From 22db48330c452c35e3981f10b5bd6cc49ce59526 Mon Sep 17 00:00:00 2001 From: Nikos Mavrogiannopoulos Date: Mon, 5 Jul 2010 10:53:45 +0200 Subject: Added libtommath for bignum operations. --- libtommath/bn_mp_read_signed_bin.c | 41 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 libtommath/bn_mp_read_signed_bin.c (limited to 'libtommath/bn_mp_read_signed_bin.c') diff --git a/libtommath/bn_mp_read_signed_bin.c b/libtommath/bn_mp_read_signed_bin.c new file mode 100644 index 0000000..8da651c --- /dev/null +++ b/libtommath/bn_mp_read_signed_bin.c @@ -0,0 +1,41 @@ +#include +#ifdef BN_MP_READ_SIGNED_BIN_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://libtom.org + */ + +/* read signed bin, big endian, first byte is 0==positive or 1==negative */ +int mp_read_signed_bin (mp_int * a, const unsigned char *b, int c) +{ + int res; + + /* read magnitude */ + if ((res = mp_read_unsigned_bin (a, b + 1, c - 1)) != MP_OKAY) { + return res; + } + + /* first byte is 0 for positive, non-zero for negative */ + if (b[0] == 0) { + a->sign = MP_ZPOS; + } else { + a->sign = MP_NEG; + } + + return MP_OKAY; +} +#endif + +/* $Source: /cvs/libtom/libtommath/bn_mp_read_signed_bin.c,v $ */ +/* $Revision: 1.5 $ */ +/* $Date: 2006/12/28 01:25:13 $ */ -- cgit