Identity & Federation Flashcards
Access Advisor
See permissions granted and when last accessed
Access Analyzer
Analyze resources that are shared with an external entity, e.g. S3 buckets
NotAction with Allow
NotAction with Allow, allows all actions except those specified in NotAction. This is better than explicit deny which will automatically reject exception Actions specified in any additional Allow Policies
NotAction with Deny
NotAction with Deny, denies all actions except those specified in NotAction
IfExists Condition Operator Example
If the resources being checked has condition key then check it against permission policy, otherwise skip the check. For cases when given action accesses multiple services, which might not have specified condition key
Null Condition Operator
Policy checks if the condition key exists at the time of authorization, e.g. condition value is false
Sevice-Linked Role Sessions and Session Revocation
Cannot be revoked.
How to revoke sts temporary access
By using AWSRevokeOlderSessions inline policy, which adds another explicit deny permissions to all actions for all sessions before the revocation time. Must have PutRolePolicy permission for the role.
Trust Policy Principals
Cannot specify *. Only users, roles, services.
External Id
Only you and authorized third party know External Id. Used when granting access to your AWS Resources to a Trusted Third Party.
Is not like secret, can be viewed again by anyone with permissions to view the role.
Used to avoid confused deputy scenario. Prevents access from unauthorized thirds party accounts, by requiring external id in addition to role arn where assuming the role.
AssumeRoleWithWebIdentity
For use with any OpenID Connect-compatible IdPs. No longer recommended, use AWS Cognito instead
Identity Federation Flavours
SAML 2.0, Custom Identity Broker, Web Identity Federation using Cognito, Web Identity Federation without Cognito, SSO, Microsoft AD
Custom Identity Broker vs SAML
The difference is in CIB it is all powered and CIB itself, not the user, talks to STS and receives temporary credentials which are used for interactions with AWS
STS Web Identity Federation vs Cognite Web Identity Federation
Cognito preferred, replaces TVM:
• Supports anonymous users
• Supports MFA
• Data synchronization
App generates ID token from IdP, gets Cognito token, then uses that token to get credentials from STS.
Web Identity Federation IAM Policy Variables examples
• cognito- identity.amazonaws.com:sub • www.amazon.com:user_id • graph.facebook.com:id • accounts.google.com:sub