int base64_binlength(char* str, uint8_t strict){
int l=0;
uint8_t term=0;
for(;;){
if(*str=='\0')
break;
if(*str=='\n' || *str=='\r'){
str++;
continue;
}
if(*str=='='){
term++;
str++;
if(term==2){
break;
}
continue;
}
if(term)
return -1;
if(ascii2bit6(*str)==-1){
if(strict)
return -1;
} else {
l++;
}
str++;
}
switch(term){
case 0:
if(l%4!=0)
return -1;
return l/4*3;
case 1:
if(l%4!=3)
return -1;
return (l+1)/4*3-1;
case 2:
if(l%4!=2)
return -1;
return (l+2)/4*3-2;
default:
return -1;
}
}
int base64dec(void *dest, const char *b64str, uint8_t strict){
uint8_t buffer[4];
uint8_t idx=0;
uint8_t term=0;
for(;;){
// cli_putstr_P(PSTR("\r\n DBG: got 0x"));
// cli_hexdump(b64str, 1);
buffer[idx]= ascii2bit6(*b64str);
// cli_putstr_P(PSTR(" --> 0x"));
// cli_hexdump(buffer+idx, 1);
if(buffer[idx]==0xFF){
if(*b64str=='='){
term++;
b64str++;
if(term==2)
goto finalize; /* definitly the end */
}else{
if(*b64str == '\0'){
goto finalize; /* definitly the end */
}else{
if(*b64str == '\r' || *b64str == '\n' || !(strict)){
b64str++; /* charcters that we simply ignore */
}else{
return -1;
}
}
}
}else{
if(term)
return -1; /* this happens if we get a '=' in the stream */
idx++;
b64str++;
}
if(idx==4){
((uint8_t*)dest)[0] = buffer[0]<<2 | buffer[1]>>4;
((uint8_t*)dest)[1] = buffer[1]<<4 | buffer[2]>>2;
((uint8_t*)dest)[2] = buffer[2]<<6 | buffer[3];
dest = (uint8_t*)dest +3;
idx=0;
}
}
