QWED Infra guards for infrastructure verification

​

1. IamGuard

​

Capabilities

• Wildcard Logic: Correctly handles s3:*, bucket/* expansion using Z3 regex (InRe).
• Conditions: Supports context keys like aws:SourceIp (CIDR blocks), aws:CurrentTime (Date comparisons), StringEquals, and StringLike.
• Deny Overrides: Mathematically proves that an explicit Deny always overrides an Allow, regardless of statement order.
• Least Privilege Analysis: verify_least_privilege(policy) proves whether a policy allows full admin access (* on *).
• Unknown Operator Fail-Closed: An unrecognized condition operator causes a BLOCKED result — never a silent pass.

​

API

guard = IamGuard()
result = guard.verify_access(policy, action="s3:GetObject", resource="*", context={})
result = guard.verify_least_privilege(policy)
diag = IamGuard.to_diagnostic(result, audit_trace=None)

​

Diagnostic Mapping

​

2. NetworkGuard

​

Capabilities

• Public Access Check: Validates if a path exists from Internet to a specific Instance.
  • Path: Internet -> IGW -> Route Table -> Subnet -> Security Group -> Instance.
• Port Verification: Ensures critical management ports (22 SSH, 3389 RDP) are not exposed to 0.0.0.0/0.
• Segmentation Verification: Proves that sensitive subnets (e.g., Database) are isolated from public subnets.
• Fail-Closed Topologies: Returns UNVERIFIABLE when the topology contains NAT Gateways, VPC Peering, NACLs, or Transit Gateway — constructs the guard cannot model deterministically.

​

API

guard = NetworkGuard()
guard.build_graph(resources)  # Build NetworkX digraph from infra definition
result = guard.verify_reachability(resources, source="internet", destination="public-subnet", port=80)
diag = NetworkGuard.to_diagnostic(result)

​

Diagnostic Mapping

​

3. CostGuard

​

Capabilities

• Budget enforcement: Blocks deployment if estimated_cost > budget.
• Anomaly detection: Flags expensive instance types (e.g., p4d.24xlarge GPU instances) as suspected hallucinations.
• Granular breakdown: Provides cost breakdown by resource type (Compute, Storage, Database).
• Fail-Closed Unknown Types: Unknown instance or volume types produce a BLOCKED result — never a silent zero-cost estimate.

​

API

guard = CostGuard()
result = guard.verify_budget(resources, budget_monthly=500.0)
diag = CostGuard.to_diagnostic(result)

​

Diagnostic Mapping

​

4. ArtifactBoundaryGuard

​

Capabilities

• Secret Detection: Scans for .pem, .key, .env, credential files, and other sensitive patterns in the package surface.
• Debug Artifact Detection: Flags test files (test_*.py), notebooks (*.ipynb), and debug directories (__pycache__, .git) included in the package.
• Build Config Validation: Parses [tool.hatch.build.targets.wheel] to confirm the package boundary is explicit. Blocks if the config is missing, invalid, or doesn’t reference the expected package name.
• Disclosure Risk Detection: Flags project-structure files (.gitignore, .dockerignore) that could leak internal conventions.
• Fail-Closed on Missing TOML Parser: If neither tomllib nor tomli is available, every package is BLOCKED.

​

API

guard = ArtifactBoundaryGuard()
result = guard.verify_package_boundary(
    package_dir=Path("./src/mypackage"),
    pyproject_path=Path("./pyproject.toml"),
    package_name="mypackage",
)
diag = ArtifactBoundaryGuard.to_diagnostic(result)

​

Diagnostic Mapping