/* * Copyright (C) 2009 Sourcefire, Inc. * * Authors: aCaB * * 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. */ /* common routines to deal with installshield archives and installers */ #if HAVE_CONFIG_H #include "clamav-config.h" #endif #define _XOPEN_SOURCE 500 #include #include #include #ifdef HAVE_UNISTD_H #include #endif #if HAVE_MMAP #ifdef HAVE_SYS_MMAN_H #include #endif #endif /* HAVE_MMAP */ #if HAVE_STRING_H #include #endif #include #if HAVE_STRINGS_H #include #endif #include #include "scanners.h" #include "cltypes.h" #include "others.h" #include "ishield.h" #ifndef O_BINARY #define O_BINARY 0 #endif #ifndef LONG_MAX #define LONG_MAX ((-1UL)>>1) #endif #ifndef HAVE_ATTRIB_PACKED #define __attribute__(x) #endif #ifdef HAVE_PRAGMA_PACK #pragma pack(1) #endif #ifdef HAVE_PRAGMA_PACK_HPPA #pragma pack 1 #endif /* PACKED things go here */ struct IS_FB { char fname[0x104]; /* MAX_PATH */ uint32_t unk1; /* 6 */ uint32_t unk2; uint64_t csize; uint32_t unk3; uint32_t unk4; /* 1 */ uint32_t unk5; uint32_t unk6; uint32_t unk7; uint32_t unk8; uint32_t unk9; uint32_t unk10; uint32_t unk11; } __attribute__((packed)); struct IS_COMPONENT { uint32_t str_name_off; uint32_t unk_str1_off; uint32_t unk_str2_off; uint16_t unk_flags; uint32_t unk_str3_off; uint32_t unk_str4_off; uint16_t ordinal_id; uint32_t str_shortname_off; uint32_t unk_str6_off; uint32_t unk_str7_off; uint32_t unk_str8_off; char guid1[16]; char guid2[16]; uint32_t unk_str9_off; char unk1[3]; uint16_t unk_flags2; uint32_t unk3[5]; uint32_t unk_str10_off; uint32_t unk4[4]; uint16_t unk5; uint16_t sub_comp_cnt; uint32_t sub_comp_offs_array; uint32_t next_comp_off; uint32_t unk_str11_off; uint32_t unk_str12_off; uint32_t unk_str13_off; uint32_t unk_str14_off; uint32_t str_next1_off; uint32_t str_next2_off; } __attribute__((packed)); struct IS_INSTTYPEHDR { uint32_t unk1; uint32_t cnt; uint32_t off; } __attribute__((packed)); struct IS_INSTTYPEITEM { uint32_t str_name1_off; uint32_t str_name2_off; uint32_t str_name3_off; uint32_t cnt; uint32_t off; } __attribute__((packed)); struct IS_OBJECTS { /* 200 */ uint32_t strings_off; /* 204 */ uint32_t zero1; /* 208 */ uint32_t comps_off; /* 20c */ uint32_t dirs_off; /* 210 */ uint32_t zero2; /* 214 */ uint32_t unk1, unk2; /* 0x4a636 304694 uguali - NOT AN OFFSET! */ /* 21c */ uint32_t dirs_cnt; /* 220 */ uint32_t zero3; /* 224 */ uint32_t dirs_sz; /* dirs_cnt * 4 */ /* 228 */ uint32_t files_cnt; /* 22c */ uint32_t dir_sz2; /* same as dirs_sz ?? */ /* 230 */ uint16_t unk5; /* 1 - comp count ?? */ /* 232 */ uint32_t insttype_off; /* 234 */ uint16_t zero4; /* 238 */ uint32_t zero5; /* 23c */ uint32_t unk7; /* 0xd0 - 208 */ /* 240 */ uint16_t unk8; /* 242 */ uint32_t unk9; /* 246 */ uint32_t unk10; } __attribute__((packed)); struct IS_FILEITEM { uint16_t flags; /* 0 = EXTERNAL | 4 = INTERNAL | 8 = NAME_fuckup_rare | c = name_fuckup_common */ uint64_t size; uint64_t csize; uint64_t stream_off; uint8_t md5[16]; uint64_t versioninfo_id; uint32_t zero1; uint32_t zero2; uint32_t str_name_off; uint16_t dir_id; uint32_t unk13; /* 0, 20, 21 ??? */ uint32_t unk14; /* timestamp ??? */ uint32_t unk15; /* begins with 1 then 2 but not the cab# ??? */ uint32_t prev_dup_id; /* msvcrt #38(0, 97, 2) #97(38, 1181, 3) ... , 0, 1) */ uint32_t next_dup_id; uint8_t flag_has_dup; /* HAS_NEXT = 2 | HAS_BOTH = 3 | HAS_PREV = 1 */ uint16_t datafile_id; } __attribute__((packed)); #ifdef HAVE_PRAGMA_PACK #pragma pack() #endif #ifdef HAVE_PRAGMA_PACK_HPPA #pragma pack #endif static int is_dump_and_scan(int desc, cli_ctx *ctx, off_t off, size_t fsize); static const uint8_t skey[] = { 0xec, 0xca, 0x79, 0xf8 }; /* ~0x13, ~0x35, ~0x86, ~0x07 */ /* Extracts the content of MSI based IS */ int cli_scanishield_msi(int desc, cli_ctx *ctx, off_t off) { uint8_t buf[BUFSIZ]; unsigned int fcount, scanned = 0; int ret; cli_dbgmsg("in ishield-msi\n"); lseek(desc, off, SEEK_SET); if(cli_readn(desc, buf, 0x20) != 0x20) { cli_dbgmsg("ishield-msi: short read for header\n"); return CL_CLEAN; } if(cli_readint32(buf + 8) | cli_readint32(buf + 0xc) | cli_readint32(buf + 0x10) | cli_readint32(buf + 0x14) | cli_readint32(buf + 0x18) | cli_readint32(buf + 0x1c)) return CL_CLEAN; if(!(fcount = cli_readint32(buf))) { cli_dbgmsg("ishield-msi: no files?\n"); return CL_CLEAN; } while(fcount--) { struct IS_FB fb; uint8_t obuf[BUFSIZ], *key = (uint8_t *)&fb.fname; char *tempfile; unsigned int i, lameidx=0, keylen; int ofd; uint64_t csize; z_stream z; if(cli_readn(desc, &fb, sizeof(fb)) != sizeof(fb)) { cli_dbgmsg("ishield-msi: short read for fileblock\n"); return CL_CLEAN; } fb.fname[sizeof(fb.fname)-1] = '\0'; csize = le64_to_host(fb.csize); if(ctx->engine->maxfilesize && csize > ctx->engine->maxfilesize) { cli_dbgmsg("ishield-msi: skipping stream due to size limits (%lu vs %lu)\n", csize, ctx->engine->maxfilesize); lseek(desc, csize, SEEK_CUR); continue; } keylen = strlen((const char *)key); if(!keylen) return CL_CLEAN; /* FIXMEISHIELD: cleanup the spam below */ cli_dbgmsg("ishield-msi: File %s (csize: %llx, unk1:%x unk2:%x unk3:%x unk4:%x unk5:%x unk6:%x unk7:%x unk8:%x unk9:%x unk10:%x unk11:%x)\n", key, (long long)csize, fb.unk1, fb.unk2, fb.unk3, fb.unk4, fb.unk5, fb.unk6, fb.unk7, fb.unk8, fb.unk9, fb.unk10, fb.unk11); if(!(tempfile = cli_gentemp(ctx->engine->tmpdir))) return CL_EMEM; if((ofd = open(tempfile, O_RDWR|O_CREAT|O_TRUNC|O_BINARY, S_IRUSR|S_IWUSR)) < 0) { cli_dbgmsg("ishield-msi: failed to create file %s\n", tempfile); free(tempfile); return CL_ECREAT; } for(i=0; i>4) | (c<<4); c ^= key[(lameidx & 0x3ff) % keylen]; buf[i] = c; } csize -= z.avail_in; z.next_in = buf; do { int inf; z.avail_out = sizeof(obuf); z.next_out = obuf; inf = inflate(&z, 0); if(inf != Z_OK && inf != Z_STREAM_END && inf != Z_BUF_ERROR) { cli_dbgmsg("ishield-msi: bad stream\n"); csize = 0; lseek(desc, csize, SEEK_CUR); break; } if (cli_writen(ofd, obuf, sizeof(obuf) - z.avail_out) < 0) { ret = CL_EWRITE; csize = 0; break; } if(ctx->engine->maxfilesize && z.total_out > ctx->engine->maxfilesize) { cli_dbgmsg("ishield-msi: trimming output file due to size limits (%lu vs %lu)\n", z.total_out, ctx->engine->maxfilesize); lseek(desc, csize, SEEK_CUR); csize = 0; break; } } while (!z.avail_out); } inflateEnd(&z); if (ret == CL_SUCCESS) { cli_dbgmsg("ishield-msi: extracted to %s\n", tempfile); lseek(ofd, 0, SEEK_SET); ret = cli_magic_scandesc(ofd, ctx); } close(ofd); if(!ctx->engine->keeptmp) if(cli_unlink(tempfile)) ret = CL_EUNLINK; free(tempfile); if(ret != CL_CLEAN) return ret; scanned++; if (ctx->engine->maxfiles && scanned>=ctx->engine->maxfiles) { cli_dbgmsg("ishield-msi: File limit reached (max: %u)\n", ctx->engine->maxfiles); return CL_EMAXFILES; } } return CL_CLEAN; } struct IS_CABSTUFF { struct CABARRAY { unsigned int cabno; off_t off; size_t sz; } *cabs; off_t hdr; size_t hdrsz; unsigned int cabcnt; }; static void md5str(uint8_t *sum); static int is_parse_hdr(int desc, cli_ctx *ctx, struct IS_CABSTUFF *c); static int is_extract_cab(int desc, cli_ctx *ctx, uint64_t off, uint64_t size, uint64_t csize); /* Extract the content of older (non-MSI) IS */ int cli_scanishield(int desc, cli_ctx *ctx, off_t off, size_t sz) { char *fname, *path, *version, *strsz, *eostr, *data; char buf[2048]; int rd, ret = CL_CLEAN; long fsize; off_t coff = off; struct IS_CABSTUFF c = { NULL, -1, 0, 0 }; while(ret == CL_CLEAN) { rd = pread(desc, buf, sizeof(buf), coff); if(rd <= 0) break; fname = buf; if(!*fname) break; path = memchr(fname, 0, rd); if(!path) break; path++; rd -= (path - buf); if(rd<=0 || !(version = memchr(path, 0, rd))) break; version++; rd -= (version - path); if(rd<=0 || !(strsz = memchr(version, 0, rd))) break; strsz++; rd -= (strsz - version); if(rd<=0 || !(data = memchr(strsz, 0, rd))) break; data++; fsize = strtol(strsz, &eostr, 10); if(fsize < 0 || fsize == LONG_MAX || !*strsz || !eostr || eostr == strsz || *eostr || (unsigned long)fsize >= sz || data - buf >= sz - fsize ) break; cli_dbgmsg("ishield: @%lx found file %s (%s) - version %s - size %lu\n", coff, fname, path, version, fsize); sz -= (data - buf) + fsize; coff += (data - buf); if(!strncasecmp(fname, "data", 4)) { long cabno; if(!strcasecmp(fname + 4, "1.hdr")) { if(c.hdr == -1) { cli_dbgmsg("ishield: added data1.hdr to array\n"); c.hdr = coff; c.hdrsz = fsize; coff += fsize; continue; } cli_warnmsg("ishield: got multiple header files\n"); } cabno = strtol(fname + 4, &eostr, 10); if(cabno > 0 && cabno < 65536 && fname[4] && eostr && eostr != &fname[4] && !strcasecmp(eostr, ".cab")) { unsigned int i; for(i=0; iengine->tmpdir))) return CL_EMEM; if((ofd = open(fname, O_RDWR|O_CREAT|O_TRUNC|O_BINARY, S_IRUSR|S_IWUSR)) < 0) { cli_errmsg("ishield: failed to create file %s\n", fname); free(fname); return CL_ECREAT; } while(fsize) { size_t rd = fsize < sizeof(buf) ? fsize : sizeof(buf); int got = pread(desc, buf, rd, off); if(got <= 0) { cli_dbgmsg("ishield: read error\n"); ret = CL_EREAD; break; } if(cli_writen(ofd, buf, got) <= 0) { ret = CL_EWRITE; break; } fsize -= got; off += got; } if(!fsize) { cli_dbgmsg("ishield: extracted to %s\n", fname); lseek(ofd, 0, SEEK_SET); ret = cli_magic_scandesc(ofd, ctx); } close(ofd); if(!ctx->engine->keeptmp) if(cli_unlink(fname)) ret = CL_EUNLINK; free(fname); return ret; } struct IS_HDR { uint32_t magic; uint32_t unk1; /* version ??? */ uint32_t unk2; /* ??? */ uint32_t data_off; uint32_t data_sz; /* ??? */ }; #define IS_FREE_HDR if(map) munmap(map, mp_hdrsz); else free(hdr); #if HAVE_MMAP #define IS_MAX_NOMAP_SZ 0x100000 #else #define IS_MAX_NOMAP_SZ CLI_MAX_ALLOCATION #endif /* Process data1.hdr and extracts all the available files from dataX.cab */ static int is_parse_hdr(int desc, cli_ctx *ctx, struct IS_CABSTUFF *c) { uint32_t h1_data_off, objs_files_cnt, objs_dirs_off; unsigned int off, i, scanned = 0; int ret = CL_BREAK; char hash[33], *hdr, *map = NULL; size_t mp_hdrsz; struct IS_HDR *h1; struct IS_OBJECTS *objs; /* struct IS_INSTTYPEHDR *typehdr; -- UNUSED */ if(!c->hdr || !c->hdrsz || !c->cabcnt) { cli_dbgmsg("is_parse_hdr: inconsistent hdr, maybe a false match\n"); return CL_CLEAN; } if(c->hdrsz < IS_MAX_NOMAP_SZ) { if(!(hdr = (char *)cli_malloc(c->hdrsz))) return CL_EMEM; if(pread(desc, hdr, c->hdrsz, c->hdr) < (ssize_t)c->hdrsz) { cli_errmsg("is_parse_hdr: short read for header\n"); free(hdr); return CL_EREAD; /* hdr must be within bounds, it's k to hard fail here */ } } else { #if defined(HAVE_MMAP) && defined(HAVE_CLI_GETPAGESIZE) int psz = cli_getpagesize(); off_t mp_hdr = (c->hdr / psz) * psz; mp_hdrsz = c->hdrsz + c->hdr - mp_hdr; if((map = mmap(NULL, mp_hdrsz, PROT_READ, MAP_PRIVATE, desc, mp_hdr))==MAP_FAILED) { cli_errmsg("is_parse_hdr: mmap failed\n"); return CL_EMEM; } hdr = map + c->hdr - mp_hdr; #else cli_warnmsg("is_parse_hdr: hdr too big and mmap is not usable\n"); return CL_CLEAN; #endif } h1 = (struct IS_HDR *)hdr; if(!CLI_ISCONTAINED(hdr, c->hdrsz, ((char *)h1), sizeof(*h1))) { cli_dbgmsg("is_parse_hdr: not enough room for H1\n"); IS_FREE_HDR; return CL_CLEAN; } h1_data_off = le32_to_host(h1->data_off); objs = (struct IS_OBJECTS *)(hdr + h1_data_off); if(!CLI_ISCONTAINED(hdr, c->hdrsz, ((char *)objs), sizeof(*objs))) { cli_dbgmsg("is_parse_hdr: not enough room for OBJECTS\n"); IS_FREE_HDR; return CL_CLEAN; } cli_dbgmsg("is_parse_hdr: magic %x, unk1 %x, unk2 %x, data_off %x, data_sz %x\n", h1->magic, h1->unk1, h1->unk2, h1_data_off, h1->data_sz); if(le32_to_host(h1->magic) != 0x28635349) { cli_dbgmsg("is_parse_hdr: bad magic. wrong version?\n"); IS_FREE_HDR; return CL_CLEAN; } /* cli_errmsg("COMPONENTS\n"); */ /* off = le32_to_host(objs->comps_off) + h1_data_off; */ /* for(i=1; ; i++) { */ /* struct IS_COMPONENT *cmp = (struct IS_COMPONENT *)(hdr + off); */ /* if(!CLI_ISCONTAINED(hdr, c->hdrsz, ((char *)cmp), sizeof(*cmp))) { */ /* cli_dbgmsg("is_extract: not enough room for COMPONENT\n"); */ /* free(hdr); */ /* return CL_CLEAN; */ /* } */ /* cli_errmsg("%06u\t%s\n", i, &hdr[le32_to_host(cmp->str_name_off) + h1_data_off]); */ /* spam_strarray(hdr, h1_data_off + cmp->sub_comp_offs_array, h1_data_off, cmp->sub_comp_cnt); */ /* if(!cmp->next_comp_off) break; */ /* off = le32_to_host(cmp->next_comp_off) + h1_data_off; */ /* } */ /* cli_errmsg("DIRECTORIES (%u)", le32_to_host(objs->dirs_cnt)); */ objs_dirs_off = le32_to_host(objs->dirs_off); /* spam_strarray(hdr, h1_data_off + objs_dirs_off, h1_data_off + objs_dirs_off, objs->dirs_cnt); */ /* typehdr = (struct INSTTYPEHDR *)&hdr[h1_data_off + le32_to_host(objs->insttype_off)]; */ /* printf("INSTTYPES (unk1: %d)\n-----------\n", typehdr->unk1); */ /* off = typehdr->off + h1_data_off; */ /* for(i=1; i<=typehdr->cnt; i++) { */ /* uint32_t x = *(uint32_t *)(&hdr[off]); */ /* struct INSTTYPEITEM *item = (struct INSTTYPEITEM *)&hdr[x + h1_data_off]; */ /* printf("%06u\t%s\t aka %s\taka %s\n", i, &hdr[item->str_name1_off + h1_data_off], &hdr[item->str_name2_off + h1_data_off], &hdr[item->str_name3_off + h1_data_off]); */ /* printf("components:\n"); */ /* spam_strarray(hdr, h1_data_off + item->off, h1_data_off, item->cnt); */ /* off+=4; */ /* } */ /* dir = &hdr[*(uint32_t *)(&hdr[h1_data_off + objs_dirs_off + 4 * file->dir_id]) + h1_data_off + objs_dirs_off] */ objs_files_cnt = le32_to_host(objs->files_cnt); off = h1_data_off + objs_dirs_off + le32_to_host(objs->dir_sz2); for(i=0; ihdrsz, ((char *)file), sizeof(*file))) { const char *dir_name = "", *file_name = ""; uint32_t dir_rel = h1_data_off + objs_dirs_off + 4 * le32_to_host(file->dir_id); /* rel off of dir entry from array of rel ptrs */ uint32_t file_rel = objs_dirs_off + h1_data_off + le32_to_host(file->str_name_off); /* rel off of fname */ uint64_t file_stream_off, file_size, file_csize; uint16_t cabno; memcpy(hash, file->md5, 16); md5str((uint8_t *)hash); if(CLI_ISCONTAINED(hdr, c->hdrsz, &hdr[dir_rel], 4)) { dir_rel = cli_readint32(&hdr[dir_rel]) + h1_data_off + objs_dirs_off; if(CLI_ISCONTAINED(hdr, c->hdrsz, &hdr[dir_rel], 1) && memchr(&hdr[dir_rel], 0, c->hdrsz - dir_rel)) dir_name = &hdr[dir_rel]; } if(CLI_ISCONTAINED(hdr, c->hdrsz, &hdr[file_rel], 1) && memchr(&hdr[file_rel], 0, c->hdrsz - file_rel)) file_name = &hdr[file_rel]; file_stream_off = le64_to_host(file->stream_off); file_size = le64_to_host(file->size); file_csize = le64_to_host(file->csize); cabno = le16_to_host(file->datafile_id); switch(le16_to_host(file->flags)) { case 0: /* FIXMEISHIELD: for FS scan ? */ cli_dbgmsg("is_parse_hdr: skipped external file:%s\\%s (size: %llu csize: %llu md5:%s)\n", dir_name, file_name, (long long)file_size, (long long)file_csize, hash); break; case 4: cli_dbgmsg("is_parse_hdr: file %s\\%s (size: %llu csize: %llu md5:%s offset:%llx (data%u.cab) 13:%x 14:%x 15:%x)\n", dir_name, file_name, (long long)file_size, (long long)file_csize, hash, (long long)file_stream_off, cabno, file->unk13, file->unk14, file->unk15); if(file->flag_has_dup & 1) cli_dbgmsg("is_parse_hdr: not scanned (dup)\n"); else { if(file_size) { unsigned int j; int cabret = CL_CLEAN; if(ctx->engine->maxfilesize && file_csize > ctx->engine->maxfilesize) { cli_dbgmsg("is_parse_hdr: skipping file due to size limits (%lu vs %lu)\n", file_csize, ctx->engine->maxfilesize); break; } for(j=0; jcabcnt && c->cabs[j].cabno != cabno; j++) {} if(j != c->cabcnt) { if(CLI_ISCONTAINED(c->cabs[j].off, c->cabs[j].sz, file_stream_off + c->cabs[j].off, file_csize)) { scanned++; if (ctx->engine->maxfiles && scanned >= ctx->engine->maxfiles) { cli_dbgmsg("is_parse_hdr: File limit reached (max: %u)\n", ctx->engine->maxfiles); IS_FREE_HDR; return CL_EMAXFILES; } cabret = is_extract_cab(desc, ctx, file_stream_off + c->cabs[j].off, file_size, file_csize); } else { ret = CL_CLEAN; cli_dbgmsg("is_parse_hdr: stream out of file\n"); } } else { ret = CL_CLEAN; cli_dbgmsg("is_parse_hdr: data%u.cab not available\n", cabno); } if(cabret == CL_BREAK) { ret = CL_CLEAN; cabret = CL_CLEAN; } if(cabret != CL_CLEAN) { IS_FREE_HDR; return cabret; } } else { cli_dbgmsg("is_parse_hdr: skipped empty file\n"); } } break; default: cli_dbgmsg("is_parse_hdr: skipped unknown file entry %u\n", i); } } else { ret = CL_CLEAN; cli_dbgmsg("is_parse_hdr: FILEITEM out of bounds\n"); } off += sizeof(*file); } IS_FREE_HDR; return ret; } static void md5str(uint8_t *sum) { int i; for(i=15; i>=0; i--) { uint8_t lo = (sum[i] & 0xf), hi = (sum[i] >> 4); lo += '0' + (lo > 9) * '\''; hi += '0' + (hi > 9) * '\''; sum[i*2+1] = lo; sum[i*2] = hi; } sum[32] = '\0'; } #define IS_CABBUFSZ 65536 static int is_extract_cab(int desc, cli_ctx *ctx, uint64_t off, uint64_t size, uint64_t csize) { uint8_t *inbuf, *outbuf; char *tempfile; FILE *in; int ofd, ret = CL_CLEAN; z_stream z; uint64_t outsz = 0; int success = 0; if((ofd=dup(desc)) < 0) { cli_errmsg("is_extract_cab: dup failed\n"); return CL_EDUP; } if(!(in = fdopen(ofd, "rb"))) { cli_errmsg("is_extract_cab: fdopen failed\n"); close(ofd); return CL_EOPEN; } #if HAVE_FSEEKO if(fseeko(in, (off_t)off, SEEK_SET)) #else if(fseek(in, (long)off, SEEK_SET)) #endif { cli_dbgmsg("is_extract_cab: fseek failed\n"); fclose(in); return CL_ESEEK; } if(!(inbuf = cli_malloc(IS_CABBUFSZ))) { fclose(in); return CL_EMEM; } if(!(outbuf = cli_malloc(IS_CABBUFSZ))) { free(inbuf); fclose(in); return CL_EMEM; } if(!(tempfile = cli_gentemp(ctx->engine->tmpdir))) { free(inbuf); free(outbuf); fclose(in); return CL_EMEM; } if((ofd = open(tempfile, O_RDWR|O_CREAT|O_TRUNC|O_BINARY, S_IRUSR|S_IWUSR)) < 0) { cli_errmsg("is_extract_cab: failed to create file %s\n", tempfile); free(tempfile); free(inbuf); free(outbuf); fclose(in); return CL_ECREAT; } while(csize) { uint16_t chunksz; success = 0; if(csize<2) { cli_dbgmsg("is_extract_cab: no room for chunk size\n"); break; } csize -= 2; if(!fread(outbuf, 2, 1, in)) { cli_dbgmsg("is_extract_cab: short read for chunk size\n"); break; } chunksz = outbuf[0] | (outbuf[1] << 8); if(!chunksz) { cli_dbgmsg("is_extract_cab: zero sized chunk\n"); continue; } if(csize < chunksz) { cli_dbgmsg("is_extract_cab: chunk is bigger than csize\n"); break; } csize -= chunksz; if(!fread(inbuf, chunksz, 1, in)) { cli_dbgmsg("is_extract_cab: short read for chunk\n"); break; } memset(&z, 0, sizeof(z)); inflateInit2(&z, -MAX_WBITS); z.next_in = (uint8_t *)inbuf; z.avail_in = chunksz; while(1) { int zret; z.next_out = outbuf; z.avail_out = IS_CABBUFSZ; zret = inflate(&z, 0); if(zret == Z_OK || zret == Z_STREAM_END || zret == Z_BUF_ERROR) { unsigned int umpd = IS_CABBUFSZ - z.avail_out; if(cli_writen(ofd, outbuf, umpd) < (ssize_t)umpd) break; outsz += umpd; if(zret == Z_STREAM_END || z.avail_out == IS_CABBUFSZ /* FIXMEISHIELD: is the latter ok? */) { success = 1; break; } if(ctx->engine->maxfilesize && z.total_out > ctx->engine->maxfilesize) { cli_dbgmsg("ishield_extract_cab: trimming output file due to size limits (%lu vs %lu)\n", z.total_out, ctx->engine->maxfilesize); success = 1; outsz = size; break; } continue; } cli_dbgmsg("is_extract_cab: file decompression failed with %d\n", zret); break; } inflateEnd(&z); if(!success) break; } fclose(in); free(inbuf); free(outbuf); if(success) { if (outsz != size) cli_dbgmsg("is_extract_cab: extracted %llu bytes to %s, expected %llu, scanning anyway.\n", (long long)outsz, tempfile, (long long)size); else cli_dbgmsg("is_extract_cab: extracted to %s\n", tempfile); lseek(ofd, 0, SEEK_SET); ret = cli_magic_scandesc(ofd, ctx); } close(ofd); if(!ctx->engine->keeptmp) if(cli_unlink(tempfile)) ret = CL_EUNLINK; free(tempfile); return success ? ret : CL_BREAK; }