denyhosts/clamscan/libclamav/uuencode.c

/*
 *  Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 *  Copyright (C) 2007-2013 Sourcefire, Inc.
 *
 *  Authors: Nigel Horne
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  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., 51 Franklin Street, Fifth Floor, Boston,
 *  MA 02110-1301, USA.
 */

#include "clamav.h"

#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <stdio.h>
#include <memory.h>
#include <sys/stat.h>
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif

#include "others.h"
#include "str.h"

#include "mbox.h"
#include "uuencode.h"

/* Maximum line length according to RFC821 */
#define RFC2821LENGTH 1000

int cli_uuencode(const char *dir, fmap_t *map)
{
    message *m;
    char buffer[RFC2821LENGTH + 1];
    size_t at = 0;

    if (!fmap_gets(map, buffer, &at, sizeof(buffer) - 1)) {
        /* empty message */
        return CL_CLEAN;
    }
    if (!isuuencodebegin(buffer)) {
        cli_dbgmsg("Message is not in uuencoded format\n");
        return CL_EFORMAT;
    }

    m = messageCreate();
    if (m == NULL) {
        return CL_EMEM;
    }

    cli_dbgmsg("found uuencode file\n");

    if (uudecodeFile(m, buffer, dir, map, &at) < 0) {
        messageDestroy(m);
        cli_dbgmsg("Message is not in uuencoded format\n");
        return CL_EFORMAT;
    }
    messageDestroy(m);

    return CL_CLEAN; /* a lie - but it gets things going */
}

/*
 * Save the uuencoded part of the file as it is read in since there's no need
 * to include it in the parse tree. Saves memory and parse time.
 * Return < 0 for failure
 */
int uudecodeFile(message *m, const char *firstline, const char *dir, fmap_t *map, size_t *at)
{
    fileblob *fb;
    char buffer[RFC2821LENGTH + 1];
    char *filename = cli_strtok(firstline, 2, " ");

    if (filename == NULL)
        return -1;

    fb = fileblobCreate();
    if (fb == NULL) {
        free(filename);
        return -1;
    }

    fileblobSetFilename(fb, dir, filename);
    cli_dbgmsg("uudecode %s\n", filename);
    free(filename);

    while (fmap_gets(map, buffer, at, sizeof(buffer) - 1)) {
        unsigned char data[1024];
        const unsigned char *uptr;
        size_t len;

        cli_chomp(buffer);
        if (strcasecmp(buffer, "end") == 0)
            break;
        if (buffer[0] == '\0')
            break;

        uptr = decodeLine(m, UUENCODE, buffer, data, sizeof(data));
        if (uptr == NULL)
            break;

        len = (size_t)(uptr - data);
        if ((len > 62) || (len == 0))
            break;

        if (fileblobAddData(fb, data, len) < 0)
            break;
    }

    fileblobDestroy(fb);

    return 1;
}