This is more than enough as it reflects to 16 asterisks in the match
string is more than enough. With larger values oss-fuzz was generating
long match strings with asterisks interleaved with normal characters,
which were timing out.
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Currently Compression=no (the default) force-disables zlib algos, while
Compression=yes force-enables it. This means that mismatching options between
client and server lead to connection failure. This can easily happen if the
server has default settings but the client specifies Compression=yes.
OpenSSH treats the option as a "prefer compression" setting:
Compression=no -> none,zlib@openssh.com,zlib (default)
Compression=yes -> zlib@openssh.com,zlib,none
This commit changes the libssh behaviour to the same as OpenSSH.
Signed-off-by: Fabian Vogt <fabian@ritter-vogt.de>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
RFC 4252 §7 states that the public key algorithm in a
SSH_MSG_USERAUTH_PK_OK response is the public key algorithm name from
the request. When using RSA with SHA-2, this will be either
"rsa-sha2-256" or "rsa-sha2-512" as specified by RFC 8332 §3.2.
However, currently libssh emits the public key type instead, which is
"ssh-rsa". This is not in conformance with the RFCs, so let's fix this
by storing the signature type and emitting it in our response instead of
the public key when sending SSH_MSG_USERAUTH_PK_OK in the server.
Signed-off-by: brian m. carlson <bk2204@github.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Similarly as we already have for the client configuraiton file
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Do not compile tests which need SSHD_EXECUTABLE when
it is not available
Signed-off-by: Norbert Pocs <npocs@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Calling some channel procedures on a freed channel is always resulting
in segmentation fault errors. The reason is that when a channel is
freed with 'ssh_channel_do_free' procedure, its 'session' field is set
to NULL; then when a channel procedure tries to access any field of
'channel->session' structure it is effectively dereferencing a NULL
pointer.
The change fixes that behavior by adding a check which ensures that a
channel state is not SSH_CHANNEL_FLAG_FREED_LOCAL before accessing its
parent session.
Also the test suite is updated to check for the fixed errors, and the
Doxygen documentation updated accordingly.
There was a bug introduced in b0fb7d15: 'ssh_channel_poll',
'ssh_channel_poll_timeout' and 'ssh_channel_get_exit_status' would
compare the channel state to the 'SSH_CHANNEL_FLAG_FREED_LOCAL'
constant to check if the channel is alive. But the procedures must
check the channel flags for the presence of
'SSH_CHANNEL_FLAG_FREED_LOCAL' bits instead. This change fixes the
bug.
Signed-off-by: Artyom V. Poptsov <poptsov.artyom@gmail.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
We do not use SHA1 as it is disabled in many systems
Verifies CVE-2021-3634
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Normally, the length of session_id and secret_hash is the same,
but if we will get into rekeying with a peer that changes preference
of key exchange algorithm, the new secret hash can be larger or
smaller than the previous session_id causing invalid reads or writes.
Resolves https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35485
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
and add LOG_SIZE macro to control the buffer size
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Change-Id: I3eaeea001fc531fdb55074fc3a9d140b27847c1f
