You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
mkp224o/base32_from.c

102 lines
3.4 KiB

#include <stddef.h>
#include <stdint.h>
#include "types.h"
#include "base32.h"
static const u8 base32f[256] = {
//00 01 02 03 04 05 06 07
//08 09 0A 0B 0C 0D 0E 0F
// 0x00..0x3F
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x00
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x08
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x10
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x18
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x20
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x28
0xFF, 0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, // 0x30
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x38
// 0x40..0x7F
0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, // 0x40
0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, // 0x48
0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, // 0x50
0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x58
0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, // 0x60
0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, // 0x68
0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, // 0x70
0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x78
// 0x80..0xBF
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
// 0xC0..0xFF
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
};
/*
+--first octet--+-second octet--+--third octet--+--forth octet--+--fifth octet--+
|7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|
+---------+-----+---+---------+-+-------+-------+-+---------+---+-----+---------+
|4 3 2 1 0|4 3 2 1 0|4 3 2 1 0|4 3 2 1 0|4 3 2 1 0|4 3 2 1 0|4 3 2 1 0|4 3 2 1 0|
+-1.index-+-2.index-+-3.index-+-4.index-+-5.index-+-6.index-+-7.index-+-8.index-+
*/
size_t base32_from(u8 *dst,u8 *dmask,const char *src)
{
size_t i, j, k = (size_t)-1, l, sk = 0;
u8 mask = 0, cmask = 0;
for (i = 0;;i += 5) {
j = i/5;
if (!src[j]) {
if (k != (size_t)-1)
dst[k] &= cmask;
if (dmask)
*dmask = cmask;
return k + 1;
}
l = i%8;
k = i/8;
if (k != sk)
cmask = 0;
sk = k;
mask = (0x1F << 3) >> l;
cmask |= mask;
//printf("1:m[%02X] cm[%02X]\n",mask,cmask);
dst[k] &= ~mask;
dst[k] |= (base32f[(u8)src[j]] << 3) >> l;
if (((0x1F << 8) >> (l+5-8)) & 0xFF) {
++k;
sk = k;
mask = ((0x1F << 8) >> (l+5-8)) & 0xFF;
cmask = mask;
//printf("2:m[%02X] cm[%02X]\n",mask,cmask);
dst[k] &= ~mask;
dst[k] |= ((base32f[(u8)src[j]] << 8) >> (l+5-8)) & 0xFF;
}
//printf("i = %02d, i/8 = %02d, i%8 = %02d, i%8+5-8 = %02d\n", i, i/8, i%8, i%8+5-8);
//printf("mask0: %02x\n", (0x1F << 3) >> (i%8));
//printf("mask1: %02x\n", ((0x1F << 8) >> (i%8+5-8)) & 0xFF);
}
}
int base32_valid(const char *src,size_t *count)
{
const char *p;
for (p = src;base32f[(u8)*p] != 0xFF;++p)
;
if (count)
*count = (size_t) (p - src);
return !*p;
}