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author | Matt Johnston <matt@ucc.asn.au> | 2006-03-08 13:23:49 +0000 |
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committer | Matt Johnston <matt@ucc.asn.au> | 2006-03-08 13:23:49 +0000 |
commit | 475aa151f9618036b90a25cf529517d04e61977f (patch) | |
tree | 453ebf8873dd287a2def6a674d42afcc6637cde2 /libtommath/bn_mp_fread.c | |
parent | 2514a6739b3268c98ef09863eff52ed086e4b6f9 (diff) | |
parent | 2b43e46e826fe9905f36b8920386e13f1f47ed65 (diff) | |
download | dropbear-475aa151f9618036b90a25cf529517d04e61977f.tar.gz |
propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 6c790cad5a7fa866ad062cb3a0c279f7ba788583)
to branch 'au.asn.ucc.matt.dropbear' (head fff0894a0399405a9410ea1c6d118f342cf2aa64)
Diffstat (limited to 'libtommath/bn_mp_fread.c')
-rw-r--r-- | libtommath/bn_mp_fread.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/libtommath/bn_mp_fread.c b/libtommath/bn_mp_fread.c new file mode 100644 index 0000000..293df3f --- /dev/null +++ b/libtommath/bn_mp_fread.c @@ -0,0 +1,63 @@ +#include <tommath.h> +#ifdef BN_MP_FREAD_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 + */ + +/* read a bigint from a file stream in ASCII */ +int mp_fread(mp_int *a, int radix, FILE *stream) +{ + int err, ch, neg, y; + + /* clear a */ + mp_zero(a); + + /* if first digit is - then set negative */ + ch = fgetc(stream); + if (ch == '-') { + neg = MP_NEG; + ch = fgetc(stream); + } else { + neg = MP_ZPOS; + } + + for (;;) { + /* find y in the radix map */ + for (y = 0; y < radix; y++) { + if (mp_s_rmap[y] == ch) { + break; + } + } + if (y == radix) { + break; + } + + /* shift up and add */ + if ((err = mp_mul_d(a, radix, a)) != MP_OKAY) { + return err; + } + if ((err = mp_add_d(a, y, a)) != MP_OKAY) { + return err; + } + + ch = fgetc(stream); + } + if (mp_cmp_d(a, 0) != MP_EQ) { + a->sign = neg; + } + + return MP_OKAY; +} + +#endif |