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authorMatt Johnston <matt@ucc.asn.au>2007-02-03 08:20:34 +0000
committerMatt Johnston <matt@ucc.asn.au>2007-02-03 08:20:34 +0000
commitd9aeb2773e236e662c8b493f4bcee978f9908d7c (patch)
treebac48e388bf3ac739ae14cdf98da0eb4bb9d17bf /libtommath/bn_mp_toradix.c
parent056b92bd4c8a42ce1843493310d382159166edb8 (diff)
parentc5fd7dd5548f28e32d846e39d17e5c4de4e769af (diff)
merge of '5fdf69ca60d1683cdd9f4c2595134bed26394834'
and '6b61c50f4cf888bea302ac8fcf5dbb573b443251' --HG-- extra : convert_revision : b1dd3b94e60a07a176dba2b035ac79968595990a
Diffstat (limited to 'libtommath/bn_mp_toradix.c')
-rw-r--r--libtommath/bn_mp_toradix.c75
1 files changed, 75 insertions, 0 deletions
diff --git a/libtommath/bn_mp_toradix.c b/libtommath/bn_mp_toradix.c
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+++ b/libtommath/bn_mp_toradix.c
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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, tomstdenis@gmail.com, http://math.libtomcrypt.com
+ */
+
+/* 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
+
+/* $Source: /cvs/libtom/libtommath/bn_mp_toradix.c,v $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2006/03/31 14:18:44 $ */