Mercurial > dropbear
diff bn_mp_copy.c @ 2:86e0b50a9b58 libtommath-orig ltm-0.30-orig
ltm 0.30 orig import
author | Matt Johnston <matt@ucc.asn.au> |
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date | Mon, 31 May 2004 18:25:22 +0000 |
parents | |
children | d29b64170cf0 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/bn_mp_copy.c Mon May 31 18:25:22 2004 +0000 @@ -0,0 +1,62 @@ +/* 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> + +/* copy, b = a */ +int +mp_copy (mp_int * a, mp_int * b) +{ + int res, n; + + /* if dst == src do nothing */ + if (a == b) { + return MP_OKAY; + } + + /* grow dest */ + if (b->alloc < a->used) { + if ((res = mp_grow (b, a->used)) != MP_OKAY) { + return res; + } + } + + /* zero b and copy the parameters over */ + { + register mp_digit *tmpa, *tmpb; + + /* pointer aliases */ + + /* source */ + tmpa = a->dp; + + /* destination */ + tmpb = b->dp; + + /* copy all the digits */ + for (n = 0; n < a->used; n++) { + *tmpb++ = *tmpa++; + } + + /* clear high digits */ + for (; n < b->used; n++) { + *tmpb++ = 0; + } + } + + /* copy used count and sign */ + b->used = a->used; + b->sign = a->sign; + return MP_OKAY; +}