gitweb.ps.run Git - matrix_esp_thesis/blob - ext/olm/lib/curve25519-donna/contrib/Curve25519Donna.java

   1 /*
   2     James Robson
   3     Public domain.
   4 */
   5
   6 public class Curve25519Donna {
   7
   8     final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();
   9
  10     public static String bytesToHex(byte[] bytes) {
  11         char[] hexChars = new char[bytes.length * 2];
  12         int v;
  13         for ( int j = 0; j < bytes.length; j++ ) {
  14             v = bytes[j] & 0xFF;
  15             hexChars[j * 2] = hexArray[v >>> 4];
  16             hexChars[j * 2 + 1] = hexArray[v & 0x0F];
  17         }
  18         return new String(hexChars);
  19     }
  20
  21     public native byte[] curve25519Donna(byte[] a, byte[] b);
  22     public native byte[] makePrivate(byte[] secret);
  23     public native byte[] getPublic(byte[] privkey);
  24     public native byte[] makeSharedSecret(byte[] privkey, byte[] theirPubKey);
  25     public native void helowrld();
  26
  27     // Uncomment if your Java is 32-bit:
  28     //static { System.loadLibrary("Curve25519Donna"); }
  29
  30     // Otherwise, load this 64-bit .jnilib:
  31     static { System.loadLibrary("Curve25519Donna_64"); }
  32
  33     /*
  34         To give the old tires a kick (OSX):
  35         java -cp `pwd` Curve25519Donna
  36     */
  37     public static void main (String[] args) {
  38
  39         Curve25519Donna c = new Curve25519Donna();
  40
  41         // These should be 32 bytes long
  42         byte[] user1Secret = "abcdefghijklmnopqrstuvwxyz123456".getBytes();
  43         byte[] user2Secret = "654321zyxwvutsrqponmlkjihgfedcba".getBytes();
  44
  45
  46         // You can use the curve function directly...
  47
  48         //byte[] o = c.curve25519Donna(a, b);
  49         //System.out.println("o = " + bytesToHex(o));
  50
  51
  52         // ... but it's not really necessary. Just use the following
  53         // convenience methods:
  54
  55         byte[] privKey = c.makePrivate(user1Secret);
  56         byte[] pubKey = c.getPublic(privKey);
  57
  58         byte[] privKey2 = c.makePrivate(user2Secret);
  59         byte[] pubKey2 = c.getPublic(privKey2);
  60
  61         System.out.println("'user1' privKey = " + bytesToHex(privKey));
  62         System.out.println("'user1' pubKey = " + bytesToHex(pubKey));
  63         System.out.println("===================================================");
  64
  65         System.out.println("'user2' privKey = " + bytesToHex(privKey2));
  66         System.out.println("'user2' pubKey = " + bytesToHex(pubKey2));
  67         System.out.println("===================================================");
  68
  69
  70         byte[] ss1 = c.makeSharedSecret(privKey, pubKey2);
  71         System.out.println("'user1' computes shared secret: " + bytesToHex(ss1));
  72
  73         byte[] ss2 = c.makeSharedSecret(privKey2, pubKey);
  74         System.out.println("'user2' computes shared secret: " + bytesToHex(ss2));
  75
  76     }
  77 }