IAM Role – Identity Providers and Federation – Certification

IAM Role – Identity Providers and Federation

  • Identify Provider can be used to grant external user identities permissions to AWS resources without having to be created within your AWS account.
  • External user identities can be authenticated either through the organization’s authentication system or through a well-know identity provider such as login with Amazon, Google etc.
  • Identity providers help keep the AWS account secure without having the need to distribute or embed long term in the application
  • To use an IdP, you create an IAM identity provider entity to establish a trust relationship between your AWS account and the IdP.
  • IAM supports IdPs that are compatible with OpenID Connect (OIDC) or SAML 2.0 (Security Assertion Markup Language 2.0)

Web Identity Federation

Complete Process Flow

IAM Web Identity Federation

  1. Mobile or Web Application needs to be configured with the IdP which gives each application a unique ID or client ID (also called audience)
  2. Create an Identity Provider entity for OIDC compatible IdP in IAM.
  3. Create IAM role and define the
    1. Trust policy –  specify the IdP (like Amazon) as the Principal (the trusted entity), and include a Condition that matches the IdP assigned app ID
    2. Permission policy – specify the permissions the application can assume
  4. Application calls the sign-in interface for the IdP to login
  5. IdP authenticates the user and returns an authentication token (OAuth access token or OIDC ID token) with information about the user to the application
  6. Application then makes an unsigned call to the STS service with the AssumeRoleWithWebIdentity action to request temporary security credentials.
  7. Application passes the IdP’s authentication token along with the Amazon Resource Name (ARN) for the IAM role created for that IdP.
  8. AWS verifies that the token is trusted and valid and if so, returns temporary security credentials (access key, secret access key, session token, expiry time) to the application that have the permissions for the role that you name in the request.
  9. STS response also includes metadata about the user from the IdP, such as the unique user ID that the IdP associates with the user.
  10. Using the Temporary credentials, the application makes signed requests to AWS
  11. User ID information from the identity provider can distinguish users in the app for e.g., objects can be put into S3 folders that include the user ID as prefixes or suffixes. This lets you create access control policies that lock the folder so only the user with that ID can access it.
  12. Application can cache the temporary security credentials and refresh them before their expiry accordingly. Temporary credentials, by default, are good for an hour.

Interactive Website provides a very good way to understand the flow

Mobile or Web Identity Federation with Cognito

Amazon Cognito

  • Use Amazon Cognito as the identity broker for almost all web identity federation scenarios
  • Amazon Cognito is easy to use and provides additional capabilities like anonymous (unauthenticated) access
  • Amazon Cognito also helps synchronizing user data across devices and providers

Web Identify Federation using Cognito

SAML 2.0-based Federation

  • AWS supports identity federation with SAML 2.0 (Security Assertion Markup Language 2.0), an open standard that many identity providers (IdPs) use.
  • SAML 2.0 based federation feature enables federated single sign-on (SSO), so users can log into the AWS Management Console or call the AWS APIs without having to create an IAM user for everyone in your organization.
  • By using SAML, the process of configuring federation with AWS can be simplified by using the IdP’s service instead of writing custom identity proxy code.
  • This is useful in organizations that have integrated their identity systems (such as Windows Active Directory or OpenLDAP) with software that can produce SAML assertions to provide information about user identity and permissions (such as Active Directory Federation Services or Shibboleth)

Complete Process Flow

SAML based Federation

  1. Create a SAML provider entity in AWS using the SAML metadata document provided by the Organizations IdP to establish a “trust” between your AWS account and the IdP
  2. SAML metadata document includes the issuer name, a creation date, an expiration date, and keys that AWS can use to validate authentication responses (assertions) from your organization.
  3. Create IAM roles which defines
    1. Trust policy with the SAML provider as the principal, which establishes a trust relationship between the organization and AWS
    2. Permission policy establishes what users from the organization are allowed to do in AWS
  4. SAML trust is completed by configuring the Organization’s IdP with information about AWS and the role(s) that you want the federated users to use. This is referred to as configuring relying party trust between your IdP and AWS
  5. Application calls the sign-in interface for the Organization IdP to login
  6. IdP authenticates the user and generates a SAML authentication response which includes assertions that identify the user and include attributes about the user
  7. Application then makes an unsigned call to the STS service with the AssumeRoleWithSAML action to request temporary security credentials.
  8. Application passes the ARN of the SAML provider, the ARN of the role to assume, the SAML assertion about the current user returned by IdP and the time for which the credentials should be valid. An optional IAM Policy parameter can be provided to further restrict the permissions to the user
  9. AWS verifies that the SAML assertion is trusted and valid and if so, returns temporary security credentials (access key, secret access key, session token, expiry time) to the application that have the permissions for the role named in the request.
  10. STS response also includes metadata about the user from the IdP, such as the unique user ID that the IdP associates with the user.
  11. Using the Temporary credentials, the application makes signed requests to AWS to access the services
  12. Application can cache the temporary security credentials and refresh them before their expiry accordingly. Temporary credentials, by default, are good for an hour.

SAML 2.0 based federation can also be used to grant access to the federated users to the AWS Management console. This requires the use of the AWS SSO endpoint instead of directly calling the AssumeRoleWithSAML API. The endpoint calls the API for the user and returns a URL that automatically redirects the user’s browser to the AWS Management Console.

Complete Process Flow

SAML based SSO to AWS Console

  1. User browses to the organization’s portal and selects the option to go to the AWS Management Console.
  2. Portal performs the function of the identity provider (IdP) that handles the exchange of trust between the organization and AWS.
  3. Portal verifies the user’s identity in the organization.
  4. Portal generates a SAML authentication response that includes assertions that identify the user and include attributes about the user.
  5. Portal sends this response to the client browser.
  6. Client browser is redirected to the AWS SSO endpoint and posts the SAML assertion.
  7. AWS SSO endpoint handles the call for the AssumeRoleWithSAML API action on the user’s behalf and requests temporary security credentials from STS and creates a console sign-in URL that uses those credentials.
  8. AWS sends the sign-in URL back to the client as a redirect.
  9. Client browser is redirected to the AWS Management Console. If the SAML authentication response includes attributes that map to multiple IAM roles, the user is first prompted to select the role to use for access to the console.

Custom Identity broker Federation

Custom Identity broker Federation

  • If the Organization doesn’t support SAML compatible IdP, a Custom Identity Broker can be used to provide the access
  • Custom Identity Broker should perform the following steps
    • Verify that the user is authenticated by the local identity system.
    • Call the AWS Security Token Service (AWS STS) AssumeRole (recommended) or GetFederationToken (by default, has a expiration period of 36 hours) APIs to obtain temporary security credentials for the user.
    • Temporary credentials limit the permissions a user has to the AWS resource
    • Call an AWS federation endpoint and supply the temporary security credentials to get a sign-in token.
    • Construct a URL for the console that includes the token.
    • URL that the federation endpoint provides is valid for 15 minutes after it is created.
    • Give the URL to the user or invoke the URL on the user’s behalf.

AWS Certification Exam Practice Questions

  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
  • AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  1. A photo-sharing service stores pictures in Amazon Simple Storage Service (S3) and allows application sign-in using an OpenID Connect-compatible identity provider. Which AWS Security Token Service approach to temporary access should you use for the Amazon S3 operations?
    1. SAML-based Identity Federation
    2. Cross-Account Access
    3. AWS IAM users
    4. Web Identity Federation
  2. Which technique can be used to integrate AWS IAM (Identity and Access Management) with an on-premise LDAP (Lightweight Directory Access Protocol) directory service?
    1. Use an IAM policy that references the LDAP account identifiers and the AWS credentials.
    2. Use SAML (Security Assertion Markup Language) to enable single sign-on between AWS and LDAP
    3. Use AWS Security Token Service from an identity broker to issue short-lived AWS credentials. (Refer Link)
    4. Use IAM roles to automatically rotate the IAM credentials when LDAP credentials are updated.
    5. Use the LDAP credentials to restrict a group of users from launching specific EC2 instance types.
  3. You are designing a photo sharing mobile app the application will store all pictures in a single Amazon S3 bucket. Users will upload pictures from their mobile device directly to Amazon S3 and will be able to view and download their own pictures directly from Amazon S3. You want to configure security to handle potentially millions of users in the most secure manner possible. What should your server-side application do when a new user registers on the photo-sharing mobile application?
    1. Create a set of long-term credentials using AWS Security Token Service with appropriate permissions Store these credentials in the mobile app and use them to access Amazon S3.
    2. Record the user’s Information in Amazon RDS and create a role in IAM with appropriate permissions. When the user uses their mobile app create temporary credentials using the AWS Security Token Service ‘AssumeRole’ function. Store these credentials in the mobile app’s memory and use them to access Amazon S3. Generate new credentials the next time the user runs the mobile app.
    3. Record the user’s Information in Amazon DynamoDB. When the user uses their mobile app create temporary credentials using AWS Security Token Service with appropriate permissions. Store these credentials in the mobile app’s memory and use them to access Amazon S3 Generate new credentials the next time the user runs the mobile app.
    4. Create IAM user. Assign appropriate permissions to the IAM user Generate an access key and secret key for the IAM user, store them in the mobile app and use these credentials to access Amazon S3.
    5. Create an IAM user. Update the bucket policy with appropriate permissions for the IAM user Generate an access Key and secret Key for the IAM user, store them In the mobile app and use these credentials to access Amazon S3.
  4. Your company has recently extended its datacenter into a VPC on AWS to add burst computing capacity as needed Members of your Network Operations Center need to be able to go to the AWS Management Console and administer Amazon EC2 instances as necessary. You don’t want to create new IAM users for each NOC member and make those users sign in again to the AWS Management Console. Which option below will meet the needs for your NOC members?
    1. Use OAuth 2.0 to retrieve temporary AWS security credentials to enable your NOC members to sign in to the AWS Management Console.
    2. Use Web Identity Federation to retrieve AWS temporary security credentials to enable your NOC members to sign in to the AWS Management Console.
    3. Use your on-premises SAML 2.O-compliant identity provider (IDP) to grant the NOC members federated access to the AWS Management Console via the AWS single sign-on (SSO) endpoint.
    4. Use your on-premises SAML 2.0-compliant identity provider (IDP) to retrieve temporary security credentials to enable NOC members to sign in to the AWS Management Console
  5. A corporate web application is deployed within an Amazon Virtual Private Cloud (VPC) and is connected to the corporate data center via an iPsec VPN. The application must authenticate against the on-premises LDAP server. After authentication, each logged-in user can only access an Amazon Simple Storage Space (S3) keyspace specific to that user. Which two approaches can satisfy these objectives? (Choose 2 answers)
    1. Develop an identity broker that authenticates against IAM security Token service to assume a IAM role in order to get temporary AWS security credentials. The application calls the identity broker to get AWS temporary security credentials with access to the appropriate S3 bucket. (Needs to authenticate against LDAP and not IAM)
    2. The application authenticates against LDAP and retrieves the name of an IAM role associated with the user. The application then calls the IAM Security Token Service to assume that IAM role. The application can use the temporary credentials to access the appropriate S3 bucket. (Authenticates with LDAP and calls the AssumeRole)
    3. Develop an identity broker that authenticates against LDAP and then calls IAM Security Token Service to get IAM federated user credentials The application calls the identity broker to get IAM federated user credentials with access to the appropriate S3 bucket. (Custom Identity broker implementation, with authentication with LDAP and using federated token)
    4. The application authenticates against LDAP the application then calls the AWS identity and Access Management (IAM) Security Token service to log in to IAM using the LDAP credentials the application can use the IAM temporary credentials to access the appropriate S3 bucket. (Can’t login to IAM using LDAP credentials)
    5. The application authenticates against IAM Security Token Service using the LDAP credentials the application uses those temporary AWS security credentials to access the appropriate S3 bucket. (Need to authenticate with LDAP)
  6. Company B is launching a new game app for mobile devices. Users will log into the game using their existing social media account to streamline data capture. Company B would like to directly save player data and scoring information from the mobile app to a DynamoDB table named Score Data When a user saves their game the progress data will be stored to the Game state S3 bucket. what is the best approach for storing data to DynamoDB and S3?
    1. Use an EC2 Instance that is launched with an EC2 role providing access to the Score Data DynamoDB table and the GameState S3 bucket that communicates with the mobile app via web services.
    2. Use temporary security credentials that assume a role providing access to the Score Data DynamoDB table and the Game State S3 bucket using web identity federation
    3. Use Login with Amazon allowing users to sign in with an Amazon account providing the mobile app with access to the Score Data DynamoDB table and the Game State S3 bucket.
    4. Use an IAM user with access credentials assigned a role providing access to the Score Data DynamoDB table and the Game State S3 bucket for distribution with the mobile app.
  7. A user has created a mobile application which makes calls to DynamoDB to fetch certain data. The application is using the DynamoDB SDK and root account access/secret access key to connect to DynamoDB from mobile. Which of the below mentioned statements is true with respect to the best practice for security in this scenario?
    1. User should create a separate IAM user for each mobile application and provide DynamoDB access with it
    2. User should create an IAM role with DynamoDB and EC2 access. Attach the role with EC2 and route all calls from the mobile through EC2
    3. The application should use an IAM role with web identity federation which validates calls to DynamoDB with identity providers, such as Google, Amazon, and Facebook
    4. Create an IAM Role with DynamoDB access and attach it with the mobile application
  8. You are managing the AWS account of a big organization. The organization has more than 1000+ employees and they want to provide access to the various services to most of the employees. Which of the below mentioned options is the best possible solution in this case?
    1. The user should create a separate IAM user for each employee and provide access to them as per the policy
    2. The user should create an IAM role and attach STS with the role. The user should attach that role to the EC2 instance and setup AWS authentication on that server
    3. The user should create IAM groups as per the organization’s departments and add each user to the group for better access control
    4. Attach an IAM role with the organization’s authentication service to authorize each user for various AWS services
  9. Your fortune 500 company has under taken a TCO analysis evaluating the use of Amazon S3 versus acquiring more hardware The outcome was that all employees would be granted access to use Amazon S3 for storage of their personal documents. Which of the following will you need to consider so you can set up a solution that incorporates single sign-on from your corporate AD or LDAP directory and restricts access for each user to a designated user folder in a bucket? (Choose 3 Answers)
    1. Setting up a federation proxy or identity provider
    2. Using AWS Security Token Service to generate temporary tokens
    3. Tagging each folder in the bucket
    4. Configuring IAM role
    5. Setting up a matching IAM user for every user in your corporate directory that needs access to a folder in the bucket
  10. An AWS customer is deploying a web application that is composed of a front-end running on Amazon EC2 and of confidential data that is stored on Amazon S3. The customer security policy that all access operations to this sensitive data must be authenticated and authorized by a centralized access management system that is operated by a separate security team. In addition, the web application team that owns and administers the EC2 web front-end instances is prohibited from having any ability to access the data that circumvents this centralized access management system. Which of the following configurations will support these requirements:
    1. Encrypt the data on Amazon S3 using a CloudHSM that is operated by the separate security team. Configure the web application to integrate with the CloudHSM for decrypting approved data access operations for trusted end-users. (S3 doesn’t integrate directly with CloudHSM, also there is no centralized access management system control)
    2. Configure the web application to authenticate end-users against the centralized access management system. Have the web application provision trusted users STS tokens entitling the download of approved data directly from Amazon S3 (Controlled access and admins cannot access the data as it needs authentication)
    3. Have the separate security team create and IAM role that is entitled to access the data on Amazon S3. Have the web application team provision their instances with this role while denying their IAM users access to the data on Amazon S3 (Web team would have access to the data)
    4. Configure the web application to authenticate end-users against the centralized access management system using SAML. Have the end-users authenticate to IAM using their SAML token and download the approved data directly from S3. (not the way SAML auth works and not sure if the centralized access management system is SAML complaint)

References

AWS IAM User Guide – Id Role Providers

AWS EC2 Security – Certification

AWS EC2 Security

EC2 Key Pairs

  • EC2 uses public-key cryptography to encrypt & decrypt login information
  • Public-key cryptography uses a public key to encrypt a piece of data, such as a password, then the recipient uses the private key to decrypt the data.
  • Public and private keys are known as a key pair.
  • To log in to an EC2 instance, a key pair needs to be created and specified when the instance is launched, and the private key can be used to connect to the instance.
  • Linux instances have no password, and the key pair is used for ssh log in
  • For Windows instances, the key pair can be used to obtain the administrator password and then log in using RDP
  • EC2 stores the public key only, and the private key resides with the user. EC2 doesn’t keep a copy of your private key
  • Public key content (on Linux instances) is placed in an entry within ~/.ssh/authorized_keys at boot time and enables the user to securely access the instance without passwords
  • Public key specified for an instance when launched is also available through its instance metadata http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key
  • EC2 Security Best Practice: Store the private keys in a secure place as anyone who possesses the private key can decrypt the login information
  • Also, if the private key is lost, there is no way to recover the same.
    • For instance store, you cannot access the instance
    • For EBS-backed Linux instances, access can be regained.
      • EBS-backed instance can be stopped, its root volume detached and attached to another instance as a data volume
      • Modify the authorized_keys file, move the volume back to the original instance, and restart the instance
  • Key pair associated with the instances can either be
    • Generated by Amazon EC2
      • Keys that Amazon EC2 uses are 2048-bit SSH-2 RSA keys.
    • Created separately (using third-party tools) and Imported into EC2
      • EC2 only accepts RSA keys and does not accept DSA keys
      • Supported lengths: 1024, 2048, and 4096
  • You can have up to five thousand key pairs per region
  • Deleting a key pair only deletes the public key and does not impact the servers already launched with the key

EC2 Security Groups

  • An EC2 instance, when launched, can be associated with one or more security groups with the instance, which acts as a virtual firewall that controls the traffic to that instance
  • Security groups helps specify rules that control the inbound traffic that’s allowed to reach the instances and the outbound traffic that’s allowed to leave the instance
  • Security groups are associated with network interfaces. Changing an instance’s security groups changes the security groups associated with the primary network interface (eth0)
  • An Network interface can be associated with 5 security groups and with 50 rules per security gorup
  • Rules for a security group can be modified at any time; the new rules are automatically applied to all instances associated with the security group.
  • All the rules from all associated security groups are evaluated to decide where to allow traffic to an instance
  • Security Group features
    • For the VPC default security group, it allows all inbound traffic from other instances associated with the default security group
    • By default, VPC default security groups or newly created security groups allow all outbound traffic
    • Security group rules are always permissive; deny rules can’t be created
    • Rules can be added and removed any time.
    • Any modification to the rules are automatically applied to the instances associated with the security group after a short period, depending on the connection tracking for the traffic
    • Security groups are stateful — if you send a request from your instance, the response traffic for that request is allowed to flow in regardless of inbound security group rules. For VPC security groups, this also means that responses to allowed inbound traffic are allowed to flow out, regardless of outbound rules
    • If multiple rules for the same protocol and port the Most permissive rule is applied for e.g. for multiple rules for tcp and port 22 for specific IP and Everyone, everyone is granted access being the most permissive rule

Connection Tracking

  • Security groups are Stateful and they use Connection tracking to track information about traffic to and from the instance.
  • This allows responses to inbound traffic to flow out of the instance regardless of outbound security group rules, and vice versa.
  • Connection Tracking is maintained only if there is no explicit Outbound rule for an Inbound request (and vice versa)
  • However, if there is an explicit Outbound rule for an Inbound request, the response traffic is allowed on the basis of the Outbound rule and not on the Tracking information
  • Any existing flow of traffic, that is tracked, is not interrupted even if the rules for the security groups are changed. To ensure traffic is immediately interrupted, use NACL as they are stateless and therefore do not allow automatic response traffic.
  • Also, If your instance (host A) initiates traffic to host B and uses a protocol other than TCP, UDP, or ICMP, your instance’s firewall only tracks the IP address and protocol number for the purpose of allowing response traffic from host B. If host B initiates traffic to your instance in a separate request within 600 seconds of the original request or response, your instance accepts it regardless of inbound security group rules, because it’s regarded as response traffic.
  • You can control this by modifying your security group’s outbound rules to permit only certain types of outbound traffic or using NACL

IAM with EC2

  • IAM policy can be defined to allow or deny a user access to the EC2 resources and actions
  • EC2 partially supports resource-level permissions. For some EC2 API actions, you cannot specify which resource a user is allowed to work with for that action; instead, you have to allow users to work with all resources for that action
  • IAM allows to control only what actions a user can perform on the EC2 resources but cannot be used to grant access for users to be able to access or login to the instances

EC2 with IAM Role

  • EC2 instances can be launched with IAM roles so that the applications can securely make API requests from your instances,
  • IAM roles prevents the need to share as well as manage, rotate the security credentials that the applications use
  • IAM role can be associated with the EC2 instance only when it is launched. Role cannot be assigned to an existing instance
  • EC2 uses an instance profile as a container for an IAM role.
    • Creation of an IAM role using the console, creates an instance profile automatically and gives it the same name as the role it corresponds to.
    • When using the AWS CLI, API, or an AWS SDK to create a role, the role and instance profile needs to be created as separate actions, and they can be given different names.
  • To launch an instance with an IAM role, the name of its instance profile needs to be specified.
  • An application on the instance can retrieve the security credentials provided by the role from the instance metadata item http://169.254.169.254/latest/meta-data/iam/security-credentials/role-name.
  • Security credentials are temporary and are rotated automatically and new credentials are made available at least five minutes prior to the expiration of the old credentials.
  • Best Practice: Always launch EC2 instance with IAM role instead of hardcoded credentials

EC2 IAM Role S3 Access

AWS Certification Exam Practice Questions

  • Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
  • AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
  • AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
  • Open to further feedback, discussion and correction.
  1. You launch an Amazon EC2 instance without an assigned AWS identity and Access Management (IAM) role. Later, you decide that the instance should be running with an IAM role. Which action must you take in order to have a running Amazon EC2 instance with an IAM role assigned to it?
    1. Create an image of the instance, and register the image with an IAM role assigned and an Amazon EBS volume mapping.
    2. Create a new IAM role with the same permissions as an existing IAM role, and assign it to the running instance.
    3. Create an image of the instance, add a new IAM role with the same permissions as the desired IAM role, and deregister the image with the new role assigned.
    4. Create an image of the instance, and use this image to launch a new instance with the desired IAM role assigned
  2. What does the following command do with respect to the Amazon EC2 security groups? ec2-revoke RevokeSecurityGroupIngress
    1. Removes one or more security groups from a rule.
    2. Removes one or more security groups from an Amazon EC2 instance.
    3. Removes one or more rules from a security group
    4. Removes a security group from our account.
  3. Which of the following cannot be used in Amazon EC2 to control who has access to specific Amazon EC2 instances?
    1. Security Groups
    2. IAM System
    3. SSH keys
    4. Windows passwords
  4. You must assign each server to at least _____ security group
    1. 3
    2. 2
    3. 4
    4. 1
  5. A company is building software on AWS that requires access to various AWS services. Which configuration should be used to ensure that AWS credentials (i.e., Access Key ID/Secret Access Key combination) are not compromised?
    1. Enable Multi-Factor Authentication for your AWS root account.
    2. Assign an IAM role to the Amazon EC2 instance
    3. Store the AWS Access Key ID/Secret Access Key combination in software comments.
    4. Assign an IAM user to the Amazon EC2 Instance.
  6. Which of the following items are required to allow an application deployed on an EC2 instance to write data to a DynamoDB table? Assume that no security keys are allowed to be stored on the EC2 instance. (Choose 2 answers)
    1. Create an IAM Role that allows write access to the DynamoDB table
    2. Add an IAM Role to a running EC2 instance.
    3. Create an IAM User that allows write access to the DynamoDB table.
    4. Add an IAM User to a running EC2 instance.
    5. Launch an EC2 Instance with the IAM Role included in the launch configuration
  7. You have an application running on an EC2 Instance, which will allow users to download files from a private S3 bucket using a pre-assigned URL. Before generating the URL the application should verify the existence of the file in S3. How should the application use AWS credentials to access the S3 bucket securely?
    1. Use the AWS account access Keys the application retrieves the credentials from the source code of the application.
    2. Create a IAM user for the application with permissions that allow list access to the S3 bucket launch the instance as the IAM user and retrieve the IAM user’s credentials from the EC2 instance user data.
    3. Create an IAM role for EC2 that allows list access to objects in the S3 bucket. Launch the instance with the role, and retrieve the role’s credentials from the EC2 Instance metadata
    4. Create an IAM user for the application with permissions that allow list access to the S3 bucket. The application retrieves the IAM user credentials from a temporary directory with permissions that allow read access only to the application user.
  8. A user has created an application, which will be hosted on EC2. The application makes calls to DynamoDB to fetch certain data. The application is using the DynamoDB SDK to connect with from the EC2 instance. Which of the below mentioned statements is true with respect to the best practice for security in this scenario?
    1. The user should attach an IAM role with DynamoDB access to the EC2 instance
    2. The user should create an IAM user with DynamoDB access and use its credentials within the application to connect with DynamoDB
    3. The user should create an IAM role, which has EC2 access so that it will allow deploying the application
    4. The user should create an IAM user with DynamoDB and EC2 access. Attach the user with the application so that it does not use the root account credentials
  9. Your application is leveraging IAM Roles for EC2 for accessing object stored in S3. Which two of the following IAM policies control access to you S3 objects.
    1. An IAM trust policy allows the EC2 instance to assume an EC2 instance role.
    2. An IAM access policy allows the EC2 role to access S3 objects
    3. An IAM bucket policy allows the EC2 role to access S3 objects. (Bucket policy is defined with S3 and not with IAM)
    4. An IAM trust policy allows applications running on the EC2 instance to assume as EC2 role (Trust policy allows EC2 instance to assume the role)
    5. An IAM trust policy allows applications running on the EC2 instance to access S3 objects. (Applications can access S3 through EC2 assuming the role)
  10. You have an application running on an EC2 Instance, which will allow users to download files from a private S3 bucket using a pre-assigned URL. Before generating the URL the application should verify the existence of the file in S3. How should the application use AWS credentials to access the S3 bucket securely?
    1. Use the AWS account access Keys the application retrieves the credentials from the source code of the application.
    2. Create a IAM user for the application with permissions that allow list access to the S3 bucket launch the instance as the IAM user and retrieve the IAM user’s credentials from the EC2 instance user data.
    3. Create an IAM role for EC2 that allows list access to objects in the S3 bucket. Launch the instance with the role, and retrieve the role’s credentials from the EC2 Instance metadata
    4. Create an IAM user for the application with permissions that allow list access to the S3 bucket. The application retrieves the IAM user credentials from a temporary directory with permissions that allow read access only to the application user.