* sts: enforce session-policy explicit deny during role chaining
A chained AssumeRole caller authenticates with an STS session token whose
inline session policy can explicitly deny sts:AssumeRole. The deny check only
evaluated the caller's named policies, so such a session could still chain into
any role its trust policy admits. Validate the session token in the deny check
and honor an explicit Deny in the inline session policy too.
* test(sts): integration coverage for AssumeRole authorization
Add an end-to-end AssumeRole authorization test (real weed mini + boto3):
a non-admin caller assumes a role its trust policy admits, an explicit
identity-side deny is blocked, and a session policy's explicit deny blocks
role chaining.
* sts: skip OIDC tokens and reject revoked sessions in the chaining deny check
Review follow-ups on the session-policy deny check:
- Guard session validation with !isOIDCToken so a bearer token our STS service
cannot validate does not error into a false deny.
- Reject a revoked session before evaluating its policy, restoring the
revocation enforcement the AssumeRole path lost when it stopped routing
through IsActionAllowed.
see https://blog.aqwari.net/xml-schema-go/
1. go get aqwari.net/xml/cmd/xsdgen
2. Add EncodingType element for ListBucketResult in AmazonS3.xsd
3. xsdgen -o s3api_xsd_generated.go -pkg s3api AmazonS3.xsd
4. Remove empty Grantee struct in s3api_xsd_generated.go
5. Remove xmlns: sed s'/http:\/\/s3.amazonaws.com\/doc\/2006-03-01\/\ //' s3api_xsd_generated.go
Chris LuandGitHub
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