clamav/libclamav/autoit.c

/*
 *  Copyright (C) 2013-2020 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 *  Copyright (C) 2007-2013 Sourcefire, Inc.
 *
 *  Authors: Alberto Wu
 *
 *  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 <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>

#if HAVE_STRING_H
#include <string.h>
#endif

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

#include "clamav.h"
#include "others.h"
#include "scanners.h"
#include "autoit.h"
#include "fmap.h"
#include "fpu.h"

static int fpu_words = FPU_ENDIAN_INITME;

/* FIXME: use unicode detection and normalization from edwin */
static unsigned int u2a(uint8_t *dest, unsigned int len)
{
    uint8_t *src = dest;
    unsigned int i, j;

    if (len < 2)
        return len;

    if (len > 4 && src[0] == 0xff && src[1] == 0xfe && src[2]) {
        len -= 2;
        src += 2;
    } else {
        unsigned int cnt = 0;
        j                = (len > 20) ? 20 : (len & ~1);

        for (i = 0; i < j; i += 2)
            cnt += (src[i] != 0 && src[i + 1] == 0);

        if (cnt * 4 < j)
            return len;
    }

    j = len;
    len >>= 1;
    for (i = 0; i < j; i += 2)
        *dest++ = src[i];

    return len;
}

/*********************
   MT realted stuff
*********************/

struct MT {
    uint32_t *next;
    uint32_t items;
    uint32_t mt[624];
};

static uint8_t MT_getnext(struct MT *MT)
{
    uint32_t r;

    if (!--MT->items) {
        uint32_t *mt = MT->mt;
        unsigned int i;

        MT->items = 624;
        MT->next  = mt;

        for (i = 0; i < 227; i++)
            mt[i] = ((((mt[i] ^ mt[i + 1]) & 0x7ffffffe) ^ mt[i]) >> 1) ^ ((0 - (mt[i + 1] & 1)) & 0x9908b0df) ^ mt[i + 397];
        for (; i < 623; i++)
            mt[i] = ((((mt[i] ^ mt[i + 1]) & 0x7ffffffe) ^ mt[i]) >> 1) ^ ((0 - (mt[i + 1] & 1)) & 0x9908b0df) ^ mt[i - 227];
        mt[623] = ((((mt[623] ^ mt[0]) & 0x7ffffffe) ^ mt[623]) >> 1) ^ ((0 - (mt[0] & 1)) & 0x9908b0df) ^ mt[i - 227];
    }

    r = *(MT->next++);
    r ^= (r >> 11);
    r ^= ((r & 0xff3a58ad) << 7);
    r ^= ((r & 0xffffdf8c) << 15);
    r ^= (r >> 18);
    return (uint8_t)(r >> 1);
}

static void MT_decrypt(uint8_t *buf, unsigned int size, uint32_t seed)
{
    struct MT MT;
    unsigned int i;
    uint32_t *mt = MT.mt;

    *mt = seed;
    for (i = 1; i < 624; i++)
        mt[i] = i + 0x6c078965 * ((mt[i - 1] >> 30) ^ mt[i - 1]);
    MT.items = 1;
    MT.next  = MT.mt;

    while (size--)
        *buf++ ^= MT_getnext(&MT);
}

/*********************
     inflate stuff
*********************/

struct UNP {
    uint8_t *outputbuf;
    uint8_t *inputbuf;
    uint32_t cur_output;
    uint32_t cur_input;
    uint32_t usize;
    uint32_t csize;
    uint32_t bits_avail;
    union {
        uint32_t full;
        struct {
#if WORDS_BIGENDIAN != 0
            uint16_t h; /* BE */
            uint16_t l;
#else
            uint16_t l; /* LE */
            uint16_t h;
#endif
        } half;
    } bitmap;
    uint32_t error;
};

static uint32_t getbits(struct UNP *UNP, uint32_t size)
{
    UNP->bitmap.half.h = 0;
    if (size > UNP->bits_avail && ((size - UNP->bits_avail - 1) / 16 + 1) * 2 > UNP->csize - UNP->cur_input) {
        cli_dbgmsg("autoit: getbits() - not enough bits available\n");
        UNP->error = 1;
        return 0; /* won't infloop nor spam */
    }
    while (size) {
        if (!UNP->bits_avail) {
            UNP->bitmap.half.l |= UNP->inputbuf[UNP->cur_input++] << 8;
            UNP->bitmap.half.l |= UNP->inputbuf[UNP->cur_input++];
            UNP->bits_avail = 16;
        }
        UNP->bitmap.full <<= 1;
        UNP->bits_avail--;
        size--;
    }
    return (uint32_t)UNP->bitmap.half.h;
}

/*********************
 autoit3 EA05 handler
*********************/

static int ea05(cli_ctx *ctx, const uint8_t *base, char *tmpd)
{
    uint8_t b[300], comp;
    uint32_t s, m4sum = 0;
    int i, ret, det = 0;
    unsigned int files = 0;
    char tempfile[1024];
    struct UNP UNP;
    fmap_t *map = *ctx->fmap;

    if (!fmap_need_ptr_once(map, base, 16))
        return CL_CLEAN;

    for (i = 0; i < 16; i++)
        m4sum += *base++;

    while ((ret = cli_checklimits("autoit", ctx, 0, 0, 0)) == CL_CLEAN) {
        if (!fmap_need_ptr_once(map, base, 8))
            return (det ? CL_VIRUS : CL_CLEAN);

        /*     MT_decrypt(buf,4,0x16fa);  waste of time */
        if ((uint32_t)cli_readint32(base) != 0xceb06dff) {
            cli_dbgmsg("autoit: no FILE magic found, extraction complete\n");
            return (det ? CL_VIRUS : CL_CLEAN);
        }

        s = cli_readint32(base + 4) ^ 0x29bc;
        if ((int32_t)s < 0)
            return (det ? CL_VIRUS : CL_CLEAN); /* the original code wouldn't seek back here */
        base += 8;
        if (cli_debug_flag && s < sizeof(b)) {
            if (!fmap_need_ptr_once(map, base, s))
                return (det ? CL_VIRUS : CL_CLEAN);
            memcpy(b, base, s);
            MT_decrypt(b, s, s + 0xa25e);
            b[s] = '\0';
            cli_dbgmsg("autoit: magic string '%s'\n", b);
        }
        base += s;

        if (!fmap_need_ptr_once(map, base, 4))
            return (det ? CL_VIRUS : CL_CLEAN);
        s = cli_readint32(base) ^ 0x29ac;
        if ((int32_t)s < 0)
            return (det ? CL_VIRUS : CL_CLEAN); /* the original code wouldn't seek back here */
        base += 4;
        if (cli_debug_flag && s < sizeof(b)) {
            if (!fmap_need_ptr_once(map, base, s))
                return (det ? CL_VIRUS : CL_CLEAN);
            memcpy(b, base, s);
            MT_decrypt(b, s, s + 0xf25e);
            b[s] = '\0';
            cli_dbgmsg("autoit: original filename '%s'\n", b);
        }
        base += s;

        if (!fmap_need_ptr_once(map, base, 13))
            return (det ? CL_VIRUS : CL_CLEAN);
        comp      = *base;
        UNP.csize = cli_readint32(base + 1) ^ 0x45aa;
        if ((int32_t)UNP.csize < 0) {
            cli_dbgmsg("autoit: bad file size - giving up\n");
            return (det ? CL_VIRUS : CL_CLEAN);
        }

        if (!UNP.csize) {
            cli_dbgmsg("autoit: skipping empty file\n");
            base += 13 + 16;
            continue;
        }
        cli_dbgmsg("autoit: compressed size: %x\n", UNP.csize);
        cli_dbgmsg("autoit: advertised uncompressed size %x\n", cli_readint32(base + 5) ^ 0x45aa);
        cli_dbgmsg("autoit: ref chksum: %x\n", cli_readint32(base + 9) ^ 0xc3d2);

        base += 13 + 16;

        if (cli_checklimits("autoit", ctx, UNP.csize, 0, 0) != CL_CLEAN) {
            base += UNP.csize;
            continue;
        }

        if (comp == 1 && UNP.csize < sizeof(union unaligned_32)) {
            cli_dbgmsg("autoit: compressed size too small, skipping\n");
            continue;
        }

        if (!(UNP.inputbuf = cli_malloc(UNP.csize)))
            return CL_EMEM;
        if (!fmap_need_ptr_once(map, base, UNP.csize)) {
            cli_dbgmsg("autoit: failed to read compressed stream. broken/truncated file?\n");
            free(UNP.inputbuf);
            return (det ? CL_VIRUS : CL_CLEAN);
        }
        memcpy(UNP.inputbuf, base, UNP.csize);
        base += UNP.csize;
        MT_decrypt(UNP.inputbuf, UNP.csize, 0x22af + m4sum);

        if (comp == 1) {
            cli_dbgmsg("autoit: file is compressed\n");
            if (cli_readint32(UNP.inputbuf) != 0x35304145) {
                cli_dbgmsg("autoit: bad magic or unsupported version\n");
                free(UNP.inputbuf);
                continue;
            }

            if (!(UNP.usize = be32_to_host(*(uint32_t *)(UNP.inputbuf + 4))))
                UNP.usize = UNP.csize; /* only a specifically crafted or badly corrupted sample should land here */
            if (cli_checklimits("autoit", ctx, UNP.usize, 0, 0) != CL_CLEAN) {
                free(UNP.inputbuf);
                continue;
            }

            if (!(UNP.outputbuf = cli_malloc(UNP.usize))) {
                free(UNP.inputbuf);
                return CL_EMEM;
            }
            cli_dbgmsg("autoit: uncompressed size again: %x\n", UNP.usize);

            UNP.cur_output  = 0;
            UNP.cur_input   = 8;
            UNP.bitmap.full = 0;
            UNP.bits_avail  = 0;
            UNP.error       = 0;

            while (!UNP.error && UNP.cur_output < UNP.usize) {
                if (getbits(&UNP, 1)) {
                    uint32_t bb, bs, addme = 0;
                    bb = getbits(&UNP, 15);

                    if ((bs = getbits(&UNP, 2)) == 3) {
                        addme = 3;
                        if ((bs = getbits(&UNP, 3)) == 7) {
                            addme = 10;
                            if ((bs = getbits(&UNP, 5)) == 31) {
                                addme = 41;
                                if ((bs = getbits(&UNP, 8)) == 255) {
                                    addme = 296;
                                    while ((bs = getbits(&UNP, 8)) == 255) {
                                        addme += 255;
                                    }
                                }
                            }
                        }
                    }
                    bs += 3 + addme;

                    if (!CLI_ISCONTAINED(UNP.outputbuf, UNP.usize, &UNP.outputbuf[UNP.cur_output], bs) ||
                        !CLI_ISCONTAINED(UNP.outputbuf, UNP.usize, &UNP.outputbuf[UNP.cur_output - bb], bs)) {
                        UNP.error = 1;
                        break;
                    }
                    while (bs--) {
                        UNP.outputbuf[UNP.cur_output] = UNP.outputbuf[UNP.cur_output - bb];
                        UNP.cur_output++;
                    }
                } else {
                    UNP.outputbuf[UNP.cur_output] = (uint8_t)getbits(&UNP, 8);
                    UNP.cur_output++;
                }
            }

            free(UNP.inputbuf);
            /* Sometimes the autoit exe is in turn packed/lamed with a runtime compressor and similar shit.
       * However, since the autoit script doesn't compress a second time very well, chances are we're
       * still able to match the headers and unpack something (see sample 0811129)
       * I'd rather unpack something (although possibly highly corrupted) than nothing at all
       *
       * - Fortuna audaces iuvat -
       */
            if (UNP.error) {
                cli_dbgmsg("autoit: decompression error after %u bytes  - partial file may exist\n", UNP.cur_output);
                UNP.usize = UNP.cur_output;
            }
        } else {
            cli_dbgmsg("autoit: file is not compressed\n");
            UNP.outputbuf = UNP.inputbuf;
            UNP.usize     = UNP.csize;
        }

        if (UNP.usize < 4) {
            cli_dbgmsg("autoit: file is too short\n");
            free(UNP.outputbuf);
            continue;
        }

        files++;

        /* FIXME: REGRESSION NEEDED! */
        /* UNP.usize = u2a(UNP.outputbuf, UNP.usize); */

        snprintf(tempfile, 1023, "%s" PATHSEP "autoit.%.3u", tmpd, files);
        tempfile[1023] = '\0';
        if ((i = open(tempfile, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, S_IRWXU)) < 0) {
            cli_dbgmsg("autoit: Can't create file %s\n", tempfile);
            free(UNP.outputbuf);
            return CL_ECREAT;
        }
        if (cli_writen(i, UNP.outputbuf, UNP.usize) != UNP.usize) {
            cli_dbgmsg("autoit: cannot write %d bytes\n", UNP.usize);
            close(i);
            free(UNP.outputbuf);
            return CL_EWRITE;
        }
        free(UNP.outputbuf);
        if (ctx->engine->keeptmp)
            cli_dbgmsg("autoit: file extracted to %s\n", tempfile);
        else
            cli_dbgmsg("autoit: file successfully extracted\n");
        if (lseek(i, 0, SEEK_SET) == -1) {
            cli_dbgmsg("autoit: call to lseek() has failed\n");
            close(i);
            return CL_ESEEK;
        }
        if (cli_magic_scandesc(i, tempfile, ctx) == CL_VIRUS) {
            if (!SCAN_ALLMATCHES) {
                close(i);
                if (!ctx->engine->keeptmp)
                    if (cli_unlink(tempfile)) return CL_EUNLINK;
                return CL_VIRUS;
            }
            det = 1;
        }
        close(i);
        if (!ctx->engine->keeptmp)
            if (cli_unlink(tempfile)) return CL_EUNLINK;
    }
    return (det ? CL_VIRUS : ret);
}

/*********************
  LAME realted stuff
*********************/

#define ROFL(a, b) ((a << (b % (sizeof(a) << 3))) | (a >> ((sizeof(a) << 3) - (b % (sizeof(a) << 3)))))

struct LAME {
    uint32_t c0;
    uint32_t c1;
    uint32_t grp1[17];
};

static double LAME_fpusht(struct LAME *l)
{
    union {
        double as_double;
        struct {
            uint32_t lo;
            uint32_t hi;
        } as_uint;
    } ret;

    uint32_t rolled = ROFL(l->grp1[l->c0], 9) + ROFL(l->grp1[l->c1], 13);

    l->grp1[l->c0] = rolled;

    if (!l->c0--) l->c0 = 16;
    if (!l->c1--) l->c1 = 16;

    /*   if (l->grp1[l->c0] == l->grp2[0]) { */
    /*     if (!memcmp(l->grp1, (uint32_t *)l + 0x24 - l->c0, 0x44)) */
    /*       return 0.0; */
    /*   } */

    if (fpu_words == FPU_ENDIAN_LITTLE) {
        ret.as_uint.lo = rolled << 0x14;
        ret.as_uint.hi = 0x3ff00000 | (rolled >> 0xc);
    } else {
        ret.as_uint.hi = rolled << 0x14;
        ret.as_uint.lo = 0x3ff00000 | (rolled >> 0xc);
    }
    return ret.as_double - 1.0;
}

static void LAME_srand(struct LAME *l, uint32_t seed)
{
    unsigned int i;

    for (i = 0; i < 17; i++) {
        seed *= 0x53A9B4FB; /*1403630843*/
        seed       = 1 - seed;
        l->grp1[i] = seed;
    }

    l->c0 = 0;
    l->c1 = 10;

    for (i = 0; i < 9; i++)
        LAME_fpusht(l);
}

static uint8_t LAME_getnext(struct LAME *l)
{
    double x;
    uint8_t ret;

    LAME_fpusht(l);
    x = LAME_fpusht(l) * 256.0;
    if ((int32_t)x < 256)
        ret = (uint8_t)x;
    else
        ret = 0xff;
    return ret;
}

static void LAME_decrypt(uint8_t *cypher, uint32_t size, uint16_t seed)
{
    struct LAME lame;
    /* mt_srand_timewrap(struct srand_struc bufDC); */

    LAME_srand(&lame, (uint32_t)seed);
    while (size--)
        *cypher++ ^= LAME_getnext(&lame);
}

/*********************
 autoit3 EA06 handler
*********************/

static int ea06(cli_ctx *ctx, const uint8_t *base, char *tmpd)
{
    uint8_t b[600], comp, script, *buf;
    uint32_t s;
    int i, ret, det = 0;
    unsigned int files = 0;
    char tempfile[1024];
    const char prefixes[] = {'\0', '\0', '@', '$', '\0', '.', '"', '#'};
    const char *opers[]   = {",", "=", ">", "<", "<>", ">=", "<=", "(", ")", "+", "-", "/", "*", "&", "[", "]", "==", "^", "+=", "-=", "/=", "*=", "&=", "?", ":"};
    struct UNP UNP;
    fmap_t *map = *ctx->fmap;

    /* Useless due to a bug in CRC calculation - LMAO!!1 */
    /*   if (cli_readn(desc, buf, 24)!=24) */
    /*     return CL_CLEAN; */
    /*   LAME_decrypt(buf, 0x10, 0x99f2); */
    /*   buf+=0x10; */
    base += 16; /* for now we just skip the garbage */

    while ((ret = cli_checklimits("cli_autoit", ctx, 0, 0, 0)) == CL_CLEAN) {
        if (!fmap_need_ptr_once(map, base, 8))
            return (det ? CL_VIRUS : CL_CLEAN);
        /*     LAME_decrypt(buf, 4, 0x18ee); waste of time */
        if (cli_readint32(base) != 0x52ca436b) {
            cli_dbgmsg("autoit: no FILE magic found, giving up\n");
            return (det ? CL_VIRUS : CL_CLEAN);
        }

        script = 0;

        s = cli_readint32(base + 4) ^ 0xadbc;
        if ((int32_t)(s * 2) < 0)
            return (det ? CL_VIRUS : CL_CLEAN); /* the original code wouldn't seek back here */
        base += 8;
        if (s < sizeof(b) / 2) {
            if (!fmap_need_ptr_once(map, base, s * 2))
                return (det ? CL_VIRUS : CL_CLEAN);
            memcpy(b, base, s * 2);
            LAME_decrypt(b, s * 2, s + 0xb33f);
            u2a(b, s * 2);
            cli_dbgmsg("autoit: magic string '%s'\n", b);
            if (s == 19 && !memcmp(">>>AUTOIT SCRIPT<<<", b, 19))
                script = 1;
        } else {
            cli_dbgmsg("autoit: magic string too long to print\n");
        }
        base += s * 2;

        if (!fmap_need_ptr_once(map, base, 4))
            return (det ? CL_VIRUS : CL_CLEAN);
        s = cli_readint32(base) ^ 0xf820;
        if ((int32_t)(s * 2) < 0)
            return (det ? CL_VIRUS : CL_CLEAN); /* the original code wouldn't seek back here */
        base += 4;
        if (cli_debug_flag && s < sizeof(b) / 2) {
            if (!fmap_need_ptr_once(map, base, s * 2))
                return (det ? CL_VIRUS : CL_CLEAN);
            memcpy(b, base, s * 2);
            LAME_decrypt(b, s * 2, s + 0xf479);
            b[s * 2]     = '\0';
            b[s * 2 + 1] = '\0';
            u2a(b, s * 2);
            cli_dbgmsg("autoit: original filename '%s'\n", b);
        }
        base += s * 2;

        if (!fmap_need_ptr_once(map, base, 13))
            return (det ? CL_VIRUS : CL_CLEAN);
        comp      = *base;
        UNP.csize = cli_readint32(base + 1) ^ 0x87bc;
        if ((int32_t)UNP.csize < 0) {
            cli_dbgmsg("autoit: bad file size - giving up\n");
            return (det ? CL_VIRUS : CL_CLEAN);
        }

        if (!UNP.csize) {
            cli_dbgmsg("autoit: skipping empty file\n");
            base += 13 + 16;
            continue;
        }
        cli_dbgmsg("autoit: compressed size: %x\n", UNP.csize);
        cli_dbgmsg("autoit: advertised uncompressed size %x\n", cli_readint32(base + 5) ^ 0x87bc);
        cli_dbgmsg("autoit: ref chksum: %x\n", cli_readint32(base + 9) ^ 0xa685);

        base += 13 + 16;

        if (cli_checklimits("autoit", ctx, UNP.csize, 0, 0) != CL_CLEAN) {
            base += UNP.csize;
            continue;
        }

        if (comp == 1 && UNP.csize < sizeof(union unaligned_32)) {
            cli_dbgmsg("autoit: compressed size too small, skipping\n");
            continue;
        }

        files++;
        if (!(UNP.inputbuf = cli_malloc(UNP.csize)))
            return CL_EMEM;
        if (!fmap_need_ptr_once(map, base, UNP.csize)) {
            cli_dbgmsg("autoit: failed to read compressed stream. broken/truncated file?\n");
            free(UNP.inputbuf);
            return (det ? CL_VIRUS : CL_CLEAN);
        }
        memcpy(UNP.inputbuf, base, UNP.csize);
        base += UNP.csize;
        LAME_decrypt(UNP.inputbuf, UNP.csize, 0x2477 /* + m4sum (broken by design) */);

        if (comp == 1) {
            cli_dbgmsg("autoit: file is compressed\n");
            if (cli_readint32(UNP.inputbuf) != 0x36304145) {
                cli_dbgmsg("autoit: bad magic or unsupported version\n");
                free(UNP.inputbuf);
                continue;
            }

            if (!(UNP.usize = be32_to_host(*(uint32_t *)(UNP.inputbuf + 4))))
                UNP.usize = UNP.csize; /* only a specifically crafted or badly corrupted sample should land here */
            if (cli_checklimits("autoit", ctx, UNP.usize, 0, 0) != CL_CLEAN) {
                free(UNP.inputbuf);
                continue;
            }
            if (!(UNP.outputbuf = cli_malloc(UNP.usize))) {
                free(UNP.inputbuf);
                return CL_EMEM;
            }
            cli_dbgmsg("autoit: uncompressed size again: %x\n", UNP.usize);

            UNP.cur_output  = 0;
            UNP.cur_input   = 8;
            UNP.bitmap.full = 0;
            UNP.bits_avail  = 0;
            UNP.error       = 0;

            while (!UNP.error && UNP.cur_output < UNP.usize) {
                if (!getbits(&UNP, 1)) {
                    uint32_t bb, bs, addme = 0;
                    bb = getbits(&UNP, 15);

                    if ((bs = getbits(&UNP, 2)) == 3) {
                        addme = 3;
                        if ((bs = getbits(&UNP, 3)) == 7) {
                            addme = 10;
                            if ((bs = getbits(&UNP, 5)) == 31) {
                                addme = 41;
                                if ((bs = getbits(&UNP, 8)) == 255) {
                                    addme = 296;
                                    while ((bs = getbits(&UNP, 8)) == 255) {
                                        addme += 255;
                                    }
                                }
                            }
                        }
                    }
                    bs += 3 + addme;

                    if (!CLI_ISCONTAINED(UNP.outputbuf, UNP.usize, &UNP.outputbuf[UNP.cur_output], bs) ||
                        !CLI_ISCONTAINED(UNP.outputbuf, UNP.usize, &UNP.outputbuf[UNP.cur_output - bb], bs)) {
                        UNP.error = 1;
                        break;
                    }
                    while (bs--) {
                        UNP.outputbuf[UNP.cur_output] = UNP.outputbuf[UNP.cur_output - bb];
                        UNP.cur_output++;
                    }
                } else {
                    UNP.outputbuf[UNP.cur_output] = (uint8_t)getbits(&UNP, 8);
                    UNP.cur_output++;
                }
            }

            free(UNP.inputbuf);
            if (UNP.error) {
                cli_dbgmsg("autoit: decompression error after %u bytes - partial file may exist\n", UNP.cur_output);
                UNP.usize = UNP.cur_output;
            }
        } else {
            cli_dbgmsg("autoit: file is not compressed\n");
            UNP.outputbuf = UNP.inputbuf;
            UNP.usize     = UNP.csize;
        }

        if (UNP.usize < 4) {
            cli_dbgmsg("autoit: file is too short\n");
            free(UNP.outputbuf);
            continue;
        }

        if (script) {
            UNP.csize = UNP.usize;
            if (!(buf = cli_malloc(UNP.csize))) {
                free(UNP.outputbuf);
                return CL_EMEM;
            }
            UNP.cur_output = 0;
            UNP.cur_input  = 4;
            UNP.bits_avail = cli_readint32((char *)UNP.outputbuf);
            UNP.error      = 0;
            cli_dbgmsg("autoit: script has got %u lines\n", UNP.bits_avail);

            while (!UNP.error && UNP.bits_avail && UNP.cur_input < UNP.usize) {
                uint8_t op;

                switch ((op = UNP.outputbuf[UNP.cur_input++])) {
                    case 5: /* <INT> */
                        if (UNP.cur_input >= UNP.usize - 4) {
                            UNP.error = 1;
                            cli_dbgmsg("autoit: not enough space for an int\n");
                            break;
                        }
                        if (UNP.cur_output + 12 >= UNP.csize) {
                            uint8_t *newout;
                            UNP.csize += 512;
                            if (!(newout = cli_realloc(buf, UNP.csize))) {
                                UNP.error = 1;
                                break;
                            }
                            buf = newout;
                        }
                        snprintf((char *)&buf[UNP.cur_output], 12, "0x%08x ", cli_readint32((char *)&UNP.outputbuf[UNP.cur_input]));
                        UNP.cur_output += 11;
                        UNP.cur_input += 4;
                        break;

                    case 0x10: /* <INT64> */
                    {
                        uint64_t val;
                        if (UNP.usize < 8 || UNP.cur_input >= UNP.usize - 8) {
                            UNP.error = 1;
                            cli_dbgmsg("autoit: not enough space for an int64\n");
                            break;
                        }
                        if (UNP.cur_output + 20 >= UNP.csize) {
                            uint8_t *newout;
                            UNP.csize += 512;
                            if (!(newout = cli_realloc(buf, UNP.csize))) {
                                UNP.error = 1;
                                break;
                            }
                            buf = newout;
                        }
                        val = (uint64_t)cli_readint32((char *)&UNP.outputbuf[UNP.cur_input + 4]);
                        val <<= 32;
                        val += (uint64_t)cli_readint32((char *)&UNP.outputbuf[UNP.cur_input]);
                        snprintf((char *)&buf[UNP.cur_output], 20, "0x%016lx ", (unsigned long int)val);
                        UNP.cur_output += 19;
                        UNP.cur_input += 8;
                        break;
                    }

                    case 0x20: /* <DOUBLE> */
                        if (UNP.usize < 8 || UNP.cur_input >= UNP.usize - 8) {
                            UNP.error = 1;
                            cli_dbgmsg("autoit: not enough space for a double\n");
                            break;
                        }
                        if (UNP.cur_output + 40 >= UNP.csize) {
                            uint8_t *newout;
                            UNP.csize += 512;
                            if (!(newout = cli_realloc(buf, UNP.csize))) {
                                UNP.error = 1;
                                break;
                            }
                            buf = newout;
                        }
                        if (fpu_words == FPU_ENDIAN_LITTLE)
                            snprintf((char *)&buf[UNP.cur_output], 39, "%g ", *(double *)&UNP.outputbuf[UNP.cur_input]);
                        else
                            do {
                                double x;
                                uint8_t *j = (uint8_t *)&x;
                                unsigned int i;

                                for (i = 0; i < 8; i++)
                                    j[7 - i] = UNP.outputbuf[UNP.cur_input + i];
                                snprintf((char *)&buf[UNP.cur_output], 39, "%g ", x); /* FIXME: check */
                            } while (0);
                        buf[UNP.cur_output + 38] = ' ';
                        buf[UNP.cur_output + 39] = '\0';
                        UNP.cur_output += strlen((char *)&buf[UNP.cur_output]);
                        UNP.cur_input += 8;
                        break;

                    case 0x30: /* COSTRUCT */
                    case 0x31: /* COMMAND */
                    case 0x32: /* MACRO */
                    case 0x33: /* VAR */
                    case 0x34: /* FUNC */
                    case 0x35: /* OBJECT */
                    case 0x36: /* STRING */
                    case 0x37: /* DIRECTIVE */
                    {
                        uint32_t chars, dchars, i;

                        if (UNP.cur_input >= UNP.usize - 4) {
                            UNP.error = 1;
                            cli_dbgmsg("autoit: not enough space for size\n");
                            break;
                        }
                        chars  = cli_readint32((char *)&UNP.outputbuf[UNP.cur_input]);
                        dchars = chars * 2;
                        UNP.cur_input += 4;

                        if (UNP.usize < dchars || UNP.cur_input >= UNP.usize - dchars) {
                            UNP.error = 1;
                            cli_dbgmsg("autoit: size too big - needed %d, total %d, avail %d\n", dchars, UNP.usize, UNP.usize - UNP.cur_input);
                            break;
                        }
                        if (UNP.cur_output + chars + 3 >= UNP.csize) {
                            uint8_t *newout;
                            UNP.csize += chars + 512;
                            if (!(newout = cli_realloc(buf, UNP.csize))) {
                                UNP.error = 1;
                                break;
                            }
                            buf = newout;
                        }

                        if (prefixes[op - 0x30])
                            buf[UNP.cur_output++] = prefixes[op - 0x30];

                        if (chars) {
                            for (i = 0; i < dchars; i += 2) {
                                UNP.outputbuf[UNP.cur_input + i] ^= (uint8_t)chars;
                                UNP.outputbuf[UNP.cur_input + i + 1] ^= (uint8_t)(chars >> 8);
                            }
                            u2a(&UNP.outputbuf[UNP.cur_input], dchars);
                            memcpy(&buf[UNP.cur_output], &UNP.outputbuf[UNP.cur_input], chars);
                            UNP.cur_output += chars;
                            UNP.cur_input += dchars;
                        }
                        if (op == 0x36)
                            buf[UNP.cur_output++] = '"';
                        if (op != 0x34)
                            buf[UNP.cur_output++] = ' ';
                    } break;

                    case 0x40: /* , */
                    case 0x41: /* = */
                    case 0x42: /* > */
                    case 0x43: /* < */
                    case 0x44: /* <> */
                    case 0x45: /* >= */
                    case 0x46: /* <= */
                    case 0x47: /* ( */
                    case 0x48: /* ) */
                    case 0x49: /* + */
                    case 0x4a: /* - */
                    case 0x4b: /* / */
                    case 0x4c: /* * */
                    case 0x4d: /* & */
                    case 0x4e: /* [ */
                    case 0x4f: /* ] */
                    case 0x50: /* == */
                    case 0x51: /* ^ */
                    case 0x52: /* += */
                    case 0x53: /* -= */
                    case 0x54: /* /= */
                    case 0x55: /* *= */
                    case 0x56: /* &= */
                    case 0x57: /* ? */
                    case 0x58: /* : */
                        if (UNP.cur_output + 4 >= UNP.csize) {
                            uint8_t *newout;
                            UNP.csize += 512;
                            if (!(newout = cli_realloc(buf, UNP.csize))) {
                                UNP.error = 1;
                                break;
                            }
                            buf = newout;
                        }
                        UNP.cur_output += snprintf((char *)&buf[UNP.cur_output], 4, "%s ", opers[op - 0x40]);
                        break;

                    case 0x7f:
                        UNP.bits_avail--;
                        if (UNP.cur_output + 1 >= UNP.csize) {
                            uint8_t *newout;
                            UNP.csize += 512;
                            if (!(newout = cli_realloc(buf, UNP.csize))) {
                                UNP.error = 1;
                                break;
                            }
                            buf = newout;
                        }
                        buf[UNP.cur_output++] = '\n';
                        break;

                    default:
                        cli_dbgmsg("autoit: found unknown op (0x%x)\n", op);
                        UNP.error = 1;
                }
            }

            if (UNP.error)
                cli_dbgmsg("autoit: decompilation aborted - partial script may exist\n");

            free(UNP.outputbuf);
        } else {
            buf            = UNP.outputbuf;
            UNP.cur_output = UNP.usize;
        }

        snprintf(tempfile, 1023, "%s" PATHSEP "autoit.%.3u", tmpd, files);
        tempfile[1023] = '\0';
        if ((i = open(tempfile, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, S_IRWXU)) < 0) {
            cli_dbgmsg("autoit: Can't create file %s\n", tempfile);
            free(buf);
            return CL_ECREAT;
        }
        if (cli_writen(i, buf, UNP.cur_output) != UNP.cur_output) {
            cli_dbgmsg("autoit: cannot write %d bytes\n", UNP.usize);
            close(i);
            free(buf);
            return CL_EWRITE;
        }
        free(buf);
        if (ctx->engine->keeptmp)
            cli_dbgmsg("autoit: %s extracted to %s\n", (script) ? "script" : "file", tempfile);
        else
            cli_dbgmsg("autoit: %s successfully extracted\n", (script) ? "script" : "file");
        if (lseek(i, 0, SEEK_SET) == -1) {
            cli_dbgmsg("autoit: call to lseek() has failed\n");
            close(i);
            return CL_ESEEK;
        }
        if (cli_magic_scandesc(i, tempfile, ctx) == CL_VIRUS) {
            if (!SCAN_ALLMATCHES) {
                close(i);
                if (!ctx->engine->keeptmp)
                    if (cli_unlink(tempfile)) return CL_EUNLINK;
                return CL_VIRUS;
            }
            det = 1;
        }
        close(i);
        if (!ctx->engine->keeptmp)
            if (cli_unlink(tempfile)) return CL_EUNLINK;
    }
    return (det ? CL_VIRUS : ret);
}

/*********************
   autoit3 wrapper
*********************/

int cli_scanautoit(cli_ctx *ctx, off_t offset)
{
    const uint8_t *version;
    int r;
    char *tmpd;
    fmap_t *map = *ctx->fmap;

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

    if (!(version = fmap_need_off_once(map, offset, sizeof(*version))))
        return CL_EREAD;

    if (!(tmpd = cli_gentemp(ctx->engine->tmpdir)))
        return CL_ETMPDIR;
    if (mkdir(tmpd, 0700)) {
        cli_dbgmsg("autoit: Can't create temporary directory %s\n", tmpd);
        free(tmpd);
        return CL_ETMPDIR;
    }
    if (ctx->engine->keeptmp)
        cli_dbgmsg("autoit: Extracting files to %s\n", tmpd);

    switch (*version) {
        case 0x35:
            r = ea05(ctx, version + 1, tmpd);
            break;
        case 0x36:
            if (fpu_words == FPU_ENDIAN_INITME)
                fpu_words = get_fpu_endian();
            if (fpu_words == FPU_ENDIAN_UNKNOWN) {
                cli_dbgmsg("autoit: EA06 support not available"
                           "(cannot extract ea06 doubles, unknown floating double representation).\n");
                r = CL_CLEAN;
            } else
                r = ea06(ctx, version + 1, tmpd);
            break;
        default:
            /* NOT REACHED */
            cli_dbgmsg("autoit: unknown method\n");
            r = CL_CLEAN;
    }

    if (!ctx->engine->keeptmp)
        cli_rmdirs(tmpd);

    free(tmpd);
    return r;
}