common/isc/hex.c

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 2001 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <port_before.h>
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <isc/misc.h>
#include <port_after.h>

static const char hex[17] = "0123456789abcdef";

int
isc_gethexstring(unsigned char *buf, size_t len, int count, FILE *fp,
         int *multiline)
{
    int c, n;
    unsigned char x;
    char *s;
    int result = count;

    x = 0; /*%< silence compiler */
    n = 0;
    while (count > 0) {
        c = fgetc(fp);

        if ((c == EOF) ||
            (c == '\n' && !*multiline) ||
            (c == '(' && *multiline) ||
            (c == ')' && !*multiline))
            goto formerr;
        /* comment */
        if (c == ';') {
            do {
                c = fgetc(fp);
            } while (c != EOF && c != '\n');
            if (c == '\n' && *multiline)
                continue;
            goto formerr;
        }
        /* white space */
        if (c == ' ' || c == '\t' || c == '\n' || c == '\r')
            continue;
        /* multiline */
        if ('(' == c || c == ')') {
            *multiline = (c == '(' /*)*/);
            continue;
        }
        if ((s = strchr(hex, tolower(c))) == NULL)
            goto formerr;
        x = (x<<4) | (s - hex);
        if (++n == 2) {
            if (len > 0U) {
                *buf++ = x;
                len--;
            } else
                result = -1;
            count--;
            n = 0;
        }
    }
    return (result);

 formerr:
    if (c == '\n')
        ungetc(c, fp);
    return (-1);
}

void
isc_puthexstring(FILE *fp, const unsigned char *buf, size_t buflen,
         size_t len1, size_t len2, const char *sep)
{
    size_t i = 0;

    if (len1 < 4U)
        len1 = 4;
    if (len2 < 4U)
        len2 = 4;
    while (buflen > 0U) {
        fputc(hex[(buf[0]>>4)&0xf], fp);
        fputc(hex[buf[0]&0xf], fp);
        i += 2;
        buflen--;
        buf++;
        if (i >= len1 && sep != NULL) {
            fputs(sep, fp);
            i = 0;
            len1 = len2;
        }
    }
}

void
isc_tohex(const unsigned char *buf, size_t buflen, char *t) {
    while (buflen > 0U) {
        *t++ = hex[(buf[0]>>4)&0xf];
        *t++ = hex[buf[0]&0xf];
        buf++;
        buflen--;
    }
    *t = '\0';
}

/*! \file */