TCP_OPT_INVALID_LEN was set if the opt len was 2. While useless
an empty SACK is not uncommon.
Seen on an iOS device talking to an Apple server.
Bug #3254.
If the DNS log version is not set, we default to v2. This should
not be warning, but better logged at the config level.
A warning will still be logged if the value is set but is not
1 or 2.
Implement min_inspect_depth for SMTP so that file_data and
regular stream matches don't go out of sync on the stream start.
Added toserver bytes tracking.
Bug #3190.
Change the meaning of the verbosity flag to change the log
level to fixed levels instead of being relative to whats
configured.
-v => INFO
-vv => PERF
-vvv => CONIFG
-vvvv => DEBUG
But do now allow -v to decrease the verbosity.
Bug #1851
The log level of individual loggers (console, file, syslog) was
being capped by the default log level. For example, if the
default log level was notice, setting the file level to info
would still result in notice level logging.
Bug #3210
Ensure that RETR (STOR) have a filename -- otherwise, treat the command
string as malformed.
Added unittests for each command and verified that SEGV's occur without
parser change and no longer occur with the parser change.
This reverts commit 6dca50a322.
The test mode should actually test in system mode by default as
that is what tools like Suricata-Update need before issuing a
reload command.
A sigmatches 'Setup' function may indicate it intends to fail
silently after the first error. It will return -2 instead of -1
in this case.
This is tracked in the DetectEngineCtx object, so errors will
be shown again at rule reloads.
Add --strict-rule-keywords commandline option to enable strict rule
parsing.
It can be used without options or with a comma separated list:
--strict-rule-keywords
--strict-rule-keywords=all
--strict-rule-keywords=classtype,reference
Parsing implementations can use SigMatchStrictEnabled to check
if strict parsing is enabled for them and act accordingly.
References are currently not used in Suricata, so erroring out on
rules using a undefined reference is too harsh.
Just issue a warning once per unique missing reference.
Still initialize the classtype hash table so that the classtypes
rules use can be added to it.
The file missing now reports a warning instead of error, as we
will continue to work.
Effect of classification on Suricata's working is minimal. Impact
of adding undefined classtypes is large: rules will fail to load
completely. This also leads multiple lines of log output per rule,
which in a large ruleset can lead to excessive output.
This patch changes the classtype keyword behavior. Instead of erroring
and invalidating a rule, we will merely warn.
The undefined classtype is then defined with a default priority,
so other rules using the classtype will not also warn. This way
there will be just a single warning per missing classtype.
Detect duplicate instances and use the one with the highest
priority.
Use new priority flag to make the logic around explicit priority
sets easier to follow.
Minor code cleanups. Also clean up unittests.
Introduce Signature init_flag to indicate priority has been set.
This will be needed in a follow-up classtype update.
Detect duplicate priority instances in a keyword, and use the
highest priority in the rule. Do issue a warning in this case.
As the file prune is now moved to the flow worker, the file
prune is run later, meaning the first file has not yet
been pruned from the file container list.
Adjust test to look for a second file, and check the
flags on that file.
For commit addressing bug 2490.
If a keyword like filemd5 was being used without a filestore,
or a file output enabled, it would be pruned before detection
had a chance to match.
Consolidate file pruning to the end of the flow worker so files
are available for detection even when a file output is not
enabled.
Redmine issue:
https://redmine.openinfosecfoundation.org/issues/2490
At the startup, if the default log dir provided either by command line
options or suricat.yaml is not writable, the error comes quite later.
This patch makes suricata exit if there is such an error in the
beginning itself.
Closes redmine ticket #2386.
In file included from suricata-common.h:471,
from app-layer-enip-common.c:27:
app-layer-enip-common.c: In function ‘DecodeCIPRequestPathPDU’:
util-debug.h:222:31: warning: ‘req_path_class8’ may be used uninitialized in this function [-Wmaybe-uninitialized]
int _sc_log_ret = snprintf(_sc_log_msg, SC_LOG_MAX_LOG_MSG_LEN, __VA_ARGS__); \
^~~~~~~~
app-layer-enip-common.c:589:13: note: ‘req_path_class8’ was declared here
uint8_t req_path_class8;
^~~~~~~~~~~~~~~
app-layer-enip-common.c:607:9: warning: ‘segment’ may be used uninitialized in this function [-Wmaybe-uninitialized]
switch (segment)
^~~~~~
app-layer-enip-common.c: In function ‘DecodeCIPResponsePDU’:
app-layer-enip-common.c:773:13: warning: ‘service’ may be used uninitialized in this function [-Wmaybe-uninitialized]
service &= 0x7f; //strip off top bit to get service code. Responses have first bit as 1
^~
app-layer-enip-common.c: In function ‘DecodeCIPRequestPDU’:
app-layer-enip-common.c:503:25: warning: ‘path_size’ may be used uninitialized in this function [-Wmaybe-uninitialized]
offset += path_size * sizeof(uint16_t); //move offset past pathsize
~~~~~~~~~~^~~~~~~~~~~~~~~~~~
app-layer-enip-common.c:506:5: warning: ‘service’ may be used uninitialized in this function [-Wmaybe-uninitialized]
switch (service)
^~~~~~
Bug #3139.
Improve warnings when eve.stats can't work because of the global config
missing or disabled.
Issue warning if global config is missing but stats are still enabled due
to the legacy stats.log.
Issue clearer warning when stats are disabled and unix socket dump-counters
command is issued.
Warnings include links to docs.
Bug #2465.
bzero(3): The bzero() function is deprecated (marked as LEGACY in
POSIX.1-2001); use memset(3) in new programs. POSIX.1-2008 removes
the specification of bzero().
Use memset instead.
Replace index by strchr and rindex by strrchr.
index(3) states "POSIX.1-2008 removes the specifications of index() and
rindex(), recommending strchr(3) and strrchr(3) instead."
Add index/rindex to banned function check so they don't get reintroduced.
Bug #1443.
OpenSSL uses 30, so this seems a reasonable limit.
Set a smaller limit than before to reduce the resources spent on
specially crafted input designed to be maximally expensive.
Set and Sequence parsers would pass on max available data instead
of the size of their object.
Malformed data could trigger massive recursion this way, leading
to spending much more resources than necessary.
Found using AFL.
Bug #3185.
Field is at data+1 offset, not +3. Also makes sure we always stay
within checked data bounds.
Reported-by: Sirko Höer -- Code Intelligence for DCSO.
Bug #3176.
Before re-assembling, check that the first fragment is large
enough to contain the IPv4 or IPv6 header to prevent
an out of bounds read (IPv4) or write (IPv6).
Reported-by: Sirko Höer -- Code Intelligence for DCSO.
Bug #3171.
Restructure code to make it clearer that either 'basic', 'extended'
or 'custom' is being printed, by creating one function for each of
the possibilities.
Add a rule keyword, dns.opcode to match on the opcode flag
found in the DNS request and response headers.
Only exact matches are allowed with negation.
Examples:
- dns.opcode:4;
- dns.opcode:!1;
This permits to use stream-depth value set for file-store.
Currently if a file is being stored and hits a limit,
such as request or response body, it will be truncated
although file-store.stream-depth is enabled but the file should be
closed and not truncated.
Two unit tests have been added to verify that:
- a file is stored correctly
- chunk's length computation doesn’t cause an underflow
output-json-ftp.c: In function ‘JsonFTPLogger’:
output-json-ftp.c:129:9: warning: ‘js_respcode_list’ may be used uninitialized in this function [-Wmaybe-uninitialized]
129 | json_object_set_new(cjs, "completion_code", js_respcode_list);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
output-json-ftp.c:74:13: note: ‘js_respcode_list’ was declared here
74 | json_t *js_respcode_list;
| ^~~~~~~~~~~~~~~~
output-json-ftp.c:128:9: warning: ‘js_resplist’ may be used uninitialized in this function [-Wmaybe-uninitialized]
128 | json_object_set_new(cjs, "reply", js_resplist);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
output-json-ftp.c:73:13: note: ‘js_resplist’ was declared here
73 | json_t *js_resplist;
| ^~~~~~~~~~~
Datasets are sets/lists of data that can be accessed or added from
the rule language.
This patch implements 3 data types:
1. string (or buffer)
2. md5
3. sha256
The patch also implements 2 new rule keywords:
1. dataset
2. datarep
The dataset keyword allows matching against a list of values to see if
it exists or not. It can also add the value to the set. The set can
optionally be stored to disk on exit.
The datarep support matching/lookups only. With each item in the set a
reputation value is stored and this value can be matched against. The
reputation value is unsigned 16 bit, so values can be between 0 and 65535.
Datasets can be registered in 2 ways:
1. through the yaml
2. through the rules
The goal of this rules based approach is that rule writers can start using
this without the need for config changes.
A dataset is implemented using a thash hash table. Each dataset is its own
separate thash.
Thread safe hash table implementation based on the Flow hash, IP Pair
hash and others.
Hash is array of buckets with per bucket locking. Each bucket has a
list of elements which also individually use locking.
1. Set WARN_UNUSED macro on DetectSignatureSetAppProto.
2. Replace all direct 'sets' of Signature::alproto from keyword registration.
Closes redmine ticket #3006.
This define is used to remove reference to capture bypass in case
no capture method implementing this is active.
This patch also introduces CAPTURE_OFFLOAD_MANAGER that is defined
if we need the flow bypass manager code.
ICMP unreachable errors are linked to the flow they send an error for.
This would lead to the detection engine calling the TX inspection
engines on them.
The stream inspect engine would default to a match for non-UDP
and non-TCP as for ICMP we're not expected to use a TX inspect engine
for stream data.
This all would lead to a false positive match.
This patch fixes this by making sure the TX engines are not called if
the packet protocol and flow protocol are not the same.
Bug #2769.
CC source-netmap.o
source-netmap.c: In function ‘NetmapOpen’:
source-netmap.c:327:56: error: ‘%s’ directive output may be truncated writing up to 15 bytes into a region of size between 10 and 57 [-Werror=format-truncation=]
snprintf(devname, sizeof(devname), "netmap:%s%s%s",
^~
ns->iface, strlen(optstr) ? "/" : "", optstr);
~~~~~~
source-netmap.c:327:9: note: ‘snprintf’ output 8 or more bytes (assuming 70) into a destination of size 64
snprintf(devname, sizeof(devname), "netmap:%s%s%s",
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ns->iface, strlen(optstr) ? "/" : "", optstr);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
source-netmap.c:330:59: error: ‘%s’ directive output may be truncated writing up to 15 bytes into a region of size between 8 and 55 [-Werror=format-truncation=]
snprintf(devname, sizeof(devname), "netmap:%s-%d%s%s",
^~
ns->iface, ring, strlen(optstr) ? "/" : "", optstr);
~~~~~~
source-netmap.c:330:9: note: ‘snprintf’ output 10 or more bytes (assuming 72) into a destination of size 64
snprintf(devname, sizeof(devname), "netmap:%s-%d%s%s",
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ns->iface, ring, strlen(optstr) ? "/" : "", optstr);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
source-netmap.c:316:54: error: ‘snprintf’ output may be truncated before the last format character [-Werror=format-truncation=]
snprintf(devname, sizeof(devname), "%s}%d%s%s",
^
source-netmap.c:316:9: note: ‘snprintf’ output 3 or more bytes (assuming 65) into a destination of size 64
snprintf(devname, sizeof(devname), "%s}%d%s%s",
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ns->iface, ring, strlen(optstr) ? "/" : "", optstr);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
Gcc 8 with -Wformat-truncation=1
Date makes it even clearer that when was the last commit for the build
that one is running. Add this info alongwith rev. Change inspired by
rustc.
Before
```
$ suricata -V
This is Suricata version 5.0.0-dev (rev 2d217e666)
```
After
```
This is Suricata version 5.0.0-dev (2d217e666 2019-07-12)
```
Closes redmine ticket #3092
This changeset breaks multi-line FTP responses into separate array
entries. Multi-line responses are those with "text-1\r\ntext-2[...]".
Each of \r\n delimited text segments is reported in the `reply` array;
each text segment _may_ include a completion code; completion codes are
reported in the `completion_code` array.
Permit picking up any reply w/o a request. Observed unsolicited server
messages before connection termination.
Previously the code assumed that this could only happen on connection
start when there was no previously recorded command.
This changeset ensures that unknown commands are logged.
Unknown commands are either
- Banner responses when connecting to the FTP port
- Commands not includes in the FtpCommands descriptor table
Modified transaction logic to create a new transaction with each
request; replies location transactions by using the oldest "open"
(unmatched) transaction or the last transaction if none are open.
When a TCP session is picked up from the response the flow is
reversed by the protocol detection code.
This would lead to duplicate logging of the response. The reason this
happened was that the per stream app progress tracker was not handled
correctly by the direction reversing code. While the streams were
swapped the stream engine would continue to use a now outdated pointer
to what had become the wrong direction.
This patches fixes this by making the stream a ptr to ptr that can be
updated by the protocol detection as well.
In addition, the progress tracking was cleaned up and the GAP error
handling in this case was improved as well.
Previously, source-pfring.c would copy the vlan_id from the extended
header only if vlan.use-for-tracking was enabled. This commit removes
that check.
Related to https://redmine.openinfosecfoundation.org/issues/3076
Fill in the vlan_id fields unconditionally. We can now remove the check
for the vlan.use-for-tracking setting in decode.c. The debug log message
is moved to suricata.c.
Since the vlan.use-for-tracking setting is now handled in flow-hash.c,
we can fill in the vlan_id fields unconditionally. This makes the vlanh
fields unnecessary.
Related to https://redmine.openinfosecfoundation.org/issues/3076
If vlan.use-for-tracking is disabled, set the vlan_id fields to 0 when
hashing or comparing flows. This is done using a bitmask as suggested by
Victor Julien in IRC, in order to avoid adding more branches to this
code.
Currently, suricata does not fill in vlan_id fields if
vlan.use-for-tracking is disabled and instead leaves them at the default
0 value, so this commit makes no functional change. This change is in
preparation for future commits where the vlan_ids will be always filled
in.
Related to https://redmine.openinfosecfoundation.org/issues/3076
Instead of the hardcode L4 matching in MPM that was recently introduced,
add an API similar to the AppLayer MPM and inspect engines.
Share part of the registration code with the AppLayer.
Implement for the tcp.hdr and udp.hdr keywords.
Implement port config handling. Also check both src port and dest
port for tunnels that only set the destination port to the VXLAN
port. At the point of the check we don't know the packet direction
yet.
Implement as Suricata tunnel similar to Teredo.
Cleanups.
Avoid clash by adding a leading underscore to the declaration in the
macro. These temporary vars should never clash with valid variables
from the code where they are called from.
Prepare MPM part of the detection engine for a new type of per
packet matching, where the L4 header will be inspected.
Preparation for TCP header inspection keyword.
Instead of hard coded calls to the inspection logic for
payload inspection and 'MATCH'-list inspection use a callback
approach. This will register a callback per 'sm_list' much like
how app-layer inspect engines are registered.
This will allow for adding more types later without adding
runtime overhead.
Implement the callback for the PMATCH and MATCH logic.
Extend the Rust parsing infrastructure with the "get event info by id"
calls. This changeset extends the parser structure, the C-based
registration handlers and the template parser.
This changeset makes changes to the TX logging path. Since the txn
is passed to the TX logger, the TX can be used directly instead of
through the TX id.
This changeset adds a mechanism to track when individual events
are logged. Transactions can be provided more than once; track
events to prevent event re-logging.
Declare _POSIX_C_SOURCE before sys/time.h to avoid:
util-time.c: In function 'SCUtcTime':
util-time.c:222:12: error: implicit declaration of function 'gmtime_r'; did you mean 'gmtime_s'? [-Werror=implicit-function-declaration]
222 | return gmtime_r(&timep, result);
| ^~~~~~~~
| gmtime_s
util-time.c:222:12: warning: returning 'int' from a function with return type 'struct tm *' makes pointer from integer without a cast [-Wint-conversion]
222 | return gmtime_r(&timep, result);
| ^~~~~~~~~~~~~~~~~~~~~~~~
util-time.c: In function 'SCLocalTime':
util-time.c:305:9: error: implicit declaration of function 'localtime_r'; did you mean 'localtime_s'? [-Werror=implicit-function-declaration]
305 | localtime_r(&timep, &cached_local_tm[lru]);
| ^~~~~~~~~~~
| localtime_s
util-time.c:321:56: warning: comparison between pointer and integer
321 | if (localtime_r(&timep, &cached_local_tm[lru]) == NULL)
| ^~
cc1.exe: some warnings being treated as errors
Tickets: #2994#3051
Packets from captured bypassed flows that are received by Suricata
before the capture method start to bypass them can represent an
important part due to various buffer and insertion delay.
This patch adds a two counters to know the number of packets and
bytes in this case.
This patch improves the bypass error handling add adds more counters
to the interface so it is possible to get a view on success and
failure of insertion in the eBPF maps via the `iface-bypassed-stat`
command.
This patch introduces and uses a new bypass strategy
based on a callback. EBPF bypass implementation is
updated to use this new strategy.
Once the flow manager detect that a flow should be timeouted,
it asks the capture method if it has seen packets in the interval.
If it is the case the lastts of the flow is updated and the timeout
is postponed.
The flow bypass stats is computed at every pass so the accounting
needs to be done at each pass. This patch fixes the accounting
in the flow_bypassed counters.
At the time of the writing, libbpf output useful error message
on strdout only and errno is not really interesting. So let's
tell user to look at stdout.
The loop on bypassed flow maps can take a few seconds on heavily
loaded system causing Suricata to not honor a stop before a few
seconds.
This patch adds the code needed to detect the need to exit from
the check loop.
For capture method that have their own flow structure (not maintained
by Suricata), it can make sense to bypass a packet even if there is
no Flow in Suricata.
For AF_PACKET it does not make sense as the eBPF map entry will
be destroyed as soon as it will be checked by the flow bypass
manager. Thus we shortcut the bypass function if ever no Flow is
attached to the packet.
This path also removes reference to Flow in the bypass functions
for AF_PACKET. It was not necessary and we possibly could benefit
of it if ever we change the bypass algorithm.
There is a synchronization issue occuring when a flow is
added to the eBPF bypass maps. The flow can have packets
in the ring buffer that have already passed the eBPF stage.
By consequences, they are not accounted in the eBPF counter
but are accounted by Suricata flow engine.
This was causing counters to be completely wrong. This code
fixes the issue by avoiding the counter change in invalid
case.
To avoid adding 4 64bits integers to the Flow structure for the
bypass accounting, we use instead a FlowStorage. This limits the
memory usage to the size of a pointer.
Only reason clock_gettime could fail is a permission so let's
error and leave the flow bypass manager if it is the case.
Also let's suppress the error message if ever the error appear in
the middle of a run (which is unlikely).
An alignement issue was preventing the code to work properly.
We introduce macros taken from Linux source code sample to get
something that should work on the long term.
By pinning the maps we are creating a file in /sys/fs/bpf that can
be used by external program to access the map. This has multiple
benefits such as handling list from an external program.
The pinned maps could be persistent accross Suricata reload but
this can be complicated in term of handling everything in the life
of Suricata.
Kernel time is not available (and/or costly) on NIC such as
Netronome so we update the logic to detect dead flows based on a
lack of update of packets counters. This way, the XDP filter will
be usable by network card.
This patch also updates the ebpf code to support per CPU and
regular mapping. Netronome is not supporting it and the structure
is using atomic for counter so the cost of simultaneous update
is really low.
This patch also updates the xdp_filter to be able to select if the
flow table is per CPU on shared. Second option will be used for
hardward offload. To deactivate the per cpu hash, you need to set
USE_PERCPU_HASH to 0.
This patch also adds an new option to af-packet named no-percpu-hash
If this option is set to yes then the Flow bypassed manager thread
will use one CPU instead of the number of cores. By doing that
we are able to handle the case where USE_PERCPU_HASH is unset (so
hardware offload for Netronome).
This patch also remove aligment indications in the eBPF filter. This
was not really needed and it seems it is causing problem with
some recent version of LLVM toolchain.
So far, if the rule loaded had a backslash character ("\") in its
content field, the rule will fail to load but without giving a
descriptive error message. This patch tells the user to escape the
troubling character.
Before
```
9409] 7/6/2019 -- 16:12:22 - (detect-engine-loader.c:184) <Error> (DetectLoadSigFile) -- [ERRCODE: SC_ERR_INVALID_SIGNATURE(39)] - error parsing signature "alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"Backslash needs escaping msg"; flow:established,to_server; content:"MyBackslash\here"; sid:86; rev:1; )" from file /var/lib/suricata/rules/myrule.rules at line 1
```
After
```
[9409] 7/6/2019 -- 16:12:22 - (detect-content.c:155) <Error> (DetectContentDataParse) -- [ERRCODE: SC_ERR_INVALID_SIGNATURE(39)] - '\' has to be escaped
[9409] 7/6/2019 -- 16:12:22 - (detect-engine-loader.c:184) <Error> (DetectLoadSigFile) -- [ERRCODE: SC_ERR_INVALID_SIGNATURE(39)] - error parsing signature "alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"Backslash needs escaping msg"; flow:established,to_server; content:"MyBackslash\here"; sid:86; rev:1; )" from file /var/lib/suricata/rules/myrule.rules at line 1
```
Closes redmine ticket #2626
Stream reassembly memcap is regulated by the Init and Cleanup
callbacks. If Init fails due to memcap reached, Cleanup had no
way of knowing and it would decrease the memcap even if it hadn't
been increased by Init. This could lead to too much memory use and
memcap counter underflow.
This patch fixes the issue by not calling Cleanup in this case. It's
fair to see a failed Init the responsibility of Init.
The capture threads can receive packets from the flow manager in their
Threadvars::stream_pq packet queue. This mechanism makes sure the packets
the flow manager injects into the engine are processed by the correct
worker thread.
If the capture thread(s) would not receive packets for a long time, the
Threadvars::stream_pq would not be checked and processed. This could
lead to packet pool depletion in the flow manager. It would also lead
to flows not being timed out/logged until either packets started flowing
again or until the engine was shut down.
The scenario is more likely to happen in a test (e.g. replay) but could
also delay logging on low traffic sensors.
If waiting for N packets move the return stack to the main
stack every time we take the return stack lock.
Make sure we consider enough packets when setting the pending pool
flush logic. This should at least make sure to have the 9 packets
the flow manager requires per run.
Match on JA3S hash using ja3s.hash keyword, e.g:
alert tls any any -> any any (msg:"ja3s.hash test";
ja3s.hash; content:"b26c652e0a402a24b5ca2a660e84f9d5"; sid:1;)
Add Ja3SGetString() to return the content of the JA3S string buffer from
the TLS session.
Example:
function init (args)
local needs = {}
needs["protocol"] = "tls"
return needs
end
function setup (args)
filename = SCLogPath() .. "/ja3s_string.log"
file = assert(io.open(filename, "a"))
end
function log (args)
ja3s_string = Ja3SGetString()
if ja3s_string == nil then
return
end
file:write(ja3s_string .. "\n")
file:flush()
end
function deinit (args)
file:close()
end
Add Ja3SGetHash() to return the content of the JA3S hash buffer from
the TLS session.
Example:
function init (args)
local needs = {}
needs["protocol"] = "tls"
return needs
end
function setup (args)
filename = SCLogPath() .. "/ja3s_hash.log"
file = assert(io.open(filename, "a"))
end
function log (args)
ja3s_hash = Ja3SGetHash()
if ja3s_hash == nil then
return
end
file:write(ja3s_hash .. "\n")
file:flush()
end
function deinit (args)
file:close()
end
In the example above, each JA3S hash is logged to a log file.
Add keyword to do "raw" matching on each of the certificates in the
TLS certificate sticky buffer.
Example:
alert tls any any -> any any (msg:"tls.certs test"; tls.certs; \
content:"|01 02 03 04|"; sid:1;)