bn_mp_addmod.c 1010 B

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  1. #include <tommath.h>
  2. #ifdef BN_MP_ADDMOD_C
  3. /* LibTomMath, multiple-precision integer library -- Tom St Denis
  4. *
  5. * LibTomMath is a library that provides multiple-precision
  6. * integer arithmetic as well as number theoretic functionality.
  7. *
  8. * The library was designed directly after the MPI library by
  9. * Michael Fromberger but has been written from scratch with
  10. * additional optimizations in place.
  11. *
  12. * The library is free for all purposes without any express
  13. * guarantee it works.
  14. *
  15. * Tom St Denis, tomstdenis@gmail.com, http://math.libtomcrypt.com
  16. */
  17. /* d = a + b (mod c) */
  18. int
  19. mp_addmod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
  20. {
  21. int res;
  22. mp_int t;
  23. if ((res = mp_init (&t)) != MP_OKAY) {
  24. return res;
  25. }
  26. if ((res = mp_add (a, b, &t)) != MP_OKAY) {
  27. mp_clear (&t);
  28. return res;
  29. }
  30. res = mp_mod (&t, c, d);
  31. mp_clear (&t);
  32. return res;
  33. }
  34. #endif
  35. /* $Source: /cvs/libtom/libtommath/bn_mp_addmod.c,v $ */
  36. /* $Revision: 1.3 $ */
  37. /* $Date: 2006/03/31 14:18:44 $ */