|
142
|
1 #include <tommath.h> |
|
|
2 #ifdef BN_MP_ADDMOD_C |
|
2
|
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, [email protected], http://math.libtomcrypt.org |
|
|
16 */ |
|
|
17 |
|
|
18 /* d = a + b (mod c) */ |
|
|
19 int |
|
|
20 mp_addmod (mp_int * a, mp_int * b, mp_int * c, mp_int * d) |
|
|
21 { |
|
|
22 int res; |
|
|
23 mp_int t; |
|
|
24 |
|
|
25 if ((res = mp_init (&t)) != MP_OKAY) { |
|
|
26 return res; |
|
|
27 } |
|
|
28 |
|
|
29 if ((res = mp_add (a, b, &t)) != MP_OKAY) { |
|
|
30 mp_clear (&t); |
|
|
31 return res; |
|
|
32 } |
|
|
33 res = mp_mod (&t, c, d); |
|
|
34 mp_clear (&t); |
|
|
35 return res; |
|
|
36 } |
|
142
|
37 #endif |
