openstack/swift
Code Issues Proposed changes

s3api: Allow CORS preflight requests

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Unfortunately, we can't identify the user, so we can't map to an
account, so we can't respect whatever CORS metadata might be set on the
container.

As a result, the allowed origins must be configured cluster-wide. Add a
new config option, cors_preflight_allow_origin, for that; default it
to blank (ie, deny preflights from all origins, preserving existing
behavior), but allow either a comma-separated list of origins or
* (to allow all origins).

Change-Id: I985143bf03125a05792e79bc5e5f83722d6431b3
Co-Authored-By: Matthew Oliver <matt@oliver.net.au>
This commit is contained in:
Tim Burke 2020-02-27 16:25:44 -08:00
parent 81db980690
commit 27a734c78a
7 changed files with 161 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
doc/saio/swift/proxy-server.conf
View File

@ -92,6 +92,7 @@ use = egg:swift#symlink
use = egg:swift#s3api
s3_acl = yes
check_bucket_owner = yes
cors_preflight_allow_origin = *
# Example to create root secret: `openssl rand -base64 32`
[filter:keymaster]

1
docker/rootfs/etc/swift/proxy-server.conf
View File

@ -82,6 +82,7 @@ use = egg:swift#symlink
# To enable, add the s3api middleware to the pipeline before tempauth
[filter:s3api]
use = egg:swift#s3api
cors_preflight_allow_origin = *
# Example to create root secret: `openssl rand -base64 32`
[filter:keymaster]

6
etc/proxy-server.conf-sample
View File

@ -629,6 +629,12 @@ use = egg:swift#s3api
# AWS allows clock skew up to 15 mins; note that older versions of swift/swift3
# allowed at most 5 mins.
# allowable_clock_skew = 900
#
# CORS preflight requests don't contain enough information for us to
# identify the account that should be used for the real request, so
# the allowed origins must be set cluster-wide. (default: blank; all
# preflight requests will be denied)
# cors_preflight_allow_origin =
# You can override the default log routing for this filter here:
# log_name = s3api

33
swift/common/middleware/s3api/s3api.py
View File

@ -157,7 +157,7 @@ from swift.common.middleware.s3api.s3response import ErrorResponse, \
InternalError, MethodNotAllowed, S3ResponseBase, S3NotImplemented
from swift.common.utils import get_logger, register_swift_info, \
config_true_value, config_positive_int_value, split_path, \
closing_if_possible
closing_if_possible, list_from_csv
from swift.common.middleware.s3api.utils import Config
from swift.common.middleware.s3api.acl_handlers import get_acl_handler
@ -277,12 +277,43 @@ class S3ApiMiddleware(object):
wsgi_conf.get('min_segment_size', 5242880))
self.conf.allowable_clock_skew = config_positive_int_value(
wsgi_conf.get('allowable_clock_skew', 15 * 60))
self.conf.cors_preflight_allow_origin = list_from_csv(wsgi_conf.get(
'cors_preflight_allow_origin', ''))
if '*' in self.conf.cors_preflight_allow_origin and \
len(self.conf.cors_preflight_allow_origin) > 1:
raise ValueError('if cors_preflight_allow_origin should include '
'all domains, * must be the only entry')
self.logger = get_logger(
wsgi_conf, log_route=wsgi_conf.get('log_name', 's3api'))
self.check_pipeline(wsgi_conf)
def __call__(self, env, start_response):
origin = env.get('HTTP_ORIGIN')
acrh = env.get('HTTP_ACCESS_CONTROL_REQUEST_HEADERS', '').lower()
if self.conf.cors_preflight_allow_origin and origin and \
env['REQUEST_METHOD'] == 'OPTIONS' and \
'authorization' in acrh and \
not env['PATH_INFO'].startswith(('/v1/', '/v1.0/')):
# I guess it's likely going to be an S3 request? *shrug*
if self.conf.cors_preflight_allow_origin != ['*'] and \
origin not in self.conf.cors_preflight_allow_origin:
start_response('401 Unauthorized', [
('Allow', 'GET, HEAD, PUT, POST, DELETE, OPTIONS'),
])
return [b'']
start_response('200 OK', [
('Allow', 'GET, HEAD, PUT, POST, DELETE, OPTIONS'),
('Access-Control-Allow-Origin', origin),
('Access-Control-Allow-Methods',
'GET, HEAD, PUT, POST, DELETE, OPTIONS'),
('Access-Control-Allow-Headers',
', '.join(set(list_from_csv(acrh)))),
('Vary', 'Origin, Access-Control-Request-Headers'),
])
return [b'']
try:
req_class = get_request_class(env, self.conf.s3_acl)
req = req_class(env, self.app, self.conf)

61
test/cors/test-s3-obj.js
View File

@ -133,28 +133,69 @@ function makeTests (params) {
Bucket: 'private-with-cors',
Key: 'obj'
})
.then(CorsBlocked)], // Pre-flight failed
['PUT',
() => MakeS3Request(service, 'putObject', {
Bucket: 'private-with-cors',
Key: 'put-target',
Body: 'test'
})
.then(CorsBlocked)], // Pre-flight failed
.then(HasStatus(200, 'OK'))
.then(CheckS3Headers)
.then(HasHeaders(['x-amz-meta-mtime']))
.then(DoesNotHaveHeaders(['X-Object-Meta-Mtime']))
.then(HasHeaders({
'Content-Type': 'application/octet-stream',
Etag: '"0f343b0931126a20f133d67c2b018a3b"'
}))
.then(BodyHasLength(1024))],
['PUT then DELETE',
() => Promise.resolve('put-target-' + Math.random()).then((objectName) => {
return MakeS3Request(service, 'putObject', {
Bucket: 'private-with-cors',
Key: objectName,
Body: 'test'
})
.then(HasStatus(200, 'OK'))
.then(CheckS3Headers)
.then(HasHeaders({
'Content-Type': 'text/html; charset=UTF-8',
Etag: '"098f6bcd4621d373cade4e832627b4f6"'
}))
.then(HasNoBody)
.then((resp) => {
return MakeS3Request(service, 'deleteObject', {
Bucket: 'private-with-cors',
Key: objectName
})
})
.then(HasStatus(204, 'No Content'))
.then(CheckTransactionIdHeaders)
.then(HasNoBody)
})],
['GET If-Match matching',
() => MakeS3Request(service, 'getObject', {
Bucket: 'private-with-cors',
Key: 'obj',
IfMatch: '0f343b0931126a20f133d67c2b018a3b'
})
.then(CorsBlocked)], // Pre-flight failed
.then(HasStatus(200, 'OK'))
.then(CheckS3Headers)
.then(HasHeaders(['x-amz-meta-mtime']))
.then(DoesNotHaveHeaders(['X-Object-Meta-Mtime']))
.then(HasHeaders({
'Content-Type': 'application/octet-stream',
Etag: '"0f343b0931126a20f133d67c2b018a3b"'
}))
.then(BodyHasLength(1024))],
['GET Range',
() => MakeS3Request(service, 'getObject', {
Bucket: 'private-with-cors',
Key: 'obj',
Range: 'bytes=100-199'
})
.then(CorsBlocked)], // Pre-flight failed
.then(HasStatus(206, 'Partial Content'))
.then(CheckS3Headers)
.then(HasHeaders(['x-amz-meta-mtime']))
.then(DoesNotHaveHeaders(['X-Object-Meta-Mtime']))
.then(HasHeaders({
'Content-Type': 'application/octet-stream',
Etag: '"0f343b0931126a20f133d67c2b018a3b"'
}))
.then(BodyHasLength(100))]
]
}

41
test/unit/common/middleware/s3api/test_obj.py
View File

@ -1724,6 +1724,47 @@ class TestS3ApiObj(S3ApiTestCase):
'test:write', 'READ', src_path='')
self.assertEqual(status.split()[0], '400')
def test_cors_preflight(self):
req = Request.blank(
'/bucket/cors-object',
environ={'REQUEST_METHOD': 'OPTIONS'},
headers={'Origin': 'http://example.com',
'Access-Control-Request-Method': 'GET',
'Access-Control-Request-Headers': 'authorization'})
self.s3api.conf.cors_preflight_allow_origin = ['*']
status, headers, body = self.call_s3api(req)
self.assertEqual(status, '200 OK')
self.assertDictEqual(headers, {
'Allow': 'GET, HEAD, PUT, POST, DELETE, OPTIONS',
'Access-Control-Allow-Origin': 'http://example.com',
'Access-Control-Allow-Methods': ('GET, HEAD, PUT, POST, DELETE, '
'OPTIONS'),
'Access-Control-Allow-Headers': 'authorization',
'Vary': 'Origin, Access-Control-Request-Headers',
})
# test more allow_origins
self.s3api.conf.cors_preflight_allow_origin = ['http://example.com',
'http://other.com']
status, headers, body = self.call_s3api(req)
self.assertEqual(status, '200 OK')
self.assertDictEqual(headers, {
'Allow': 'GET, HEAD, PUT, POST, DELETE, OPTIONS',
'Access-Control-Allow-Origin': 'http://example.com',
'Access-Control-Allow-Methods': ('GET, HEAD, PUT, POST, DELETE, '
'OPTIONS'),
'Access-Control-Allow-Headers': 'authorization',
'Vary': 'Origin, Access-Control-Request-Headers',
})
# Wrong protocol
self.s3api.conf.cors_preflight_allow_origin = ['https://example.com']
status, headers, body = self.call_s3api(req)
self.assertEqual(status, '401 Unauthorized')
self.assertEqual(headers, {
'Allow': 'GET, HEAD, PUT, POST, DELETE, OPTIONS',
})
def test_cors_headers(self):
# note: Access-Control-Allow-Methods would normally be expected in
# response to an OPTIONS request but its included here in GET/PUT tests

29
test/unit/common/middleware/s3api/test_s3api.py
View File

@ -118,6 +118,7 @@ class TestS3ApiMiddleware(S3ApiTestCase):
'min_segment_size': 5242880,
'multi_delete_concurrency': 2,
's3_acl': False,
'cors_preflight_allow_origin': [],
})
s3api = S3ApiMiddleware(None, {})
self.assertEqual(expected, s3api.conf)
@ -140,10 +141,38 @@ class TestS3ApiMiddleware(S3ApiTestCase):
'min_segment_size': 1000000,
'multi_delete_concurrency': 1,
's3_acl': True,
'cors_preflight_allow_origin': 'foo.example.com,bar.example.com',
}
s3api = S3ApiMiddleware(None, conf)
conf['cors_preflight_allow_origin'] = \
conf['cors_preflight_allow_origin'].split(',')
self.assertEqual(conf, s3api.conf)
# test allow_origin list with a '*' fails.
conf = {
'storage_domain': 'somewhere',
'location': 'us-west-1',
'force_swift_request_proxy_log': True,
'dns_compliant_bucket_names': False,
'allow_multipart_uploads': False,
'allow_no_owner': True,
'allowable_clock_skew': 300,
'auth_pipeline_check': False,
'check_bucket_owner': True,
'max_bucket_listing': 500,
'max_multi_delete_objects': 600,
'max_parts_listing': 70,
'max_upload_part_num': 800,
'min_segment_size': 1000000,
'multi_delete_concurrency': 1,
's3_acl': True,
'cors_preflight_allow_origin': 'foo.example.com,bar.example.com,*',
}
with self.assertRaises(ValueError) as ex:
S3ApiMiddleware(None, conf)
self.assertIn("if cors_preflight_allow_origin should include all "
"domains, * must be the only entry", str(ex.exception))
def check_bad_positive_ints(**kwargs):
bad_conf = dict(conf, **kwargs)
self.assertRaises(ValueError, S3ApiMiddleware, None, bad_conf)