/src/suricata7/src/detect-transform-compress-whitespace.c

Source
/* Copyright (C) 2007-2020 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 Victor Julien <victor@inliniac.net>
 *
 * Implements the compress_whitespace transform keyword
 */

#include "suricata-common.h"

#include "detect.h"
#include "detect-engine.h"
#include "detect-engine-prefilter.h"
#include "detect-parse.h"
#include "detect-transform-compress-whitespace.h"

#include "util-unittest.h"
#include "util-print.h"

static int DetectTransformCompressWhitespaceSetup (DetectEngineCtx *, Signature *, const char *);
#ifdef UNITTESTS
static void DetectTransformCompressWhitespaceRegisterTests(void);
#endif
static void TransformCompressWhitespace(InspectionBuffer *buffer, void *options);
static bool TransformCompressWhitespaceValidate(
        const uint8_t *content, uint16_t content_len, void *options);

void DetectTransformCompressWhitespaceRegister(void)
{
    sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].name = "compress_whitespace";
    sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].desc =
        "modify buffer to compress consecutive whitespace characters "
        "into a single one before inspection";
    sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].url =
        "/rules/transforms.html#compress-whitespace";
    sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].Transform =
        TransformCompressWhitespace;
    sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].TransformValidate =
            TransformCompressWhitespaceValidate;
    sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].Setup =
        DetectTransformCompressWhitespaceSetup;
#ifdef UNITTESTS
    sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].RegisterTests =
        DetectTransformCompressWhitespaceRegisterTests;
#endif
    sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].flags |= SIGMATCH_NOOPT;
}

/**
 *  \internal
 *  \brief Apply the compress_whitespace keyword to the last pattern match
 *  \param det_ctx detection engine ctx
 *  \param s signature
 *  \param nullstr should be null
 *  \retval 0 ok
 *  \retval -1 failure
 */
static int DetectTransformCompressWhitespaceSetup (DetectEngineCtx *de_ctx, Signature *s, const char *nullstr)
{
    SCEnter();
    int r = DetectSignatureAddTransform(s, DETECT_TRANSFORM_COMPRESS_WHITESPACE, NULL);
    SCReturnInt(r);
}

/*
 *  \brief Validate content bytes to see if it's compatible with this transform
 *  \param content Byte array to check for compatibility
 *  \param content_len Number of bytes to check
 *  \param options Ignored
 *  \retval false If the string contains spaces
 *  \retval true Otherwise.
 */
static bool TransformCompressWhitespaceValidate(
        const uint8_t *content, uint16_t content_len, void *options)
{
    if (content) {
        for (uint32_t i = 0; i < content_len; i++) {
            if (!isspace(*content++)) {
                continue;
            }
            if ((i + 1) < content_len && isspace(*content)) {
                return false;
            }
        }
    }
    return true;
}

static void TransformCompressWhitespace(InspectionBuffer *buffer, void *options)
{
    const uint8_t *input = buffer->inspect;
    const uint32_t input_len = buffer->inspect_len;
    if (input_len == 0) {
        return;
    }

    // we can only shrink
    uint8_t *output = InspectionBufferCheckAndExpand(buffer, input_len);
    if (output == NULL) {
        return;
    }
    uint8_t *oi = output, *os = output;

    //PrintRawDataFp(stdout, input, input_len);
    for (uint32_t i = 0; i < input_len; ) {
        if (!(isspace(*input))) {
            *oi++ = *input++;
            i++;
        } else {
            *oi++ = *input++;
            i++;

            while (i < input_len && isspace(*input)) {
                input++;
                i++;
            }
        }
    }
    uint32_t output_size = oi - os;
    //PrintRawDataFp(stdout, output, output_size);

    InspectionBufferTruncate(buffer, output_size);
}

#ifdef UNITTESTS
static int TransformDoubleWhitespace(InspectionBuffer *buffer)
{
    const uint8_t *input = buffer->inspect;
    const uint32_t input_len = buffer->inspect_len;
    uint8_t output[input_len * 2]; // if all chars are whitespace this fits
    memset(&output, 0, input_len * 2);
    uint8_t *oi = output, *os = output;

    PrintRawDataFp(stdout, input, input_len);
    for (uint32_t i = 0; i < input_len; i++) {
        if (isspace(*input)) {
            *oi++ = *input;
        }
        *oi++ = *input;
        input++;
    }
    uint32_t output_size = oi - os;
    PrintRawDataFp(stdout, output, output_size);

    InspectionBufferCopy(buffer, os, output_size);
    return 0;
}

static int DetectTransformCompressWhitespaceTest01(void)
{
    const uint8_t *input = (const uint8_t *)" A B C D ";
    uint32_t input_len = strlen((char *)input);

    InspectionBuffer buffer;
    InspectionBufferInit(&buffer, 9);
    InspectionBufferSetup(NULL, -1, &buffer, input, input_len);
    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
    TransformCompressWhitespace(&buffer, NULL);
    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
    InspectionBufferFree(&buffer);
    PASS;
}

static int DetectTransformCompressWhitespaceTest02(void)
{
    const uint8_t *input = (const uint8_t *)" A B C D ";
    uint32_t input_len = strlen((char *)input);

    InspectionBuffer buffer;
    InspectionBufferInit(&buffer, 9);
    InspectionBufferSetup(NULL, -1, &buffer, input, input_len);
    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
    TransformDoubleWhitespace(&buffer);
    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
    TransformDoubleWhitespace(&buffer);
    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
    TransformCompressWhitespace(&buffer, NULL);
    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
    InspectionBufferFree(&buffer);
    PASS;
}

static int DetectTransformCompressWhitespaceTest03(void)
{
    const uint8_t *input = (const uint8_t *)" A B C D  ";
    uint32_t input_len = strlen((char *)input);

    InspectionBuffer buffer;
    InspectionBufferInit(&buffer, 10);
    InspectionBufferSetup(NULL, -1, &buffer, input, input_len);
    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
    FAIL_IF(TransformCompressWhitespaceValidate(buffer.inspect, buffer.inspect_len, NULL));
    PASS;
}

static int DetectTransformCompressWhitespaceTest04(void)
{
    const uint8_t *input = (const uint8_t *)" A B C D ";
    uint32_t input_len = strlen((char *)input);

    InspectionBuffer buffer;
    InspectionBufferInit(&buffer, 9);
    InspectionBufferSetup(NULL, -1, &buffer, input, input_len);
    TransformDoubleWhitespace(&buffer);
    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
    FAIL_IF(TransformCompressWhitespaceValidate(buffer.inspect, buffer.inspect_len, NULL));
    PASS;
}

static void DetectTransformCompressWhitespaceRegisterTests(void)
{
    UtRegisterTest("DetectTransformCompressWhitespaceTest01",
            DetectTransformCompressWhitespaceTest01);
    UtRegisterTest("DetectTransformCompressWhitespaceTest02",
            DetectTransformCompressWhitespaceTest02);
    UtRegisterTest(
            "DetectTransformCompressWhitespaceTest03", DetectTransformCompressWhitespaceTest03);
    UtRegisterTest(
            "DetectTransformCompressWhitespaceTest04", DetectTransformCompressWhitespaceTest04);
}
#endif

Coverage Report

Created: 2025-11-16 07:09

Line	Count	Source
1		/* Copyright (C) 2007-2020 Open Information Security Foundation
2		*
3		* You can copy, redistribute or modify this Program under the terms of
4		* the GNU General Public License version 2 as published by the Free
5		* Software Foundation.
6		*
7		* This program is distributed in the hope that it will be useful,
8		* but WITHOUT ANY WARRANTY; without even the implied warranty of
9		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10		* GNU General Public License for more details.
11		*
12		* You should have received a copy of the GNU General Public License
13		* version 2 along with this program; if not, write to the Free Software
14		* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
15		* 02110-1301, USA.
16		*/
17
18		/**
19		* \file
20		*
21		* \author Victor Julien <victor@inliniac.net>
22		*
23		* Implements the compress_whitespace transform keyword
24		*/
25
26		#include "suricata-common.h"
27
28		#include "detect.h"
29		#include "detect-engine.h"
30		#include "detect-engine-prefilter.h"
31		#include "detect-parse.h"
32		#include "detect-transform-compress-whitespace.h"
33
34		#include "util-unittest.h"
35		#include "util-print.h"
36
37		static int DetectTransformCompressWhitespaceSetup (DetectEngineCtx , Signature , const char *);
38		#ifdef UNITTESTS
39		static void DetectTransformCompressWhitespaceRegisterTests(void);
40		#endif
41		static void TransformCompressWhitespace(InspectionBuffer buffer, void options);
42		static bool TransformCompressWhitespaceValidate(
43		const uint8_t content, uint16_t content_len, void options);
44
45		void DetectTransformCompressWhitespaceRegister(void)
46	34	{
47	34	sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].name = "compress_whitespace";
48	34	sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].desc =
49	34	"modify buffer to compress consecutive whitespace characters "
50	34	"into a single one before inspection";
51	34	sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].url =
52	34	"/rules/transforms.html#compress-whitespace";
53	34	sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].Transform =
54	34	TransformCompressWhitespace;
55	34	sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].TransformValidate =
56	34	TransformCompressWhitespaceValidate;
57	34	sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].Setup =
58	34	DetectTransformCompressWhitespaceSetup;
59		#ifdef UNITTESTS
60		sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].RegisterTests =
61		DetectTransformCompressWhitespaceRegisterTests;
62		#endif
63	34	sigmatch_table[DETECT_TRANSFORM_COMPRESS_WHITESPACE].flags \|= SIGMATCH_NOOPT;
64	34	}
65
66		/**
67		* \internal
68		* \brief Apply the compress_whitespace keyword to the last pattern match
69		* \param det_ctx detection engine ctx
70		* \param s signature
71		* \param nullstr should be null
72		* \retval 0 ok
73		* \retval -1 failure
74		*/
75		static int DetectTransformCompressWhitespaceSetup (DetectEngineCtx de_ctx, Signature s, const char *nullstr)
76	704	{
77	704	SCEnter();
78	704	int r = DetectSignatureAddTransform(s, DETECT_TRANSFORM_COMPRESS_WHITESPACE, NULL);
79	704	SCReturnInt(r);
80	704	}
81
82		/*
83		* \brief Validate content bytes to see if it's compatible with this transform
84		* \param content Byte array to check for compatibility
85		* \param content_len Number of bytes to check
86		* \param options Ignored
87		* \retval false If the string contains spaces
88		* \retval true Otherwise.
89		*/
90		static bool TransformCompressWhitespaceValidate(
91		const uint8_t content, uint16_t content_len, void options)
92	571	{
93	571	if (content) {
94	7.86k	for (uint32_t i = 0; i < content_len; i++) {
95	7.30k	if (!isspace(*content++)) {
96	6.50k	continue;
97	6.50k	}
98	797	if ((i + 1) < content_len && isspace(*content)) {
99	9	return false;
100	9	}
101	797	}
102	571	}
103	562	return true;
104	571	}
105
106		static void TransformCompressWhitespace(InspectionBuffer buffer, void options)
107	735	{
108	735	const uint8_t *input = buffer->inspect;
109	735	const uint32_t input_len = buffer->inspect_len;
110	735	if (input_len == 0) {
111	0	return;
112	0	}
113
114		// we can only shrink
115	735	uint8_t *output = InspectionBufferCheckAndExpand(buffer, input_len);
116	735	if (output == NULL) {
117	0	return;
118	0	}
119	735	uint8_t oi = output, os = output;
120
121		//PrintRawDataFp(stdout, input, input_len);
122	392k	for (uint32_t i = 0; i < input_len; ) {
123	391k	if (!(isspace(*input))) {
124	378k	oi++ = input++;
125	378k	i++;
126	378k	} else {
127	12.9k	oi++ = input++;
128	12.9k	i++;
129
130	19.1k	while (i < input_len && isspace(*input)) {
131	6.14k	input++;
132	6.14k	i++;
133	6.14k	}
134	12.9k	}
135	391k	}
136	735	uint32_t output_size = oi - os;
137		//PrintRawDataFp(stdout, output, output_size);
138
139	735	InspectionBufferTruncate(buffer, output_size);
140	735	}
141
142		#ifdef UNITTESTS
143		static int TransformDoubleWhitespace(InspectionBuffer *buffer)
144		{
145		const uint8_t *input = buffer->inspect;
146		const uint32_t input_len = buffer->inspect_len;
147		uint8_t output[input_len * 2]; // if all chars are whitespace this fits
148		memset(&output, 0, input_len * 2);
149		uint8_t oi = output, os = output;
150
151		PrintRawDataFp(stdout, input, input_len);
152		for (uint32_t i = 0; i < input_len; i++) {
153		if (isspace(*input)) {
154		oi++ = input;
155		}
156		oi++ = input;
157		input++;
158		}
159		uint32_t output_size = oi - os;
160		PrintRawDataFp(stdout, output, output_size);
161
162		InspectionBufferCopy(buffer, os, output_size);
163		return 0;
164		}
165
166		static int DetectTransformCompressWhitespaceTest01(void)
167		{
168		const uint8_t input = (const uint8_t )" A B C D ";
169		uint32_t input_len = strlen((char *)input);
170
171		InspectionBuffer buffer;
172		InspectionBufferInit(&buffer, 9);
173		InspectionBufferSetup(NULL, -1, &buffer, input, input_len);
174		PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
175		TransformCompressWhitespace(&buffer, NULL);
176		PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
177		InspectionBufferFree(&buffer);
178		PASS;
179		}
180
181		static int DetectTransformCompressWhitespaceTest02(void)
182		{
183		const uint8_t input = (const uint8_t )" A B C D ";
184		uint32_t input_len = strlen((char *)input);
185
186		InspectionBuffer buffer;
187		InspectionBufferInit(&buffer, 9);
188		InspectionBufferSetup(NULL, -1, &buffer, input, input_len);
189		PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
190		TransformDoubleWhitespace(&buffer);
191		PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
192		TransformDoubleWhitespace(&buffer);
193		PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
194		TransformCompressWhitespace(&buffer, NULL);
195		PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
196		InspectionBufferFree(&buffer);
197		PASS;
198		}
199
200		static int DetectTransformCompressWhitespaceTest03(void)
201		{
202		const uint8_t input = (const uint8_t )" A B C D ";
203		uint32_t input_len = strlen((char *)input);
204
205		InspectionBuffer buffer;
206		InspectionBufferInit(&buffer, 10);
207		InspectionBufferSetup(NULL, -1, &buffer, input, input_len);
208		PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
209		FAIL_IF(TransformCompressWhitespaceValidate(buffer.inspect, buffer.inspect_len, NULL));
210		PASS;
211		}
212
213		static int DetectTransformCompressWhitespaceTest04(void)
214		{
215		const uint8_t input = (const uint8_t )" A B C D ";
216		uint32_t input_len = strlen((char *)input);
217
218		InspectionBuffer buffer;
219		InspectionBufferInit(&buffer, 9);
220		InspectionBufferSetup(NULL, -1, &buffer, input, input_len);
221		TransformDoubleWhitespace(&buffer);
222		PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
223		FAIL_IF(TransformCompressWhitespaceValidate(buffer.inspect, buffer.inspect_len, NULL));
224		PASS;
225		}
226
227		static void DetectTransformCompressWhitespaceRegisterTests(void)
228		{
229		UtRegisterTest("DetectTransformCompressWhitespaceTest01",
230		DetectTransformCompressWhitespaceTest01);
231		UtRegisterTest("DetectTransformCompressWhitespaceTest02",
232		DetectTransformCompressWhitespaceTest02);
233		UtRegisterTest(
234		"DetectTransformCompressWhitespaceTest03", DetectTransformCompressWhitespaceTest03);
235		UtRegisterTest(
236		"DetectTransformCompressWhitespaceTest04", DetectTransformCompressWhitespaceTest04);
237		}
238		#endif