BigIntUtils (Bouncy Castle Library 1.52 API Specification)

org.bouncycastle.pqc.math.linearalgebra

## Class BigIntUtils

- java.lang.Object
- - org.bouncycastle.pqc.math.linearalgebra.BigIntUtils

-     public final class BigIntUtils
      extends java.lang.Object

  FIXME: is this really necessary?!

- - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `static boolean` | `equals(java.math.BigInteger[] a, java.math.BigInteger[] b)` Checks if two BigInteger arrays contain the same entries
    `static void` | `fill(java.math.BigInteger[] array, java.math.BigInteger value)` Fill the given BigInteger array with the given value.
    `static java.math.BigInteger[]` | `subArray(java.math.BigInteger[] input, int start, int end)` Generates a subarray of a given BigInteger array.
    `static int[]` | `toIntArray(java.math.BigInteger[] input)` Converts a BigInteger array into an integer array
    `static int[]` | `toIntArrayModQ(int q, java.math.BigInteger[] input)` Converts a BigInteger array into an integer array, reducing all BigIntegers mod q.
    `static byte[]` | `toMinimalByteArray(java.math.BigInteger value)` Return the value of `big` as a byte array.

    - ### Methods inherited from class java.lang.Object

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

- - ### Method Detail

    - #### equals

          public static boolean equals(java.math.BigInteger[] a,
                       java.math.BigInteger[] b)

      Checks if two BigInteger arrays contain the same entries
      Parameters:
        `a` - first BigInteger array
        `b` - second BigInteger array
      Returns:
        true or false

    - #### fill

          public static void fill(java.math.BigInteger[] array,
                  java.math.BigInteger value)

      Fill the given BigInteger array with the given value.
      Parameters:
        `array` - the array
        `value` - the value

    - #### subArray

          public static java.math.BigInteger[] subArray(java.math.BigInteger[] input,
                                        int start,
                                        int end)

      Generates a subarray of a given BigInteger array.
      Parameters:
        `input` - - the input BigInteger array
        `start` - - the start index
        `end` - - the end index
      Returns:
        a subarray of `input`, ranging from `start` to `end`

    - #### toIntArray

          public static int[] toIntArray(java.math.BigInteger[] input)

      Converts a BigInteger array into an integer array
      Parameters:
        `input` - - the BigInteger array
      Returns:
        the integer array

    - #### toIntArrayModQ

          public static int[] toIntArrayModQ(int q,
                             java.math.BigInteger[] input)

      Converts a BigInteger array into an integer array, reducing all BigIntegers mod q.
      Parameters:
        `q` - - the modulus
        `input` - - the BigInteger array
      Returns:
        the integer array

    - #### toMinimalByteArray

          public static byte[] toMinimalByteArray(java.math.BigInteger value)

      Return the value of `big` as a byte array. Although BigInteger has such a method, it uses an extra bit to indicate the sign of the number. For elliptic curve cryptography, the numbers usually are positive. Thus, this helper method returns a byte array of minimal length, ignoring the sign of the number.
      Parameters:
        `value` - the `BigInteger` value to be converted to a byte array
      Returns:
        the value `big` as byte array