| /* LibTomMath, multiple-precision integer library -- Tom St Denis |
| * |
| * LibTomMath is a library that provides multiple-precision |
| * integer arithmetic as well as number theoretic functionality. |
| * |
| * The library was designed directly after the MPI library by |
| * Michael Fromberger but has been written from scratch with |
| * additional optimizations in place. |
| * |
| * The library is free for all purposes without any express |
| * guarantee it works. |
| * |
| * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org |
| */ |
| #include <tommath.h> |
| |
| /* this table gives the # of rabin miller trials for a prob of failure lower than 2^-96 */ |
| static const struct { |
| int k, t; |
| } sizes[] = { |
| { 128, 28 }, |
| { 256, 16 }, |
| { 384, 10 }, |
| { 512, 7 }, |
| { 640, 6 }, |
| { 768, 5 }, |
| { 896, 4 }, |
| { 1024, 4 }, |
| { 1152, 3 }, |
| { 1280, 3 }, |
| { 1408, 3 }, |
| { 1536, 3 }, |
| { 1664, 3 }, |
| { 1792, 2 } }; |
| |
| /* returns # of RM trials required for a given bit size */ |
| int mp_prime_rabin_miller_trials(int size) |
| { |
| int x; |
| |
| for (x = 0; x < (int)(sizeof(sizes)/(sizeof(sizes[0]))); x++) { |
| if (sizes[x].k == size) { |
| return sizes[x].t; |
| } else if (sizes[x].k > size) { |
| return (x == 0) ? sizes[0].t : sizes[x - 1].t; |
| } |
| } |
| return 1; |
| } |
| |
| |