org.spongycastle.pqc.math.linearalgebra

Class BigEndianConversions

java.lang.Object

org.spongycastle.pqc.math.linearalgebra.BigEndianConversions

public final class BigEndianConversions
extends java.lang.Object

This is a utility class containing data type conversions using big-endian byte order.

See Also:

LittleEndianConversions

Method Summary

Modifier and Type	Method and Description
static byte[]	I2OSP(int x) Convert an integer to an octet string of length 4 according to IEEE 1363, Section 5.5.3.
static void	I2OSP(int input, byte[] output, int outOff) Convert an integer to an octet string of length 4 according to IEEE 1363, Section 5.5.3.
static void	I2OSP(int input, byte[] output, int outOff, int length) Convert an integer to an octet string of the specified length according to IEEE 1363, Section 5.5.3.
static byte[]	I2OSP(int x, int oLen) Convert an integer to an octet string according to IEEE 1363, Section 5.5.3.
static byte[]	I2OSP(long input) Convert an integer to an octet string of length 8 according to IEEE 1363, Section 5.5.3.
static void	I2OSP(long input, byte[] output, int outOff) Convert an integer to an octet string of length 8 according to IEEE 1363, Section 5.5.3.
static int	OS2IP(byte[] input) Convert an octet string to an integer according to IEEE 1363, Section 5.5.3.
static int	OS2IP(byte[] input, int inOff) Convert a byte array of length 4 beginning at offset into an integer.
static int	OS2IP(byte[] input, int inOff, int inLen) Convert an octet string to an integer according to IEEE 1363, Section 5.5.3.
static long	OS2LIP(byte[] input, int inOff) Convert a byte array of length 8 beginning at inOff into a long integer.
static byte[]	toByteArray(int[] input) Convert an int array into a byte array.
static byte[]	toByteArray(int[] input, int length) Convert an int array into a byte array of the specified length.
static int[]	toIntArray(byte[] input) Convert a byte array into an int array.

Methods inherited from class java.lang.Object

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

Method Detail

I2OSP

public static byte[] I2OSP(int x)

Convert an integer to an octet string of length 4 according to IEEE 1363, Section 5.5.3.

Parameters:

x - the integer to convert

Returns:

the converted integer

I2OSP

public static byte[] I2OSP(int x,
                           int oLen)
                    throws java.lang.ArithmeticException

Convert an integer to an octet string according to IEEE 1363, Section 5.5.3. Length checking is performed.

Parameters:

x - the integer to convert

oLen - the desired length of the octet string

Returns:

an octet string of length oLen representing the integer x, or null if the integer is negative

Throws:

java.lang.ArithmeticException - if x can't be encoded into oLen octets.

I2OSP

public static void I2OSP(int input,
                         byte[] output,
                         int outOff)

Convert an integer to an octet string of length 4 according to IEEE 1363, Section 5.5.3.

Parameters:

input - the integer to convert

output - byte array holding the output

outOff - offset in output array where the result is stored

I2OSP

public static byte[] I2OSP(long input)

Convert an integer to an octet string of length 8 according to IEEE 1363, Section 5.5.3.

Parameters:

input - the integer to convert

Returns:

the converted integer

I2OSP

public static void I2OSP(long input,
                         byte[] output,
                         int outOff)

Convert an integer to an octet string of length 8 according to IEEE 1363, Section 5.5.3.

Parameters:

input - the integer to convert

output - byte array holding the output

outOff - offset in output array where the result is stored

I2OSP

public static void I2OSP(int input,
                         byte[] output,
                         int outOff,
                         int length)

Convert an integer to an octet string of the specified length according to IEEE 1363, Section 5.5.3. No length checking is performed (i.e., if the integer cannot be encoded into length octets, it is truncated).

Parameters:

input - the integer to convert

output - byte array holding the output

outOff - offset in output array where the result is stored

length - the length of the encoding

OS2IP

public static int OS2IP(byte[] input)

Convert an octet string to an integer according to IEEE 1363, Section 5.5.3.

Parameters:

input - the byte array holding the octet string

Returns:

an integer representing the octet string input, or 0 if the represented integer is negative or too large or the byte array is empty

Throws:

java.lang.ArithmeticException - if the length of the given octet string is larger than 4.

OS2IP

public static int OS2IP(byte[] input,
                        int inOff)

Convert a byte array of length 4 beginning at offset into an integer.

Parameters:

input - the byte array

inOff - the offset into the byte array

Returns:

the resulting integer

OS2IP

public static int OS2IP(byte[] input,
                        int inOff,
                        int inLen)

Convert an octet string to an integer according to IEEE 1363, Section 5.5.3.

Parameters:

input - the byte array holding the octet string

inOff - the offset in the input byte array where the octet string starts

inLen - the length of the encoded integer

Returns:

an integer representing the octet string bytes, or 0 if the represented integer is negative or too large or the byte array is empty

OS2LIP

public static long OS2LIP(byte[] input,
                          int inOff)

Convert a byte array of length 8 beginning at inOff into a long integer.

Parameters:

input - the byte array

inOff - the offset into the byte array

Returns:

the resulting long integer

toByteArray

public static byte[] toByteArray(int[] input)

Convert an int array into a byte array.

Parameters:

input - the int array

Returns:

the converted array

toByteArray

public static byte[] toByteArray(int[] input,
                                 int length)

Convert an int array into a byte array of the specified length. No length checking is performed (i.e., if the last integer cannot be encoded into length % 4 octets, it is truncated).

Parameters:

input - the int array

length - the length of the converted array

Returns:

the converted array

toIntArray

public static int[] toIntArray(byte[] input)

Convert a byte array into an int array.

Parameters:

input - the byte array

Returns:

the converted array