37 lines
966 B
C
37 lines
966 B
C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
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*
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* LibTomMath is a library that provides multiple-precision
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* integer arithmetic as well as number theoretic functionality.
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*
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* The library was designed directly after the MPI library by
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* Michael Fromberger but has been written from scratch with
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* additional optimizations in place.
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*
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* The library is free for all purposes without any express
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* guarantee it works.
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*
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* Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
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*/
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#include <tommath.h>
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/* read signed bin, big endian, first byte is 0==positive or 1==negative */
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int
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mp_read_signed_bin (mp_int * a, unsigned char *b, int c)
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{
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int res;
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/* read magnitude */
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if ((res = mp_read_unsigned_bin (a, b + 1, c - 1)) != MP_OKAY) {
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return res;
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}
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/* first byte is 0 for positive, non-zero for negative */
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if (b[0] == 0) {
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a->sign = MP_ZPOS;
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} else {
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a->sign = MP_NEG;
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}
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return MP_OKAY;
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}
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