net.i2p.crypto.eddsa
Class Utils

java.lang.Object
  extended by net.i2p.crypto.eddsa.Utils

public class Utils
extends Object

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

Since:
0.9.15
Author:
str4d

Constructor Summary
Utils()
           
 
Method Summary
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.

Returns:
1 if b and c are equal, 0 otherwise.

equal

public static int equal(byte[] b,
                        byte[] c)
Constant-time byte[] comparison.

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.