Re: [libvirt PATCH v6 34/36] qemu: implement ssh-agent auth for ssh disks with nbdkit

It's not possible to use password-protected ssh keys directly with libvirt because libvirt doesn't have any way to prompt a user for the password. To accomodate password-protected key files, an administrator can add these keys to an ssh agent and then configure the domain with the path to the ssh-agent socket. Note that this requires an administrator or management app to configure the ssh-agent with an appropriate socket path and add the necessary keys to it. In addition, it does not currently work with selinux enabled. The ssh-agent socket would need a label that libvirt would be allowed to access rather than unconfined_t. Signed-off-by: Jonathon Jongsma <jjongsma(a)redhat.com&gt; --- src/conf/domain_conf.c | 11 ++++++++--- src/conf/storage_source_conf.c | 1 + src/conf/storage_source_conf.h | 1 + src/qemu/qemu_nbdkit.c | 10 ++++++++++ .../disk-network-ssh-key.args.disk0 | 6 +++--- .../disk-network-ssh-key.args.disk1 | 9 +++++++++ tests/qemuxml2argvdata/disk-network-ssh-key.xml | 17 ++++++++++++++--- 7 files changed, 46 insertions(+), 9 deletions(-) create mode 100644 tests/qemunbdkitdata/disk-network-ssh-key.args.disk1 diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 08cf1be656..a70d7bf613 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -7257,8 +7257,11 @@ virDomainDiskSourceNetworkParse(xmlNodePtr node, if (!(src->ssh_user = virXMLPropStringRequired(tmpnode, "username"))) return -1; - if (!(src->ssh_keyfile = virXMLPropStringRequired(tmpnode, "keyfile"))) - return -1; + /* optional path to an ssh key file */ + src->ssh_keyfile = virXMLPropString(tmpnode, "keyfile"); + + /* optional ssh-agent socket location */ + src->ssh_agent = virXMLPropString(tmpnode, "agentsock");

} } @@ -22175,13 +22178,15 @@ virDomainDiskSourceFormatNetwork(virBuffer *attrBuf, if (src->protocol == VIR_STORAGE_NET_PROTOCOL_SSH) { if (src->ssh_known_hosts_file) virBufferEscapeString(childBuf, "<knownHosts path='%s'/>\n", src->ssh_known_hosts_file); - if (src->ssh_keyfile) { + if (src->ssh_keyfile || src->ssh_agent) { virBufferAddLit(childBuf, "<identity");

if (src->ssh_user) virBufferEscapeString(childBuf, " username='%s'", src->ssh_user); if (src->ssh_keyfile) virBufferEscapeString(childBuf, " keyfile='%s'", src->ssh_keyfile); + if (src->ssh_agent) + virBufferEscapeString(childBuf, " agentsock='%s'", src->ssh_agent);

virBufferAddLit(childBuf, "/>\n"); }

diff --git a/src/conf/storage_source_conf.h b/src/conf/storage_source_conf.h index 8c805664af..061faa66cb 100644 --- a/src/conf/storage_source_conf.h +++ b/src/conf/storage_source_conf.h @@ -411,6 +411,7 @@ struct _virStorageSource { bool ssh_host_key_check_disabled; char *ssh_known_hosts_file; char *ssh_keyfile; + char *ssh_agent;

/* nfs_user and nfs_group store the strings passed in by the user for NFS params. * nfs_uid and nfs_gid represent the converted/looked up ID numbers which are used