s3test: In ceph-nautilus branch , some fails_strict_rfc2616 test failed, Is this normal?

[WeiGuo Ren <rwg1335252904@xxxxxxxxx>]

I want to test  test_object_create_bad_md5_unreadable. but rgw send
400(e.status),rather than 403.I dont understand it. The code is.
@tag('auth_common')
@attr(resource='object')
@attr(method='put')
@attr(operation='create w/non-graphics in MD5')
@attr(assertion='fails 403')
@attr('fails_strict_rfc2616')
@nose.with_setup(teardown=_clear_custom_headers)
def test_object_create_bad_md5_unreadable():
    key = _setup_bad_object({'Content-MD5': '\x07'})

    e = assert_raises(boto.exception.S3ResponseError,
key.set_contents_from_string, 'bar')
    eq(e.status, 403)
    eq(e.reason, 'Forbidden')
    assert e.error_code in ('AccessDenied', 'SignatureDoesNotMatch')