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
|
Method Summary |
static byte[] |
asUnsignedByteArray(java.math.BigInteger value)
Return the passed in value as an unsigned byte array. |
static void |
asUnsignedByteArray(java.math.BigInteger value,
byte[] buf,
int off,
int len)
Write the passed in value as unsigned bytes to the specified buffer range, padded with
leading zeros as necessary. |
static byte[] |
asUnsignedByteArray(int length,
java.math.BigInteger value)
Return the passed in value as an unsigned byte array of the specified length, padded with
leading zeros as necessary.. |
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 |
ZERO
public static final java.math.BigInteger ZERO
ONE
public static final java.math.BigInteger ONE
BigIntegers
public BigIntegers()
asUnsignedByteArray
public static byte[] asUnsignedByteArray(java.math.BigInteger value)
- Return the passed in value as an unsigned byte array.
- Parameters:
value
- the 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 of the specified length, padded with
leading zeros as necessary..
- Parameters:
length
- the fixed length of the resultvalue
- the value to be converted.- Returns:
- a byte array padded to a fixed length with leading zeros.
asUnsignedByteArray
public static void asUnsignedByteArray(java.math.BigInteger value,
byte[] buf,
int off,
int len)
- Write the passed in value as unsigned bytes to the specified buffer range, padded with
leading zeros as necessary.
- Parameters:
value
- the value to be converted.buf
- the buffer to which the value is written.off
- the start offset in array buf at which the data is written.len
- the fixed length of data written (possibly padded with leading zeros).
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 generatedmax
- the greatest value that may be generatedrandom
- 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