fmorg-git commented on code in PR #9223: URL: https://github.com/apache/ozone/pull/9223#discussion_r2604480207
########## hadoop-hdds/docs/content/design/ozone-sts.md: ########## @@ -0,0 +1,220 @@ +--- +title: AWS STS Design for Ozone S3 +summary: STS Support in Ozone +date: 2025-10-30 +jira: HDDS-13323 +status: implementing +author: Madhan Neethiraj, Ren Koike, Fabian Morgan, Stephen O'Donnell, Istvan Fajth, Uma Maheswara Rao Gangumalla +--- +<!-- + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. See accompanying LICENSE file. +--> + +# AWS STS Design for Ozone S3 + +# 1. Introduction + +S3 credentials used to communicate with Ozone S3 APIs are based on a Kerberos identity. + +Historically, the Ozone community has had interest in a REST API capable of programmatically generating +temporary S3 credentials. + +Amazon AWS has the [Security Token Service (STS)](https://docs.aws.amazon.com/STS/latest/APIReference/welcome.html) which +provides the ability to generate short-lived access to resources. + +The primary scope of this document is to detail the initial implementation of STS within the Ozone ecosystem. + +# 2. Why Use STS Tokens? + +Providing short-lived access to various resources in Ozone is useful in scenarios such as Data Lake +solutions that want to aggregate data across multiple cloud providers. + +# 3. How Ozone STS Works + +The initial implementation of Ozone STS supports only the [AssumeRole](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html) +API from the AWS specification. A new STS endpoint `/sts` on port `9880` will be created to service STS requests in the S3 Gateway. +We use a separate port for STS to align with AWS so we don't have conflicts at a later time. This means we have: +- Admin port for Ozone specific S3 admin operations +- STS port for STS APIs, analogous to AWS' separate STS endpoint +- Existing dedicated port/endpoint for S3 object APIs. + +Furthermore, the initial implementation of Ozone STS focuses only on Apache Ranger for authorization in the first phase, +as it aligns more with IAM policies. Support for the Ozone Native Authorizer may be provided in a future phase. +Consideration for the Ozone Native Authorizer will be given when processing IAM policies as described below. + +## 3.1 Capabilities + +The Ozone STS implementation has the following capabilities: + +- Create temporary credentials that last from a minimum of 15 minutes to a maximum of 12 hours. The +return value of the AssumeRole call will be temporary credentials consisting of 3 components: + - accessKeyId - a generated String identifier (cryptographically strong using SecureRandom) beginning with the sequence "ASIA" + - secretAccessKey - a generated String password (cryptographically strong using SecureRandom) + - sessionToken - a Base64-encoded opaque String identifier +- The temporary credentials will have the permissions associated with a role. Furthermore, an +[AWS IAM Session Policy](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html#policies_session) can +**optionally** be sent in the AssumeRole API call to limit the scope of the permissions further. If +an IAM policy is specified, the temporary credential will have the permissions comprising the intersection of the role permissions +and the IAM policy permissions. **Note:** If the IAM policy is specified and does not grant any permissions, then +the generated temporary credentials won't have any permissions and will essentially be useless. + +## 3.2 Limitations in AssumeRole API Support + +The AWS AssumeRole API has various required and optional fields. We will support the two required fields, i.e. `RoleArn` +and `RoleSessionName`. Additionally, we will support the following optional fields (all others will be rejected): +- `DurationSeconds` +- `Policy` + +## 3.3 Limitations in IAM Session Policy Support + +The AWS IAM policy specification is vast and wide-ranging. The initial Ozone STS implementation supports a limited +subset of its capabilities. The restrictions are outlined below: + +- The only supported prefix in ResourceArn is `arn:aws:s3:::` - all others will be rejected. **Note**: a ResourceArn +of `*` is supported as well. +- The only supported Condition operator is `StringEquals` - all others will be rejected. +- The only supported Condition attribute is `s3:prefix` - all others will be rejected. +- Only one Condition operator per Statement is supported - a Statement with more than one Condition will be rejected. +- The only supported Effect is `Allow` - all others will be rejected. +- If a (currently) unsupported S3 action is requested, such as `s3:GetAccelerateConfiguration`, it will be silently ignored. +Similarly, an invalid S3 action will be silently ignored. +- Supported wildcard expansions in Actions are: `s3:*`, `s3:Get*`, `s3:Put*`, `s3:List*`, +`s3:Create*`, and `s3:Delete*`. +- If using OzoneNativeAuthorizer, bucket wildcards (ex. ResourceArn `arn:aws:s3:::*`, `arn:aws:s3:::bucket*` or `*`) will be rejected, Review Comment: updated ########## hadoop-hdds/docs/content/design/ozone-sts.md: ########## @@ -0,0 +1,220 @@ +--- +title: AWS STS Design for Ozone S3 +summary: STS Support in Ozone +date: 2025-10-30 +jira: HDDS-13323 +status: implementing +author: Madhan Neethiraj, Ren Koike, Fabian Morgan, Stephen O'Donnell, Istvan Fajth, Uma Maheswara Rao Gangumalla +--- +<!-- + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. See accompanying LICENSE file. +--> + +# AWS STS Design for Ozone S3 + +# 1. Introduction + +S3 credentials used to communicate with Ozone S3 APIs are based on a Kerberos identity. + +Historically, the Ozone community has had interest in a REST API capable of programmatically generating +temporary S3 credentials. + +Amazon AWS has the [Security Token Service (STS)](https://docs.aws.amazon.com/STS/latest/APIReference/welcome.html) which +provides the ability to generate short-lived access to resources. + +The primary scope of this document is to detail the initial implementation of STS within the Ozone ecosystem. + +# 2. Why Use STS Tokens? + +Providing short-lived access to various resources in Ozone is useful in scenarios such as Data Lake +solutions that want to aggregate data across multiple cloud providers. + +# 3. How Ozone STS Works + +The initial implementation of Ozone STS supports only the [AssumeRole](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html) +API from the AWS specification. A new STS endpoint `/sts` on port `9880` will be created to service STS requests in the S3 Gateway. +We use a separate port for STS to align with AWS so we don't have conflicts at a later time. This means we have: +- Admin port for Ozone specific S3 admin operations +- STS port for STS APIs, analogous to AWS' separate STS endpoint +- Existing dedicated port/endpoint for S3 object APIs. + +Furthermore, the initial implementation of Ozone STS focuses only on Apache Ranger for authorization in the first phase, +as it aligns more with IAM policies. Support for the Ozone Native Authorizer may be provided in a future phase. +Consideration for the Ozone Native Authorizer will be given when processing IAM policies as described below. + +## 3.1 Capabilities + +The Ozone STS implementation has the following capabilities: + +- Create temporary credentials that last from a minimum of 15 minutes to a maximum of 12 hours. The +return value of the AssumeRole call will be temporary credentials consisting of 3 components: + - accessKeyId - a generated String identifier (cryptographically strong using SecureRandom) beginning with the sequence "ASIA" + - secretAccessKey - a generated String password (cryptographically strong using SecureRandom) + - sessionToken - a Base64-encoded opaque String identifier +- The temporary credentials will have the permissions associated with a role. Furthermore, an +[AWS IAM Session Policy](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html#policies_session) can +**optionally** be sent in the AssumeRole API call to limit the scope of the permissions further. If +an IAM policy is specified, the temporary credential will have the permissions comprising the intersection of the role permissions +and the IAM policy permissions. **Note:** If the IAM policy is specified and does not grant any permissions, then +the generated temporary credentials won't have any permissions and will essentially be useless. + +## 3.2 Limitations in AssumeRole API Support + +The AWS AssumeRole API has various required and optional fields. We will support the two required fields, i.e. `RoleArn` +and `RoleSessionName`. Additionally, we will support the following optional fields (all others will be rejected): +- `DurationSeconds` +- `Policy` + +## 3.3 Limitations in IAM Session Policy Support + +The AWS IAM policy specification is vast and wide-ranging. The initial Ozone STS implementation supports a limited +subset of its capabilities. The restrictions are outlined below: + +- The only supported prefix in ResourceArn is `arn:aws:s3:::` - all others will be rejected. **Note**: a ResourceArn +of `*` is supported as well. +- The only supported Condition operator is `StringEquals` - all others will be rejected. +- The only supported Condition attribute is `s3:prefix` - all others will be rejected. +- Only one Condition operator per Statement is supported - a Statement with more than one Condition will be rejected. +- The only supported Effect is `Allow` - all others will be rejected. +- If a (currently) unsupported S3 action is requested, such as `s3:GetAccelerateConfiguration`, it will be silently ignored. +Similarly, an invalid S3 action will be silently ignored. +- Supported wildcard expansions in Actions are: `s3:*`, `s3:Get*`, `s3:Put*`, `s3:List*`, +`s3:Create*`, and `s3:Delete*`. +- If using OzoneNativeAuthorizer, bucket wildcards (ex. ResourceArn `arn:aws:s3:::*`, `arn:aws:s3:::bucket*` or `*`) will be rejected, +as wildcards are not supported for buckets for the OzoneNativeAuthorizer. +However, certain object wildcards be accepted. For example, ResourceArn `arn:aws:s3:::myBucket/*` and `arn:aws:s3:::myBucket/folder/logs/*` +will be accepted but `arn:aws:s3:::myBucket/file*.txt` +will not be accepted. Again, these restrictions correspond to the capabilities of the OzoneNativeAuthorizer. + +A sample IAM policy that allows read access to all objects in the `example-bucket` bucket is shown below: +```JSON +{ + "Version": "2012-10-17", + "Statement": [ + { + "Effect": "Allow", + "Action": "s3:GetObject", + "Resource": "arn:aws:s3:::example-bucket/*" + } + ] +} + +``` + +### 3.3.1 Additional Context on Design Behavior + +As mentioned above, some limitations in IAM Session Policy support result in API calls being rejected, while others are +silently ignored. This design behavior came after (much) discussion with external teams. One external team will send +S3 actions that Ozone doesn't support, and they don't have flexibility to change what they are sending, so that's one +reason for the silent ignore. This external team also mentioned that some research indicates AWS also does not fail +the AssumeRole request just because the inline session policy references unknown or unsupported actions, but rather +it will fail when the temporary credentials are used, so this design is accordance with that finding. Another external +team agreed that behavior is fine for actions, but does not work for Conditions, because one can have a Condition to +restrict calls by sourceIp, and if we silently ignore this, the client may incorrectly think the temporary credentials +are restricted for use by that IP address, so the consensus was to reject the request for that scenario. + +## 3.4 SessionToken Format + +As mentioned above, one of the return values from the AssumeRole call will be the sessionToken. To support not +storing temporary credentials server-side in Ozone, the sessionToken will comprise various components needed to validate +subsequent S3 calls that use the token. The sessionToken will have the following information encoded: + +- originalAccessKeyId - this is the Kerberos identity of the user that created the sessionToken via the AssumeRole call. +When the temporary credentials are used to make S3 API calls, this Kerberos identity (in conjunction with the role permissions and +optional session policy) will be used to authorize the call. This identity is included in the sessionToken because +S3 API calls (such as PutObject) require a Kerberos identity, but the temporary credentials don't have a +Kerberos identity associated to them, therefore the Kerberos identity of the user that created the token will be used in +these cases. +- roleArn - the role used in the original AssumeRole call +- encrypted secretAccessKey - this will be used to validate the AWS signature when the temporary credentials are used +to make S3 API calls +- sessionPolicy - when using the RangerOzoneAuthorizer, if Ranger successfully authorizes the AssumeRole call, +it will return a String representing the role the token was authorized for. Furthermore, if an AWS IAM Session Policy +was included with the AssumeRole request, the String return value will also include resources (i.e. buckets, keys, etc.) +and permissions (i.e. ACLType) corresponding to the AWS IAM Session Policy. These resources and permissions, if present, +would further limit the scope of the permissions and resources granted by the role in Ranger, such that the temporary +credential will have the permissions comprising the intersection of the role permissions and the sessionPolicy permissions. +- HMAC-SHA256 signature - used to ensure the sessionToken was created by Ozone and was not altered since it was created. +- expiration time of the token (via `ShortLivedTokenIdentifier#getExpiry()`) +- UUID of the OzoneManager secret key used to sign the sessionToken and encrypt the secretAccessKey (via `ShortLivedTokenIdentifier#getSecretKeyId()`) + +## 3.5 STS Token Revocation + +In the rare event temporary credentials need to be revoked (ex. for security reasons), a table in the OzoneManager RocksDB will be created +to store revoked tokens, and a command-line utility will be created to add tokens to the table. A background cleaner service +will be created to run every 3 hours to delete revoked tokens that have been in the table for more than 12 hours. The +input parameter for the command-line utility will be the accessKeyId of the temporary token - this value is returned in +plain text as a result of the AssumeRole call (mentioned above). In this way, specific STS tokens can be revoked as opposed +to all tokens. Furthermore, AWS doesn't have a standard API to revoke tokens therefore we are creating our own system. + +## 3.6 Prerequisites + +A user must be configured with a Kerberos identity in Ozone and the S3 `getSecret` command +must be called to issue permanent S3 credentials. With these credentials, the AssumeRole API call can be made, but additional +steps below are needed for the call to be successfully authorized. +When using RangerOzoneAuthorizer, a role must be configured in Ranger UI for each role the AssumeRole API +can be used with. The user making the AssumeRole call must be in this role, and this role must have access Review Comment: updated -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
