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/* CC0 license (public domain) - see LICENSE file for details */
#include "config.h"
#include "hex.h"
#include <stdio.h>
#include <stdlib.h>
static bool char_to_hex(unsigned char *val, char c)
{
if (c >= '0' && c <= '9') {
*val = c - '0';
return true;
}
if (c >= 'a' && c <= 'f') {
*val = c - 'a' + 10;
return true;
}
if (c >= 'A' && c <= 'F') {
*val = c - 'A' + 10;
return true;
}
return false;
}
bool hex_decode(const char *str, size_t slen, void *buf, size_t bufsize)
{
unsigned char v1, v2;
unsigned char *p = buf;
while (slen > 1) {
if (!char_to_hex(&v1, str[0]) || !char_to_hex(&v2, str[1]))
return false;
if (!bufsize)
return false;
*(p++) = (v1 << 4) | v2;
str += 2;
slen -= 2;
bufsize--;
}
return slen == 0 && bufsize == 0;
}
static const char HEX_CHARS[] = "0123456789abcdef";
bool hex_encode(const void *buf, size_t bufsize, char *dest, size_t destsize)
{
size_t used = 0;
if (destsize < 1)
return false;
while (used < bufsize) {
unsigned int c = ((const unsigned char *)buf)[used];
if (destsize < 3)
return false;
*(dest++) = HEX_CHARS[(c >> 4) & 0xF];
*(dest++) = HEX_CHARS[c & 0xF];
used++;
destsize -= 2;
}
*dest = '\0';
return used + 1;
}
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