diff options
author | Matt Johnston <matt@ucc.asn.au> | 2006-03-08 13:23:49 +0000 |
---|---|---|
committer | Matt Johnston <matt@ucc.asn.au> | 2006-03-08 13:23:49 +0000 |
commit | 8608a8e64c1aeda096867f43f89e29e1aee207ae (patch) | |
tree | 453ebf8873dd287a2def6a674d42afcc6637cde2 /libtommath/bn_mp_toradix.c | |
parent | 2481693cf23dba90c693762a528d2923cde9c9cc (diff) | |
parent | 882a9ced901348b3a48023443bfd23e0ef9d9b67 (diff) |
propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 6c790cad5a7fa866ad062cb3a0c279f7ba788583)
to branch 'au.asn.ucc.matt.dropbear' (head fff0894a0399405a9410ea1c6d118f342cf2aa64)
--HG--
extra : convert_revision : fdf4a7a3b97ae5046139915de7e40399cceb2c01
Diffstat (limited to 'libtommath/bn_mp_toradix.c')
-rw-r--r-- | libtommath/bn_mp_toradix.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/libtommath/bn_mp_toradix.c b/libtommath/bn_mp_toradix.c new file mode 100644 index 0000000..a206d5e --- /dev/null +++ b/libtommath/bn_mp_toradix.c @@ -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, tomstdenis@iahu.ca, 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 |