diff --git a/src/Makefile.am b/src/Makefile.am index a61cbdf0e0..2c7919fdd7 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -154,6 +154,7 @@ detect-asn1.c detect-asn1.h \ detect-filename.c detect-filename.h \ detect-fileext.c detect-fileext.h \ detect-filestore.c detect-filestore.h \ +detect-filemagic.c detect-filemagic.h \ detect-http-stat-code.c detect-http-stat-code.h \ detect-ssl-version.c detect-ssl-version.h \ detect-ssl-state.c detect-ssl-state.h \ diff --git a/src/detect-engine-file.c b/src/detect-engine-file.c index 92a8804c68..2e62f1a8c8 100644 --- a/src/detect-engine-file.c +++ b/src/detect-engine-file.c @@ -104,6 +104,12 @@ static int DetectFileInspect(ThreadVars *tv, DetectEngineThreadCtx *det_ctx, Flo break; } + if (s->file_flags & FILE_SIG_NEED_FILECONTENT && file->chunks_head == NULL) { + SCLogDebug("sig needs file content, but we don't have any"); + r = 0; + break; + } + /* run the file match functions. */ for (sm = s->sm_lists[DETECT_SM_LIST_FILEMATCH]; sm != NULL; sm = sm->next) { SCLogDebug("sm %p, sm->next %p", sm, sm->next); diff --git a/src/detect-filemagic.c b/src/detect-filemagic.c new file mode 100644 index 0000000000..459c704e78 --- /dev/null +++ b/src/detect-filemagic.c @@ -0,0 +1,363 @@ +/* Copyright (C) 2007-2011 Open Information Security Foundation + * + * You can copy, redistribute or modify this Program 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 + * version 2 along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +/** + * \file + * + * \author Victor Julien + * + */ + +#include "suricata-common.h" +#include "threads.h" +#include "debug.h" +#include "decode.h" + +#include "detect.h" +#include "detect-parse.h" + +#include "detect-engine.h" +#include "detect-engine-mpm.h" +#include "detect-engine-state.h" + +#include "flow.h" +#include "flow-var.h" +#include "flow-util.h" + +#include "util-debug.h" +#include "util-spm-bm.h" +#include "util-magic.h" + +#include "util-unittest.h" +#include "util-unittest-helper.h" + +#include "app-layer.h" + +#include "stream-tcp.h" + +#include "detect-filemagic.h" + +int DetectFilemagicMatch (ThreadVars *, DetectEngineThreadCtx *, Flow *, uint8_t, void *, Signature *, SigMatch *); +static int DetectFilemagicSetup (DetectEngineCtx *, Signature *, char *); +void DetectFilemagicRegisterTests(void); +void DetectFilemagicFree(void *); + +/** + * \brief Registration function for keyword: filemagic + */ +void DetectFilemagicRegister(void) { + sigmatch_table[DETECT_FILEMAGIC].name = "filemagic"; + sigmatch_table[DETECT_FILEMAGIC].Match = NULL; + sigmatch_table[DETECT_FILEMAGIC].AppLayerMatch = DetectFilemagicMatch; + sigmatch_table[DETECT_FILEMAGIC].alproto = ALPROTO_HTTP; + sigmatch_table[DETECT_FILEMAGIC].Setup = DetectFilemagicSetup; + sigmatch_table[DETECT_FILEMAGIC].Free = DetectFilemagicFree; + sigmatch_table[DETECT_FILEMAGIC].RegisterTests = DetectFilemagicRegisterTests; + + SCLogDebug("registering filemagic rule option"); + return; +} + +#define FILEMAGIC_MIN_SIZE 512 + +/** + * \brief run the magic check + * + * \param file the file + * + * \retval -1 error + * \retval 0 ok + */ +static int FilemagicLookup(FlowFile *file) { + if (file == NULL || file->chunks_head == NULL) { + SCReturnInt(-1); + } + + if (file->chunks_head->len >= FILEMAGIC_MIN_SIZE) { + file->magic = MagicLookup(file->chunks_head->data, FILEMAGIC_MIN_SIZE); + } else { + uint8_t *buf = SCMalloc(FILEMAGIC_MIN_SIZE); + uint32_t size = 0; + + if (buf != NULL) { + FlowFileData *ffd = file->chunks_head; + + for ( ; ffd != NULL; ffd = ffd->next) { + uint32_t copy_len = ffd->len; + if (size + ffd->len > FILEMAGIC_MIN_SIZE) + copy_len = FILEMAGIC_MIN_SIZE - size; + + memcpy(buf + size, ffd->data, copy_len); + size += copy_len; + + if (size >= FILEMAGIC_MIN_SIZE) { + file->magic = MagicLookup(buf, size); + break; + } + + /* file is done but smaller than FILEMAGIC_MIN_SIZE */ + if (ffd->next == NULL && file->state >= FLOWFILE_STATE_CLOSED) { + file->magic = MagicLookup(buf, size); + break; + } + } + + SCFree(buf); + } + } + + SCReturnInt(0); +} + +/** + * \brief match the specified filemagic + * + * \param t pointer to thread vars + * \param det_ctx pointer to the pattern matcher thread + * \param p pointer to the current packet + * \param m pointer to the sigmatch that we will cast into DetectFilemagicData + * + * \retval 0 no match + * \retval 1 match + */ +int DetectFilemagicMatch (ThreadVars *t, DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags, void *state, Signature *s, SigMatch *m) +{ + SCEnter(); + int ret = 0; + + DetectFilemagicData *filemagic = m->ctx; + FlowFile *file = (FlowFile *)state; + + if (file->txid < det_ctx->tx_id) + SCReturnInt(0); + + if (file->txid > det_ctx->tx_id) + SCReturnInt(0); + + if (file->magic == NULL) { + FilemagicLookup(file); + } + + if (file->magic != NULL) { + SCLogDebug("magic %s", file->magic); + + if (BoyerMooreNocase(filemagic->name, filemagic->len, (uint8_t *)file->magic, + strlen(file->magic), filemagic->bm_ctx->bmGs, + filemagic->bm_ctx->bmBc) != NULL) + { +#ifdef DEBUG + if (SCLogDebugEnabled()) { + char *name = SCMalloc(filemagic->len + 1); + memcpy(name, filemagic->name, filemagic->len); + name[filemagic->len] = '\0'; + SCLogDebug("will look for filemagic %s", name); + } +#endif + + if (!(filemagic->flags & DETECT_CONTENT_NEGATED)) { + ret = 1; + } + } + + if (ret == 0 && filemagic->flags & DETECT_CONTENT_NEGATED) { + SCLogDebug("negated match"); + ret = 1; + } + } + + SCReturnInt(ret); +} + +/** + * \brief Parse the filemagic keyword + * + * \param idstr Pointer to the user provided option + * + * \retval filemagic pointer to DetectFilemagicData on success + * \retval NULL on failure + */ +DetectFilemagicData *DetectFilemagicParse (char *str) +{ + DetectFilemagicData *filemagic = NULL; + + /* We have a correct filemagic option */ + filemagic = SCMalloc(sizeof(DetectFilemagicData)); + if (filemagic == NULL) + goto error; + + memset(filemagic, 0x00, sizeof(DetectFilemagicData)); + + if (DetectParseContentString (str, &filemagic->name, &filemagic->len, &filemagic->flags) == -1) { + goto error; + } + + filemagic->bm_ctx = BoyerMooreCtxInit(filemagic->name, filemagic->len); + if (filemagic->bm_ctx == NULL) { + goto error; + } + + SCLogDebug("flags %02X", filemagic->flags); + if (filemagic->flags & DETECT_CONTENT_NEGATED) { + SCLogDebug("negated filemagic"); + } + + BoyerMooreCtxToNocase(filemagic->bm_ctx, filemagic->name, filemagic->len); +#ifdef DEBUG + if (SCLogDebugEnabled()) { + char *name = SCMalloc(filemagic->len + 1); + memcpy(name, filemagic->name, filemagic->len); + name[filemagic->len] = '\0'; + SCLogDebug("will look for filemagic %s", name); + } +#endif + + return filemagic; + +error: + if (filemagic != NULL) + DetectFilemagicFree(filemagic); + return NULL; +} + +/** + * \brief this function is used to parse filemagic options + * \brief into the current signature + * + * \param de_ctx pointer to the Detection Engine Context + * \param s pointer to the Current Signature + * \param str pointer to the user provided "filemagic" option + * + * \retval 0 on Success + * \retval -1 on Failure + */ +static int DetectFilemagicSetup (DetectEngineCtx *de_ctx, Signature *s, char *str) +{ + DetectFilemagicData *filemagic = NULL; + SigMatch *sm = NULL; + + filemagic = DetectFilemagicParse(str); + if (filemagic == NULL) + goto error; + + /* Okay so far so good, lets get this into a SigMatch + * and put it in the Signature. */ + sm = SigMatchAlloc(); + if (sm == NULL) + goto error; + + sm->type = DETECT_FILEMAGIC; + sm->ctx = (void *)filemagic; + + SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_FILEMATCH); + + if (s->alproto != ALPROTO_UNKNOWN && s->alproto != ALPROTO_HTTP) { + SCLogError(SC_ERR_CONFLICTING_RULE_KEYWORDS, "rule contains conflicting keywords."); + goto error; + } + + AppLayerHtpNeedFileInspection(); + + s->alproto = ALPROTO_HTTP; + + s->file_flags |= (FILE_SIG_NEED_FILE|FILE_SIG_NEED_FILECONTENT); + return 0; + +error: + if (filemagic != NULL) + DetectFilemagicFree(filemagic); + if (sm != NULL) + SCFree(sm); + return -1; +} + +/** + * \brief this function will free memory associated with DetectFilemagicData + * + * \param filemagic pointer to DetectFilemagicData + */ +void DetectFilemagicFree(void *ptr) { + if (ptr != NULL) { + DetectFilemagicData *filemagic = (DetectFilemagicData *)ptr; + if (filemagic->bm_ctx != NULL) { + BoyerMooreCtxDeInit(filemagic->bm_ctx); + } + SCFree(filemagic); + } +} + +#ifdef UNITTESTS /* UNITTESTS */ + +/** + * \test DetectFilemagicTestParse01 + */ +int DetectFilemagicTestParse01 (void) { + DetectFilemagicData *dnd = DetectFilemagicParse("secret.pdf"); + if (dnd != NULL) { + DetectFilemagicFree(dnd); + return 1; + } + return 0; +} + +/** + * \test DetectFilemagicTestParse02 + */ +int DetectFilemagicTestParse02 (void) { + int result = 0; + + DetectFilemagicData *dnd = DetectFilemagicParse("\"backup.tar.gz\""); + if (dnd != NULL) { + if (dnd->len == 13 && memcmp(dnd->name, "backup.tar.gz", 13) == 0) { + result = 1; + } + + DetectFilemagicFree(dnd); + return result; + } + return 0; +} + +/** + * \test DetectFilemagicTestParse03 + */ +int DetectFilemagicTestParse03 (void) { + int result = 0; + + DetectFilemagicData *dnd = DetectFilemagicParse("cmd.exe"); + if (dnd != NULL) { + if (dnd->len == 7 && memcmp(dnd->name, "cmd.exe", 7) == 0) { + result = 1; + } + + DetectFilemagicFree(dnd); + return result; + } + return 0; +} + +#endif /* UNITTESTS */ + +/** + * \brief this function registers unit tests for DetectFilemagic + */ +void DetectFilemagicRegisterTests(void) { +#ifdef UNITTESTS /* UNITTESTS */ + UtRegisterTest("DetectFilemagicTestParse01", DetectFilemagicTestParse01, 1); + UtRegisterTest("DetectFilemagicTestParse02", DetectFilemagicTestParse02, 1); + UtRegisterTest("DetectFilemagicTestParse03", DetectFilemagicTestParse03, 1); +#endif /* UNITTESTS */ +} diff --git a/src/detect-filemagic.h b/src/detect-filemagic.h new file mode 100644 index 0000000000..6aaddb5e01 --- /dev/null +++ b/src/detect-filemagic.h @@ -0,0 +1,39 @@ +/* Copyright (C) 2007-2011 Open Information Security Foundation + * + * You can copy, redistribute or modify this Program 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 + * version 2 along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +/** + * \file + * + * \author Victor Julien + */ + +#ifndef __DETECT_FILEMAGIC_H__ +#define __DETECT_FILEMAGIC_H__ + +#include "util-spm-bm.h" + +typedef struct DetectFilemagicData { + uint8_t *name; /** name of the file to match */ + BmCtx *bm_ctx; /** BM context */ + uint16_t len; /** name length */ + uint32_t flags; +} DetectFilemagicData; + +/* prototypes */ +void DetectFilemagicRegister (void); + +#endif /* __DETECT_FILEMAGIC_H__ */ diff --git a/src/detect-filename.c b/src/detect-filename.c index c6a80ea342..dbc1f7d497 100644 --- a/src/detect-filename.c +++ b/src/detect-filename.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2007-2010 Open Information Security Foundation +/* Copyright (C) 2007-2011 Open Information Security Foundation * * You can copy, redistribute or modify this Program under the terms of * the GNU General Public License version 2 as published by the Free diff --git a/src/detect.c b/src/detect.c index e36c55d6c6..1cfcff8830 100644 --- a/src/detect.c +++ b/src/detect.c @@ -93,6 +93,7 @@ #include "detect-filename.h" #include "detect-fileext.h" #include "detect-filestore.h" +#include "detect-filemagic.h" #include "detect-dsize.h" #include "detect-flowvar.h" #include "detect-flowint.h" @@ -4333,6 +4334,7 @@ void SigTableSetup(void) { DetectFilenameRegister(); DetectFileextRegister(); DetectFilestoreRegister(); + DetectFilemagicRegister(); uint8_t i = 0; for (i = 0; i < DETECT_TBLSIZE; i++) { diff --git a/src/detect.h b/src/detect.h index f993bec4de..18fe75cd3e 100644 --- a/src/detect.h +++ b/src/detect.h @@ -1042,6 +1042,7 @@ enum { DETECT_FILENAME, DETECT_FILEEXT, DETECT_FILESTORE, + DETECT_FILEMAGIC, /* make sure this stays last */ DETECT_TBLSIZE, diff --git a/src/flow-file.h b/src/flow-file.h index cdcb403dbc..5753f51205 100644 --- a/src/flow-file.h +++ b/src/flow-file.h @@ -58,6 +58,7 @@ typedef struct FlowFile_ { uint16_t name_len; int16_t state; int fd; /**< file discriptor for storing files */ + const char *magic; FlowFileData *chunks_head; FlowFileData *chunks_tail; struct FlowFile_ *next;