com.sun.squawk.security.ecc
Class FFA

java.lang.Object
  com.sun.squawk.security.ecc.FFA

public final class FFA
extends Object

Simple and fast big-integer implementation suited for public key cryptography. API: Conventions (for all functions but 'mul' and 'sqr'): The functions require that their arguments have the same length. The arguments are given in the following sequence: r ... result a ... operand a b ... operand b The same int-array that is used for one or more of the operands can be used to store the result at the same time. Exceptions: - For 'mul' and 'sqr', the result must have twice the size of the operands. Therefore it is not possible to store the result to the same array that is used for either of the operands. - 'copy' and 'cmp' can handle arrays of different sizes. In addition, this class provides methods to acquire varibles of a specific size. To reduce creation of new objects, it is possible to release the variables after use, so that they can be recycled (re-acquired). Implementation details: Big integers are represented by int-arrays in little endian word order, using only 28 bits per word. Example: a[0] ... bits 27 ~ 0 a[1] ... bits 55 ~ 28 etc. Bits 31 ~ 28 in each integer are 0.

BITS_PER_WORD

public static final int BITS_PER_WORD

See Also:

Constant Field Values

BMASK

public static final int BMASK

See Also:

Constant Field Values

FFA

public FFA(int bitLength)

acquireVar

public int[] acquireVar(int bits)

acquireVar

public int[] acquireVar()

acquireDoubleVar

public int[] acquireDoubleVar()

releaseVar

public void releaseVar(int[] var)

getBitSize

public int getBitSize()

getByteSize

public int getByteSize()

getIntSize

public int getIntSize()

toString

public String toString(int[] a)

from

public int[] from(int[] r,
                  String a)

from

public int[] from(String a)

from

public int[] from(int[] r,
                  int[] a)

from

public int[] from(int[] a)

from

public int[] from(int[] r,
                  byte[] a,
                  int ofs,
                  int len)

from

public int[] from(byte[] a,
                  int ofs,
                  int len)

toByteArray

public void toByteArray(byte[] dst,
                        int ofs,
                        int len,
                        int[] a)

add

public int add(int[] r,
               int[] a,
               int[] b)

sub

public int sub(int[] r,
               int[] a,
               int[] b)

mul

public void mul(int[] r,
                int[] a,
                int[] b)

sqr

public void sqr(int[] r,
                int[] a)

shl

public int shl(int[] r,
               int[] a,
               int n)

shr

public int shr(int[] r,
               int[] a,
               int n)

xor

public void xor(int[] r,
                int[] a,
                int[] b)

copy

public void copy(int[] r,
                 int[] a)

adjustLength

public int[] adjustLength(int[] a)

cmp

public int cmp(int[] a,
               int[] b)

bitLength

public int bitLength(int[] a)

testBit

public boolean testBit(int[] a,
                       int bit)

isEven

public boolean isEven(int[] a)

isOdd

public boolean isOdd(int[] a)

is

public boolean is(int[] a,
                  int val)

set

public void set(int[] r,
                int val)

mod

public void mod(int[] a,
                int[] b)