smb: add smb.version keyword

Ticket: OISF#5075

Signed-off-by: jason taylor <[email protected]>

rust/src/smb/detect.rs

@@ -21,6 +21,9 @@ use crate::smb::smb::*;
 use crate::dcerpc::detect::{DCEIfaceData, DCEOpnumData, DETECT_DCE_OPNUM_RANGE_UNINITIALIZED};
 use crate::dcerpc::dcerpc::DCERPC_TYPE_REQUEST;
 use crate::detect::uint::detect_match_uint;
+use std::ffi::CStr;
+use std::os::raw::{c_char, c_void};
+use crate::smb::smb::SMBTransaction;
 
 #[no_mangle]
 pub unsafe extern "C" fn rs_smb_tx_get_share(tx: &mut SMBTransaction,
@@ -192,3 +195,70 @@ pub unsafe extern "C" fn rs_smb_tx_get_ntlmssp_domain(tx: &mut SMBTransaction,
     *buffer_len = 0;
     return 0;
 }
+
+#[no_mangle]
+pub unsafe extern "C" fn rs_smb_version_match(
+    tx: &mut SMBTransaction, version_data: &mut u8,
+) -> u8 {
+
+    let version = tx.vercmd.get_version();
+    if version == *version_data {
+        return 1;
+    }
+
+    return 0;
+}
+
+
+#[no_mangle]
+pub unsafe extern "C" fn rs_smb_version_parse(carg: *const c_char) -> *mut c_void {
+    if carg.is_null() {
+        return std::ptr::null_mut();
+    }
+
+    if let Ok(arg) = CStr::from_ptr(carg).to_str() {
+        if let Ok(detect) = parse_version_data(arg) {
+            return Box::into_raw(Box::new(detect)) as *mut _;
+        }
+    }
+
+    return std::ptr::null_mut();
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn rs_smb_version_free(ptr: *mut c_void) {
+    if ptr != std::ptr::null_mut() {
+        std::mem::drop(Box::from_raw(ptr as *mut u8));
+    }
+}
+
+fn parse_version_data(arg: &str) -> Result<u8, ()> {
+    let arg = arg.trim();
+    let version = u8::from_str_radix(&arg, 10).map_err(|_| ())?;
+
+    if version != 1 && version != 2 {
+        return Err(());
+    }
+
+    return Ok(version);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_cmd_data() {
+        assert_eq!(Err(()), parse_version_data("0"));
+        assert_eq!(1u8, parse_version_data("1").unwrap());
+        assert_eq!(2u8, parse_version_data("2").unwrap());
+        assert_eq!(Err(()), parse_version_data("3"));
+    }
+
+    #[test]
+    fn test_parse_cmd_data_with_spaces() {
+        assert_eq!(1u8, parse_version_data(" 1").unwrap());
+        assert_eq!(2u8, parse_version_data(" 2 ").unwrap());
+    }
+
+}

src/Makefile.am

@@ -296,6 +296,7 @@ noinst_HEADERS = \
 	detect-sip-uri.h \
 	detect-smb-ntlmssp.h \
 	detect-smb-share.h \
+	detect-smb-version.h \
 	detect-snmp-community.h \
 	detect-snmp-pdu_type.h \
 	detect-snmp-usm.h \
@@ -913,6 +914,7 @@ libsuricata_c_a_SOURCES = \
 	detect-sip-uri.c \
 	detect-smb-ntlmssp.c \
 	detect-smb-share.c \
+	detect-smb-version.c \
 	detect-snmp-community.c \
 	detect-snmp-pdu_type.c \
 	detect-snmp-usm.c \

src/detect-engine-register.c

@@ -80,6 +80,7 @@
 #include "detect-config.h"
 
 #include "detect-smb-share.h"
+#include "detect-smb-version.h"
 
 #include "detect-base64-decode.h"
 #include "detect-base64-data.h"
@@ -618,6 +619,8 @@ void SigTableSetup(void)
     DetectSmbShareRegister();
     DetectSmbNtlmsspUserRegister();
     DetectSmbNtlmsspDomainRegister();
+    DetectSmbVersionRegister();
+
     DetectTlsRegister();
     DetectTlsValidityRegister();
     DetectTlsVersionRegister();

src/detect-engine-register.h

@@ -203,6 +203,7 @@ enum DetectKeywordId {
     DETECT_SMB_SHARE,
     DETECT_SMB_NTLMSSP_USER,
     DETECT_SMB_NTLMSSP_DOMAIN,
+    DETECT_SMB_VERSION,
 
     DETECT_ASN1,
 

src/detect-smb-version.c

@@ -0,0 +1,155 @@
+/* Copyright (C) 2022-2023 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 Eloy Pérez
+ * \author Jason Taylor
+ *
+ * Implements the smb.version keyword
+ */
+
+#include "suricata-common.h"
+
+#include "detect.h"
+#include "detect-parse.h"
+
+#include "detect-engine.h"
+#include "detect-engine-mpm.h"
+#include "detect-engine-state.h"
+#include "detect-engine-prefilter.h"
+#include "detect-engine-content-inspection.h"
+
+#include "detect-smb-version.h"
+#include "rust.h"
+
+#define BUFFER_NAME  "smb_version"
+#define KEYWORD_NAME "smb.version"
+#define KEYWORD_ID   DETECT_SMB_VERSION
+
+static int g_smb_version_list_id = 0;
+
+static void DetectSmbVersionFree(DetectEngineCtx *de_ctx, void *ptr)
+{
+
+    SCLogDebug("smb_version: DetectSmbVersionFree");
+    rs_smb_version_free(ptr);
+}
+
+/**
+ * \brief Creates a SigMatch for the "smb.version" keyword being sent as argument,
+ *        and appends it to the rs_smb_version_match Signature(s).
+ *
+ * \param de_ctx Pointer to the detection engine context.
+ * \param s      Pointer to signature for the current Signature being parsed
+ *               from the rules.
+ * \param arg    Pointer to the string holding the keyword value.
+ *
+ * \retval 0 on success, -1 on failure
+ */
+
+static int DetectSmbVersionSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg)
+{
+    SCLogDebug("smb_version: DetectSmbVersionSetup");
+
+    if (DetectSignatureSetAppProto(s, ALPROTO_SMB) < 0)
+        return -1;
+
+    if (arg == NULL) {
+        SCLogError("Error parsing smb.version option in signature, it needs a value");
+        return -1;
+    }
+
+    if (DetectGetLastSMFromLists(s, DETECT_SMB_VERSION, -1)) {
+        SCLogError("Can't use 2 or more smb.version declarations in "
+                   "the same sig. Invalidating signature.");
+        return -1;
+    }
+
+    void *dod = rs_smb_version_parse(arg);
+
+    if (dod == NULL) {
+        SCLogError("Error parsing smb.version option in signature");
+        return -1;
+    }
+
+    if (SigMatchAppendSMToList(
+                de_ctx, s, DETECT_SMB_VERSION, (SigMatchCtx *)dod, g_smb_version_list_id) == NULL) {
+        DetectSmbVersionFree(de_ctx, dod);
+        return -1;
+    }
+
+    return 0;
+}
+
+/**
+ * \brief App layer match function for the "smb.version" keyword.
+ *
+ * \param t       Pointer to the ThreadVars instance.
+ * \param det_ctx Pointer to the DetectEngineThreadCtx.
+ * \param f       Pointer to the flow.
+ * \param flags   Pointer to the flags indicating the flow direction.
+ * \param state   Pointer to the app layer state data.
+ * \param s       Pointer to the Signature instance.
+ * \param m       Pointer to the SigMatch.
+ *
+ * \retval 1 On Match.
+ * \retval 0 On no match.
+ */
+
+static int DetectSmbVersionMatchRust(DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags,
+        void *state, void *txv, const Signature *s, const SigMatchCtx *m)
+{
+
+    SCLogDebug("smb_version: DetectSmbVersionMatchRust");
+
+    int matchvalue = rs_smb_version_match(txv, (void *)m);
+
+    if (matchvalue != 1) {
+        SCLogDebug("rs_smb_version_match: didn't match");
+        SCReturnInt(0);
+    } else {
+        SCLogDebug("rs_smb_version_match: matched!");
+        return matchvalue;
+    }
+}
+
+/**
+ * \brief Registers the keyword handlers for the "smb_version" keyword.
+ */
+
+void DetectSmbVersionRegister(void)
+{
+    sigmatch_table[DETECT_SMB_VERSION].name = KEYWORD_NAME;
+    sigmatch_table[DETECT_SMB_VERSION].Setup = DetectSmbVersionSetup;
+    sigmatch_table[DETECT_SMB_VERSION].Match = NULL;
+    sigmatch_table[DETECT_SMB_VERSION].AppLayerTxMatch = DetectSmbVersionMatchRust;
+    sigmatch_table[DETECT_SMB_VERSION].Free = DetectSmbVersionFree;
+    sigmatch_table[DETECT_SMB_VERSION].desc = "smb keyword to match on SMB version";
+    sigmatch_table[DETECT_FLOW_AGE].url = "/rules/smb-keywords.html#smb-version";
+
+    DetectAppLayerInspectEngineRegister(
+            BUFFER_NAME, ALPROTO_SMB, SIG_FLAG_TOSERVER, 0, DetectEngineInspectGenericList, NULL);
+
+    DetectAppLayerInspectEngineRegister(
+            BUFFER_NAME, ALPROTO_SMB, SIG_FLAG_TOCLIENT, 0, DetectEngineInspectGenericList, NULL);
+
+    g_smb_version_list_id = DetectBufferTypeRegister(BUFFER_NAME);
+
+    SCLogDebug("registering " BUFFER_NAME " rule option");
+}

src/detect-smb-version.h

@@ -0,0 +1,25 @@
+/* Copyright (C) 2022-2023 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.
+ */
+
+#ifndef __DETECT_SMB_VERSION_H__
+#define __DETECT_SMB_VERSION_H__
+
+/** \brief registers the keyword into the engine. Called from
+ *         detect.c::SigTableSetup() */
+void DetectSmbVersionRegister(void);
+
+#endif /* __DETECT_SMB_VERSION_H__ */