/*
 *  Extract VBA source code for component MS Office Documents
 *
 *  Copyright (C) 2013-2020 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 *  Copyright (C) 2007-2013 Sourcefire, Inc.
 *
 *  Authors: Trog, 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.
 */

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

#include <stdio.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <fcntl.h>
#include <stdlib.h>
#include <ctype.h>
#include <zlib.h>

#include "clamav.h"

#include "others.h"
#include "scanners.h"
#include "vba_extract.h"
#ifdef CL_DEBUG
#include "mbox.h"
#endif
#include "blob.h"
#ifdef HAVE_JSON
#include "json.h"
#endif

#define PPT_LZW_BUFFSIZE 8192
#define VBA_COMPRESSION_WINDOW 4096
#define MIDDLE_SIZE 20
#define MAX_VBA_COUNT 1000 /* If there's more than 1000 macros something's up! */

#ifndef HAVE_ATTRIB_PACKED
#define __attribute__(x)
#endif

/*
 * VBA (Visual Basic for Applications), versions 5 and 6
 */
struct vba56_header {
    unsigned char magic[2];
    unsigned char version[4];
    unsigned char ignore[28];
};

typedef struct {
    uint32_t sig;
    const char *ver;
    int big_endian; /* e.g. MAC Office */
} vba_version_t;

static int skip_past_nul(int fd);
static int read_uint16(int fd, uint16_t *u, int big_endian);
static int read_uint32(int fd, uint32_t *u, int big_endian);
static int seekandread(int fd, off_t offset, int whence, void *data, size_t len);
static vba_project_t *create_vba_project(int record_count, const char *dir, struct uniq *U);

static uint16_t
vba_endian_convert_16(uint16_t value, int big_endian)
{
    if (big_endian)
        return (uint16_t)be16_to_host(value);
    else
        return le16_to_host(value);
}

/* Seems to be a duplicate of riff_endian_convert_32() */
static uint32_t
vba_endian_convert_32(uint32_t value, int big_endian)
{
    if (big_endian)
        return be32_to_host(value);
    else
        return le32_to_host(value);
}

static char *
get_unicode_name(const char *name, int size, int big_endian)
{
    int i, increment;
    char *newname, *ret;

    if ((name == NULL) || (*name == '\0') || (size <= 0))
        return NULL;

    newname = (char *)cli_malloc(size * 7 + 1);
    if (newname == NULL) {
        cli_errmsg("get_unicode_name: Unable to allocate memory for newname\n");
        return NULL;
    }

    if ((!big_endian) && (size & 0x1)) {
        cli_dbgmsg("get_unicode_name: odd number of bytes %d\n", size);
        --size;
    }

    increment = (big_endian) ? 1 : 2;
    ret       = newname;

    for (i = 0; i < size; i += increment) {
        if ((!(name[i] & 0x80)) && isprint(name[i])) {
            *ret++ = tolower(name[i]);
        } else {
            if ((name[i] < 10) && (name[i] >= 0)) {
                *ret++ = '_';
                *ret++ = (char)(name[i] + '0');
            } else {
                uint16_t x;
                if ((i + 1) >= size)
                    break;
                x = (uint16_t)((name[i] < 0 ? 0 : name[i] << 8) | name[i + 1]);

                *ret++ = '_';
                *ret++ = (char)('a' + ((x & 0xF)));
                *ret++ = (char)('a' + ((x >> 4) & 0xF));
                *ret++ = (char)('a' + ((x >> 8) & 0xF));
                *ret++ = 'a';
                *ret++ = 'a';
            }
            *ret++ = '_';
        }
    }

    *ret = '\0';

    /* Saves a lot of memory */
    ret = cli_realloc(newname, (ret - newname) + 1);
    return ret ? ret : newname;
}

static void vba56_test_middle(int fd)
{
    char test_middle[MIDDLE_SIZE];

    /* MacOffice middle */
    static const uint8_t middle1_str[MIDDLE_SIZE] = {
        0x00, 0x01, 0x0d, 0x45, 0x2e, 0xe1, 0xe0, 0x8f, 0x10, 0x1a,
        0x85, 0x2e, 0x02, 0x60, 0x8c, 0x4d, 0x0b, 0xb4, 0x00, 0x00};
    /* MS Office middle */
    static const uint8_t middle2_str[MIDDLE_SIZE] = {
        0x00, 0x00, 0xe1, 0x2e, 0x45, 0x0d, 0x8f, 0xe0, 0x1a, 0x10,
        0x85, 0x2e, 0x02, 0x60, 0x8c, 0x4d, 0x0b, 0xb4, 0x00, 0x00};

    if (cli_readn(fd, &test_middle, MIDDLE_SIZE) != MIDDLE_SIZE)
        return;

    if ((memcmp(test_middle, middle1_str, MIDDLE_SIZE) != 0) &&
        (memcmp(test_middle, middle2_str, MIDDLE_SIZE) != 0)) {
        cli_dbgmsg("middle not found\n");
        if (lseek(fd, -MIDDLE_SIZE, SEEK_CUR) == -1) {
            cli_dbgmsg("vba_test_middle: call to lseek() failed\n");
            return;
        }
    } else
        cli_dbgmsg("middle found\n");
}

/* return count of valid strings found, 0 on error */
static int
vba_read_project_strings(int fd, int big_endian)
{
    unsigned char *buf = NULL;
    uint16_t buflen    = 0;
    uint16_t length    = 0;
    int ret = 0, getnewlength = 1;

    for (;;) {
        off_t offset;
        char *name;

        /* if no initial name length, exit */
        if (getnewlength && !read_uint16(fd, &length, big_endian)) {
            ret = 0;
            break;
        }
        getnewlength = 0;

        /* if too short, break */
        if (length < 6) {
            if (lseek(fd, -2, SEEK_CUR) == -1) {
                cli_dbgmsg("vba_read_project_strings: call to lseek() has failed\n");
                ret = 0;
            }
            break;
        }
        /* ensure buffer is large enough */
        if (length > buflen) {
            unsigned char *newbuf = (unsigned char *)cli_realloc(buf, length);
            if (newbuf == NULL) {
                ret = 0;
                break;
            }
            buflen = length;
            buf    = newbuf;
        }

        /* save current offset */
        offset = lseek(fd, 0, SEEK_CUR);
        if (offset == -1) {
            cli_dbgmsg("vba_read_project_strings: call to lseek() has failed\n");
            ret = 0;
            break;
        }

        /* if read name failed, break */
        if (cli_readn(fd, buf, (size_t)length) != (size_t)length) {
            cli_dbgmsg("read name failed - rewinding\n");
            if (lseek(fd, offset, SEEK_SET) == -1) {
                cli_dbgmsg("call to lseek() in read name failed\n");
                ret = 0;
            }
            break;
        }
        name = get_unicode_name((const char *)buf, length, big_endian);
        cli_dbgmsg("length: %d, name: %s\n", length, (name) ? name : "[null]");

        /* if invalid name, break */
        if ((name == NULL) || (memcmp("*\\", name, 2) != 0) ||
            (strchr("ghcd", name[2]) == NULL)) {
            /* Not a valid string, rewind */
            if (lseek(fd, -(length + 2), SEEK_CUR) == -1) {
                cli_dbgmsg("call to lseek() after get_unicode_name has failed\n");
                ret = 0;
            }
            free(name);
            break;
        }
        free(name);

        /* can't get length, break */
        if (!read_uint16(fd, &length, big_endian)) {
            break;
        }

        ret++;

        /* continue on reasonable length value */
        if ((length != 0) && (length != 65535)) {
            continue;
        }

        /* determine offset and run middle test */
        offset = lseek(fd, 10, SEEK_CUR);
        if (offset == -1) {
            cli_dbgmsg("call to lseek() has failed\n");
            ret = 0;
            break;
        }
        cli_dbgmsg("offset: %lu\n", (unsigned long)offset);
        vba56_test_middle(fd);
        getnewlength = 1;
    }

    free(buf);
    return ret;
}

vba_project_t *
cli_vba_readdir(const char *dir, struct uniq *U, uint32_t which)
{
    unsigned char *buf;
    const unsigned char vba56_signature[] = {0xcc, 0x61};
    uint16_t record_count, buflen, ffff, byte_count;
    uint32_t offset;
    int i, j, fd, big_endian = FALSE;
    vba_project_t *vba_project;
    struct vba56_header v56h;
    off_t seekback;
    char fullname[1024], *hash;
    uint32_t hashcnt = 0;

    cli_dbgmsg("in cli_vba_readdir()\n");

    if (dir == NULL)
        return NULL;

    /*
	 * _VBA_PROJECT files are embedded within office documents (OLE2)
	 */

    if (CL_SUCCESS != uniq_get(U, "_vba_project", 12, &hash, &hashcnt)) {
        cli_dbgmsg("vba_readdir: uniq_get('_vba_project') failed. Unable to check # of embedded vba proj files\n");
        return NULL;
    }
    if (hashcnt == 0) {
        return NULL;
    }
    snprintf(fullname, sizeof(fullname), "%s" PATHSEP "%s_%u", dir, hash, which);
    fullname[sizeof(fullname) - 1] = '\0';
    fd                             = open(fullname, O_RDONLY | O_BINARY);

    if (fd == -1)
        return NULL;

    if (cli_readn(fd, &v56h, sizeof(struct vba56_header)) != sizeof(struct vba56_header)) {
        close(fd);
        return NULL;
    }
    if (memcmp(v56h.magic, vba56_signature, sizeof(v56h.magic)) != 0) {
        close(fd);
        return NULL;
    }

    i = vba_read_project_strings(fd, TRUE);
    if ((seekback = lseek(fd, 0, SEEK_CUR)) == -1) {
        cli_dbgmsg("vba_readdir: lseek() failed. Unable to guess VBA type\n");
        close(fd);
        return NULL;
    }
    if (lseek(fd, sizeof(struct vba56_header), SEEK_SET) == -1) {
        cli_dbgmsg("vba_readdir: lseek() failed. Unable to guess VBA type\n");
        close(fd);
        return NULL;
    }
    j = vba_read_project_strings(fd, FALSE);
    if (!i && !j) {
        close(fd);
        cli_dbgmsg("vba_readdir: Unable to guess VBA type\n");
        return NULL;
    }
    if (i > j) {
        big_endian = TRUE;
        if (lseek(fd, seekback, SEEK_SET) == -1) {
            cli_dbgmsg("vba_readdir: call to lseek() while guessing big-endian has failed\n");
            close(fd);
            return NULL;
        }
        cli_dbgmsg("vba_readdir: Guessing big-endian\n");
    } else {
        cli_dbgmsg("vba_readdir: Guessing little-endian\n");
    }

    /* junk some more stuff */
    do
        if (cli_readn(fd, &ffff, 2) != 2) {
            close(fd);
            return NULL;
        }
    while (ffff != 0xFFFF);

    /* check for alignment error */
    if (!seekandread(fd, -3, SEEK_CUR, &ffff, sizeof(uint16_t))) {
        close(fd);
        return NULL;
    }
    if (ffff != 0xFFFF) {
        if (lseek(fd, 1, SEEK_CUR) == -1) {
            cli_dbgmsg("call to lseek() while checking alignment error has failed\n");
            close(fd);
            return NULL;
        }
    }

    if (!read_uint16(fd, &ffff, big_endian)) {
        close(fd);
        return NULL;
    }

    if (ffff != 0xFFFF) {
        if (lseek(fd, ffff, SEEK_CUR) == -1) {
            cli_dbgmsg("call to lseek() while checking alignment error has failed\n");
            close(fd);
            return NULL;
        }
    }

    if (!read_uint16(fd, &ffff, big_endian)) {
        close(fd);
        return NULL;
    }

    if (ffff == 0xFFFF)
        ffff = 0;

    if (lseek(fd, ffff + 100, SEEK_CUR) == -1) {
        cli_dbgmsg("call to lseek() failed\n");
        close(fd);
        return NULL;
    }

    if (!read_uint16(fd, &record_count, big_endian)) {
        close(fd);
        return NULL;
    }
    cli_dbgmsg("vba_readdir: VBA Record count %d\n", record_count);
    if (record_count == 0) {
        /* No macros, assume clean */
        close(fd);
        return NULL;
    }
    if (record_count > MAX_VBA_COUNT) {
        /* Almost certainly an error */
        cli_dbgmsg("vba_readdir: VBA Record count too big\n");
        close(fd);
        return NULL;
    }

    vba_project = create_vba_project(record_count, dir, U);
    if (vba_project == NULL) {
        close(fd);
        return NULL;
    }
    buf    = NULL;
    buflen = 0;
    for (i = 0; i < record_count; i++) {
        uint16_t length;
        char *ptr;

        vba_project->colls[i] = 0;
        if (!read_uint16(fd, &length, big_endian))
            break;

        if (length == 0) {
            cli_dbgmsg("vba_readdir: zero name length\n");
            break;
        }
        if (length > buflen) {
            unsigned char *newbuf = (unsigned char *)cli_realloc(buf, length);
            if (newbuf == NULL)
                break;
            buflen = length;
            buf    = newbuf;
        }
        if (cli_readn(fd, buf, (size_t)length) != (size_t)length) {
            cli_dbgmsg("vba_readdir: read name failed\n");
            break;
        }
        ptr = get_unicode_name((const char *)buf, length, big_endian);
        if (ptr == NULL) break;
        if (CL_SUCCESS != uniq_get(U, ptr, strlen(ptr), &hash, &hashcnt)) {
            cli_dbgmsg("vba_readdir: uniq_get('%s') failed.\n", ptr);
            free(ptr);
            break;
        }
        vba_project->colls[i] = hashcnt;
        if (0 == vba_project->colls[i]) {
            cli_dbgmsg("vba_readdir: cannot find project %s (%s)\n", ptr, hash);
            free(ptr);
            break;
        }
        cli_dbgmsg("vba_readdir: project name: %s (%s)\n", ptr, hash);
        free(ptr);
        vba_project->name[i] = hash;
        if (!read_uint16(fd, &length, big_endian))
            break;
        lseek(fd, length, SEEK_CUR);

        if (!read_uint16(fd, &ffff, big_endian))
            break;
        if (ffff == 0xFFFF) {
            lseek(fd, 2, SEEK_CUR);
            if (!read_uint16(fd, &ffff, big_endian))
                break;
            lseek(fd, ffff + 8, SEEK_CUR);
        } else
            lseek(fd, ffff + 10, SEEK_CUR);

        if (!read_uint16(fd, &byte_count, big_endian))
            break;
        lseek(fd, (8 * byte_count) + 5, SEEK_CUR);
        if (!read_uint32(fd, &offset, big_endian))
            break;
        cli_dbgmsg("vba_readdir: offset: %u\n", (unsigned int)offset);
        vba_project->offset[i] = offset;
        lseek(fd, 2, SEEK_CUR);
    }

    if (buf)
        free(buf);

    close(fd);

    if (i < record_count) {
        free(vba_project->name);
        free(vba_project->colls);
        free(vba_project->dir);
        free(vba_project->offset);
        free(vba_project);
        return NULL;
    }

    return vba_project;
}

unsigned char *
cli_vba_inflate(int fd, off_t offset, size_t *size)
{
    unsigned int pos, shift, mask, distance, clean;
    uint8_t flag;
    uint16_t token;
    blob *b;
    unsigned char buffer[VBA_COMPRESSION_WINDOW];

    if (fd < 0)
        return NULL;

    b = blobCreate();

    if (b == NULL)
        return NULL;

    memset(buffer, 0, sizeof(buffer));
    lseek(fd, offset + 3, SEEK_SET); /* 1byte ?? , 2byte length ?? */
    clean = TRUE;
    pos   = 0;

    while (cli_readn(fd, &flag, 1) == 1) {
        for (mask = 1; mask < 0x100; mask <<= 1) {
            unsigned int winpos = pos % VBA_COMPRESSION_WINDOW;
            if (flag & mask) {
                uint16_t len;
                unsigned int srcpos;

                if (!read_uint16(fd, &token, FALSE)) {
                    blobDestroy(b);
                    if (size)
                        *size = 0;
                    return NULL;
                }
                shift    = 12 - (winpos > 0x10) - (winpos > 0x20) - (winpos > 0x40) - (winpos > 0x80) - (winpos > 0x100) - (winpos > 0x200) - (winpos > 0x400) - (winpos > 0x800);
                len      = (uint16_t)((token & ((1 << shift) - 1)) + 3);
                distance = token >> shift;

                srcpos = pos - distance - 1;
                if ((((srcpos + len) % VBA_COMPRESSION_WINDOW) < winpos) &&
                    ((winpos + len) < VBA_COMPRESSION_WINDOW) &&
                    (((srcpos % VBA_COMPRESSION_WINDOW) + len) < VBA_COMPRESSION_WINDOW) &&
                    (len <= VBA_COMPRESSION_WINDOW)) {
                    srcpos %= VBA_COMPRESSION_WINDOW;
                    memcpy(&buffer[winpos], &buffer[srcpos],
                           len);
                    pos += len;
                } else
                    while (len-- > 0) {
                        srcpos                                 = (pos - distance - 1) % VBA_COMPRESSION_WINDOW;
                        buffer[pos++ % VBA_COMPRESSION_WINDOW] = buffer[srcpos];
                    }
            } else {
                if ((pos != 0) && (winpos == 0) && clean) {
                    if (cli_readn(fd, &token, 2) != 2) {
                        blobDestroy(b);
                        if (size)
                            *size = 0;
                        return NULL;
                    }
                    (void)blobAddData(b, buffer, VBA_COMPRESSION_WINDOW);
                    clean = FALSE;
                    break;
                }
                if (cli_readn(fd, &buffer[winpos], 1) == 1)
                    pos++;
            }
            clean = TRUE;
        }
    }

    if (blobAddData(b, buffer, pos % VBA_COMPRESSION_WINDOW) < 0) {
        blobDestroy(b);
        if (size)
            *size = 0;
        return NULL;
    }

    if (size)
        *size = blobGetDataSize(b);
    return (unsigned char *)blobToMem(b);
}

/*
 * See also cli_filecopy()
 */
static void
ole_copy_file_data(int s, int d, uint32_t len)
{
    unsigned char data[FILEBUFF];

    while (len > 0) {
        size_t todo = MIN(sizeof(data), len);

        if (cli_readn(s, data, todo) != todo)
            break;
        if (cli_writen(d, data, todo) != todo)
            break;

        if (todo > len) {
            break;
        } else {
            len -= todo;
        }
    }
}

int cli_scan_ole10(int fd, cli_ctx *ctx)
{
    int ofd, ret;
    uint32_t object_size;
    STATBUF statbuf;
    char *fullname;

    if (fd < 0)
        return CL_CLEAN;

    lseek(fd, 0, SEEK_SET);
    if (!read_uint32(fd, &object_size, FALSE))
        return CL_CLEAN;

    if (FSTAT(fd, &statbuf) == -1)
        return CL_ESTAT;

    if ((statbuf.st_size - object_size) >= 4) {
        /* Probably the OLE type id */
        if (lseek(fd, 2, SEEK_CUR) == -1) {
            return CL_CLEAN;
        }

        /* Attachment name */
        if (!skip_past_nul(fd))
            return CL_CLEAN;

        /* Attachment full path */
        if (!skip_past_nul(fd))
            return CL_CLEAN;

        /* ??? */
        if (lseek(fd, 8, SEEK_CUR) == -1)
            return CL_CLEAN;

        /* Attachment full path */
        if (!skip_past_nul(fd))
            return CL_CLEAN;

        if (!read_uint32(fd, &object_size, FALSE))
            return CL_CLEAN;
    }
    if (!(fullname = cli_gentemp(ctx ? ctx->engine->tmpdir : NULL))) {
        return CL_EMEM;
    }
    ofd = open(fullname, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_EXCL,
               S_IWUSR | S_IRUSR);
    if (ofd < 0) {
        cli_warnmsg("cli_decode_ole_object: can't create %s\n", fullname);
        free(fullname);
        return CL_ECREAT;
    }
    cli_dbgmsg("cli_decode_ole_object: decoding to %s\n", fullname);
    ole_copy_file_data(fd, ofd, object_size);
    lseek(ofd, 0, SEEK_SET);
    ret = cli_magic_scandesc(ofd, fullname, ctx);
    close(ofd);
    if (ctx && !ctx->engine->keeptmp)
        if (cli_unlink(fullname))
            ret = CL_EUNLINK;
    free(fullname);
    return ret;
}

/*
 * Powerpoint files
 */
typedef struct {
    uint16_t type;
    uint32_t length;
} atom_header_t;

static int
ppt_read_atom_header(int fd, atom_header_t *atom_header)
{
    uint16_t v;
    struct ppt_header {
        uint16_t ver;
        uint16_t type;
        uint32_t length;
    } h;

    cli_dbgmsg("in ppt_read_atom_header\n");
    if (cli_readn(fd, &h, sizeof(struct ppt_header)) != sizeof(struct ppt_header)) {
        cli_dbgmsg("read ppt_header failed\n");
        return FALSE;
    }
    v = vba_endian_convert_16(h.ver, FALSE);
    cli_dbgmsg("\tversion: 0x%.2x\n", v & 0xF);
    cli_dbgmsg("\tinstance: 0x%.2x\n", v >> 4);

    atom_header->type = vba_endian_convert_16(h.type, FALSE);
    cli_dbgmsg("\ttype: 0x%.4x\n", atom_header->type);
    atom_header->length = vba_endian_convert_32(h.length, FALSE);
    cli_dbgmsg("\tlength: 0x%.8x\n", (int)atom_header->length);

    return TRUE;
}

/*
 * TODO: combine shared code with flatedecode() or cli_unzip_single()
 *	Needs cli_unzip_single to have a "length" argument
 */
static int
ppt_unlzw(const char *dir, int fd, uint32_t length)
{
    int ofd;
    z_stream stream;
    unsigned char inbuff[PPT_LZW_BUFFSIZE], outbuff[PPT_LZW_BUFFSIZE];
    char fullname[NAME_MAX + 1];

    snprintf(fullname, sizeof(fullname) - 1, "%s" PATHSEP "ppt%.8lx.doc",
             dir, (long)lseek(fd, 0L, SEEK_CUR));

    ofd = open(fullname, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_EXCL,
               S_IWUSR | S_IRUSR);
    if (ofd == -1) {
        cli_warnmsg("ppt_unlzw: can't create %s\n", fullname);
        return FALSE;
    }

    stream.zalloc    = Z_NULL;
    stream.zfree     = Z_NULL;
    stream.opaque    = (void *)NULL;
    stream.next_in   = (Bytef *)inbuff;
    stream.next_out  = outbuff;
    stream.avail_out = sizeof(outbuff);
    stream.avail_in  = MIN(length, PPT_LZW_BUFFSIZE);

    if (cli_readn(fd, inbuff, (size_t)stream.avail_in) != (size_t)stream.avail_in) {
        close(ofd);
        cli_unlink(fullname);
        return FALSE;
    }
    length -= stream.avail_in;

    if (inflateInit(&stream) != Z_OK) {
        close(ofd);
        cli_unlink(fullname);
        cli_warnmsg("ppt_unlzw: inflateInit failed\n");
        return FALSE;
    }

    do {
        if (stream.avail_out == 0) {
            if (cli_writen(ofd, outbuff, PPT_LZW_BUFFSIZE) != PPT_LZW_BUFFSIZE) {
                close(ofd);
                inflateEnd(&stream);
                return FALSE;
            }
            stream.next_out  = outbuff;
            stream.avail_out = PPT_LZW_BUFFSIZE;
        }
        if (stream.avail_in == 0) {
            stream.next_in  = inbuff;
            stream.avail_in = MIN(length, PPT_LZW_BUFFSIZE);
            if (cli_readn(fd, inbuff, (size_t)stream.avail_in) != (size_t)stream.avail_in) {
                close(ofd);
                inflateEnd(&stream);
                return FALSE;
            }
            length -= stream.avail_in;
        }
    } while (inflate(&stream, Z_NO_FLUSH) == Z_OK);

    if (cli_writen(ofd, outbuff, PPT_LZW_BUFFSIZE - stream.avail_out) != (size_t)(PPT_LZW_BUFFSIZE - stream.avail_out)) {
        close(ofd);
        inflateEnd(&stream);
        return FALSE;
    }
    close(ofd);
    return inflateEnd(&stream) == Z_OK;
}

static const char *
ppt_stream_iter(int fd, const char *dir)
{
    atom_header_t atom_header;

    while (ppt_read_atom_header(fd, &atom_header)) {
        if (atom_header.length == 0)
            return NULL;

        if (atom_header.type == 0x1011) {
            uint32_t length;

            /* Skip over ID */
            if (lseek(fd, sizeof(uint32_t), SEEK_CUR) == -1) {
                cli_dbgmsg("ppt_stream_iter: seek failed\n");
                return NULL;
            }
            length = atom_header.length - 4;
            cli_dbgmsg("length: %d\n", (int)length);
            if (!ppt_unlzw(dir, fd, length)) {
                cli_dbgmsg("ppt_unlzw failed\n");
                return NULL;
            }
        } else {
            off_t offset = lseek(fd, 0, SEEK_CUR);
            /* Check we don't wrap */
            if ((offset + (off_t)atom_header.length) < offset) {
                break;
            }
            offset += atom_header.length;
            if (lseek(fd, offset, SEEK_SET) != offset) {
                break;
            }
        }
    }
    return dir;
}

char *
cli_ppt_vba_read(int ifd, cli_ctx *ctx)
{
    char *dir;
    const char *ret;

    /* Create a directory to store the extracted OLE2 objects */
    dir = cli_gentemp(ctx ? ctx->engine->tmpdir : NULL);
    if (dir == NULL)
        return NULL;
    if (mkdir(dir, 0700)) {
        cli_errmsg("cli_ppt_vba_read: Can't create temporary directory %s\n", dir);
        free(dir);
        return NULL;
    }
    ret = ppt_stream_iter(ifd, dir);
    if (ret == NULL) {
        cli_rmdirs(dir);
        free(dir);
        return NULL;
    }
    return dir;
}

/*
 * Word 6 macros
 */
typedef struct {
    unsigned char unused[12];
    uint32_t macro_offset;
    uint32_t macro_len;
} mso_fib_t;

typedef struct macro_entry_tag {
    uint32_t len;
    uint32_t offset;
    unsigned char key;
} macro_entry_t;

typedef struct macro_info_tag {
    struct macro_entry_tag *entries;
    uint16_t count;
} macro_info_t;

static int
word_read_fib(int fd, mso_fib_t *fib)
{
    struct {
        uint32_t offset;
        uint32_t len;
    } macro_details;

    if (!seekandread(fd, 0x118, SEEK_SET, &macro_details, sizeof(macro_details))) {
        cli_dbgmsg("read word_fib failed\n");
        return FALSE;
    }
    fib->macro_offset = vba_endian_convert_32(macro_details.offset, FALSE);
    fib->macro_len    = vba_endian_convert_32(macro_details.len, FALSE);

    return TRUE;
}

static int
word_read_macro_entry(int fd, macro_info_t *macro_info)
{
    size_t msize;
    uint16_t count = macro_info->count;
    macro_entry_t *macro_entry;
#ifdef HAVE_PRAGMA_PACK
#pragma pack(1)
#endif

#ifdef HAVE_PRAGMA_PACK_HPPA
#pragma pack 1
#endif
    struct macro {
        unsigned char version;
        unsigned char key;
        unsigned char ignore[10];
        uint32_t len __attribute__((packed));
        uint32_t state __attribute__((packed));
        uint32_t offset __attribute__((packed));
    } * m;
    const struct macro *n;
#ifdef HAVE_PRAGMA_PACK
#pragma pack()
#endif

#ifdef HAVE_PRAGMA_PACK_HPPA
#pragma pack
#endif
    if (count == 0)
        return TRUE;

    msize = count * sizeof(struct macro);
    m     = cli_malloc(msize);
    if (m == NULL) {
        cli_errmsg("word_read_macro_entry: Unable to allocate memory for 'm'\n");
        return FALSE;
    }

    if (cli_readn(fd, m, msize) != msize) {
        free(m);
        cli_warnmsg("read %u macro_entries failed\n", count);
        return FALSE;
    }
    macro_entry = macro_info->entries;
    n           = m;
    do {
        macro_entry->key    = n->key;
        macro_entry->len    = vba_endian_convert_32(n->len, FALSE);
        macro_entry->offset = vba_endian_convert_32(n->offset, FALSE);
        macro_entry++;
        n++;
    } while (--count > 0);
    free(m);
    return TRUE;
}

static macro_info_t *
word_read_macro_info(int fd, macro_info_t *macro_info)
{
    if (!read_uint16(fd, &macro_info->count, FALSE)) {
        cli_dbgmsg("read macro_info failed\n");
        macro_info->count = 0;
        return NULL;
    }
    cli_dbgmsg("macro count: %d\n", macro_info->count);
    if (macro_info->count == 0)
        return NULL;
    macro_info->entries = (macro_entry_t *)cli_malloc(sizeof(macro_entry_t) * macro_info->count);
    if (macro_info->entries == NULL) {
        macro_info->count = 0;
        cli_errmsg("word_read_macro_info: Unable to allocate memory for macro_info->entries\n");
        return NULL;
    }
    if (!word_read_macro_entry(fd, macro_info)) {
        free(macro_info->entries);
        macro_info->count = 0;
        return NULL;
    }
    return macro_info;
}

static int
word_skip_oxo3(int fd)
{
    uint8_t count;

    if (cli_readn(fd, &count, 1) != 1) {
        cli_dbgmsg("read oxo3 record1 failed\n");
        return FALSE;
    }
    cli_dbgmsg("oxo3 records1: %d\n", count);

    if (!seekandread(fd, count * 14, SEEK_CUR, &count, 1)) {
        cli_dbgmsg("read oxo3 record2 failed\n");
        return FALSE;
    }

    if (count == 0) {
        uint8_t twobytes[2];

        if (cli_readn(fd, twobytes, 2) != 2) {
            cli_dbgmsg("read oxo3 failed\n");
            return FALSE;
        }
        if (twobytes[0] != 2) {
            lseek(fd, -2, SEEK_CUR);
            return TRUE;
        }
        count = twobytes[1];
    }
    if (count > 0)
        if (lseek(fd, (count * 4) + 1, SEEK_CUR) == -1) {
            cli_dbgmsg("lseek oxo3 failed\n");
            return FALSE;
        }

    cli_dbgmsg("oxo3 records2: %d\n", count);
    return TRUE;
}

static int
word_skip_menu_info(int fd)
{
    uint16_t count;

    if (!read_uint16(fd, &count, FALSE)) {
        cli_dbgmsg("read menu_info failed\n");
        return FALSE;
    }
    cli_dbgmsg("menu_info count: %d\n", count);

    if (count)
        if (lseek(fd, count * 12, SEEK_CUR) == -1)
            return FALSE;
    return TRUE;
}

static int
word_skip_macro_extnames(int fd)
{
    int is_unicode, nbytes;
    int16_t size;

    if (!read_uint16(fd, (uint16_t *)&size, FALSE)) {
        cli_dbgmsg("read macro_extnames failed\n");
        return FALSE;
    }
    if (size == -1) { /* Unicode flag */
        if (!read_uint16(fd, (uint16_t *)&size, FALSE)) {
            cli_dbgmsg("read macro_extnames failed\n");
            return FALSE;
        }
        is_unicode = 1;
    } else
        is_unicode = 0;

    cli_dbgmsg("ext names size: 0x%x\n", size);

    nbytes = size;
    while (nbytes > 0) {
        uint8_t length;
        off_t offset;

        if (cli_readn(fd, &length, 1) != 1) {
            cli_dbgmsg("read macro_extnames failed\n");
            return FALSE;
        }

        if (is_unicode)
            offset = (off_t)length * 2 + 1;
        else
            offset = (off_t)length;

        /* ignore numref as well */
        if (lseek(fd, offset + sizeof(uint16_t), SEEK_CUR) == -1) {
            cli_dbgmsg("read macro_extnames failed to seek\n");
            return FALSE;
        }
        nbytes -= size;
    }
    return TRUE;
}

static int
word_skip_macro_intnames(int fd)
{
    uint16_t count;

    if (!read_uint16(fd, &count, FALSE)) {
        cli_dbgmsg("read macro_intnames failed\n");
        return FALSE;
    }
    cli_dbgmsg("intnames count: %u\n", (unsigned int)count);

    while (count-- > 0) {
        uint8_t length;

        /* id */
        if (!seekandread(fd, sizeof(uint16_t), SEEK_CUR, &length, sizeof(uint8_t))) {
            cli_dbgmsg("skip_macro_intnames failed\n");
            return FALSE;
        }

        /* Internal name, plus one byte of unknown data */
        if (lseek(fd, length + 1, SEEK_CUR) == -1) {
            cli_dbgmsg("skip_macro_intnames failed\n");
            return FALSE;
        }
    }
    return TRUE;
}

vba_project_t *
cli_wm_readdir(int fd)
{
    int done;
    off_t end_offset;
    unsigned char info_id;
    macro_info_t macro_info;
    vba_project_t *vba_project;
    mso_fib_t fib;

    if (!word_read_fib(fd, &fib))
        return NULL;

    if (fib.macro_len == 0) {
        cli_dbgmsg("wm_readdir: No macros detected\n");
        /* Must be clean */
        return NULL;
    }
    cli_dbgmsg("wm_readdir: macro offset: 0x%.4x\n", (int)fib.macro_offset);
    cli_dbgmsg("wm_readdir: macro len: 0x%.4x\n\n", (int)fib.macro_len);

    /* Go one past the start to ignore start_id */
    if (lseek(fd, fib.macro_offset + 1, SEEK_SET) != (off_t)(fib.macro_offset + 1)) {
        cli_dbgmsg("wm_readdir: lseek macro_offset failed\n");
        return NULL;
    }

    end_offset         = fib.macro_offset + fib.macro_len;
    done               = FALSE;
    macro_info.entries = NULL;
    macro_info.count   = 0;

    while ((lseek(fd, 0, SEEK_CUR) < end_offset) && !done) {
        if (cli_readn(fd, &info_id, 1) != 1) {
            cli_dbgmsg("wm_readdir: read macro_info failed\n");
            break;
        }
        switch (info_id) {
            case 0x01:
                if (macro_info.count)
                    free(macro_info.entries);
                word_read_macro_info(fd, &macro_info);
                done = TRUE;
                break;
            case 0x03:
                if (!word_skip_oxo3(fd))
                    done = TRUE;
                break;
            case 0x05:
                if (!word_skip_menu_info(fd))
                    done = TRUE;
                break;
            case 0x10:
                if (!word_skip_macro_extnames(fd))
                    done = TRUE;
                break;
            case 0x11:
                if (!word_skip_macro_intnames(fd))
                    done = TRUE;
                break;
            case 0x40: /* end marker */
            case 0x12: /* ??? */
                done = TRUE;
                break;
            default:
                cli_dbgmsg("wm_readdir: unknown type: 0x%x\n", info_id);
                done = TRUE;
        }
    }

    if (macro_info.count == 0)
        return NULL;

    vba_project = create_vba_project(macro_info.count, "", NULL);

    if (vba_project) {
        vba_project->length = (uint32_t *)cli_malloc(sizeof(uint32_t) *
                                                     macro_info.count);
        vba_project->key    = (unsigned char *)cli_malloc(sizeof(unsigned char) *
                                                       macro_info.count);
        if ((vba_project->length != NULL) &&
            (vba_project->key != NULL)) {
            int i;
            const macro_entry_t *m = macro_info.entries;

            for (i = 0; i < macro_info.count; i++) {
                vba_project->offset[i] = m->offset;
                vba_project->length[i] = m->len;
                vba_project->key[i]    = m->key;
                m++;
            }
        } else {
            cli_errmsg("cli_wm_readdir: Unable to allocate memory for vba_project\n");
            free(vba_project->name);
            free(vba_project->colls);
            free(vba_project->dir);
            free(vba_project->offset);
            if (vba_project->length)
                free(vba_project->length);
            if (vba_project->key)
                free(vba_project->key);
            free(vba_project);
            vba_project = NULL;
        }
    }
    free(macro_info.entries);

    return vba_project;
}

unsigned char *
cli_wm_decrypt_macro(int fd, off_t offset, uint32_t len, unsigned char key)
{
    unsigned char *buff;

    if (len == 0)
        return NULL;

    if (fd < 0)
        return NULL;

    buff = (unsigned char *)cli_malloc(len);
    if (buff == NULL) {
        cli_errmsg("cli_wm_decrypt_macro: Unable to allocate memory for buff\n");
        return NULL;
    }

    if (!seekandread(fd, offset, SEEK_SET, buff, len)) {
        free(buff);
        return NULL;
    }
    if (key) {
        unsigned char *p;

        for (p = buff; p < &buff[len]; p++)
            *p ^= key;
    }
    return buff;
}

/*
 * Keep reading bytes until we reach a NUL. Returns 0 if none is found
 */
static int
skip_past_nul(int fd)
{
    char *end;
    char smallbuf[128];

    do {
        size_t nread = cli_readn(fd, smallbuf, sizeof(smallbuf));
        if ((nread == 0) || (nread == (size_t)-1))
            return FALSE;
        end = memchr(smallbuf, '\0', nread);
        if (end) {
            if (lseek(fd, 1 + (end - smallbuf) - (off_t)nread, SEEK_CUR) < 0)
                return FALSE;
            return TRUE;
        }
    } while (1);
}

/*
 * Read 2 bytes as a 16-bit number, host byte order. Return success or fail
 */
static int
read_uint16(int fd, uint16_t *u, int big_endian)
{
    if (cli_readn(fd, u, sizeof(uint16_t)) != sizeof(uint16_t))
        return FALSE;

    *u = vba_endian_convert_16(*u, big_endian);

    return TRUE;
}

/*
 * Read 4 bytes as a 32-bit number, host byte order. Return success or fail
 */
static int
read_uint32(int fd, uint32_t *u, int big_endian)
{
    if (cli_readn(fd, u, sizeof(uint32_t)) != sizeof(uint32_t))
        return FALSE;

    *u = vba_endian_convert_32(*u, big_endian);

    return TRUE;
}

/*
 * Miss some bytes then read a bit
 */
static int
seekandread(int fd, off_t offset, int whence, void *data, size_t len)
{
    if (lseek(fd, offset, whence) == (off_t)-1) {
        cli_dbgmsg("lseek failed\n");
        return FALSE;
    }
    return cli_readn(fd, data, len) == len;
}

/*
 * Create and initialise a vba_project structure
 */
static vba_project_t *
create_vba_project(int record_count, const char *dir, struct uniq *U)
{
    vba_project_t *ret;

    ret = (vba_project_t *)cli_calloc(1, sizeof(struct vba_project_tag));

    if (ret == NULL) {
        cli_errmsg("create_vba_project: Unable to allocate memory for vba project structure\n");
        return NULL;
    }

    ret->name   = (char **)cli_malloc(sizeof(char *) * record_count);
    ret->colls  = (uint32_t *)cli_malloc(sizeof(uint32_t) * record_count);
    ret->dir    = cli_strdup(dir);
    ret->offset = (uint32_t *)cli_malloc(sizeof(uint32_t) * record_count);

    if ((ret->colls == NULL) || (ret->name == NULL) || (ret->dir == NULL) || (ret->offset == NULL)) {
        cli_free_vba_project(ret);
        cli_errmsg("create_vba_project: Unable to allocate memory for vba project elements\n");
        return NULL;
    }
    ret->count = record_count;
    ret->U     = U;

    return ret;
}

/**
 * @brief Free up the memory associated with the vba_project_t type.
 *
 * @param project A vba_project_t type allocated by one of these:
 *  - create_vba_project()
 *  - cli_wm_readdir()
 *  - cli_vba_readdir()
 */
void cli_free_vba_project(vba_project_t *vba_project)
{
    if (vba_project) {
        if (vba_project->dir)
            free(vba_project->dir);
        if (vba_project->colls)
            free(vba_project->colls);
        if (vba_project->name)
            free(vba_project->name);
        if (vba_project->offset)
            free(vba_project->offset);
        if (vba_project->length)
            free(vba_project->length);
        if (vba_project->key)
            free(vba_project->key);
        free(vba_project);
    }

    return;
}