Mercurial > dropbear
view libtommath/bn_mp_dr_is_modulus.c @ 374:87ae4565679d channel-fix
merge of 'a94c5265558121fe936519b5d9a5eb27f95e9d9d'
and 'd348546b80847bc0d42a7b5208bb31a54f1fdfaf'
author | Matt Johnston <matt@ucc.asn.au> |
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date | Tue, 05 Dec 2006 13:28:44 +0000 |
parents | eed26cff980b |
children | 5ff8218bcee9 |
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#include <tommath.h> #ifdef BN_MP_DR_IS_MODULUS_C /* 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 */ /* determines if a number is a valid DR modulus */ int mp_dr_is_modulus(mp_int *a) { int ix; /* must be at least two digits */ if (a->used < 2) { return 0; } /* must be of the form b**k - a [a <= b] so all * but the first digit must be equal to -1 (mod b). */ for (ix = 1; ix < a->used; ix++) { if (a->dp[ix] != MP_MASK) { return 0; } } return 1; } #endif