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-rw-r--r--libtommath/bn_mp_read_radix.c78
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diff --git a/libtommath/bn_mp_read_radix.c b/libtommath/bn_mp_read_radix.c
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+++ b/libtommath/bn_mp_read_radix.c
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+#include <tommath.h>
+#ifdef BN_MP_READ_RADIX_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 string [ASCII] in a given radix */
+int mp_read_radix (mp_int * a, char *str, int radix)
+{
+ int y, res, neg;
+ char ch;
+
+ /* make sure the radix is ok */
+ if (radix < 2 || radix > 64) {
+ return MP_VAL;
+ }
+
+ /* if the leading digit is a
+ * minus set the sign to negative.
+ */
+ if (*str == '-') {
+ ++str;
+ neg = MP_NEG;
+ } else {
+ neg = MP_ZPOS;
+ }
+
+ /* set the integer to the default of zero */
+ mp_zero (a);
+
+ /* process each digit of the string */
+ while (*str) {
+ /* if the radix < 36 the conversion is case insensitive
+ * this allows numbers like 1AB and 1ab to represent the same value
+ * [e.g. in hex]
+ */
+ ch = (char) ((radix < 36) ? toupper (*str) : *str);
+ for (y = 0; y < 64; y++) {
+ if (ch == mp_s_rmap[y]) {
+ break;
+ }
+ }
+
+ /* if the char was found in the map
+ * and is less than the given radix add it
+ * to the number, otherwise exit the loop.
+ */
+ if (y < radix) {
+ if ((res = mp_mul_d (a, (mp_digit) radix, a)) != MP_OKAY) {
+ return res;
+ }
+ if ((res = mp_add_d (a, (mp_digit) y, a)) != MP_OKAY) {
+ return res;
+ }
+ } else {
+ break;
+ }
+ ++str;
+ }
+
+ /* set the sign only if a != 0 */
+ if (mp_iszero(a) != 1) {
+ a->sign = neg;
+ }
+ return MP_OKAY;
+}
+#endif