Merge branch 'better/read_radix' into develop

This closes #92
This commit is contained in:
Steffen Jaeckel 2017-10-15 12:03:10 +02:00
commit d0cb8ba954
4 changed files with 36 additions and 18 deletions

View File

@ -20,6 +20,7 @@
int mp_fread(mp_int *a, int radix, FILE *stream)
{
int err, ch, neg, y;
unsigned pos;
/* clear a */
mp_zero(a);
@ -34,13 +35,14 @@ int mp_fread(mp_int *a, int radix, FILE *stream)
}
for (;;) {
/* find y in the radix map */
for (y = 0; y < radix; y++) {
if (mp_s_rmap[y] == ch) {
pos = ch - '(';
if (mp_s_rmap_reverse_sz < pos) {
break;
}
}
if (y == radix) {
y = mp_s_rmap_reverse[pos];
if (y == 0xff || y >= radix) {
break;
}

View File

@ -17,6 +17,20 @@
/* chars used in radix conversions */
const char *mp_s_rmap = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+/";
const uint8_t mp_s_rmap_reverse[] = {
0xff, 0xff, 0xff, 0x3e, 0xff, 0xff, 0xff, 0x3f, /* ()*+,-./ */
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 01234567 */
0x08, 0x09, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 89:;<=>? */
0xff, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, /* @ABCDEFG */
0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, /* HIJKLMNO */
0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, /* PQRSTUVW */
0x21, 0x22, 0x23, 0xff, 0xff, 0xff, 0xff, 0xff, /* XYZ[\]^_ */
0xff, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, /* `abcdefg */
0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, /* hijklmno */
0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, /* pqrstuvw */
0x3b, 0x3c, 0x3d, 0xff, 0xff, 0xff, 0xff, 0xff, /* xyz{|}~. */
};
const size_t mp_s_rmap_reverse_sz = sizeof(mp_s_rmap_reverse);
#endif
/* ref: $Format:%D$ */

View File

@ -19,6 +19,7 @@
int mp_read_radix(mp_int *a, const char *str, int radix)
{
int y, res, neg;
unsigned pos;
char ch;
/* zero the digit bignum */
@ -49,26 +50,25 @@ int mp_read_radix(mp_int *a, const char *str, int radix)
* [e.g. in hex]
*/
ch = (radix <= 36) ? (char)toupper((int)*str) : *str;
for (y = 0; y < 64; y++) {
if (ch == mp_s_rmap[y]) {
pos = ch - '(';
if (mp_s_rmap_reverse_sz < pos) {
break;
}
}
y = mp_s_rmap_reverse[pos];
/* 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 (y == 0xff || y >= radix) {
break;
}
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;
}

View File

@ -76,6 +76,8 @@ int s_mp_exptmod(const mp_int *G, const mp_int *X, const mp_int *P, mp_int *Y, i
void bn_reverse(unsigned char *s, int len);
extern const char *mp_s_rmap;
extern const uint8_t mp_s_rmap_reverse[];
extern const size_t mp_s_rmap_reverse_sz;
/* Fancy macro to set an MPI from another type.
* There are several things assumed: