The Ed25519 key pairs are much shorter than RSA pairs and are supported
by default in OpenSSH. Looking at websites explaining how to create new
SSH keys, many suggest using Ed25519 rather than RSA, however consider
the former as not yet widely established. OpenWrt likely has a positive
influence on that development.
As enabling Ed25519 is a compile time option, it is currently not
possible to install the feature via `opkg` nor select that option in an
ImageBuilder.
Due to the size impact of **12kB** the option should only be enabled for
devices with `!SMALL_FLASH`.
This approach seems cleaner than splitting `dropbear` into two packages
like `dropbear` and `dropbear-ed25519`.
Signed-off-by: Paul Spooren <mail@aparcar.org>
If not needed, disabling scp allows for a nice size reduction.
Dropbear executable size comparison:
153621 bytes (baseline)
133077 bytes (without scp)
In other words, we trim a total of 20544 bytes.
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
The ssh symlink was still being created even when dbclient was disabled in the
build configuration. Fix this annoyance.
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
Upstream in commit 972d723484d8 ("split signkey_type and signature_type
for RSA sha1 vs sha256") has added strict checking of pubkey algorithms
which made keys with SHA-256 hashing algorithm unusable as they still
reuse the `ssh-rsa` public key format. So fix this by disabling the
check for `rsa-sha2-256` pubkeys.
Ref: https://tools.ietf.org/html/rfc8332#section-3
Fixes: d4c80f5b17 ("dropbear: bump to 2020.80")
Tested-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
This replaces deprecated backticks by more versatile $(...) syntax.
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
[add commit description]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Backport patches which fix compile issue for uClibc-ng :
dbrandom.c:174:8: warning: implicit declaration of function 'getrandom'; did you mean 'genrandom'? [-Wimplicit-function-declaration]
ret = getrandom(buf, sizeof(buf), GRND_NONBLOCK);
^~~~~~~~~
genrandom
dbrandom.c:174:36: error: 'GRND_NONBLOCK' undeclared (first use in this function); did you mean 'SOCK_NONBLOCK'?
ret = getrandom(buf, sizeof(buf), GRND_NONBLOCK);
^~~~~~~~~~~~~
SOCK_NONBLOCK
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
- drop patches (applied upstream):
* 010-backport-change-address-logging.patch
* 020-backport-ed25519-support.patch
* 021-backport-chacha20-poly1305-support.patch
- backport patches:
* 010-backport-disable-toom-and-karatsuba.patch:
reduce dropbear binary size (about ~8Kb).
- refresh patches.
- don't bother anymore with following config options
because they are disabled in upstream too:
* DROPBEAR_3DES
* DROPBEAR_ENABLE_CBC_MODE
* DROPBEAR_SHA1_96_HMAC
- explicitly disable DO_MOTD as it was before commit a1099ed:
upstream has (accidentally) switched it to 0 in release 2019.77,
but reverted back in release 2020.79.
Signed-off-by: Konstantin Demin <rockdrilla@gmail.com>
201e359 Handle early exit when addrstring isn't set
fa4c464 Improve address logging on early exit messages (#83)
Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
The sender domain has a DMARC Reject/Quarantine policy which disallows
sending mailing list messages using the original "From" header.
To mitigate this problem, the original message has been wrapped
automatically by the mailing list software.
Failsafe code of dropbear should be in the dropbear package not the
base-files package.
Signed-off-by: Kyle Copperfield <kmcopper@danwin1210.me>
This activates PIE ASLR support by default when the regular option is
selected.
This increases the binary size by 18% uncompressed and 17% compressed
on MIPS BE.
old:
164,261 /usr/sbin/dropbear
85,648 dropbear_2019.78-2_mips_24kc.ipk
new:
194,492 /usr/sbin/dropbear
100,309 dropbear_2019.78-2_mips_24kc.ipk
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Petr Štetiar <ynezz@true.cz>
If CONFIG_DROPBEAR_ZLIB is set, building fails at the packaging stage
due to an undeclared dependency on libz.so.1.
As is already done for the main dropbear package, conditionally add a
dependency on zlib.
Signed-off-by: Matt Merhar <mattmerhar@protonmail.com>
Required as dependency on dropbear config headers is not tracked in
dropbear build system
Fixes FS#2275
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
Fix dbclient regression in 2019.77. After exiting the terminal would be left
in a bad state. Reported by Ryan Woodsmall
drop patch applied upstream:
010-tty-modes-werent-reset-for-client.patch
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
- 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>
