rpc: prefer SHA256 host key fingerprint with new libssh

The host key fingerprint for SSH servers is used in a scenario where
cryptographic strength is important. We should thus be defaulting to
use of SHA256 where available. We only need SHA1 for Ubuntu 18.04
which does not have libssh >= 0.8.1

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This commit is contained in:
Daniel P. Berrangé 2021-06-23 10:46:48 +01:00
parent b683978f1f
commit fdaddd910e

View File

@ -39,6 +39,12 @@ VIR_LOG_INIT("rpc.netlibsshsession");
#define VIR_NET_LIBSSH_BUFFER_SIZE 1024
#if LIBSSH_VERSION_INT < SSH_VERSION_INT(0, 8, 1)
# define VIR_SSH_HOSTKEY_HASH SSH_PUBLICKEY_HASH_SHA1
#else
# define VIR_SSH_HOSTKEY_HASH SSH_PUBLICKEY_HASH_SHA256
#endif
/* TRACE_LIBSSH=<level> enables tracing in libssh itself.
* The meaning of <level> is described here:
* https://api.libssh.org/master/group__libssh__log.html
@ -203,9 +209,10 @@ virLibsshServerKeyAsString(virNetLibsshSession *sess)
return NULL;
}
/* calculate remote key hash, using SHA1 algorithm that is
* usual in OpenSSH. The returned value must be freed */
ret = ssh_get_publickey_hash(key, SSH_PUBLICKEY_HASH_SHA1,
/* calculate remote key hash, using SHA256 algorithm that is
* the default in modern OpenSSH, fallback to SHA1 for older
* libssh. The returned value must be freed */
ret = ssh_get_publickey_hash(key, VIR_SSH_HOSTKEY_HASH,
&keyhash, &keyhashlen);
ssh_key_free(key);
if (ret < 0) {