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Diffstat (limited to '')
-rw-r--r-- | src/detect-transform-strip-pseudo-headers.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/src/detect-transform-strip-pseudo-headers.c b/src/detect-transform-strip-pseudo-headers.c new file mode 100644 index 0000000..450900d --- /dev/null +++ b/src/detect-transform-strip-pseudo-headers.c @@ -0,0 +1,100 @@ +/* Copyright (C) 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 Philippe Antoine <contact@catenacyber.fr> + * + * Implements the strip_pseudo_headers transform keyword with option support + */ + +#include "suricata-common.h" +#include "detect.h" +#include "detect-engine.h" +#include "detect-parse.h" +#include "detect-transform-strip-pseudo-headers.h" + +/** + * \internal + * \brief Apply the strip_pseudo_headers keyword to the last pattern match + * \param det_ctx detection engine ctx + * \param s signature + * \param optstr options string + * \retval 0 ok + * \retval -1 failure + */ +static int DetectTransformStripPseudoHeadersSetup( + DetectEngineCtx *de_ctx, Signature *s, const char *optstr) +{ + SCEnter(); + int r = DetectSignatureAddTransform(s, DETECT_TRANSFORM_STRIP_PSEUDO_HEADERS, NULL); + SCReturnInt(r); +} + +static void DetectTransformStripPseudoHeaders(InspectionBuffer *buffer, void *options) +{ + const uint8_t *input = buffer->inspect; + const uint32_t input_len = buffer->inspect_len; + if (input_len == 0) { + return; + } + uint8_t output[input_len]; + + bool new_line = true; + bool pseudo = false; + uint32_t j = 0; + for (uint32_t i = 0; i < input_len; i++) { + if (new_line) { + if (input[i] == ':') { + pseudo = true; + } + if (input[i] != '\r' && input[i] != '\n') { + new_line = false; + } + } else { + if (input[i] == '\n') { + new_line = true; + if (!pseudo) { + output[j] = input[i]; + j++; + } + pseudo = false; + continue; + } + } + if (!pseudo) { + output[j] = input[i]; + j++; + } + } + InspectionBufferCopy(buffer, output, j); +} + +void DetectTransformStripPseudoHeadersRegister(void) +{ + sigmatch_table[DETECT_TRANSFORM_STRIP_PSEUDO_HEADERS].name = "strip_pseudo_headers"; + sigmatch_table[DETECT_TRANSFORM_STRIP_PSEUDO_HEADERS].desc = + "modify buffer via stripping pseudo headers"; + sigmatch_table[DETECT_TRANSFORM_STRIP_PSEUDO_HEADERS].url = + "/rules/transforms.html#strip_pseudo_headers"; + sigmatch_table[DETECT_TRANSFORM_STRIP_PSEUDO_HEADERS].Transform = + DetectTransformStripPseudoHeaders; + sigmatch_table[DETECT_TRANSFORM_STRIP_PSEUDO_HEADERS].Setup = + DetectTransformStripPseudoHeadersSetup; + sigmatch_table[DETECT_TRANSFORM_STRIP_PSEUDO_HEADERS].flags |= SIGMATCH_NOOPT; +} |