mirror of https://github.com/OISF/suricata
Add filemd5 keyword that loads a list of md5's to match a file's md5 against.
Victor Julien
13 years ago
parent
8cfc23ee22
commit
9f7588a756
@ -0,0 +1,361 @@
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/* Copyright (C) 2007-2012 Open Information Security Foundation
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*
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* You can copy, redistribute or modify this Program under the terms of
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* the GNU General Public License version 2 as published by the Free
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* Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* version 2 along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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/**
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* \file
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*
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* \author Victor Julien <victor@inliniac.net>
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*
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*/
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#include "suricata-common.h"
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#include "threads.h"
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#include "debug.h"
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#include "decode.h"
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#include "detect.h"
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#include "detect-parse.h"
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#include "detect-engine.h"
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#include "detect-engine-mpm.h"
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#include "detect-engine-state.h"
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#include "flow.h"
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#include "flow-var.h"
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#include "flow-util.h"
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#include "util-debug.h"
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#include "util-spm-bm.h"
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#include "util-print.h"
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#include "util-unittest.h"
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#include "util-unittest-helper.h"
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#include "app-layer.h"
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#include "stream-tcp.h"
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#include "detect-filemd5.h"
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#include "queue.h"
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#include "util-rohash.h"
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int DetectFileMd5Match (ThreadVars *, DetectEngineThreadCtx *, Flow *, uint8_t, void *, Signature *, SigMatch *);
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static int DetectFileMd5Setup (DetectEngineCtx *, Signature *, char *);
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void DetectFileMd5RegisterTests(void);
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void DetectFileMd5Free(void *);
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/**
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* \brief Registration function for keyword: filemd5
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*/
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void DetectFileMd5Register(void) {
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sigmatch_table[DETECT_FILEMD5].name = "filemd5";
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sigmatch_table[DETECT_FILEMD5].Match = NULL;
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sigmatch_table[DETECT_FILEMD5].AppLayerMatch = DetectFileMd5Match;
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sigmatch_table[DETECT_FILEMD5].alproto = ALPROTO_HTTP;
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sigmatch_table[DETECT_FILEMD5].Setup = DetectFileMd5Setup;
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sigmatch_table[DETECT_FILEMD5].Free = DetectFileMd5Free;
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sigmatch_table[DETECT_FILEMD5].RegisterTests = DetectFileMd5RegisterTests;
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SCLogDebug("registering filemd5 rule option");
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return;
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}
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static int Md5ReadString(uint8_t *md5, char *str) {
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if (strlen(str) != 32) {
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SCLogError(SC_ERR_INVALID_MD5, "md5 string not 32 bytes");
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return -1;
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}
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int i, x;
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for (x = 0, i = 0; i < 32; i+=2, x++) {
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char buf[3] = { 0, 0, 0};
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buf[0] = str[i];
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buf[1] = str[i+1];
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long value = strtol(buf, NULL, 16);
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if (value >= 0 && value <= 255)
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md5[x] = (uint8_t)value;
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else {
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SCLogError(SC_ERR_INVALID_MD5, "md5 byte out of range %ld", value);
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return -1;
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}
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}
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return 1;
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}
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static int MD5LoadHash(ROHashTable *hash, char *string) {
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uint8_t md5[16];
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if (Md5ReadString(md5, string) == 1) {
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if (ROHashInitQueueValue(hash, &md5, (uint16_t)sizeof(md5)) != 1)
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return -1;
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}
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return 1;
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}
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static int MD5MatchLookupBuffer(ROHashTable *hash, uint8_t *buf, size_t buflen) {
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void *ptr = ROHashLookup(hash, buf, (uint16_t)buflen);
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if (ptr == NULL)
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return 0;
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else
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return 1;
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}
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static int MD5MatchLookupString(ROHashTable *hash, char *string) {
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uint8_t md5[16];
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if (Md5ReadString(md5, string) == 1) {
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void *ptr = ROHashLookup(hash, &md5, (uint16_t)sizeof(md5));
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if (ptr == NULL)
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return 0;
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else
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return 1;
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}
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return 0;
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}
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/**
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* \brief match the specified filemd5
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*
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* \param t pointer to thread vars
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* \param det_ctx pointer to the pattern matcher thread
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* \param p pointer to the current packet
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* \param m pointer to the sigmatch that we will cast into DetectFileMd5Data
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*
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* \retval 0 no match
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* \retval 1 match
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*/
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int DetectFileMd5Match (ThreadVars *t, DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags, void *state, Signature *s, SigMatch *m)
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{
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SCEnter();
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int ret = 0;
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DetectFileMd5Data *filemd5 = (DetectFileMd5Data *)m->ctx;
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File *file = (File *)state;
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if (file->txid < det_ctx->tx_id) {
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SCReturnInt(0);
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}
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if (file->txid > det_ctx->tx_id) {
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SCReturnInt(0);
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}
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if (file->state != FILE_STATE_CLOSED) {
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SCReturnInt(0);
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}
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if (file->flags & FILE_MD5) {
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if (MD5MatchLookupBuffer(filemd5->hash, file->md5, sizeof(file->md5)) == 1) {
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ret = 1;
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}
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}
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SCReturnInt(ret);
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}
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/**
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* \brief Parse the filemd5 keyword
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*
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* \param idstr Pointer to the user provided option
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*
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* \retval filemd5 pointer to DetectFileMd5Data on success
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* \retval NULL on failure
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*/
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DetectFileMd5Data *DetectFileMd5Parse (char *str)
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{
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DetectFileMd5Data *filemd5 = NULL;
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/* We have a correct filemd5 option */
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filemd5 = SCMalloc(sizeof(DetectFileMd5Data));
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if (filemd5 == NULL)
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goto error;
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memset(filemd5, 0x00, sizeof(DetectFileMd5Data));
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filemd5->hash = ROHashInit(18, 16);
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if (filemd5->hash == NULL) {
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goto error;
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}
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/* get full filename */
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char *filename = DetectLoadCompleteSigPath(str);
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if (filename == NULL) {
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goto error;
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}
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char line[8192] = "";
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FILE *fp = fopen(filename, "r");
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if (fp == NULL) {
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SCLogError(SC_ERR_OPENING_RULE_FILE, "opening md5 file %s: %s", filename, strerror(errno));
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return NULL;
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}
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while(fgets(line, (int)sizeof(line), fp) != NULL) {
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size_t len = strlen(line);
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/* ignore comments and empty lines */
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if (line[0] == '\n' || line [0] == '\r' || line[0] == ' ' || line[0] == '#' || line[0] == '\t')
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continue;
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while (isspace(line[--len]));
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/* Check if we have a trailing newline, and remove it */
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len = strlen(line);
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if (len > 0 && (line[len - 1] == '\n' || line[len - 1] == '\r')) {
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line[len - 1] = '\0';
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}
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/* cut off longer lines */
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if (strlen(line) > 32)
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line[32] = 0x00;
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if (MD5LoadHash(filemd5->hash, line) != 1) {
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goto error;
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}
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}
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fclose(fp);
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fp = NULL;
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if (ROHashInitFinalize(filemd5->hash) != 1) {
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goto error;
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}
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SCLogInfo("MD5 hash size %u bytes", ROHashMemorySize(filemd5->hash));
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return filemd5;
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error:
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if (filemd5 != NULL)
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DetectFileMd5Free(filemd5);
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return NULL;
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}
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/**
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* \brief this function is used to parse filemd5 options
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* \brief into the current signature
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*
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* \param de_ctx pointer to the Detection Engine Context
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* \param s pointer to the Current Signature
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* \param str pointer to the user provided "filemd5" option
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*
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* \retval 0 on Success
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* \retval -1 on Failure
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*/
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static int DetectFileMd5Setup (DetectEngineCtx *de_ctx, Signature *s, char *str)
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{
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DetectFileMd5Data *filemd5 = NULL;
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SigMatch *sm = NULL;
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filemd5 = DetectFileMd5Parse(str);
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if (filemd5 == NULL)
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goto error;
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/* Okay so far so good, lets get this into a SigMatch
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* and put it in the Signature. */
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sm = SigMatchAlloc();
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if (sm == NULL)
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goto error;
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sm->type = DETECT_FILEMD5;
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sm->ctx = (void *)filemd5;
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SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_FILEMATCH);
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if (s->alproto != ALPROTO_UNKNOWN && s->alproto != ALPROTO_HTTP) {
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SCLogError(SC_ERR_CONFLICTING_RULE_KEYWORDS, "rule contains conflicting keywords.");
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goto error;
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}
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AppLayerHtpNeedFileInspection();
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/** \todo remove this once we support more than http */
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s->alproto = ALPROTO_HTTP;
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s->file_flags |= (FILE_SIG_NEED_FILE|FILE_SIG_NEED_FILEMD5);
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return 0;
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error:
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if (filemd5 != NULL)
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DetectFileMd5Free(filemd5);
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if (sm != NULL)
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SCFree(sm);
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return -1;
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}
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/**
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* \brief this function will free memory associated with DetectFileMd5Data
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*
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* \param filemd5 pointer to DetectFileMd5Data
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*/
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void DetectFileMd5Free(void *ptr) {
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if (ptr != NULL) {
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DetectFileMd5Data *filemd5 = (DetectFileMd5Data *)ptr;
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SCFree(filemd5);
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}
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}
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#ifdef UNITTESTS
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static int MD5MatchTest01(void) {
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ROHashTable *hash = ROHashInit(4, 16);
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if (hash == NULL) {
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return 0;
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}
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if (MD5LoadHash(hash, "d80f93a93dc5f3ee945704754d6e0a36") != 1)
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return 0;
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if (MD5LoadHash(hash, "92a49985b384f0d993a36e4c2d45e206") != 1)
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return 0;
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if (MD5LoadHash(hash, "11adeaacc8c309815f7bc3e33888f281") != 1)
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return 0;
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if (MD5LoadHash(hash, "22e10a8fe02344ade0bea8836a1714af") != 1)
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return 0;
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if (MD5LoadHash(hash, "c3db2cbf02c68f073afcaee5634677bc") != 1)
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return 0;
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if (MD5LoadHash(hash, "7ed095da259638f42402fb9e74287a17") != 1)
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return 0;
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if (ROHashInitFinalize(hash) != 1) {
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return 0;
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}
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if (MD5MatchLookupString(hash, "d80f93a93dc5f3ee945704754d6e0a36") != 1)
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return 0;
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if (MD5MatchLookupString(hash, "92a49985b384f0d993a36e4c2d45e206") != 1)
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return 0;
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if (MD5MatchLookupString(hash, "11adeaacc8c309815f7bc3e33888f281") != 1)
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return 0;
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if (MD5MatchLookupString(hash, "22e10a8fe02344ade0bea8836a1714af") != 1)
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return 0;
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if (MD5MatchLookupString(hash, "c3db2cbf02c68f073afcaee5634677bc") != 1)
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return 0;
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if (MD5MatchLookupString(hash, "7ed095da259638f42402fb9e74287a17") != 1)
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return 0;
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/* shouldnt match */
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if (MD5MatchLookupString(hash, "33333333333333333333333333333333") == 1)
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return 0;
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ROHashFree(hash);
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return 1;
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}
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#endif
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void DetectFileMd5RegisterTests(void) {
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#ifdef UNITTESTS
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UtRegisterTest("MD5MatchTest01", MD5MatchTest01, 1);
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#endif
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}
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@ -0,0 +1,36 @@
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/* Copyright (C) 2007-2012 Open Information Security Foundation
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*
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* You can copy, redistribute or modify this Program under the terms of
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* the GNU General Public License version 2 as published by the Free
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||||
* Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* version 2 along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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/**
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* \file
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*
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* \author Victor Julien <victor@inliniac.net>
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*/
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#ifndef __DETECT_FILEMD5_H__
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#define __DETECT_FILEMD5_H__
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#include "util-rohash.h"
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typedef struct DetectFileMd5Data {
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ROHashTable *hash;
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} DetectFileMd5Data;
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/* prototypes */
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void DetectFileMd5cRegister (void);
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#endif /* __DETECT_FILEMD5_H__ */
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