kolibrios-fun/programs/develop/libraries/base64/base64.c
Anton Krotov 40faa04f49 base64.obj: decoding algorithm skips spaces, newlines and tabs
git-svn-id: svn://kolibrios.org@9637 a494cfbc-eb01-0410-851d-a64ba20cac60
2022-01-15 05:31:50 +00:00

126 lines
2.1 KiB
C

#include "base64.h"
///===============
char base64_table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
///===============
char* strchr (const char *s, int c)
{
do {
if (*s == c)
{
return (char*)s;
}
} while (*s++);
return (0);
}
///===============
int base64_encode(char inp[], char outp[], int len)
{
int i, j;
unsigned char chr[3];
for (i = 0, j=-1; i < len; i+=3)
{
chr[0] = (unsigned char) inp[i];
if (i < len)
{
chr[1] = (unsigned char) inp[i+1];
chr[2] = (unsigned char) inp[i+2];
}
outp[++j] = base64_table[ chr[0]>>2 ];
outp[++j] = base64_table[ ((chr[0] & 3) << 4) | (chr[1] >> 4) ];
outp[++j] = base64_table[ ((chr[1] & 15) << 2) | (chr[2] >> 6) ];
outp[++j] = base64_table[ chr[2] & 63 ];
}
switch (len%3)
{
case 1:
outp[j-1] = outp[j] = '=';
break;
case 2:
outp[j] = '=';
break;
default:
break;
};
outp[j+1] = '\0';
return j+1;
}
///===============
int base64_decode(char inp[], char outp[], int len)
{
int i, j, k, n;
char *chr_adr;
char chr[4];
i = 0;
j = -1;
k = 0;
while (i < len)
{
for (n = 0; n <= 3; n++)
{
chr[n] = 0;
while ((inp[i] <= 0x20) & (i < len))
i++;
if (i < len)
{
if ((n >= 2) & (inp[i] == '='))
k++;
else
{
chr_adr = strchr(base64_table, inp[i]);
if (chr_adr)
chr[n] = chr_adr - base64_table;
}
i++;
}
}
outp[++j] = ((chr[0] << 2) | (chr[1] >> 4));
outp[++j] = ((chr[1] << 4) | (chr[2] >> 2));
outp[++j] = ((chr[2] & 0x03 )<< 6) | (chr[3] & 0x3f);
}
outp[j+1-k] = '\0';
return j+1-k;
}
///===============
#define NULL ((void*)0)
typedef struct
{
void *name;
void *function;
} export_t;
char szbase64_encode[]={"base64_encode"};
char szbase64_decode[]={"base64_decode"};
export_t EXPORTS[] =
{
{szbase64_encode, (void*) base64_encode},
{szbase64_decode, (void*) base64_decode},
{ NULL, NULL },
};
///===============