Package org.bouncycastle.pqc.math.linearalgebra

## Class BigEndianConversions

- java.lang.Object
- - org.bouncycastle.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

    All Methods Static Methods Concrete Methods
    Modifier and Type | Method | 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