hexstrtobin.c

Go to the documentation of this file.

/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <ctype.h>
#include <lib.h>
 
size_t hexstrtobin(const char *str, uint8_t *buf, size_t len)
{
        size_t count, ptr = 0;
        uint8_t byte;
 
        for (byte = count = 0; str && *str; str++) {
                uint8_t c = *str;
 
                if (!isxdigit(c))
                        continue;
                if (isdigit(c))
                        c -= '0';
                else
                        c = tolower(c) - 'a' + 10;
 
                byte <<= 4;
                byte |= c;
 
                if (++count > 1) {
                        if (ptr >= len)
                                return ptr;
                        buf[ptr++] = byte;
                        byte = count = 0;
                }
        }
 
        return ptr;
}