- limit ECC support to ec*-sha2-nistp256:
* DROPBEAR_ECC now provides only basic support for ECC
- provide full ECC support as an option:
* DROPBEAR_ECC_FULL brings back support for ec{dh,dsa}-sha2-nistp{384,521}
- update feature costs in binary size
Signed-off-by: Konstantin Demin <rockdrilla@gmail.com>
* option "keyfile" is more generic than "rsakeyfile".
* option "rsakeyfile" is considered to be deprecated and should be removed
in future releases.
* warn user (in syslog) if option "rsakeyfile" is used
* better check options ("rsakeyfile" and "keyfile"): don't append
"-r keyfile" to command line if file is absent (doesn't exist or empty),
warn user (in syslog) about such files
Signed-off-by: Konstantin Demin <rockdrilla@gmail.com>
Felix Fietkau pointed out that bundled libtomcrypt/libtommath do funny stuff with CFLAGS.
fix this with checking environment variable OPENWRT_BUILD in both libs.
change in dropbear binary size is drastical: 221621 -> 164277.
Signed-off-by: Konstantin Demin <rockdrilla@gmail.com>
compiler complains about messed up CFLAGS in build log:
<command-line>: warning: "_FORTIFY_SOURCE" redefined
<command-line>: note: this is the location of the previous definition
and then linker fails:
mips-openwrt-linux-musl-gcc [...] -o dropbearmulti [...]
collect2: fatal error: ld terminated with signal 11 [Segmentation fault]
compilation terminated.
/staging_dir/toolchain-mips_24kc_gcc-8.2.0_musl/mips-openwrt-linux-musl/bin/ld: /tmp/cc27zORz.ltrans0.ltrans.o: relocation R_MIPS_HI16 against `cipher_descriptor' can not be used when making a shared object; recompile with -fPIC
/staging_dir/toolchain-mips_24kc_gcc-8.2.0_musl/mips-openwrt-linux-musl/bin/ld: /tmp/cc27zORz.ltrans1.ltrans.o: relocation R_MIPS_HI16 against `ses' can not be used when making a shared object; recompile with -fPIC
/staging_dir/toolchain-mips_24kc_gcc-8.2.0_musl/mips-openwrt-linux-musl/bin/ld: /tmp/cc27zORz.ltrans2.ltrans.o: relocation R_MIPS_HI16 against `cipher_descriptor' can not be used when making a shared object; recompile with -fPIC
/staging_dir/toolchain-mips_24kc_gcc-8.2.0_musl/mips-openwrt-linux-musl/bin/ld: BFD (GNU Binutils) 2.31.1 assertion fail elfxx-mips.c:6550
[...]
/staging_dir/toolchain-mips_24kc_gcc-8.2.0_musl/mips-openwrt-linux-musl/bin/ld: BFD (GNU Binutils) 2.31.1 assertion fail elfxx-mips.c:6550
make[3]: *** [Makefile:198: dropbearmulti] Error 1
make[3]: *** Deleting file 'dropbearmulti'
make[3]: Leaving directory '/build_dir/target-mips_24kc_musl/dropbear-2018.76'
make[2]: *** [Makefile:158: /build_dir/target-mips_24kc_musl/dropbear-2018.76/.built] Error 2
make[2]: Leaving directory '/package/network/services/dropbear'
This FTBFS issue was caused by hardening flags set up by dropbear's configure script.
By default, Dropbear offers hardening via CFLAGS and LDFLAGS,
but this may break or confuse OpenWrt settings.
Remove most Dropbear's hardening settings in favour of precise build,
but preserve Spectre v2 mitigations:
* -mfunction-return=thunk
* -mindirect-branch=thunk
Signed-off-by: Konstantin Demin <rockdrilla@gmail.com>
This adds a wrapper (uci_load_validate) for uci_validate_section() that
allows callers (through a callback function) to access the values set by
uci_validate_section(), without having to manually declare a
(potentially long) list of local variables.
The callback function receives two arguments when called, the config
section name and the return value of uci_validate_section().
If no callback function is given, then the wrapper exits with the value
returned by uci_validate_section().
This also updates several init scripts to use the new wrapper function.
Signed-off-by: Jeffery To <jeffery.to@gmail.com>
Interface triggers are installed by the dropbear init script in case an
interface is configured for a given dropbear uci section.
As dropbear is started after network the interface trigger event can be
missed during a small window; this is especially the case if lan is
specified as interface.
Fix this by starting dropbear before network so no interface trigger
is missed. As dropbear is started earlier than netifd add a boot function
to avoid the usage of network.sh functions as call to such functions will
fail at boottime.
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
Acked-by: Jo-Philipp Wich <jo@mein.io>
CVE description :
The recv_msg_userauth_request function in svr-auth.c in Dropbear through
2018.76 is prone to a user enumeration vulnerability because username
validity affects how fields in SSH_MSG_USERAUTH messages are handled,
a similar issue to CVE-2018-15473 in an unrelated codebase.
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
Override the default shutdown action (stop) and close all processes
of dropbear
Since commit 498fe85, the stop action only closes the process
that's listening for new connections, maintaining the ones with
existing clients.
This poses a problem when restarting or shutting-down a device,
because the connections with existing SSH clients, like OpenSSH,
are not properly closed, causing them to hang.
This situation can be avoided by closing all dropbear processes when
shutting-down the system, which closes properly the connections with
current clients.
Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>
[Luis: Rework commit message]
Signed-off-by: Luis Araneda <luaraneda@gmail.com>
The default receive window size in dropbear is hardcoded to 24576 byte
to limit memory usage. This value was chosen for 100Mbps networks, and
limits the throughput of scp on faster networks. It also severely limits
scp throughput on high-latency links.
Add an option to set the receive window size so that people can improve
performance without having to recompile dropbear.
Setting the window size to the highest value supported by dropbear
improves throughput from my build machine to an APU2 on the same LAN
from 7MB/s to 7.9MB/s, and to an APU2 over a link with ~65ms latency
from 320KB/s to 7.5MB/s.
Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
As MD5 is known weak for many years and more and more
penetration test tools complain about enabled MD5 HMAC
I think it's time to drop it.
By disabling the MD5 HMAC support dropbear will also
automatically use SHA1 for fingerprints.
This shouldn't be a problem too.
Signed-off-by: Martin Schiller <ms@dev.tdt.de>
CPE ids helps to tracks CVE in packages.
https://cpe.mitre.org/specification/
Thanks to swalker for CPE to package mapping and
keep tracking CVEs.
Acked-by: Jo-Philipp Wich <jo@mein.io>
Signed-off-by: Alexander Couzens <lynxis@fe80.eu>
Adds config option to enable compression support which is usefull
when using a terminal sessions over a slow link. Impact on binary
size is negligible but additional 60 kB (uncompressed) is needed for
a shared zlib library.
Signed-off-by: Marcin Jurkowski <marcin1j@gmail.com>
ssh and scp commands interfere with OpenSSH when installed in /usr/bin .
One use case is when installing dropbear to get root access when only OpenSSH is available (OpenSSH disallows root password logins). Once dropbear installs, it replaces OpenSSH's executables, even when removed with opkg. OpenSSH must be reinstalled to get them back.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Add a uci option to set the new max auth tries paramater in dropbear.
Set the default to 3, as 10 seems excessive.
Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Add support for '-T n' for a run-time specification for maximum number
of authentication attempts where 'n' is between 1 and compile time
option MAX_AUTH_TRIES.
A default number of tries can be specified at compile time using
'DEFAULT_AUTH_TRIES' which itself defaults to MAX_AUTH_TRIES for
backwards compatibility.
Signed-off-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
- Security: Fix double-free in server TCP listener cleanup A double-free
in the server could be triggered by an authenticated user if dropbear is
running with -a (Allow connections to forwarded ports from any host)
This could potentially allow arbitrary code execution as root by an
authenticated user. Affects versions 2013.56 to 2016.74. Thanks to Mark
Shepard for reporting the crash.
CVE-2017-9078 https://secure.ucc.asn.au/hg/dropbear/rev/c8114a48837c
- Security: Fix information disclosure with ~/.ssh/authorized_keys
symlink. Dropbear parsed authorized_keys as root, even if it were a
symlink. The fix is to switch to user permissions when opening
authorized_keys
A user could symlink their ~/.ssh/authorized_keys to a root-owned file
they couldn't normally read. If they managed to get that file to contain
valid authorized_keys with command= options it might be possible to read
other contents of that file.
This information disclosure is to an already authenticated user.
Thanks to Jann Horn of Google Project Zero for reporting this.
CVE-2017-9079 https://secure.ucc.asn.au/hg/dropbear/rev/0d889b068123
Refresh patches, rework 100-pubkey_path.patch to work with new
authorized_keys validation.
Signed-off-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
Install procd interface triggers only for interfaces which are enabled
so dropbear instances running on (an) enabled interface(s) are not
restarted due to an interface trigger of an interface which is disabled.
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
The only HMACs currently available use MD5 and SHA1, both of which have known
weaknesses. We already compile in the SHA256 code since we use Curve25519
by default, so there's no significant size penalty to enabling this.
Signed-off-by: Joseph C. Sible <josephcsible@users.noreply.github.com>
Harmonise handling of DEFAULT_PATH by removing the patch introducing #ifndef
guards around the path, and only using one means to set the path in the
makefile.
Signed-off-by: Dario Ernst <Dario.Ernst@riverbed.com>
Configurations without shadow passwords have been broken since the removal
of telnet: as the default entry in /etc/passwd is not empty (but rather
unset), there will be no way to log onto such a system by default. As
disabling shadow passwords is not useful anyways, remove this configuration
option.
The config symbol is kept (for a while), as packages from feeds depend on
it.
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
As security precaution and to limit the attack surface based on
the version reported by tools like nmap mask out the dropbear
version so the version is not visible anymore by snooping on the
wire. Version is still visible by 'dropbear -V'
Based on a patch by Hans Dedecker <dedeckeh@gmail.com>
Signed-off-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
Signed-off-by: Felix Fietkau <nbd@nbd.name> [remove trailing _]
- Security: Message printout was vulnerable to format string injection.
If specific usernames including "%" symbols can be created on a system
(validated by getpwnam()) then an attacker could run arbitrary code as root
when connecting to Dropbear server.
A dbclient user who can control username or host arguments could potentially
run arbitrary code as the dbclient user. This could be a problem if scripts
or webpages pass untrusted input to the dbclient program.
- Security: dropbearconvert import of OpenSSH keys could run arbitrary code as
the local dropbearconvert user when parsing malicious key files
- Security: dbclient could run arbitrary code as the local dbclient user if
particular -m or -c arguments are provided. This could be an issue where
dbclient is used in scripts.
- Security: dbclient or dropbear server could expose process memory to the
running user if compiled with DEBUG_TRACE and running with -v
The security issues were reported by an anonymous researcher working with
Beyond Security's SecuriTeam Secure Disclosure www.beyondsecurity.com/ssd.html
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
Fix a „semantic typo“ introduced in b78aae793e,
where TARGET_INIT_PATH was used instead of CONFIG_TARGET_INIT_PATH.
Signed-off-by: Dario Ernst <Dario.Ernst@riverbed.com>
Update the dropbear package to version 2016.73, refresh patches.
The measured .ipk sizes on an x86_64 build are:
94588 dropbear_2015.71-3_x86_64.ipk
95316 dropbear_2016.73-1_x86_64.ipk
This is an increase of roughly 700 bytes after compression.
Tested-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
The option --disable-utmpx was deleted by accident in commit 7545c1d;
add it again to the CONFIGURE_ARGS list
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
A dropbear instance having an interface config won't start if the interface is down as no
IP address is available.
Adding interface triggers for each configured interface executing the dropbear reload script
will start the dropbear instance when the interface is up.
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
Utmp support tracks who is currenlty logged in by logging info to the file /var/run/utmp (supported by busybox)
Putuline support will use the utmp structure to write to the utmp file
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
While technically required by the RFC, they are usually completely
unused (DSA), or have security issues (3DES, CBC)
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
SVN-Revision: 46814
