blocks have the same contents, false if not

squashBytesToInts

public static void squashBytesToInts(byte[] inBytes,
                                     int inOff,
                                     int[] outInts,
                                     int outOff,
                                     int intLen)

Parameters:

inBytes -

inOff -

outInts -

outOff -

intLen -

spreadIntsToBytes

public static void spreadIntsToBytes(int[] inInts,
                                     int inOff,
                                     byte[] outBytes,
                                     int outOff,
                                     int intLen)

squashBytesToIntsLE

public static void squashBytesToIntsLE(byte[] inBytes,
                                       int inOff,
                                       int[] outInts,
                                       int outOff,
                                       int intLen)

spreadIntsToBytesLE

public static void spreadIntsToBytesLE(int[] inInts,
                                       int inOff,
                                       byte[] outBytes,
                                       int outOff,
                                       int intLen)

Spreads ints into bytes in little endian bytes ordering. That means least significant byte first, most significant byte last.

See Also:

spreadIntsToBytes(int[], int, byte[], int, int)

squashBytesToShortsBE

public static void squashBytesToShortsBE(byte[] inBytes,
                                         int inOff,
                                         int[] outShorts,
                                         int outOff,
                                         int shortLen)

spreadShortsToBytesBE

public static void spreadShortsToBytesBE(int[] inShorts,
                                         int inOff,
                                         byte[] outBytes,
                                         int outOff,
                                         int shortLen)

squashBytesToShortsLE

public static void squashBytesToShortsLE(byte[] inBytes,
                                         int inOff,
                                         int[] outShorts,
                                         int outOff,
                                         int shortLen)

spreadShortsToBytesLE

public static void spreadShortsToBytesLE(int[] inShorts,
                                         int inOff,
                                         byte[] outBytes,
                                         int outOff,
                                         int shortLen)

Spreads shorts ints into bytes in little endian bytes ordering. That means least significant byte first, most significant byte last.

See Also:

spreadIntsToBytes(int[], int, byte[], int, int)