Mercurial > dropbear
view bn_mp_set_int.c @ 19:e1037a1e12e7 libtommath-orig
0.30 release of LibTomMath
author | Matt Johnston <matt@ucc.asn.au> |
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date | Tue, 15 Jun 2004 14:42:57 +0000 |
parents | 86e0b50a9b58 |
children | d29b64170cf0 |
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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> /* set a 32-bit const */ int mp_set_int (mp_int * a, unsigned long b) { int x, res; mp_zero (a); /* set four bits at a time */ for (x = 0; x < 8; x++) { /* shift the number up four bits */ if ((res = mp_mul_2d (a, 4, a)) != MP_OKAY) { return res; } /* OR in the top four bits of the source */ a->dp[0] |= (b >> 28) & 15; /* shift the source up to the next four bits */ b <<= 4; /* ensure that digits are not clamped off */ a->used += 1; } mp_clamp (a); return MP_OKAY; }