crypto/openssh/verify.c

   1 /* $OpenBSD: verify.c,v 1.3 2013/12/09 11:03:45 markus Exp $ */
   2
   3 /*
   4  * Public Domain, Author: Daniel J. Bernstein
   5  * Copied from nacl-20110221/crypto_verify/32/ref/verify.c
   6  */
   7
   8 #include "includes.h"
   9
  10 #include "crypto_api.h"
  11
  12 int crypto_verify_32(const unsigned char *x,const unsigned char *y)
  13 {
  14   unsigned int differentbits = 0;
  15 #define F(i) differentbits |= x[i] ^ y[i];
  16   F(0)
  17   F(1)
  18   F(2)
  19   F(3)
  20   F(4)
  21   F(5)
  22   F(6)
  23   F(7)
  24   F(8)
  25   F(9)
  26   F(10)
  27   F(11)
  28   F(12)
  29   F(13)
  30   F(14)
  31   F(15)
  32   F(16)
  33   F(17)
  34   F(18)
  35   F(19)
  36   F(20)
  37   F(21)
  38   F(22)
  39   F(23)
  40   F(24)
  41   F(25)
  42   F(26)
  43   F(27)
  44   F(28)
  45   F(29)
  46   F(30)
  47   F(31)
  48   return (1 & ((differentbits - 1) >> 8)) - 1;
  49 }