Mercurial > dropbear
view bn_prime_sizes_tab.c @ 145:a96ff234ff19 libtommath
propagate of fc94c38452d9fd684a8e1eb9e3a73120aac0d38f and 3e4de4cbef3d9035a7b2f0c25e9f86e297f9f6d1 from branch 'au.asn.ucc.matt.ltm-orig' to 'au.asn.ucc.matt.ltm-db'
author | Matt Johnston <matt@ucc.asn.au> |
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date | Sun, 19 Dec 2004 15:57:19 +0000 |
parents | 22d5cf7d4b1a |
children |
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/* 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, [email protected], 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; }