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diff --git a/doc/radosgw/s3/authentication.rst b/doc/radosgw/s3/authentication.rst new file mode 100644 index 00000000..10143290 --- /dev/null +++ b/doc/radosgw/s3/authentication.rst @@ -0,0 +1,231 @@ +========================= + Authentication and ACLs +========================= + +Requests to the RADOS Gateway (RGW) can be either authenticated or +unauthenticated. RGW assumes unauthenticated requests are sent by an anonymous +user. RGW supports canned ACLs. + +Authentication +-------------- +Authenticating a request requires including an access key and a Hash-based +Message Authentication Code (HMAC) in the request before it is sent to the +RGW server. RGW uses an S3-compatible authentication approach. + +:: + + HTTP/1.1 + PUT /buckets/bucket/object.mpeg + Host: cname.domain.com + Date: Mon, 2 Jan 2012 00:01:01 +0000 + Content-Encoding: mpeg + Content-Length: 9999999 + + Authorization: AWS {access-key}:{hash-of-header-and-secret} + +In the foregoing example, replace ``{access-key}`` with the value for your access +key ID followed by a colon (``:``). Replace ``{hash-of-header-and-secret}`` with +a hash of the header string and the secret corresponding to the access key ID. + +To generate the hash of the header string and secret, you must: + +#. Get the value of the header string. +#. Normalize the request header string into canonical form. +#. Generate an HMAC using a SHA-1 hashing algorithm. + See `RFC 2104`_ and `HMAC`_ for details. +#. Encode the ``hmac`` result as base-64. + +To normalize the header into canonical form: + +#. Get all fields beginning with ``x-amz-``. +#. Ensure that the fields are all lowercase. +#. Sort the fields lexicographically. +#. Combine multiple instances of the same field name into a + single field and separate the field values with a comma. +#. Replace white space and line breaks in field values with a single space. +#. Remove white space before and after colons. +#. Append a new line after each field. +#. Merge the fields back into the header. + +Replace the ``{hash-of-header-and-secret}`` with the base-64 encoded HMAC string. + +Authentication against OpenStack Keystone +----------------------------------------- + +In a radosgw instance that is configured with authentication against +OpenStack Keystone, it is possible to use Keystone as an authoritative +source for S3 API authentication. To do so, you must set: + +* the ``rgw keystone`` configuration options explained in :doc:`../keystone`, +* ``rgw s3 auth use keystone = true``. + +In addition, a user wishing to use the S3 API must obtain an AWS-style +access key and secret key. They can do so with the ``openstack ec2 +credentials create`` command:: + + $ openstack --os-interface public ec2 credentials create + +------------+---------------------------------------------------------------------------------------------------------------------------------------------+ + | Field | Value | + +------------+---------------------------------------------------------------------------------------------------------------------------------------------+ + | access | c921676aaabbccdeadbeef7e8b0eeb2c | + | links | {u'self': u'https://auth.example.com:5000/v3/users/7ecbebaffeabbddeadbeefa23267ccbb24/credentials/OS-EC2/c921676aaabbccdeadbeef7e8b0eeb2c'} | + | project_id | 5ed51981aab4679851adeadbeef6ebf7 | + | secret | ******************************** | + | trust_id | None | + | user_id | 7ecbebaffeabbddeadbeefa23267cc24 | + +------------+---------------------------------------------------------------------------------------------------------------------------------------------+ + +The thus-generated access and secret key can then be used for S3 API +access to radosgw. + +.. note:: Consider that most production radosgw deployments + authenticating against OpenStack Keystone are also set up + for :doc:`../multitenancy`, for which special + considerations apply with respect to S3 signed URLs and + public read ACLs. + +Access Control Lists (ACLs) +--------------------------- + +RGW supports S3-compatible ACL functionality. An ACL is a list of access grants +that specify which operations a user can perform on a bucket or on an object. +Each grant has a different meaning when applied to a bucket versus applied to +an object: + ++------------------+--------------------------------------------------------+----------------------------------------------+ +| Permission | Bucket | Object | ++==================+========================================================+==============================================+ +| ``READ`` | Grantee can list the objects in the bucket. | Grantee can read the object. | ++------------------+--------------------------------------------------------+----------------------------------------------+ +| ``WRITE`` | Grantee can write or delete objects in the bucket. | N/A | ++------------------+--------------------------------------------------------+----------------------------------------------+ +| ``READ_ACP`` | Grantee can read bucket ACL. | Grantee can read the object ACL. | ++------------------+--------------------------------------------------------+----------------------------------------------+ +| ``WRITE_ACP`` | Grantee can write bucket ACL. | Grantee can write to the object ACL. | ++------------------+--------------------------------------------------------+----------------------------------------------+ +| ``FULL_CONTROL`` | Grantee has full permissions for object in the bucket. | Grantee can read or write to the object ACL. | ++------------------+--------------------------------------------------------+----------------------------------------------+ + +Internally, S3 operations are mapped to ACL permissions thus: + ++---------------------------------------+---------------+ +| Operation | Permission | ++=======================================+===============+ +| ``s3:GetObject`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:GetObjectTorrent`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:GetObjectVersion`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:GetObjectVersionTorrent`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:GetObjectTagging`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:GetObjectVersionTagging`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:ListAllMyBuckets`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:ListBucket`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:ListBucketMultipartUploads`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:ListBucketVersions`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:ListMultipartUploadParts`` | ``READ`` | ++---------------------------------------+---------------+ +| ``s3:AbortMultipartUpload`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:CreateBucket`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:DeleteBucket`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:DeleteObject`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:s3DeleteObjectVersion`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:PutObject`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:PutObjectTagging`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:PutObjectVersionTagging`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:DeleteObjectTagging`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:DeleteObjectVersionTagging`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:RestoreObject`` | ``WRITE`` | ++---------------------------------------+---------------+ +| ``s3:GetAccelerateConfiguration`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetBucketAcl`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetBucketCORS`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetBucketLocation`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetBucketLogging`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetBucketNotification`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetBucketPolicy`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetBucketRequestPayment`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetBucketTagging`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetBucketVersioning`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetBucketWebsite`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetLifecycleConfiguration`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetObjectAcl`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetObjectVersionAcl`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:GetReplicationConfiguration`` | ``READ_ACP`` | ++---------------------------------------+---------------+ +| ``s3:DeleteBucketPolicy`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:DeleteBucketWebsite`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:DeleteReplicationConfiguration`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutAccelerateConfiguration`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutBucketAcl`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutBucketCORS`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutBucketLogging`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutBucketNotification`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutBucketPolicy`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutBucketRequestPayment`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutBucketTagging`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutPutBucketVersioning`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutBucketWebsite`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutLifecycleConfiguration`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutObjectAcl`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutObjectVersionAcl`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ +| ``s3:PutReplicationConfiguration`` | ``WRITE_ACP`` | ++---------------------------------------+---------------+ + +Some mappings, (e.g. ``s3:CreateBucket`` to ``WRITE``) are not +applicable to S3 operation, but are required to allow Swift and S3 to +access the same resources when things like Swift user ACLs are in +play. This is one of the many reasons that you should use S3 bucket +policies rather than S3 ACLs when possible. + + +.. _RFC 2104: http://www.ietf.org/rfc/rfc2104.txt +.. _HMAC: https://en.wikipedia.org/wiki/HMAC |