Mercurial > dropbear
diff libtommath/bn_mp_toradix.c @ 302:973fccb59ea4 ucc-axis-hack
propagate from branch 'au.asn.ucc.matt.dropbear' (head 11034278bd1917bebcbdc69cf53b1891ce9db121)
to branch 'au.asn.ucc.matt.dropbear.ucc-axis-hack' (head 10a1f614fec73d0820c3f61160d9db409b9beb46)
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sat, 25 Mar 2006 12:59:58 +0000 |
parents | eed26cff980b |
children | 5ff8218bcee9 |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libtommath/bn_mp_toradix.c Sat Mar 25 12:59:58 2006 +0000 @@ -0,0 +1,71 @@ +#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