Enable retrieving the "ecdsa-sha2-nistpNNN" name of ECDSA keys with a
new 'ssh_pki_key_ecdsa_name' API. This gives more information than the
'ssh_key_type_to_char' API, which yields "ssh-ecdsa" for ECDSA keys.
The motivation is that this info is useful to have in a server context.
The torture_pki unit test is updated to include the new API, and a few
more passes are added to additionally test 384 and 521-bit keys.
Signed-off-by: Jon Simons <jon@jonsimons.org>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
48aca98cd5