From: Jeff Lucovsky Date: Fri, 28 Mar 2025 15:01:15 +0000 (-0400) Subject: detect/ftp: ftp.command_data keyword X-Git-Tag: suricata-8.0.0-beta1~70 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=559cdc358d9dbe58f586de7f81321a1b8c3534f9;p=thirdparty%2Fsuricata.git detect/ftp: ftp.command_data keyword Issue: 7503 Add the rule keyword ftp.command_data; a sticky buffer that matches on the values send with FTP commands, e.g., USER someuser --- diff --git a/src/Makefile.am b/src/Makefile.am index 8746f25b8b..3591e11018 100755 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -170,6 +170,7 @@ noinst_HEADERS = \ detect-ftpbounce.h \ detect-ftpdata.h \ detect-ftp-command.h \ + detect-ftp-command-data.h \ detect-geoip.h \ detect-gid.h \ detect.h \ @@ -754,6 +755,7 @@ libsuricata_c_a_SOURCES = \ detect-ftpbounce.c \ detect-ftpdata.c \ detect-ftp-command.c \ + detect-ftp-command-data.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 a42cbdd2e2..6c1880a7b4 100644 --- a/src/detect-engine-register.c +++ b/src/detect-engine-register.c @@ -213,6 +213,7 @@ #include "detect-ja4-hash.h" #include "detect-ftp-command.h" #include "detect-entropy.h" +#include "detect-ftp-command-data.h" #include "detect-bypass.h" #include "detect-ftpdata.h" @@ -712,6 +713,7 @@ void SigTableSetup(void) DetectQuicCyuStringRegister(); DetectJa4HashRegister(); DetectFtpCommandRegister(); + DetectFtpCommandDataRegister(); DetectBypassRegister(); DetectConfigRegister(); diff --git a/src/detect-engine-register.h b/src/detect-engine-register.h index 5ae44b186f..64355e04e4 100644 --- a/src/detect-engine-register.h +++ b/src/detect-engine-register.h @@ -333,6 +333,7 @@ enum DetectKeywordId { DETECT_JA4_HASH, DETECT_FTP_COMMAND, + DETECT_FTP_COMMAND_DATA, DETECT_VLAN_ID, DETECT_VLAN_LAYERS, diff --git a/src/detect-ftp-command-data.c b/src/detect-ftp-command-data.c new file mode 100644 index 0000000000..4bed3d7a40 --- /dev/null +++ b/src/detect-ftp-command-data.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.command_data sticky buffer + * + */ + +#include "suricata-common.h" +#include "detect.h" + +#include "detect-parse.h" +#include "detect-engine.h" +#include "detect-engine-mpm.h" +#include "detect-engine-prefilter.h" +#include "detect-engine-helper.h" +#include "detect-content.h" + +#include "flow.h" + +#include "util-debug.h" + +#include "app-layer.h" +#include "app-layer-ftp.h" + +#include "detect-ftp-command-data.h" + +#define KEYWORD_NAME "ftp.command_data" +#define KEYWORD_DOC "ftp-keywords.html#ftp-command_data" +#define BUFFER_NAME "ftp.command_data" +#define BUFFER_DESC "ftp command_data" + +static int g_ftp_cmd_data_buffer_id = 0; + +static int DetectFtpCommandDataSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str) +{ + if (DetectBufferSetActiveList(de_ctx, s, g_ftp_cmd_data_buffer_id) < 0) + return -1; + + if (DetectSignatureSetAppProto(s, ALPROTO_FTP) < 0) + return -1; + + return 0; +} + +static bool DetectFTPCommandDataGetData( + void *txv, const uint8_t _flow_flags, const uint8_t **buffer, uint32_t *buffer_len) +{ + FTPTransaction *tx = (FTPTransaction *)txv; + + if (tx->command_descriptor.command_code == FTP_COMMAND_UNKNOWN) + return false; + + const char *b; + uint8_t b_len; + if (SCGetFtpCommandInfo(tx->command_descriptor.command_index, &b, NULL, &b_len)) { + if ((tx->request_length - b_len - 1) > 0) { + // command data starts here: advance past command + 1 space + *buffer = tx->request + b_len + 1; + *buffer_len = tx->request_length - b_len - 1; + SCLogDebug("command data: \"%s\" [bytes %d]", *buffer, *buffer_len); + return true; + } + } + + *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) +{ + return DetectHelperGetData( + det_ctx, transforms, _f, _flow_flags, txv, list_id, DetectFTPCommandDataGetData); +} + +void DetectFtpCommandDataRegister(void) +{ + /* ftp.command sticky buffer */ + sigmatch_table[DETECT_FTP_COMMAND_DATA].name = KEYWORD_NAME; + sigmatch_table[DETECT_FTP_COMMAND_DATA].desc = + "sticky buffer to match on the FTP command data buffer"; + sigmatch_table[DETECT_FTP_COMMAND_DATA].url = "/rules/" KEYWORD_DOC; + sigmatch_table[DETECT_FTP_COMMAND_DATA].Setup = DetectFtpCommandDataSetup; + sigmatch_table[DETECT_FTP_COMMAND_DATA].flags |= SIGMATCH_NOOPT; + + DetectHelperBufferMpmRegister( + BUFFER_NAME, BUFFER_NAME, ALPROTO_FTP, false, true, GetDataWrapper); + + DetectBufferTypeSetDescriptionByName(BUFFER_NAME, BUFFER_DESC); + + g_ftp_cmd_data_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME); + + SCLogDebug("registering " BUFFER_NAME " rule option"); +} diff --git a/src/detect-ftp-command-data.h b/src/detect-ftp-command-data.h new file mode 100644 index 0000000000..d28b5a91cc --- /dev/null +++ b/src/detect-ftp-command-data.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_COMMAND_DATA_H +#define SURICATA_DETECT_FTP_COMMAND_DATA_H + +void DetectFtpCommandDataRegister(void); + +#endif /* SURICATA_DETECT_FTP_COMMAND_DATA_H */