- [client+server] Fernando Arnaboldi from IOActive found that strict
filesystem permissions for various fwknop files are not verified. Added
warnings whenever permissions are not strict enough, and ensured that
files created by the fwknop client and server are only set to user
read/write.
- [client] Fernando Arnaboldi from IOActive found a local buffer overflow
in --last processing with a maliciously constructed ~/.fwknop.run file.
This has been fixed with proper validation of .fwknop.run arguments.
Chop any trailing '/' char, be more careful about handling incoming large HTTP
responses, print the HTTP request and response in --verbose --verbose mode.
Applied patch from Jonathan Schulz to ensure that the fwknop client reads all
data from a remote webserver when resolving the client IP address in -R mode.
Jonathan indicated that some webservers would transfer HTTP headers and data
separately, and a single recv() would therefore fail to get the necessary IP
information.
This commit fixes the following (found with the test suite in valgrind mode):
568 bytes in 1 blocks are still reachable in loss record 1 of 1
at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x50B1C9A: __fopen_internal (iofopen.c:76)
by 0x10D0CD: process_rc (config_init.c:516)
by 0x10D645: config_init (config_init.c:752)
by 0x10AB13: main (fwknop.c:70)
This commit fixes the following memory caught with the test suite in valgrind
mode:
HEAP SUMMARY:
in use at exit: 285 bytes in 4 blocks
total heap usage: 11 allocs, 7 frees, 3,179 bytes allocated
5 bytes in 1 blocks are indirectly lost in loss record 1 of 4
at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x50CB801: strdup (strdup.c:43)
by 0x4E3A7B2: fko_set_username (fko_user.c:96)
by 0x4E39628: fko_new (fko_funcs.c:86)
by 0x10AB54: main (fwknop.c:83)
7 bytes in 1 blocks are indirectly lost in loss record 2 of 4
at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x4E395D7: fko_new (fko_funcs.c:62)
by 0x10AB54: main (fwknop.c:83)
17 bytes in 1 blocks are indirectly lost in loss record 3 of 4
at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x4E3A06A: fko_set_rand_value (fko_rand_value.c:114)
by 0x4E39605: fko_new (fko_funcs.c:75)
by 0x10AB54: main (fwknop.c:83)
285 (256 direct, 29 indirect) bytes in 1 blocks are definitely lost in loss record 4 of 4
at 0x4C29DB4: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x4E395BA: fko_new (fko_funcs.c:46)
by 0x10AB54: main (fwknop.c:83)
LEAK SUMMARY:
definitely lost: 256 bytes in 1 blocks
indirectly lost: 29 bytes in 3 blocks
possibly lost: 0 bytes in 0 blocks
still reachable: 0 bytes in 0 blocks
suppressed: 0 bytes in 0 blocks
This commit fixes memory leaks like the following in the fwknop client:
HEAP SUMMARY:
in use at exit: 300 bytes in 11 blocks
total heap usage: 100 allocs, 89 frees, 16,583 bytes allocated
16 bytes in 1 blocks are indirectly lost in loss record 1 of 11
at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x5146C59: __nss_lookup_function (nsswitch.c:456)
by 0x5C3D63E: ???
by 0x50FF3FC: getpwuid_r@@GLIBC_2.2.5 (getXXbyYY_r.c:256)
by 0x508938E: cuserid (cuserid.c:37)
by 0x4E3983A: fko_set_username (fko_user.c:65)
by 0x4E38D5C: fko_new (fko_funcs.c:84)
by 0x10A824: main (fwknop.c:75)
16 bytes in 1 blocks are indirectly lost in loss record 2 of 11
at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x5146C59: __nss_lookup_function (nsswitch.c:456)
by 0x5C3D658: ???
by 0x50FF3FC: getpwuid_r@@GLIBC_2.2.5 (getXXbyYY_r.c:256)
by 0x508938E: cuserid (cuserid.c:37)
by 0x4E3983A: fko_set_username (fko_user.c:65)
by 0x4E38D5C: fko_new (fko_funcs.c:84)
by 0x10A824: main (fwknop.c:75)
16 bytes in 1 blocks are indirectly lost in loss record 3 of 11
at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x5146C59: __nss_lookup_function (nsswitch.c:456)
by 0x5C3D672: ???
by 0x50FF3FC: getpwuid_r@@GLIBC_2.2.5 (getXXbyYY_r.c:256)
by 0x508938E: cuserid (cuserid.c:37)
by 0x4E3983A: fko_set_username (fko_user.c:65)
by 0x4E38D5C: fko_new (fko_funcs.c:84)
by 0x10A824: main (fwknop.c:75)
16 bytes in 1 blocks are indirectly lost in loss record 4 of 11
at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x5146C59: __nss_lookup_function (nsswitch.c:456)
by 0x5C3D68C: ???
by 0x50FF3FC: getpwuid_r@@GLIBC_2.2.5 (getXXbyYY_r.c:256)
by 0x508938E: cuserid (cuserid.c:37)
by 0x4E3983A: fko_set_username (fko_user.c:65)
by 0x4E38D5C: fko_new (fko_funcs.c:84)
by 0x10A824: main (fwknop.c:75)
When using the --nat-local argument on the fwknop client command line, the
fwknopd server needs to add an INPUT ACCEPT rule for the requested access
since the incoming connection is destined for a local socket. Added test
suite support to test --nat-local access.
[test suite] Minor bug fix to ensure that all file_find_regex() calls return
true if all regex's are matched and false if any regex does not match data in
the specified file.
Now that encryptions keys and hmac keys may be acquired from /dev/random with
--key-gen (and base64 encoded), they may contain NULL bytes. This emphasizes
the need to not leverage code that assumes C-style strings when making use of
key information.
This commit fixes a bug where the same encryption key used for two stanzas in
the access.conf file would result in access requests that matched the second
stanza to always be treated as a replay attack. This has been fixed for
the fwknop-2.0.1 release, and was reported by Andy Rowland. Now the fwknopd
server computes the SHA256 digest of raw incoming payload data before
decryption, and compares this against all previous hashes. Previous to this
commit, fwknopd would add a new hash to the replay digest list right after
the first access.conf stanza match, so when SPA packet data matched the
second access.conf stanza a matching replay digest would already be there.
Added --key-gen to allow KEY_BASE64 and HMAC_KEY_BASE64 keys to be created from
reading random data from /dev/random. These keys can be placed within server
access.conf files and corresponding client .fwknoprc files for SPA
communications. The HMAC key is not used yet with this commit, but that is
coming.
This is a significant update to allow AES encryption modes to be selected on a
per-key basis. For now, only ECB and CBC (recommended) modes are supported.
The default is ECB modes in order to maintain backwards compatibility with the
older perl version of fwknop and the Crypt::CBC CPAN module. This will likely
be changed to use CBC mode by default because of its better security
properties.
In the access.conf file on the server side, there is a new configuration
variable "ENCRYPTION_MODE" that controls the mode for the corresponding AES
key. On the client side, a new command line argument "--encryption-mode"
controls how the client encrypts SPA packets.
This commit adds a new configuration variable "FORCE_NAT" to the access.conf
file:
For any valid SPA packet, force the requested connection to be NAT'd
through to the specified (usually internal) IP and port value. This is
useful if there are multiple internal systems running a service such as
SSHD, and you want to give transparent access to only one internal system
for each stanza in the access.conf file. This way, multiple external
users can each directly access only one internal system per SPA key.
This commit also implements a few minor code cleanups.
The two memory leaks were found with the test suite running in
--enable-valgrind mode - here are the relevant error messages:
For fwknopd server GPG clean up:
==345== 9 bytes in 1 blocks are definitely lost in loss record 2 of 2
==345== at 0x4C2815C: malloc (vg_replace_malloc.c:236)
==345== by 0x52F6B81: strdup (strdup.c:43)
==345== by 0x10FA57: add_string_list_ent (access.c:308)
==345== by 0x110513: parse_access_file (access.c:387)
==345== by 0x10B5FB: main (fwknopd.c:193)
For fwknop client rc file processing:
==8045== 568 bytes in 1 blocks are still reachable in loss record 12 of 12
==8045== at 0x4C2815C: malloc (vg_replace_malloc.c:236)
==8045== by 0x50A53AA: __fopen_internal (iofopen.c:76)
==8045== by 0x10C3FF: process_rc (config_init.c:446)
==8045== by 0x10C8F6: config_init (config_init.c:671)
==8045== by 0x10AC9E: main (fwknop.c:62)
There is also a new clean_exit() function that makes it easier to ensure that
resources are deallocated upon existing.
Added the 'const' qualifier to function prototype variables where possible.
In addition, reduced some functions to file-scope with 'static' where possible.
Also made a few minor changes to remove extra whitespace, and fixed a bug
in create_fwknoprc() to ensure the new fwknoprc filehandle is closed.
This change fixes the following compiler warning that was seen with many of
the source files in server/
fwknopd_common.h:223: warning: ‘config_map’ defined but not used
This commit fixes several compiler warnings like the following (now that -Wall
is the default):
config_init.h:68: warning: ‘cmd_opts’ defined but not used
In the save_args() function the args_str_len variable was being used before
being initialized as reported via the splint static code analysis tool. Here
is the splint output that found this bug:
client/fwknop.c:650:13: Variable args_str_len used before definition
An rvalue is used that may not be initialized to a value on some execution
path. (Use -usedef to inhibit warning)
