detect/transform: add to_sha1 keyword

doc/userguide/rules/transforms.rst

@@ -49,6 +49,19 @@ Example::
 
 .. note:: depends on libnss being compiled into Suricata
 
+to_sha1
+---------
+
+Takes the buffer, calculates the SHA-1 hash and passes the raw hash value
+on.
+
+Example::
+
+    alert http any any -> any any (http_request_line; to_sha1; \
+        content:"|54A9 7A8A B09C 1B81 3725 2214 51D3 F997 F015 9DD7|"; sid:1;)
+
+.. note:: depends on libnss being compiled into Suricata
+
 to_sha256
 ---------
 

src/Makefile.am

@@ -268,6 +268,7 @@ detect-tos.c detect-tos.h \
 detect-transform-compress-whitespace.c detect-transform-compress-whitespace.h \
 detect-transform-strip-whitespace.c detect-transform-strip-whitespace.h \
 detect-transform-md5.c detect-transform-md5.h \
+detect-transform-sha1.c detect-transform-sha1.h \
 detect-transform-sha256.c detect-transform-sha256.h \
 detect-ttl.c detect-ttl.h \
 detect-uricontent.c detect-uricontent.h \

src/detect-engine-register.c

@@ -193,6 +193,7 @@
 #include "detect-transform-compress-whitespace.h"
 #include "detect-transform-strip-whitespace.h"
 #include "detect-transform-md5.h"
+#include "detect-transform-sha1.h"
 #include "detect-transform-sha256.h"
 
 #include "util-rule-vars.h"
@@ -527,6 +528,7 @@ void SigTableSetup(void)
     DetectTransformCompressWhitespaceRegister();
     DetectTransformStripWhitespaceRegister();
     DetectTransformMd5Register();
+    DetectTransformSha1Register();
     DetectTransformSha256Register();
 
     /* close keyword registration */

src/detect-engine-register.h

@@ -216,6 +216,7 @@ enum {
     DETECT_TRANSFORM_COMPRESS_WHITESPACE,
     DETECT_TRANSFORM_STRIP_WHITESPACE,
     DETECT_TRANSFORM_MD5,
+    DETECT_TRANSFORM_SHA1,
     DETECT_TRANSFORM_SHA256,
 
     /* make sure this stays last */

src/detect-transform-sha1.c

@@ -0,0 +1,130 @@
+/* Copyright (C) 2007-2018 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 sha1 transformation keyword
+ */
+
+#include "suricata-common.h"
+
+#include "detect.h"
+#include "detect-engine.h"
+#include "detect-engine-prefilter.h"
+#include "detect-parse.h"
+#include "detect-transform-sha1.h"
+
+#include "util-unittest.h"
+#include "util-print.h"
+
+static int DetectTransformToSha1Setup (DetectEngineCtx *, Signature *, const char *);
+#ifdef HAVE_NSS
+static void DetectTransformToSha1RegisterTests(void);
+static void TransformToSha1(InspectionBuffer *buffer);
+#endif
+
+void DetectTransformSha1Register(void)
+{
+    sigmatch_table[DETECT_TRANSFORM_SHA1].name = "to_sha1";
+    sigmatch_table[DETECT_TRANSFORM_SHA1].desc =
+        "convert to sha1 hash of the buffer";
+    sigmatch_table[DETECT_TRANSFORM_SHA1].url =
+        DOC_URL DOC_VERSION "/rules/transforms.html#to_sha1";
+    sigmatch_table[DETECT_TRANSFORM_SHA1].Setup =
+        DetectTransformToSha1Setup;
+#ifdef HAVE_NSS
+    sigmatch_table[DETECT_TRANSFORM_SHA1].Transform =
+        TransformToSha1;
+    sigmatch_table[DETECT_TRANSFORM_SHA1].RegisterTests =
+        DetectTransformToSha1RegisterTests;
+#endif
+    sigmatch_table[DETECT_TRANSFORM_SHA1].flags |= SIGMATCH_NOOPT;
+}
+
+#ifndef HAVE_NSS
+static int DetectTransformToSha1Setup (DetectEngineCtx *de_ctx, Signature *s, const char *nullstr)
+{
+    SCLogError(SC_ERR_NO_SHA1_SUPPORT, "no SHA-1 calculation support built in, "
+            "needed for to_sha1 keyword");
+    return -1;
+}
+#else
+/**
+ *  \internal
+ *  \brief Apply the nocase keyword to the last pattern match, either content or uricontent
+ *  \param det_ctx detection engine ctx
+ *  \param s signature
+ *  \param nullstr should be null
+ *  \retval 0 ok
+ *  \retval -1 failure
+ */
+static int DetectTransformToSha1Setup (DetectEngineCtx *de_ctx, Signature *s, const char *nullstr)
+{
+    SCEnter();
+    int r = DetectSignatureAddTransform(s, DETECT_TRANSFORM_SHA1);
+    SCReturnInt(r);
+}
+
+static void TransformToSha1(InspectionBuffer *buffer)
+{
+    const uint8_t *input = buffer->inspect;
+    const uint32_t input_len = buffer->inspect_len;
+    uint8_t output[SHA1_LENGTH];
+
+    //PrintRawDataFp(stdout, input, input_len);
+
+    HASHContext *sha1_ctx = HASH_Create(HASH_AlgSHA1);
+    if (sha1_ctx) {
+        HASH_Begin(sha1_ctx);
+        HASH_Update(sha1_ctx, input, input_len);
+        unsigned int len = 0;
+        HASH_End(sha1_ctx, output, &len, sizeof(output));
+        HASH_Destroy(sha1_ctx);
+
+        InspectionBufferCopy(buffer, output, sizeof(output));
+    }
+}
+
+#ifdef UNITTESTS
+static int DetectTransformToSha1Test01(void)
+{
+    const uint8_t *input = (const uint8_t *)" A B C D ";
+    uint32_t input_len = strlen((char *)input);
+
+    InspectionBuffer buffer;
+    InspectionBufferInit(&buffer, 8);
+    InspectionBufferSetup(&buffer, input, input_len);
+    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
+    TransformToSha1(&buffer);
+    PrintRawDataFp(stdout, buffer.inspect, buffer.inspect_len);
+    InspectionBufferFree(&buffer);
+    PASS;
+}
+
+#endif
+
+static void DetectTransformToSha1RegisterTests(void)
+{
+#ifdef UNITTESTS
+    UtRegisterTest("DetectTransformToSha1Test01",
+            DetectTransformToSha1Test01);
+#endif
+}
+#endif

src/detect-transform-sha1.h

@@ -0,0 +1,30 @@
+/* Copyright (C) 2017 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>
+ */
+
+#ifndef __DETECT_TRANSFORM_SHA1_H__
+#define __DETECT_TRANSFORM_SHA1_H__
+
+/* prototypes */
+void DetectTransformSha1Register (void);
+
+#endif /* __DETECT_TRANSFORM_SHA1_H__ */