The value of tmnxIPsecStaticSAAuthKey specifies the key used
for the authentication algorithm defined by tmnxIPsecStaticSAAuthAlgorithm.
The length of the key must match the length required by the
authentication algorithm. If a key of another length is set, the
request will fail with an 'inconsistentValue' error.
The default value for tmnxIPsecStaticSAAuthKey is an empty string,
in this case the static SA cannot be used.
When read, tmnxIPsecStaticSAAuthKey always returns an octet string of length zero.
This is an optional object when creating an entry in tmnxIPsecStaticSATable.