From e0131f60987040f1dcaa7e171a2f04ebd2b09198 Mon Sep 17 00:00:00 2001 From: Jeff Lucovsky Date: Thu, 27 Mar 2025 10:30:47 -0400 Subject: [PATCH] detect/ftp: Add ftp.reply rule keyword Issue: 7508 Add the rule detection keyword "ftp.reply". This is a multi-buffer command. --- src/Makefile.am | 2 + src/detect-engine-register.c | 2 + src/detect-engine-register.h | 1 + src/detect-ftp-reply.c | 114 +++++++++++++++++++++++++++++++++++ src/detect-ftp-reply.h | 29 +++++++++ 5 files changed, 148 insertions(+) create mode 100644 src/detect-ftp-reply.c create mode 100644 src/detect-ftp-reply.h diff --git a/src/Makefile.am b/src/Makefile.am index e436335629..dadd0cf405 100755 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -172,6 +172,7 @@ noinst_HEADERS = \ detect-ftpdata.h \ detect-ftp-command.h \ detect-ftp-command-data.h \ + detect-ftp-reply.h \ detect-geoip.h \ detect-gid.h \ detect.h \ @@ -761,6 +762,7 @@ libsuricata_c_a_SOURCES = \ detect-ftpdata.c \ detect-ftp-command.c \ detect-ftp-command-data.c \ + detect-ftp-reply.c \ detect-geoip.c \ detect-gid.c \ detect-hostbits.c \ diff --git a/src/detect-engine-register.c b/src/detect-engine-register.c index 2ec99aad85..97ef5075d3 100644 --- a/src/detect-engine-register.c +++ b/src/detect-engine-register.c @@ -215,6 +215,7 @@ #include "detect-ftp-command.h" #include "detect-entropy.h" #include "detect-ftp-command-data.h" +#include "detect-ftp-reply.h" #include "detect-bypass.h" #include "detect-ftpdata.h" @@ -719,6 +720,7 @@ void SigTableSetup(void) DetectJa4HashRegister(); DetectFtpCommandRegister(); DetectFtpCommandDataRegister(); + DetectFtpReplyRegister(); DetectBypassRegister(); DetectConfigRegister(); diff --git a/src/detect-engine-register.h b/src/detect-engine-register.h index 08246a4f19..dbadd4d206 100644 --- a/src/detect-engine-register.h +++ b/src/detect-engine-register.h @@ -335,6 +335,7 @@ enum DetectKeywordId { DETECT_FTP_COMMAND, DETECT_FTP_COMMAND_DATA, + DETECT_FTP_REPLY, DETECT_VLAN_ID, DETECT_VLAN_LAYERS, diff --git a/src/detect-ftp-reply.c b/src/detect-ftp-reply.c new file mode 100644 index 0000000000..f90e7d5328 --- /dev/null +++ b/src/detect-ftp-reply.c @@ -0,0 +1,114 @@ +/* Copyright (C) 2025 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. + */ + +/** + * + * \author Jeff Lucovsky + * + * Implements the ftp.reply sticky buffer + * + */ + +#include "suricata-common.h" + +#include "detect.h" +#include "detect-parse.h" +#include "detect-engine.h" +#include "detect-engine-helper.h" +#include "detect-engine-content-inspection.h" +#include "detect-ftp-reply.h" + +#include "app-layer.h" +#include "app-layer-ftp.h" + +#include "flow.h" + +#include "util-debug.h" + +#include "rust.h" + +#define KEYWORD_NAME "ftp.reply" +#define KEYWORD_DOC "ftp-keywords.html#ftp-reply" +#define BUFFER_NAME "ftp.reply" +#define BUFFER_DESC "ftp reply" + +static int g_ftp_reply_buffer_id = 0; + +static int DetectFtpReplySetup(DetectEngineCtx *de_ctx, Signature *s, const char *str) +{ + if (DetectBufferSetActiveList(de_ctx, s, g_ftp_reply_buffer_id) < 0) + return -1; + + if (DetectSignatureSetAppProto(s, ALPROTO_FTP) < 0) + return -1; + + return 0; +} + +static bool DetectFTPReplyGetData(void *txv, uint8_t _flow_flags, uint32_t index, + const uint8_t **buffer, uint32_t *buffer_len) +{ + FTPTransaction *tx = (FTPTransaction *)txv; + + if (tx->command_descriptor.command_code == FTP_COMMAND_UNKNOWN) + return false; + + if (!TAILQ_EMPTY(&tx->response_list)) { + uint32_t count = 0; + FTPResponseWrapper *wrapper; + TAILQ_FOREACH (wrapper, &tx->response_list, next) { + DEBUG_VALIDATE_BUG_ON(wrapper->response == NULL); + if (index == count) { + *buffer = (const uint8_t *)wrapper->response->response; + *buffer_len = wrapper->response->length; + return true; + } + count++; + } + } + + *buffer = NULL; + *buffer_len = 0; + return false; +} + +static InspectionBuffer *GetDataWrapper(DetectEngineThreadCtx *det_ctx, + const DetectEngineTransforms *transforms, Flow *_f, const uint8_t _flow_flags, void *txv, + const int list_id, uint32_t index) +{ + return DetectHelperGetMultiData( + det_ctx, transforms, _f, _flow_flags, txv, list_id, index, DetectFTPReplyGetData); +} + +void DetectFtpReplyRegister(void) +{ + /* ftp.reply sticky buffer */ + sigmatch_table[DETECT_FTP_REPLY].name = KEYWORD_NAME; + sigmatch_table[DETECT_FTP_REPLY].desc = "sticky buffer to match on the FTP reply buffer"; + sigmatch_table[DETECT_FTP_REPLY].url = "/rules/" KEYWORD_DOC; + sigmatch_table[DETECT_FTP_REPLY].Setup = DetectFtpReplySetup; + sigmatch_table[DETECT_FTP_REPLY].flags |= SIGMATCH_NOOPT; + + DetectAppLayerMultiRegister( + BUFFER_NAME, ALPROTO_FTP, SIG_FLAG_TOCLIENT, 0, GetDataWrapper, 2, 1); + + DetectBufferTypeSetDescriptionByName(BUFFER_NAME, BUFFER_DESC); + + g_ftp_reply_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME); + + SCLogDebug("registering " BUFFER_NAME " rule option"); +} diff --git a/src/detect-ftp-reply.h b/src/detect-ftp-reply.h new file mode 100644 index 0000000000..e8efb6d23a --- /dev/null +++ b/src/detect-ftp-reply.h @@ -0,0 +1,29 @@ +/* Copyright (C) 2025 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 Jeff Lucovsky + */ + +#ifndef SURICATA_DETECT_FTP_REPLY_H +#define SURICATA_DETECT_FTP_REPLY_H + +void DetectFtpReplyRegister(void); + +#endif /* SURICATA_DETECT_FTP_REPLY_H */