Previously, if the SSH_OPTIONS_HOSTKEYS option was set by any mean,
including the client configuration file, the keys in known_hosts files
wouldn't be considered before advertising the list of wanted host keys.
This could result in the client requesting the server to provide a
signature using a key not present in the known_hosts files (e.g. when
the first wanted algorithm in SSH_OPTIONS_HOSTKEYS is not present in the
known_hosts files), causing a host key mismatch and possible key
rejection.
Now, the keys present in the known_hosts files are prioritized over the
other wanted keys. This do not change the fact that only keys of types
present in the list set in SSH_OPTIONS_HOSTKEYS will be accepted and
prioritized following the order defined by such list.
The new wanted list of hostkeys is given by:
- The keys present in known_hosts files, ordered by preference defined
in SSH_OPTIONS_HOSTKEYS. If the option is not set, a default order
of preference is used.
- The other keys present in the same option are appended without adding
duplicates. If the option is not set, the default list of keys is
used.
Fixes: T156
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit f18a7cc17e)
The added internal function obtain a newly allocated string containing a
list of the signature types that can be generated by the keys present in
the known_hosts files, separated by commas.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit 65a38759ca)
Added a function to remove duplicates from lists. This function is used
in a new provided function to append lists removing duplicates.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit 548753b338)
Avoid trying to open the files if they are not accessible. This was
already treated as a non-error, but with this we save one function call.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit e5a64a3d6b)
The memory allocated for host_port can leak if the global knownhosts
file is unaccessible.
Found by address sanitizer build in CI.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit fe248414fe)
Previously, if the global known_hosts file (default:
/etc/ssh/ssh_known_hosts) was inaccessible, the check for known hosts
failed. This makes the check to fail if both files are inaccessible.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit 4adb13d9e3)
The internal function ssh_connect_host() is not used.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
(cherry picked from commit a82993b320)
In non-blocking mode, it is expected SSH_AGAIN to be returned many
times. Do not flood the log with error messages.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
(cherry picked from commit 1d54a3880d)
When we are talking to old OpenSSH versions which does not support
rsa-sha2-{256,512}-cert-v01@openssh.com or SHA2 in certificates,
fallback to old supported values.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit 4b7ce75e1f)
When the session is a client session, reject tcpip-forward requests.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit 1aef599ab1)
When an unknown global request is received, consume the message to avoid
sending UNIMPLEMENTED later. Only report the failure if the request
wants a reply.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit 3d7d3f303e)
Fixes: T76 for gcrypt and mbedtls backends
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
(cherry picked from commit d627cba476)
Use uint32_t when expecting 32 bits unsigned int. Use PRIu32 macro to
print correctly independently of the architecture.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Do not use long long as equivalent as int64_t.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Don't use long unsigned int as equivalent as uint32_t. Use macros to
correctly print the values independently of the architecture.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
This also adds documentation for it.
Fixes T144
Signed-off-by: David Wedderwille <davidwe@posteo.de>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Previously, if the client supported rsa-sha2-256 or rsa-sha2-512, the
server would advertise the extensions as supported without checking its
own list of allowed algorithms. Now the server will only advertise
allowed signature algorithms.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Send only allowed algorithms in server-sig-algs extension if in FIPS
mode.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
There is actually a bug in OpenSSH's ssh-agent of handling these
requests [1], but this change follows the way how OpenSSH clients
behave in regards to the communication with agent.
Without this change, the agent is asked to provide SHA1 signature
with certificates, which is not right if we negotiated SHA2 extensions.
[1] https://bugzilla.mindrot.org/show_bug.cgi?id=3016
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Make ssh_fallback_group() to duplicate the modulus and generator.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
When in FIPS mode, filter the algorithms to enable only the allowed
ones. If any algorithm is explicitly set through options or
configuration file, they are kept.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
This allows the use of the new PKCS#8 PEM files and does not
limit libssh to using only the "traditional" PEM files, that
are not default in OpenSSL since 1.0.0 and which do not work
at all in FIPS mode.
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Since OpenSSL 1.0.0, the "traditional" PEM format was deprecated
in favor of the PKCS#8 PEM files which is more standardized,
more secure and does not depend on the MD5 hash, which is not
available for example in FIPS mode.
This requires using the new EVP_PKEY API for reading private key
blobs.
Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Do not use MD5 when generating fingerprints in FIPS mode. The call will
fail in such case. The test suite was updated with a negative test for
this case.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Make ssh_bind_options_parse_config() to fail if setting a known option
fails. Previously the return value of ssh_bind_options_set() were
ignored when configuring the server through a configuration file.
Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
