Mercurial > dropbear
view libtommath/bn_mp_toradix.c @ 330:5488db2e9e4e
merge of 332f709a4cb39cde4cedab7c3be89e05f3023067
and ca4ca78b82c5d430c69ce01bf794e8886ce81431
author | Matt Johnston <matt@ucc.asn.au> |
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date | Sat, 10 Jun 2006 16:39:40 +0000 |
parents | eed26cff980b |
children | 5ff8218bcee9 |
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#include <tommath.h> #ifdef BN_MP_TORADIX_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, [email protected], http://math.libtomcrypt.org */ /* stores a bignum as a ASCII string in a given radix (2..64) */ int mp_toradix (mp_int * a, char *str, int radix) { int res, digs; mp_int t; mp_digit d; char *_s = str; /* check range of the radix */ if (radix < 2 || radix > 64) { return MP_VAL; } /* quick out if its zero */ if (mp_iszero(a) == 1) { *str++ = '0'; *str = '\0'; return MP_OKAY; } if ((res = mp_init_copy (&t, a)) != MP_OKAY) { return res; } /* if it is negative output a - */ if (t.sign == MP_NEG) { ++_s; *str++ = '-'; t.sign = MP_ZPOS; } digs = 0; while (mp_iszero (&t) == 0) { if ((res = mp_div_d (&t, (mp_digit) radix, &t, &d)) != MP_OKAY) { mp_clear (&t); return res; } *str++ = mp_s_rmap[d]; ++digs; } /* reverse the digits of the string. In this case _s points * to the first digit [exluding the sign] of the number] */ bn_reverse ((unsigned char *)_s, digs); /* append a NULL so the string is properly terminated */ *str = '\0'; mp_clear (&t); return MP_OKAY; } #endif