All the places in auth.cc where we constructed an api_error with inline
strings now use api_error factory functions.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
All internal execution always uses query text as a key in the
cache of internal prepared statements. There is no need
to publish API for executing an internal prepared statement object.
The folded execute_internal() calls an internal prepare() and then
internal execute().
execute_internal(cache=true) does exactly that.
The authorization signature contains both a full obligatory date header
and a shortened datestamp - an additional verification step ensures that
the shortened stamp matches the full date.
AWS signatures have a 15min expiration policy. For compatibility,
the same policy is applied for alternator requests. The policy also
ensures that signatures expanding more than 15 minutes into the future
are treated as unsafe and thus not accepted.
As a first step towards coupling alternator authorization with Scylla
authorization, a helper function for extracting the key (salted_hash)
belonging to the user is added.
A function for computing the auth signature from user requests
is added, along with helper functions. The implementation
is based on gnutls's HMAC.
Refs #5046
