Description of problem:

with non-default setting of rgw_s3_auth_order that puts "local" before "external", s3 requests with keystone ec2 credentials fail with:

> 2024-07-19T20:26:54.036+0000 7f18284d2640 20 req 16144285743181518599 0.000000000s s3:list_buckets rgw::auth::s3::LocalEngine rejected with reason=-2028
> 2024-07-19T20:26:54.036+0000 7f18284d2640 20 req 16144285743181518599 0.000000000s s3:list_buckets rgw::auth::s3::AWSAuthStrategy rejected with reason=-2028
> 2024-07-19T20:26:54.036+0000 7f18284d2640  5 req 16144285743181518599 0.000000000s s3:list_buckets Failed the auth strategy, reason=-2028
> 2024-07-19T20:26:54.036+0000 7f18284d2640 10 failed to authorize request

in this case, the local engine's error prevents us from trying the external (keystone) engine, so we return that error directly


Version-Release number of selected component (if applicable):


How reproducible: when keystone is used for s3 auth and rgw_s3_auth_order is reversed


Steps to Reproduce:
1. set up keystone and ec2 credentials
2. configure "rgw_s3_auth_order: sts, local, external"
3. issue s3 requests with ec2 credentials

Actual results:

403 Forbidden (InvalidAccessKeyId)

Expected results:

200 OK

Additional info: