net.i2p.crypto.eddsa

Class Utils

java.lang.Object

net.i2p.crypto.eddsa.Utils

public class Utils
extends Object

Basic utilities for EdDSA. Not for external use, not maintained as a public API.

Author:

str4d

Constructor Summary

Constructors

Constructor and Description
Utils()

Method Summary

Modifier and Type	Method and Description
static int	bit(byte[] h, int i) Get the i'th bit of a byte array.
static String	bytesToHex(byte[] raw) Converts bytes to a hex string.
static int	equal(byte[] b, byte[] c) Constant-time byte[] comparison.
static int	equal(int b, int c) Constant-time byte comparison.
static byte[]	hexToBytes(String s) Converts a hex string to bytes.
static int	negative(int b) Constant-time determine if byte is negative.

Methods inherited from class java.lang.Object

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

Constructor Detail

Utils

public Utils()

Method Detail

equal

public static int equal(int b,
                        int c)

Constant-time byte comparison.

Parameters:

b - a byte

c - a byte

Returns:

1 if b and c are equal, 0 otherwise.

equal

public static int equal(byte[] b,
                        byte[] c)

Constant-time byte[] comparison.

Parameters:

b - a byte[]

c - a byte[]

Returns:

1 if b and c are equal, 0 otherwise.

negative

public static int negative(int b)

Constant-time determine if byte is negative.

Parameters:

b - the byte to check.

Returns:

1 if the byte is negative, 0 otherwise.

bit

public static int bit(byte[] h,
                      int i)

Get the i'th bit of a byte array.

Parameters:

h - the byte array.

i - the bit index.

Returns:

0 or 1, the value of the i'th bit in h

hexToBytes

public static byte[] hexToBytes(String s)

Converts a hex string to bytes.

Parameters:

s - the hex string to be converted.

Returns:

the byte[]

bytesToHex

public static String bytesToHex(byte[] raw)

Converts bytes to a hex string.

Parameters:

raw - the byte[] to be converted.

Returns:

the hex representation as a string.