diff options
author | Lucas Kanashiro <kanashiro@debian.org> | 2017-06-25 00:00:40 -0300 |
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committer | Lucas Kanashiro <kanashiro@debian.org> | 2017-06-25 00:00:40 -0300 |
commit | ea35d105ec8dbf421ad1803bcb72e097d2295a18 (patch) | |
tree | 2aa3f333938fb6886d020d7deb5bc7b4d010afca /src/ltm/bn_mp_get_long.c |
Import original source of CryptX 0.048
Diffstat (limited to 'src/ltm/bn_mp_get_long.c')
-rw-r--r-- | src/ltm/bn_mp_get_long.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/src/ltm/bn_mp_get_long.c b/src/ltm/bn_mp_get_long.c new file mode 100644 index 00000000..7c3d0fe1 --- /dev/null +++ b/src/ltm/bn_mp_get_long.c @@ -0,0 +1,41 @@ +#include <tommath_private.h> +#ifdef BN_MP_GET_LONG_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, tstdenis82@gmail.com, http://libtom.org + */ + +/* get the lower unsigned long of an mp_int, platform dependent */ +unsigned long mp_get_long(mp_int * a) +{ + int i; + unsigned long res; + + if (a->used == 0) { + return 0; + } + + /* get number of digits of the lsb we have to read */ + i = MIN(a->used,(int)(((sizeof(unsigned long) * CHAR_BIT) + DIGIT_BIT - 1) / DIGIT_BIT)) - 1; + + /* get most significant digit of result */ + res = DIGIT(a,i); + +#if (ULONG_MAX != 0xffffffffuL) || (DIGIT_BIT < 32) + while (--i >= 0) { + res = (res << DIGIT_BIT) | DIGIT(a,i); + } +#endif + return res; +} +#endif |