`12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485` ``````#include #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@gmail.com, http://libtom.org */ /* read a string [ASCII] in a given radix */ int mp_read_radix (mp_int * a, const char *str, int radix) { int y, res, neg; char ch; /* zero the digit bignum */ mp_zero(a); /* 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 /* \$Source\$ */ /* \$Revision: 0.41 \$ */ /* \$Date: 2007-04-18 09:58:18 +0000 \$ */ ``````