--- /dev/null
+/* Copyright (C) 2007-2012 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 <victor@inliniac.net>
+ *
+ */
+
+#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-print.h"
+
+#include "util-unittest.h"
+#include "util-unittest-helper.h"
+
+#include "app-layer.h"
+
+#include "stream-tcp.h"
+
+#include "detect-filemd5.h"
+
+#include "queue.h"
+#include "util-rohash.h"
+
+int DetectFileMd5Match (ThreadVars *, DetectEngineThreadCtx *, Flow *, uint8_t, void *, Signature *, SigMatch *);
+static int DetectFileMd5Setup (DetectEngineCtx *, Signature *, char *);
+void DetectFileMd5RegisterTests(void);
+void DetectFileMd5Free(void *);
+
+/**
+ * \brief Registration function for keyword: filemd5
+ */
+void DetectFileMd5Register(void) {
+ sigmatch_table[DETECT_FILEMD5].name = "filemd5";
+ sigmatch_table[DETECT_FILEMD5].Match = NULL;
+ sigmatch_table[DETECT_FILEMD5].AppLayerMatch = DetectFileMd5Match;
+ sigmatch_table[DETECT_FILEMD5].alproto = ALPROTO_HTTP;
+ sigmatch_table[DETECT_FILEMD5].Setup = DetectFileMd5Setup;
+ sigmatch_table[DETECT_FILEMD5].Free = DetectFileMd5Free;
+ sigmatch_table[DETECT_FILEMD5].RegisterTests = DetectFileMd5RegisterTests;
+
+ SCLogDebug("registering filemd5 rule option");
+ return;
+}
+
+static int Md5ReadString(uint8_t *md5, char *str) {
+ if (strlen(str) != 32) {
+ SCLogError(SC_ERR_INVALID_MD5, "md5 string not 32 bytes");
+ return -1;
+ }
+
+ int i, x;
+ for (x = 0, i = 0; i < 32; i+=2, x++) {
+ char buf[3] = { 0, 0, 0};
+ buf[0] = str[i];
+ buf[1] = str[i+1];
+
+ long value = strtol(buf, NULL, 16);
+ if (value >= 0 && value <= 255)
+ md5[x] = (uint8_t)value;
+ else {
+ SCLogError(SC_ERR_INVALID_MD5, "md5 byte out of range %ld", value);
+ return -1;
+ }
+ }
+
+ return 1;
+}
+
+static int MD5LoadHash(ROHashTable *hash, char *string) {
+ uint8_t md5[16];
+
+ if (Md5ReadString(md5, string) == 1) {
+ if (ROHashInitQueueValue(hash, &md5, (uint16_t)sizeof(md5)) != 1)
+ return -1;
+ }
+
+ return 1;
+}
+
+static int MD5MatchLookupBuffer(ROHashTable *hash, uint8_t *buf, size_t buflen) {
+ void *ptr = ROHashLookup(hash, buf, (uint16_t)buflen);
+ if (ptr == NULL)
+ return 0;
+ else
+ return 1;
+}
+
+static int MD5MatchLookupString(ROHashTable *hash, char *string) {
+ uint8_t md5[16];
+ if (Md5ReadString(md5, string) == 1) {
+ void *ptr = ROHashLookup(hash, &md5, (uint16_t)sizeof(md5));
+ if (ptr == NULL)
+ return 0;
+ else
+ return 1;
+ }
+ return 0;
+}
+
+/**
+ * \brief match the specified filemd5
+ *
+ * \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 DetectFileMd5Data
+ *
+ * \retval 0 no match
+ * \retval 1 match
+ */
+int DetectFileMd5Match (ThreadVars *t, DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags, void *state, Signature *s, SigMatch *m)
+{
+ SCEnter();
+ int ret = 0;
+ DetectFileMd5Data *filemd5 = (DetectFileMd5Data *)m->ctx;
+
+ File *file = (File *)state;
+
+ if (file->txid < det_ctx->tx_id) {
+ SCReturnInt(0);
+ }
+
+ if (file->txid > det_ctx->tx_id) {
+ SCReturnInt(0);
+ }
+
+ if (file->state != FILE_STATE_CLOSED) {
+ SCReturnInt(0);
+ }
+
+ if (file->flags & FILE_MD5) {
+ if (MD5MatchLookupBuffer(filemd5->hash, file->md5, sizeof(file->md5)) == 1) {
+ ret = 1;
+ }
+ }
+
+ SCReturnInt(ret);
+}
+
+/**
+ * \brief Parse the filemd5 keyword
+ *
+ * \param idstr Pointer to the user provided option
+ *
+ * \retval filemd5 pointer to DetectFileMd5Data on success
+ * \retval NULL on failure
+ */
+DetectFileMd5Data *DetectFileMd5Parse (char *str)
+{
+ DetectFileMd5Data *filemd5 = NULL;
+
+ /* We have a correct filemd5 option */
+ filemd5 = SCMalloc(sizeof(DetectFileMd5Data));
+ if (filemd5 == NULL)
+ goto error;
+
+ memset(filemd5, 0x00, sizeof(DetectFileMd5Data));
+
+ filemd5->hash = ROHashInit(18, 16);
+ if (filemd5->hash == NULL) {
+ goto error;
+ }
+
+ /* get full filename */
+ char *filename = DetectLoadCompleteSigPath(str);
+ if (filename == NULL) {
+ goto error;
+ }
+
+ char line[8192] = "";
+ FILE *fp = fopen(filename, "r");
+ if (fp == NULL) {
+ SCLogError(SC_ERR_OPENING_RULE_FILE, "opening md5 file %s: %s", filename, strerror(errno));
+ return NULL;
+ }
+
+ while(fgets(line, (int)sizeof(line), fp) != NULL) {
+ size_t len = strlen(line);
+
+ /* ignore comments and empty lines */
+ if (line[0] == '\n' || line [0] == '\r' || line[0] == ' ' || line[0] == '#' || line[0] == '\t')
+ continue;
+
+ while (isspace(line[--len]));
+
+ /* Check if we have a trailing newline, and remove it */
+ len = strlen(line);
+ if (len > 0 && (line[len - 1] == '\n' || line[len - 1] == '\r')) {
+ line[len - 1] = '\0';
+ }
+
+ /* cut off longer lines */
+ if (strlen(line) > 32)
+ line[32] = 0x00;
+
+ if (MD5LoadHash(filemd5->hash, line) != 1) {
+ goto error;
+ }
+ }
+ fclose(fp);
+ fp = NULL;
+
+ if (ROHashInitFinalize(filemd5->hash) != 1) {
+ goto error;
+ }
+ SCLogInfo("MD5 hash size %u bytes", ROHashMemorySize(filemd5->hash));
+
+ return filemd5;
+
+error:
+ if (filemd5 != NULL)
+ DetectFileMd5Free(filemd5);
+ return NULL;
+}
+
+/**
+ * \brief this function is used to parse filemd5 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 "filemd5" option
+ *
+ * \retval 0 on Success
+ * \retval -1 on Failure
+ */
+static int DetectFileMd5Setup (DetectEngineCtx *de_ctx, Signature *s, char *str)
+{
+ DetectFileMd5Data *filemd5 = NULL;
+ SigMatch *sm = NULL;
+
+ filemd5 = DetectFileMd5Parse(str);
+ if (filemd5 == 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_FILEMD5;
+ sm->ctx = (void *)filemd5;
+
+ 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();
+
+ /** \todo remove this once we support more than http */
+ s->alproto = ALPROTO_HTTP;
+
+ s->file_flags |= (FILE_SIG_NEED_FILE|FILE_SIG_NEED_FILEMD5);
+ return 0;
+
+error:
+ if (filemd5 != NULL)
+ DetectFileMd5Free(filemd5);
+ if (sm != NULL)
+ SCFree(sm);
+ return -1;
+}
+
+/**
+ * \brief this function will free memory associated with DetectFileMd5Data
+ *
+ * \param filemd5 pointer to DetectFileMd5Data
+ */
+void DetectFileMd5Free(void *ptr) {
+ if (ptr != NULL) {
+ DetectFileMd5Data *filemd5 = (DetectFileMd5Data *)ptr;
+ SCFree(filemd5);
+ }
+}
+
+#ifdef UNITTESTS
+static int MD5MatchTest01(void) {
+ ROHashTable *hash = ROHashInit(4, 16);
+ if (hash == NULL) {
+ return 0;
+ }
+ if (MD5LoadHash(hash, "d80f93a93dc5f3ee945704754d6e0a36") != 1)
+ return 0;
+ if (MD5LoadHash(hash, "92a49985b384f0d993a36e4c2d45e206") != 1)
+ return 0;
+ if (MD5LoadHash(hash, "11adeaacc8c309815f7bc3e33888f281") != 1)
+ return 0;
+ if (MD5LoadHash(hash, "22e10a8fe02344ade0bea8836a1714af") != 1)
+ return 0;
+ if (MD5LoadHash(hash, "c3db2cbf02c68f073afcaee5634677bc") != 1)
+ return 0;
+ if (MD5LoadHash(hash, "7ed095da259638f42402fb9e74287a17") != 1)
+ return 0;
+
+ if (ROHashInitFinalize(hash) != 1) {
+ return 0;
+ }
+
+ if (MD5MatchLookupString(hash, "d80f93a93dc5f3ee945704754d6e0a36") != 1)
+ return 0;
+ if (MD5MatchLookupString(hash, "92a49985b384f0d993a36e4c2d45e206") != 1)
+ return 0;
+ if (MD5MatchLookupString(hash, "11adeaacc8c309815f7bc3e33888f281") != 1)
+ return 0;
+ if (MD5MatchLookupString(hash, "22e10a8fe02344ade0bea8836a1714af") != 1)
+ return 0;
+ if (MD5MatchLookupString(hash, "c3db2cbf02c68f073afcaee5634677bc") != 1)
+ return 0;
+ if (MD5MatchLookupString(hash, "7ed095da259638f42402fb9e74287a17") != 1)
+ return 0;
+ /* shouldnt match */
+ if (MD5MatchLookupString(hash, "33333333333333333333333333333333") == 1)
+ return 0;
+
+ ROHashFree(hash);
+ return 1;
+}
+#endif
+
+void DetectFileMd5RegisterTests(void) {
+#ifdef UNITTESTS
+ UtRegisterTest("MD5MatchTest01", MD5MatchTest01, 1);
+#endif
+}
projects / thirdparty / suricata.git / commitdiff
