The security improvement to perform file realpath lookups prior to a
scan has the adverse effect of causing file scans to fail on Windows
when scanning on some filesystems.
Specifically, it was observed that the ImDisk driver doesn't handle the
IRP_MJ_QUERY_INFORMATION message so the call to look up the realpath
using GetFinalPathNameByHandleW() doesn't work.
There are two other API's I've found which can query the real file path.
The first is to create a file mapping of the target file and then use
GetMappedFileNameW() to get the file path. The other is to use the
NtQueryObject() undocumented NT API to get the file path. Each of
these should return roughly the same thing. For files in an ImDisk
RAM-disk drive, the resulting filepath for R:\clam.exe would
be \\Device\ImDisk0\clam.exe. The trouble is, mapping
\\Device\ImDisk0\clam.exe back to R:\clam.exe would rely on an
assumption that ImDisk is using the default drive letter, which is a tad
hacky.
Instead, this patch simply allows the scan to proceed if the realpath
lookup failed. If the user is using the quarantine (remove/move)
features AND if the scan target filepath has a directory junction (soft
link), then the quarantine action will fail. It's not ideal but it is
quite unlikely.
Changing umask for PID files from `0002` to `0022` to limit write access
to the current user only, removing group write access.
Changing directory permissions for the freshclam tmp directories from
`0755` to `0700` because only the freshclam user needs access to these
directories.
Patch courtesy of Tuomo Soini
The UnRAR library requires the character-classification locale to be set
to the empty string "" so it will be set according to the environment
variables, as seeen in the rar.cpp example application `main()`.
Without this, extracting RAR archives containing unicode filenames on
non-Windows, non-macOS operating systems may fail.
Drop privileges in the parent process before waiting for the signal
from the child process, so that the parent properly responds to
the signal and terminates.
Verify that the log file will be owned by user that the deamon will
run as.
Explicitly set PID file ownership to root when starting the daemon
as root with the PID file enabled.
There is an autotools variable and clamav-config.h macro BUILD_CLAMD
which dates back 17 years to a time where libpthread support was
optional and users could build clamscan without building clamd,
clamdscan, clamav-milter, etc. We don't live in that world anymore and
certainly don't test that configuration.
To get the NotifyClamd freshclam feature to work with CMake builds we
either have to define BUILD_CLAMD from CMake as well, or remove the
feature entirely. I chose to remove it, because we don't test builds
without BUILD_CLAMD enabled and it adds needless complexity to our build
system and source.
This patch adds experimental-quality CMake build tooling.
The libmspack build required a modification to use "" instead of <> for
header #includes. This will hopefully be included in the libmspack
upstream project when adding CMake build tooling to libmspack.
Removed use of libltdl when using CMake.
Flex & Bison are now required to build.
If -DMAINTAINER_MODE, then GPERF is also required, though it currently
doesn't actually do anything. TODO!
I found that the autotools build system was generating the lexer output
but not actually compiling it, instead using previously generated (and
manually renamed) lexer c source. As a consequence, changes to the .l
and .y files weren't making it into the build. To resolve this, I
removed generated flex/bison files and fixed the tooling to use the
freshly generated files. Flex and bison are now required build tools.
On Windows, this adds a dependency on the winflexbison package,
which can be obtained using Chocolatey or may be manually installed.
CMake tooling only has partial support for building with external LLVM
library, and no support for the internal LLVM (to be removed in the
future). I.e. The CMake build currently only supports the bytecode
interpreter.
Many files used include paths relative to the top source directory or
relative to the current project, rather than relative to each build
target. Modern CMake support requires including internal dependency
headers the same way you would external dependency headers (albeit
with "" instead of <>). This meant correcting all header includes to
be relative to the build targets and not relative to the workspace.
For example, ...
```c
include "../libclamav/clamav.h"
include "clamd/clamd_others.h"
```
... becomes:
```c
// libclamav
include "clamav.h"
// clamd
include "clamd_others.h"
```
Fixes header name conflicts by renaming a few of the files.
Converted the "shared" code into a static library, which depends on
libclamav. The ironically named "shared" static library provides
features common to the ClamAV apps which are not required in
libclamav itself and are not intended for use by downstream projects.
This change was required for correct modern CMake practices but was
also required to use the automake "subdir-objects" option.
This eliminates warnings when running autoreconf which, in the next
version of autoconf & automake are likely to break the build.
libclamav used to build in multiple stages where an earlier stage is
a static library containing utils required by the "shared" code.
Linking clamdscan and clamdtop with this libclamav utils static lib
allowed these two apps to function without libclamav. While this is
nice in theory, the practical gains are minimal and it complicates
the build system. As such, the autotools and CMake tooling was
simplified for improved maintainability and this feature was thrown
out. clamdtop and clamdscan now require libclamav to function.
Removed the nopthreads version of the autotools
libclamav_internal_utils static library and added pthread linking to
a couple apps that may have issues building on some platforms without
it, with the intention of removing needless complexity from the
source. Kept the regular version of libclamav_internal_utils.la
though it is no longer used anywhere but in libclamav.
Added an experimental doxygen build option which attempts to build
clamav.h and libfreshclam doxygen html docs.
The CMake build tooling also may build the example program(s), which
isn't a feature in the Autotools build system.
Changed C standard to C90+ due to inline linking issues with socket.h
when linking libfreshclam.so on Linux.
Generate common.rc for win32.
Fix tabs/spaces in shared Makefile.am, and remove vestigial ifndef
from misc.c.
Add CMake files to the automake dist, so users can try the new
CMake tooling w/out having to build from a git clone.
clamonacc changes:
- Renamed FANOTIFY macro to HAVE_SYS_FANOTIFY_H to better match other
similar macros.
- Added a new clamav-clamonacc.service systemd unit file, based on
the work of ChadDevOps & Aaron Brighton.
- Added missing clamonacc man page.
Updates to clamdscan man page, add missing options.
Remove vestigial CL_NOLIBCLAMAV definitions (all apps now use
libclamav).
Rename Windows mspack.dll to libmspack.dll so all ClamAV-built
libraries have the lib-prefix with Visual Studio as with CMake.
This patch relocates the real-path check from clamdscan and clamonacc
to clamd. While clamonacc is unlikely to send directories or symlinks
to be scanned, clamdscan may send directories. Real-path checks have
to be performed on the files, not the directories -- both because the
directories may contain symlinks and because the cli_realpath()
function wasn't written to support directories on Windows.
Removed all autotools generates files. Autotools (autoconf, automake,
libtool, pkg-config, m4) will be required from now on for builds from
git clones.
Added autogen.sh to be run before ./configure.
Significant update to main .gitignore file.
Removed extraneous .gitignore files. A Git repository only needs one
.gitignore file.
dboptions should be an unsigned int.
Julius Plenz accidentally missing from NEWS.md.
Fail out if cl_engine_settings_apply() fails, because the only possible
cause of failure is a malloc issue.
Add clamd config option to force blocking clamd database reload to
conserve RAM. Users may set `ConcurrentDatabaseReload no` in their
clamd.conf config file to force a blocking reload.
The blocking mode will still perform the reload in a new thread, but
will first free the current database, wait for scans targeting that
database to complete, and then load the new database in the new thread
and wait (`pthread_join()`) on that thread. Once loaded, any pending
scans will continue. This is effectively the same behavior as how
clamd reloads worked before the multi-threaded database reload feature
was added.
Offload the DB load to a separate thread and only replace the current
engine instance afterwards.
While reload is pending:
- existing scan requests use the old db (this is unchanged)
- new scan requests are honored instead of blocked and they also use
the old db (this is new)
After the reload is complete:
- existing scan requests use the old db (this is unchanged)
- new scan requests use the new db (this is unchanged)
The existing engine is refcounted so it'll be eventually freed when no
longer in use.
Reload requests while reload is pending are silently ignored (i.e. It
never forks more than a single reload thread).
Patch courtesy of Alberto Wu. We would also like to thank Julius Plenz
for original work on this issue, as well as Alexander Sulfrian,
Arjen de Korte, David Heidelberg, and Ged Haywood for their work
updating and testing these patches.
On some systems, the VirusEvent feature doubles the amount of RAM being used
because fork() duplicates the loaded signature database in the new process.
This commit changes fork() to vfork() so that VirusEvent won't fail if these systems
don't have enough memory.
Add Data-Loss-Prevention option to detect credit cards only, excluding
debit and private label cards where possible.
You can select the credit card-only DLP mode for clamscan with the
`--structured-cc-mode` command-line option.
You can select the credit card-only DLP mode for clamd with the
`StructuredCCOnly` clamd.conf config option.
This patch also adds credit card matching for additional vendors:
- Mastercard 2016
- China Union Pay
- Discover 2009
If the clamd.conf enables the LocalSocket option and sets the unix
socket file in a directory that does not exist, clamd creates the
missing directory but with invalid 000 permissions bits, causing socket
creation to fail.
This patch sets the umask temporarily to allow creation of the
directory w/ dwrxwr-wr- (766) permissions.
Removing problematic call to convert file descriptors to filepaths.
Added filename and tempfile names to scandesc calls in clamd.
Added a general scan option to treat the scan engine as unprivileged,
meaning that the scan engine will not have read access to the file.
Added check to drop a temp file for RAR's where the we don't have
read access to the filepath provided (i.e. unprivileged is set, or
access() check fails).
New features added to freshclam:
- Update signature definitions over HTTPS.
- Support for HTTP protocol v1.1 (formerly v1.0).
- New libfreshclam library with an all new API and versioning separate from libclamav (v2.0.0). This library is now build and installed alongside libclamav as a hard dependency of freshclam.
- The ability to opt-in and opt-out of standard and optional official ClamAV databases (ExtraDatabase, ExcludeDatabase)
- The option to specify the protocol and port number of official and private mirror servers.
- Support for additional types of proxy servers beyond plain HTTP (SOCKS 4, SOCKS 5).
Features removed from freshclam:
- Mirror management (mirrors.dat) file. This feature is no longer needed as official signature databases are distributed using a paid content delivery network (Cloudflare).
This commit also adds the following features for Windows users:
- The clamsubmit tool.
- The json-c library dependency, which will enable the --gen-json option in clamscan.
- Third party libraries under the win32/3rdparty directory have been removed. Developers will need to build the libraries separately from ClamAV and provide the headers and lib/dll library files the same way they do for OpenSSL. This includes libxml2, pthread-win32, bzip2, zlib, pcre2 as well as new dependencies: curl, json-c. Developers are encouraged to use the build tool Mussels to simplify this task.
Micah Snyder (micasnyd)