Bouncy Castle Cryptography Library 1.64

org.bouncycastle.util
Class BigIntegers

java.lang.Object
  |
  +--org.bouncycastle.util.BigIntegers

public final class BigIntegers
extends java.lang.Object

BigInteger utilities.


Field Summary
static java.math.BigInteger ONE
           
static java.math.BigInteger ZERO
           
 
Constructor Summary
BigIntegers()
           
 
Method Summary
static byte[] asUnsignedByteArray(java.math.BigInteger value)
          Return the passed in value as an unsigned byte array.
static byte[] asUnsignedByteArray(int length, java.math.BigInteger value)
          Return the passed in value as an unsigned byte array.
static java.math.BigInteger createRandomBigInteger(int bitLength, java.security.SecureRandom random)
          Return a positive BigInteger in the range of 0 to 2**bitLength - 1.
static java.math.BigInteger createRandomInRange(java.math.BigInteger min, java.math.BigInteger max, java.security.SecureRandom random)
          Return a random BigInteger not less than 'min' and not greater than 'max'
static java.math.BigInteger createRandomPrime(int bitLength, int certainty, java.security.SecureRandom random)
          Return a prime number candidate of the specified bit length.
static java.math.BigInteger fromUnsignedByteArray(byte[] buf)
           
static java.math.BigInteger fromUnsignedByteArray(byte[] buf, int off, int length)
           
static int getUnsignedByteLength(java.math.BigInteger n)
           
static int intValueExact(java.math.BigInteger x)
           
static long longValueExact(java.math.BigInteger x)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

ZERO

public static final java.math.BigInteger ZERO

ONE

public static final java.math.BigInteger ONE
Constructor Detail

BigIntegers

public BigIntegers()
Method Detail

asUnsignedByteArray

public static byte[] asUnsignedByteArray(java.math.BigInteger value)
Return the passed in value as an unsigned byte array.
Parameters:
value - value to be converted.
Returns:
a byte array without a leading zero byte if present in the signed encoding.

asUnsignedByteArray

public static byte[] asUnsignedByteArray(int length,
                                         java.math.BigInteger value)
Return the passed in value as an unsigned byte array.
Parameters:
value - value to be converted.
Returns:
a byte array without a leading zero byte if present in the signed encoding.

createRandomInRange

public static java.math.BigInteger createRandomInRange(java.math.BigInteger min,
                                                       java.math.BigInteger max,
                                                       java.security.SecureRandom random)
Return a random BigInteger not less than 'min' and not greater than 'max'
Parameters:
min - the least value that may be generated
max - the greatest value that may be generated
random - the source of randomness
Returns:
a random BigInteger value in the range [min,max]

fromUnsignedByteArray

public static java.math.BigInteger fromUnsignedByteArray(byte[] buf)

fromUnsignedByteArray

public static java.math.BigInteger fromUnsignedByteArray(byte[] buf,
                                                         int off,
                                                         int length)

intValueExact

public static int intValueExact(java.math.BigInteger x)

longValueExact

public static long longValueExact(java.math.BigInteger x)

getUnsignedByteLength

public static int getUnsignedByteLength(java.math.BigInteger n)

createRandomBigInteger

public static java.math.BigInteger createRandomBigInteger(int bitLength,
                                                          java.security.SecureRandom random)
Return a positive BigInteger in the range of 0 to 2**bitLength - 1.
Parameters:
bitLength - maximum bit length for the generated BigInteger.
random - a source of randomness.
Returns:
a positive BigInteger

createRandomPrime

public static java.math.BigInteger createRandomPrime(int bitLength,
                                                     int certainty,
                                                     java.security.SecureRandom random)
Return a prime number candidate of the specified bit length.
Parameters:
bitLength - bit length for the generated BigInteger.
random - a source of randomness.
Returns:
a positive BigInteger of numBits length

Bouncy Castle Cryptography Library 1.64