As of ClamAV 0.105, PCRE2 is required. PCRE (1) is not an option, and
there is also no option to disable PCRE support.
This commit removes the dead code associated with those old build
options.
We add the _OR_GOTO_DONE suffix to the macros that go to done if the
allocation fails. This makes it obvious what is different about the
macro versus the equivalent function, and that error handling is
built-in.
Renamed the cli_strdup to safer_strdup to make it obvious that it exists
because it is safer than regular strdup. Regular strdup doesn't have the
NULL check before trying to dup, and so may result in a NULL-deref
crash.
Also remove unused STRDUP (_OR_GOTO_DONE) macro, since the one with the
NULL-check is preferred.
We have some special functions to wrap malloc, calloc, and realloc to
make sure we don't allocate more than some limit, similar to the
max-filesize and max-scansize limits. Our wrappers are really only
needed when allocating memory for scans based on untrusted user input,
where a scan file could have bytes that claim you need to allocate
some ridiculous amount of memory. Right now they're named:
- cli_malloc
- cli_calloc
- cli_realloc
- cli_realloc2
... and these names do not convey their purpose
This commit renames them to:
- cli_max_malloc
- cli_max_calloc
- cli_max_realloc
- cli_max_realloc2
The realloc ones also have an additional feature in that they will not
free your pointer if you try to realloc to 0 bytes. Freeing the memory
is undefined by the C spec, and only done with some realloc
implementations, so this stabilizes on the behavior of not doing that,
which should prevent accidental double-free's.
So for the case where you may want to realloc and do not need to have a
maximum, this commit adds the following functions:
- cli_safer_realloc
- cli_safer_realloc2
These are used for the MPOOL_REALLOC and MPOOL_REALLOC2 macros when
MPOOL is disabled (e.g. because mmap-support is not found), so as to
match the behavior in the mpool_realloc/2 functions that do not make use
of the allocation-limit.
Includes rudimentary support for getting slices from FMap's and for
interacting with libclamav's context structure.
For now will use a Cisco-Talos org fork of the onenote_parser
until the feature to read open a onenote section from a slice (instead
of from a filepath) is added to the upstream.
Developers of FreeBSD base system are currently working to upgrade its
LLVM/Clang/LLDB/LLD to 17. As a part of it they tried building all
ports in FreeBSD ports collections to check if build of them succeeds
with LLVM/Clang/LLD 17. As a result there are some ports that fail to
be built with it and unfortunately `security/clamav` is one of
them. The build of it fails with link error as following.
```
ld: error: version script assignment of 'CLAMAV_PRIVATE' to symbol 'cli_cvdunpack' failed: symbol not defined
ld: error: version script assignment of 'CLAMAV_PRIVATE' to symbol 'cli_dbgmsg_internal' failed: symbol not defined
ld: error: version script assignment of 'CLAMAV_PRIVATE' to symbol 'init_domainlist' failed: symbol not defined
ld: error: version script assignment of 'CLAMAV_PRIVATE' to symbol 'init_whitelist' failed: symbol not defined
ld: error: version script assignment of 'CLAMAV_PRIVATE' to symbol 'cli_parse_add' failed: symbol not defined
ld: error: version script assignment of 'CLAMAV_PRIVATE' to symbol 'cli_bytecode_context_clear' failed: symbol not defined
cc: error: linker command failed with exit code 1 (use -v to see invocation)
```
According to the investigation of ClamAV's source code,
`cli_cvdunpack` is a static function so it isn't visible to external
consumers. And other mentioned symbols aren't found anywhere. So fix
link error by removing all of them from linker version script.
These symbols are used by an internal python tool for generating
signatures:
- fuzzy_hash_calculate_image
- ffierror_fmt
`ffierror_fmt` is required to free the error structure passed back in
case of an error.
Since version 1.1.0 started using libclamav.map again, we need to
explicitly export these symbols.
Add a new cl_engine_set_clcb_vba() function to set a cb_vba callback
function and add clcb_generic_data handler prototype to the clamav.h
public API.
The cb_vba callback function will be run whenever VBA is extracted from
office documents. The provided data will be a normalized copy of the
original VBA. This callback is added to support Sigtool so it can use
the same VBA extraction logic as when scanning documents.
Change the Sigtool temp directory creation for any commands that use
temp directories so that you can select a custom temp directory with the
`--tempdir=PATH` option, and can retain the temp files with the
`--leave-temps` option.
Added `--tempdir` and `--leave-temps` to the Sigtool `--help` output.
Added `--tempdir` and `--leave-temps` to the Sigtool manpage.
* Add a new function cl_cvdgetage() to the libclamav API.
This function will retrieve the age of the youngest file in a
database directory, or the age of a single CVD (or CLD) file.
* Add new clamscan option --fail-if-cvd-older-than=days
When passed, causes clamscan to exit with a non-zero return code
if the virus database is older than the specified number of days.
* Add new clamd option --fail-if-cvd-older-than=days
When passed, causes clamd to exit on start-up with a non-zero
return code if the virus database is older than the specified
number of days.
Additionally, we introduce FailIfCvdOlderThan as a clamd.conf
synonym for --fail-if-cvd-older-than.
Fixes#820
libclamav.map: Add missing symbol and correct symbol version.
libclamunrar.map: Use symbol version-script for libclamunrar, too.
Thank you to Sebastian Andrzej Siewior for the help.
Also fix a unittest linker issue...
Adding libclamav.map causes libclamav to no longer export zlib
when zlib is statically linked.
What was weird is that libxml2 depends on zlib and the check_clamav
unit test program was using those symbols from libclamav.
Introducing libclamav.map broke that even though we were explicitly
trying to link check_clamav with ZLIB::ZLIB as well.
For reasons I can't explain, linking check_clamav with the
ClamAV::common library managed to properly link it with ZLIB::ZLIB
and so the undefined references go away.
Also in this commit, I've removed the `.map` files from .gitignore
I'm not sure why they were ignored before.
libclamav callbacks can be used to access embedded file content at each
layer of extraction during the course of a scan. The existing callbacks
only provide access to the file descriptor and a guess at the file type.
This patch adds a new callback for the purposes of file/archive
inspection that provides additional insight into the embedded file.
This includes:
- ancestors: an array of parent file names
- parent file size: the size of the direct parent layer
- file name: current layer's filename, if any.
- file buffer (pointer)
- file size: size of file buffer
- file type: just a guess at the current file's type
- file descriptor: may be -1 if the layer is in-memory only.
- layer attributes: a flag field. see LAYER_ATTRIBUTE_* defines in clamav.h
Two new example apps are added that are automatically built when
compiling under CMake:
- ex2 demonstrates the prescan callback.
- ex3 demonstrates the new file inspection callback.
The examples are now installed if enabled, so you can test them in the
Docker image, and so that they'll be colocated with the DLLs so you can
test them on Windows. The installed examples should also be able to find
the UnRAR library at run time, without having to set LD_LIBRARY_PATH.
This commit also sets the fmap->name in an fmap-scan using the basname
of the provided filename if the caller provided the filename and the
provided fmap does not have the name set.
An ENABLE_TESTS CMake option is provided so that users can disable
testing if they don't want it. Instructions for how to use this
included in the INSTALL.cmake.md file.
If you run `ctest`, each testcase will write out a log file to the
<build>/unit_tests directory.
As with Autotools' make check, the test files are from test/.split
and unit_tests/.split files, but for CMake these are generated at
build time instead of at test time.
On Posix systems, sets the LD_LIBRARY_PATH so that ClamAV-compiled
libraries can be loaded when running tests.
On Windows systems, CTest will identify and collect all library
dependencies and assemble a temporarily install under the
build/unit_tests directory so that the libraries can be loaded when
running tests.
The same feature is used on Windows when using CMake to install to
collect all DLL dependencies so that users don't have to install them
manually afterwards.
Each of the CTest tests are run using a custom wrapper around Python's
unittest framework, which is also responsible for finding and inserting
valgrind into the valgrind tests on Posix systems.
Unlike with Autotools, the CMake CTest Valgrind-tests are enabled by
default, if Valgrind can be found. There's no need to set VG=1.
CTest's memcheck module is NOT supported, because we use Python to
orchestrate our tests.
Added a bunch of Windows compatibility changes to the unit tests.
These were primarily changing / to PATHSEP and making adjustments
to use Win32 C headers and ifdef out the POSIX ones which aren't
available on Windows. Also disabled a bunch of tests on Win32
that don't work on Windows, notably the mmap ones and FD-passing
(i.e. FILEDES) ones.
Add JSON_C_HAVE_INTTYPES_H definition to clamav-config.h to eliminate
warnings on Windows where json.h is included after inttypes.h because
json-c's inttypes replacement relies on it.
This is a it of a hack and may be removed if json-c fixes their
inttypes header stuff in the future.
Add preprocessor definitions on Windows to disable MSVC warnings about
CRT secure and nonstandard functions. While there may be a better
solution, this is needed to be able to see other more serious warnings.
Add missing file comment block and copyright statement for clamsubmit.c.
Also change json-c/json.h include filename to json.h in clamsubmit.c.
The directory name is not required.
Changed the hash table data integer type from long, which is poorly
defined, to size_t -- which is capable of storing a pointer. Fixed a
bunch of casts regarding this variable to eliminate warnings.
Fixed two bugs causing utf8 encoding unit tests to fail on Windows:
- The in_size variable should be the number of bytes, not the character
count. This was was causing the SHIFT_JIS (japanese codepage) to UTF8
transcoding test to only transcode half the bytes.
- It turns out that the MultiByteToWideChar() API can't transcode
UTF16-BE to UTF16-LE. The solution is to just iterate over the buffer
and flip the bytes on each uint16_t. This but was causing the UTF16-BE
to UTF8 tests to fail.
I also split up the utf8 transcoding tests into separate tests so I
could see all of the failures instead of just the first one.
Added a flags parameter to the unit test function to open testfiles
because it turns out that on Windows if a file contains the \r\n it will
replace it with just \n if you opened the file as a text file instead of
as binary. However, if we open the CBC files as binary, then a bunch of
bytecode tests fail. So I've changed the tests to open the CBC files in
the bytecode tests as text files and open all other files as binary.
Ported the feature tests from shell scripts to Python using a modified
version of our QA test-framework, which is largely compatible and will
allow us to migrate some QA tests into this repo. I'd like to add GitHub
Actions pipelines in the future so that all public PR's get some testing
before anyone has to manually review them.
The clamd --log option was missing from the help string, though it
definitely works. I've added it in this commit.
It appears that clamd.c was never clang-format'd, so this commit also
reformats clamd.c.
Some of the check_clamd tests expected the path returned by clamd to
match character for character with original path sent to clamd. However,
as we now evaluate real paths before a scan, the path returned by clamd
isn't going to match the relative (and possibly symlink-ridden) path
passed to clamdscan. I fixed this test by changing the test to search
for the basename: <signature> FOUND within the response instead of
matching the exact path.
Autotools: Link check_clamd with libclamav so we can use our utility
functions in check_clamd.c.
The fmap_duplicate function is used create a new fmap with a view into
an existing fmap. When the new view is a different size than the old
fmap, a new hash must be calculated for the duplicate fmap. However,
when the duplicated fmap is the same size as the original fmap, the hash
will be the same and there's no point recalculating.
The issue is apparent when scanning large EXE files because the hash was
being calculated at the beginning and end of the scan.
Digging into this issue revealed that hash calculations for fmaps were
also being performed at the wrong place. For scans of maps we use
fmap_duplicate() early in the process to apply the name API argument to
the duplicate fmap. Fixing the logic so we doing recalculate the hash
revealed that we never calculated hashes for fmap's created from buffers
in the first place, so that also had to be fixed be relocating where the
hash is calculated.
I also found that fmap_duplicate()'s offset argument used an off_t,
though it and all caller offsets are not allowed to be negative. This
was a bit of tangent to fix a bunch of off_t variables and paramters
that should've been size_t.
Added a couple unit tests to verify that making duplicate fmaps, and
duplicate-duplicate fmaps works as expected after the change.
Changed CLI_ISCONTAINED() and CLI_ISCONTAINED2() macros to cast to
size_t, because pointers and buffer sizes may not be negative, and these
two macros do not rely on substraction.
This improvement looks up the filename given the file descriptor.
This is supported on Mac and Linux but not presently supported
on other UNIX operating systems. FD-passing is not available on
Windows.
On supported systems, the verdict in the clamd log and the VirusEvent
will show the actual file path instead of something like fd[14].
Also relocated codepage table from msdoc.h to entconv.h
Also adds new macros for codepages to reduce use of magic numbers when
referencing code pages elsewhere in libclamav.
A malicious user could replace a scan target's directory with a symlink
to another path to trick clamscan, clamdscan, or clamonacc into removing
or moving a different file (eg. a critical system file). The issue would
affect users that use the `--move` or `--remove` options for clamscan,
clamdscan, and clamonacc.
This patch gets the real path for the scan target before the scan,
and if the file alerts and the --move or --remove quarantine features
are used, it mitigates the symlink attack by traversing the path one
directory at a time until reaching the leaf directory where the scan
target file resides before unlinking (or renaming) the file directly.
This commit applies a similar tactic used in the previous commit for
Windows builds, using the Win32 Native API to traverse a path and delete
or move files by handle rather than by file path.
I had some trouble using SetFileInformationByHandle to rename a file by
handle, so for Windows instead it will copy the file to the new location
and then use the safe unlink technique to remove the old file. If the
symlink attack occurs, the unlink will fail, and the system will not be
damaged.
For more information about AV quarantine attacks using links, see the
[RACK911 Lab's report](https://www.rack911labs.com/research/exploiting-almost-every-antivirus-software)
Many of the core scanning functions' names no longer represent their
specific purpose or arguments. This commit aims to make the names more
intuitive. Names are now prefixed with "magic" if they involve
file-typing and file-type parsing. In addition, each function now
includes the type of input being scanned whether its "desc", "fmap", or
"buff". Some of the APIs also now specify "type" to indicate that a type
other than "ANY" may be passed in to select the type rather than use
file type magic for type recognition.
| current name | new name |
| ------------------------- | --------------------------------- |
| magic_scandesc() | cli_magic_scan() |
| cli_magic_scandesc_type() | <delete> |
| cli_magic_scandesc() | cli_magic_scan_desc() |
| cli_base_scandesc() | cli_magic_scan_desc_type() |
| cli_partition_scandesc() | <delete> |
| cli_map_scandesc() | magic_scan_nested_fmap_type() |
| cli_map_scan() | cli_magic_scan_nested_fmap_type() |
| cli_mem_scandesc() | cli_magic_scan_buff() |
| cli_scanbuff() | cli_scan_buff() |
| cli_scandesc() | cli_scan_desc() |
| cli_fmap_scandesc() | cli_scan_fmap() |
| cli_scanfile() | cli_magic_scan_file() |
| cli_scandir() | cli_magic_scan_dir() |
| cli_filetype2() | cli_determine_fmap_type() |
| cli_filetype() | cli_compare_ftm_file() |
| cli_partitiontype() | cli_compare_ftm_partition() |
| cli_scanraw() | scanraw() |
Disable line wrap when printing the progress bar so that small terminal
windows do not see excessive lines printed.
Reduce the number of characters in the progress bar to accomodate
80-char width terminals.
Correctly display number of kilobytes (KiB) in progress bar. Previously
was showing # of MiB but printing "KiB".
Instead of checking the Authenticode header as an FP prevention
mechanism, we now check it in the beginning if it exists. Also,
we can now do actual blacklisting with .crb rules (previously, a
blacklist rule just let you override a whitelist rule).
Micah Snyder