hex.c

这是一个完全开放的

/*
 * jabberd - Jabber Open Source Server
 * Copyright (c) 2002-2003 Jeremie Miller, Thomas Muldowney,
 *                         Ryan Eatmon, Robert Norris
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA02111-1307USA
 */

/* simple hex conversion functions */

/** turn raw into hex - out must be (inlen*2)+1 */
void hex_from_raw(char *in, int inlen, char *out) {
    int i, h, l;

    for(i = 0; i < inlen; i++) {
        h = in[i] & 0xf0;
        h >>= 4;
        l = in[i] & 0x0f;
        out[i * 2] = (h >= 0x0 && h <= 0x9) ? (h + 0x30) : (h + 0x57);
        out[i * 2 + 1] = (l >= 0x0 && l <= 0x9) ? (l + 0x30) : (l + 0x57);
    }
    out[i * 2] = '\0';
}

/** turn hex into raw - out must be (inlen/2) */
int hex_to_raw(char *in, int inlen, char *out) {
    int i, o, h, l;

    /* need +ve even input */
    if(inlen == 0 || (inlen / 2 * 2) != inlen)
        return 1;

    for(i = o = 0; i < inlen; i += 2, o++) {
        h = (in[i] >= 0x30 && in[i] <= 0x39) ? (in[i] - 0x30) : (in[i] >= 0x41 && in[i] <= 0x64) ? (in[i] - 0x36) : (in[i] >= 0x61 && in[i] <= 0x66) ? (in[i] - 0x56) : -1;
        l = (in[i + 1] >= 0x30 && in[i + 1] <= 0x39) ? (in[i + 1] - 0x30) : (in[i + 1] >= 0x41 && in[i + 1] <= 0x64) ? (in[i + 1] - 0x36) : (in[i + 1] >= 0x61 && in[i + 1] <= 0x66) ? (in[i + 1] - 0x56) : -1;

        if(h < 0 || l < 0)
            return 1;

        out[o] = (h << 4) + l;
    }

    return 0;
}