50 lines
876 B
C
50 lines
876 B
C
#include "hex.h"
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#include <errno.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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int hex_encode(const void *const b, char *hex, const size_t buflen,
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size_t hexlen)
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{
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const char *buf = b;
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for (size_t i = 0; i < buflen; i++)
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{
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const int r = snprintf(hex, hexlen, "%02hhx", *(const char *)buf++);
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if (r < 0 || r >= hexlen)
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return -1;
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hexlen -= r;
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hex += 2;
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}
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return 0;
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}
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int hex_decode(const char *const hex, void *const b, size_t n)
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{
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unsigned char *buf = b;
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for (const char *s = hex; *s; s += 2)
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{
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const char nibble[sizeof "00"] = {*s, *(s + 1)};
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if (!n)
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return -1;
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char *end;
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errno = 0;
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*buf++ = strtoul(nibble, &end, 16);
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if (errno || *end)
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return -1;
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n--;
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}
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return n ? -1 : 0;
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}
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