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It's no longer possible for libvirt to connect over the ssh transport from RHEL 9 to RHEL 5. This is because SHA1 signatures have been effectively banned in RHEL 9 at the openssl level. They are required to check the RHEL 5 host key. Note this is a separate issue from openssh requiring additional configuration in order to connect to older servers. Connecting from a RHEL 9 client to RHEL 5 server: $ cat ~/.ssh/config Host 192.168.0.91 KexAlgorithms +diffie-hellman-group14-sha1 MACs +hmac-sha1 HostKeyAlgorithms +ssh-rsa PubkeyAcceptedKeyTypes +ssh-rsa PubkeyAcceptedAlgorithms +ssh-rsa $ virsh -c 'qemu+ssh://root@192.168.0.91/system' list error: failed to connect to the hypervisor error: Cannot recv data: ssh_dispatch_run_fatal: Connection to 192.168.0.91 port 22: error in libcrypto: Connection reset by peer "error in libcrypto: Connection reset by peer" is the characteristic error of openssl having been modified to disable SHA1 by default. (You will not see this on non-RHEL-derived distros.) You could enable the legacy crypto policy which downgrades security on the entire host, but a more fine-grained way to do this is to create an alternate openssl configuration file that enables the "forbidden" signatures. However this requires passing the OPENSSL_CONF environment variable through to ssh to specify the alternate configuration. Libvirt filters out this environment variable, but this commit allows it through. With this commit: $ cat /var/tmp/openssl.cnf .include /etc/ssl/openssl.cnf [openssl_init] alg_section = evp_properties [evp_properties] rh-allow-sha1-signatures = yes $ OPENSSL_CONF=/var/tmp/openssl.cnf ./run virsh -c 'qemu+ssh://root@192.168.0.91/system' list root@192.168.0.91's password: Id Name State -------------------- Essentially my argument here is that OPENSSL_CONF is sufficiently similar in nature to KRB5CCNAME, SSH* and XAUTHORITY that we should permit it to be passed through. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2062360 Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Acked-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser General Public License, version 2.1 (or later). Some parts of the code that are not part of the C library may have the more restrictive GNU General Public License, version 2.0 (or later). See the files COPYING.LESSER and COPYING for full license terms & conditions.
Installation
Instructions on building and installing libvirt can be found on the website:
https://libvirt.org/compiling.html
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: