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author | William Joye <wjoye@cfa.harvard.edu> | 2016-12-21 22:56:22 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2016-12-21 22:56:22 (GMT) |
commit | d1a6de55efc90f190dee42ab8c4fa9070834e77d (patch) | |
tree | ec633f5608ef498bee52a5f42c12c49493ec8bf8 /tcl8.6/libtommath/bn_mp_get_int.c | |
parent | 5514e37335c012cc70f5b9aee3cedfe3d57f583f (diff) | |
parent | 98acd3f494b28ddd8c345a2bb9311e41e2d56ddd (diff) | |
download | blt-d1a6de55efc90f190dee42ab8c4fa9070834e77d.zip blt-d1a6de55efc90f190dee42ab8c4fa9070834e77d.tar.gz blt-d1a6de55efc90f190dee42ab8c4fa9070834e77d.tar.bz2 |
Merge commit '98acd3f494b28ddd8c345a2bb9311e41e2d56ddd' as 'tcl8.6'
Diffstat (limited to 'tcl8.6/libtommath/bn_mp_get_int.c')
-rw-r--r-- | tcl8.6/libtommath/bn_mp_get_int.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/tcl8.6/libtommath/bn_mp_get_int.c b/tcl8.6/libtommath/bn_mp_get_int.c new file mode 100644 index 0000000..762cb23 --- /dev/null +++ b/tcl8.6/libtommath/bn_mp_get_int.c @@ -0,0 +1,41 @@ +#include <tommath.h> +#ifdef BN_MP_GET_INT_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, tomstdenis@gmail.com, http://math.libtomcrypt.com + */ + +/* get the lower 32-bits of an mp_int */ +unsigned long mp_get_int(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); + + while (--i >= 0) { + res = (res << DIGIT_BIT) | DIGIT(a,i); + } + + /* force result to 32-bits always so it is consistent on non 32-bit platforms */ + return res & 0xFFFFFFFFUL; +} +#endif |