Proposed flow for this scenario
- Original caller
- Trust and caller authorization where applicable
- Selected role session
- Role and session permissions
- Resource action
- Explicit deny and boundary result
This flow describes a design to evaluate. Follow the supported console workflow below to practice with local resources. Its scope appears with the controls; no cloud resources are provisioned.
Decision checkpoints
| Choice | Fits when | Watch for |
|---|---|---|
| Trust/caller authorization repair | The intended actor cannot obtain the selected role identity. | Adding object permissions while assumption still fails. |
| Workload permission repair | Assumption succeeds but a later action is denied. | Changing trust to every principal to fix an S3 denial. |
Find which identity made the failed request
A synthetic QuantumSketch operator can see a role but cannot assume it. Separately, a LetX role can be assumed but cannot read its export object. Record the original caller, requested role and later request identity rather than describing both as one permission problem.
Trust and applicable caller authorization determine assumption. Real same-account direct trust grants and account-root delegation have different evaluation details, so avoid the blanket claim that every trust statement has identical caller-policy requirements.
Role permission is not an invitation to assume it
Giving a role S3 actions does not authorize every person or service to become that role. Conversely, a permissive trust policy grants no general S3/EC2 actions to the resulting session. Review the identity and resource policies for the actual downstream request.
Permissions boundaries and session policy restrictions can constrain the result; an explicit deny remains meaningful. Compare the effective selected action rather than assuming a familiar policy name proves access. Unsupported policy constructs need their own scope review.
Run the assumption and action drill separately
Create a role with a narrowly intended local trust policy, attempt its modeled assumption and inspect the outcome. Repair the intended trust/caller relationship, then use the simulated session for a bounded S3 action.
Keep the downstream action denied until its own permission is added, then repeat it. Local sessions are browser teaching identities with no AWS credentials. The model supports selected same-account trust and permission forms, not every federation, cross-account, organization or real STS behavior.
Changed scenario and evidence
Question: the operator successfully assumes the role, but its GetObject fails under a session restriction. Should trust now allow more principals? No. The assumption already passed; inspect the effective action, resource and restriction.
Use the role and S3 console links below to practice the selected assumption and subsequent action; local sessions never issue real STS credentials. Record before-and-after identity, role and action evidence. Least privilege requires both an intentional assumption boundary and an intentional workload permission boundary, not a green assumption badge alone.
Practice the supported console workflow
Sources and scope
Reviewed against these official references. The model’s supported scope appears alongside its controls.
How we review explanations