IAM Policy & Directory Setup for S3 Access via Single Sign-On (SSO)

SecureCart is implementing Amazon S3 as a central storage solution for employees to store personal documents.

• 1,200 employees need access to their designated folders in an S3 bucket.

• Access must be restricted per user—each user should only access their own folder.

• SecureCart integrates with corporate Active Directory (AD)/Okta for SSO authentication.

• AWS Security Token Service (STS) issues temporary credentials for secure access.

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📌 Solution Architecture

✅ SecureCart Components: ✔ IAM Role → Defines permissions for S3 and is assumed via federation. ✔ IAM Policy → Restricts access to a specific folder in S3 per user. ✔ AWS Identity Provider (IdP) → Connects SecureCart’s corporate directory (Active Directory, Okta, OneLogin). ✔ AWS Security Token Service (STS) → Issues temporary credentials for authenticated users. ✔ Amazon S3 Bucket Policies → Ensures folder-level access control.

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📌 Step-by-Step Setup for SecureCart IAM & Directory Integration

1️⃣ Set Up Identity Federation for SecureCart

🔹 SecureCart uses AWS IAM Identity Center (SSO) or an external IdP (Okta, ADFS, OneLogin, etc.). 🔹 Establish SAML 2.0 or OpenID Connect (OIDC) federation to allow user authentication via SecureCart's corporate directory. 🔹 After successful authentication, AWS STS issues a temporary IAM session token.

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2️⃣ Create an IAM Role for Federated Users

📌 This role allows federated users to access only their respective S3 folder.

🔹 IAM Role Creation (AWS Console)

1️⃣ Navigate to IAM → Roles → Click Create Role. 2️⃣ Select Identity Provider (IdP) Federation → Choose SAML 2.0 Federation. 3️⃣ Attach the IAM Policy (see below) to restrict folder access. 4️⃣ Define trust relationships to allow STS authentication.

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3️⃣ Attach an IAM Policy for Per-User S3 Folder Access

📌 This policy ensures that each SecureCart employee only accesses their assigned S3 folder.

jsonCopyEdit{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "s3:ListBucket"
      ],
      "Resource": "arn:aws:s3:::securecart-user-docs",
      "Condition": {
        "StringLike": {
          "s3:prefix": ["${aws:userid}/*"]
        }
      }
    },
    {
      "Effect": "Allow",
      "Action": [
        "s3:GetObject",
        "s3:PutObject",
        "s3:DeleteObject"
      ],
      "Resource": "arn:aws:s3:::securecart-user-docs/${aws:userid}/*"
    }
  ]
}

🔹 Key Features: ✅ Restricts S3 access per user (${aws:userid} dynamically maps to the user’s directory ID). ✅ Allows only authenticated users to list and manage their own S3 folder. ✅ Prevents unauthorized users from accessing other users’ folders.

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4️⃣ Enable AWS STS for Temporary Credentials

📌 AWS Security Token Service (STS) issues temporary session-based credentials.

🔹 How it works: ✅ SecureCart users authenticate via SSO (Okta, ADFS, OneLogin, etc.). ✅ AWS STS generates a temporary session token. ✅ The IAM Role is assumed using the temporary credentials. ✅ The user can then access only their S3 folder.

🔹 AWS CLI Example: Generate Temporary STS Credentials

shCopyEditaws sts assume-role-with-saml --role-arn arn:aws:iam::123456789012:role/SecureCartS3Access \
  --principal-arn arn:aws:iam::123456789012:saml-provider/Okta \
  --saml-assertion file://saml-response.xml

---

5️⃣ (Optional) Enforce Additional S3 Security Controls

✔ S3 Bucket Policy: Ensures per-user access and prevents bucket deletion. ✔ S3 Server-Side Encryption (SSE-KMS): Encrypts stored documents. ✔ Enable AWS CloudTrail: Logs and audits S3 access attempts.

🔹 Example S3 Bucket Policy

jsonCopyEdit{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Deny",
      "Principal": "*",
      "Action": "s3:DeleteBucket",
      "Resource": "arn:aws:s3:::securecart-user-docs"
    }
  ]
}

✅ Prevents accidental deletion of the S3 bucket while still allowing per-user access.

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📌 Summary

✔ SecureCart employees authenticate using SSO via Okta, ADFS, or another IdP. ✔ IAM roles & policies ensure that each user can only access their folder in S3. ✔ AWS STS provides temporary credentials to remove the need for static IAM credentials. ✔ S3 bucket policies and IAM permissions enforce least privilege security.

SecureCart: User Experience Flow for IAM-Integrated S3 Access via SSO

This flow outlines how SecureCart employees authenticate, receive temporary IAM permissions, and securely access their designated Amazon S3 folders using Single Sign-On (SSO) and AWS Security Token Service (STS).

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📌 User Experience Flow Overview

Actors Involved:

✔ SecureCart Employee – Needs access to their personal S3 storage. ✔ AWS IAM Identity Center (SSO) – Authenticates users via SecureCart's corporate directory (Okta, ADFS, OneLogin). ✔ AWS Security Token Service (STS) – Issues temporary IAM credentials after authentication. ✔ Amazon S3 – Stores user-specific documents in designated folders.

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📌 Step-by-Step User Experience Flow

1️⃣ User Authentication via SecureCart SSO

👤 Action:

1. User visits SecureCart’s SSO login page (sso.securecart.com).

2. Enters corporate credentials (e.g., [e-mail]).

3. Redirected to the corporate IdP (Okta, ADFS, or another SAML/OIDC provider).

4. Authenticates using SSO (may include MFA for security).

5. User is verified → Session token issued.

🔹 Behind the Scenes: ✅ AWS IAM Identity Center (SSO) federates authentication via Okta, ADFS, or OneLogin. ✅ AWS Identity Provider (IdP) validates user identity and grants access. ✅ AWS STS generates temporary IAM credentials.

---

2️⃣ AWS IAM Role Assumption via STS

👤 Action:

1. SSO session redirects the user to AWS.

2. IAM Role is automatically assumed (based on user permissions).

3. AWS STS issues temporary credentials (valid for up to 12 hours).

4. User gets redirected to SecureCart’s document storage portal.

🔹 Behind the Scenes: ✅ The user’s IAM role is assigned dynamically based on corporate directory attributes. ✅ AWS IAM enforces S3 folder-level access control using IAM policies.

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3️⃣ User Access to Amazon S3 via SecureCart’s UI

👤 Action:

1. The SecureCart document portal displays the user’s assigned folder.

2. User uploads, downloads, or deletes files within their S3 personal folder.

3. Any unauthorized access attempts are blocked (e.g., trying to access another user’s folder).

🔹 Behind the Scenes: ✅ IAM policies restrict access to s3://securecart-user-docs/${aws:userid}/*. ✅ S3 bucket policies reinforce security by preventing public access. ✅ AWS CloudTrail logs track user activity for compliance.

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4️⃣ Automatic Session Expiration & Renewal

👤 Action:

1. The user's temporary IAM session expires after the set duration (default 1 hour).

2. The user must re-authenticate via SSO to receive a new session.

3. If MFA is enforced, users must re-verify their identity.

🔹 Behind the Scenes: ✅ AWS STS expires temporary credentials for security. ✅ SecureCart’s application automatically renews tokens for active sessions.

---

📌 SecureCart User Experience Flow Diagram

pgsqlCopyEdit+---------------------------+
| SecureCart Employee       |
+---------------------------+
           |
           | (1) Login to SecureCart SSO  
           V
+---------------------------+
| Okta / ADFS / OneLogin    |  ← (SAML/OIDC Authentication)
+---------------------------+
           |
           | (2) Federated login → AWS IAM Identity Center (SSO)
           V
+---------------------------+
| AWS IAM Identity Center   |
+---------------------------+
           |
           | (3) STS issues temporary IAM credentials  
           V
+---------------------------+
| AWS IAM Role Assumption  |  
+---------------------------+
           |
           | (4) Redirect user to SecureCart Document Portal  
           V
+---------------------------+
| SecureCart S3 Storage UI  |
+---------------------------+
           |
           | (5) User accesses designated S3 folder  
           V
+---------------------------+
| Amazon S3                 |
+---------------------------+

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📌 User Experience Summary

✅ Seamless SSO authentication using Okta, ADFS, or OneLogin. ✅ Automatic IAM role assumption with STS for temporary credentials. ✅ Secure, folder-level access to Amazon S3 using IAM policies. ✅ Session expiration & renewal enforces security best practices. ✅ Real-time monitoring via AWS CloudTrail for compliance.

---

🚀 Would you like a hands-on lab to configure IAM Federation for SecureCart’s S3 access?

You said:

is identity center required in this scenario

ChatGPT said:

No, AWS IAM Identity Center (SSO) is not required in this scenario—but it can be used if SecureCart prefers a centralized approach for managing AWS access.

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📌 Why is Identity Center (SSO) Not Required?

✅ Federated Access via SAML or OIDC can be directly configured between SecureCart's corporate IdP (e.g., Okta, ADFS, OneLogin) and AWS IAM roles without using IAM Identity Center. ✅ AWS Security Token Service (STS) can issue temporary IAM credentials based on SAML/OIDC authentication. ✅ IAM roles and policies can be configured for fine-grained access control without requiring IAM Identity Center.

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📌 When Would SecureCart Use IAM Identity Center?

🔹 If SecureCart wants to centralize access management across multiple AWS accounts. 🔹 If SecureCart prefers managing user groups and permission sets centrally. 🔹 If SecureCart needs integrated AWS SSO features (e.g., AWS Console access with a single login). 🔹 If SecureCart wants AWS service-level authorization beyond IAM roles (e.g., for Redshift, QuickSight, or AWS Organizations integration).

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📌 How Would SecureCart Authenticate Without IAM Identity Center?

Option 1: Direct Federation with AWS IAM Roles

✔ Configure Okta/ADFS/OneLogin as an Identity Provider (IdP) in IAM. ✔ Define IAM roles that map user attributes (e.g., user ID, department). ✔ Users log in via SecureCart’s corporate IdP, which authenticates them and passes SAML/OIDC assertions to AWS. ✔ AWS STS issues temporary credentials for IAM role assumption.

🔹 Benefits: ✅ No additional setup required for IAM Identity Center. ✅ Works well for single AWS account setups. ✅ Provides direct access to IAM roles without managing permission sets.

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Option 2: Use IAM Identity Center for SSO (Optional)

✔ IAM Identity Center acts as a bridge between SecureCart’s IdP and AWS IAM roles. ✔ IAM Identity Center manages group-based access and AWS account-level permissions. ✔ Users log into IAM Identity Center, assume permission sets, and get temporary IAM credentials.

🔹 Benefits: ✅ Best for multi-account AWS environments. ✅ Easier access control management for large organizations. ✅ Works well for role-based AWS access management.

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📌 Conclusion

❌ IAM Identity Center is NOT required for SecureCart's S3 federated access. ✅ SecureCart can directly configure federated access via IAM roles & AWS STS. ✅ Use IAM Identity Center only if managing multiple AWS accounts and centralizing access control.

🚀 Would you like a hands-on guide for setting up direct federation without IAM Identity Center?

You said:

provide use exprience flow with identity center not involved

ChatGPT said:

SecureCart: User Experience Flow for IAM-Integrated S3 Access via SSO (Without IAM Identity Center)

This flow outlines how SecureCart employees authenticate via corporate SSO (Okta, ADFS, OneLogin, etc.), receive temporary IAM permissions, and securely access their designated Amazon S3 folders using AWS IAM roles and Security Token Service (STS) without involving IAM Identity Center.

---

📌 User Experience Flow Overview

Actors Involved:

✔ SecureCart Employee – Needs access to their personal S3 storage. ✔ Corporate Identity Provider (IdP) – SecureCart's authentication provider (Okta, ADFS, OneLogin, etc.). ✔ AWS IAM Role – Grants permissions to S3 based on federated authentication. ✔ AWS Security Token Service (STS) – Issues temporary IAM credentials after authentication. ✔ Amazon S3 – Stores user-specific documents in designated folders.

---

📌 Step-by-Step User Experience Flow

1️⃣ User Authentication via SecureCart’s Corporate SSO

👤 Action:

1. User visits SecureCart’s corporate login page (sso.securecart.com).

2. Enters corporate credentials (e.g., [e-mail]).

3. Redirected to the corporate IdP (Okta, ADFS, OneLogin).

4. Authenticates using SSO (may include MFA for security).

5. User is verified → A SAML/OIDC assertion is generated and sent to AWS.

🔹 Behind the Scenes: ✅ SecureCart’s IdP validates user identity using existing corporate credentials. ✅ IdP sends a SAML/OIDC assertion to AWS that includes user attributes (e.g., department, user ID).

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2️⃣ AWS IAM Role Assumption via STS

👤 Action:

1. AWS IAM processes the SAML/OIDC assertion from the SecureCart IdP.

2. IAM maps the user’s attributes to a pre-configured IAM Role.

3. AWS STS issues temporary credentials for the IAM Role.

4. User gets redirected to SecureCart’s document storage portal.

🔹 Behind the Scenes: ✅ IAM Role assumption grants access based on user attributes (e.g., department=engineering). ✅ AWS STS issues temporary IAM credentials valid for a configured duration (e.g., 1 hour). ✅ IAM does NOT create persistent IAM users, reducing security risks.

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3️⃣ User Access to Amazon S3 via SecureCart’s UI

👤 Action:

1. SecureCart’s document portal displays only the user’s designated folder.

2. User uploads, downloads, or deletes files within their personal S3 folder.

3. Any attempt to access another user’s folder is denied by IAM policies.

🔹 Behind the Scenes: ✅ IAM restricts S3 access per user using policies with dynamic conditions. ✅ S3 blocks unauthorized access using bucket policies and IAM role restrictions. ✅ AWS CloudTrail logs track all S3 access for auditing.

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4️⃣ Automatic Session Expiration & Renewal

👤 Action:

1. The user's temporary IAM session expires (default 1 hour, configurable up to 12 hours).

2. The user must re-authenticate via SecureCart’s IdP to obtain new credentials.

3. If MFA is enforced, users must re-verify their identity before accessing S3 again.

🔹 Behind the Scenes: ✅ AWS STS expires temporary credentials to enforce security best practices. ✅ SecureCart’s system automatically re-authenticates active users when their session expires.

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📌 SecureCart User Experience Flow Diagram (Without IAM Identity Center)

pgsqlCopyEdit+---------------------------+
| SecureCart Employee       |
+---------------------------+
           |
           | (1) Login to SecureCart SSO  
           V
+---------------------------+
| Okta / ADFS / OneLogin    |  ← (SAML/OIDC Authentication)
+---------------------------+
           |
           | (2) IdP generates SAML/OIDC assertion
           V
+---------------------------+
| AWS IAM Role Assumption   |  
+---------------------------+
           |
           | (3) STS issues temporary IAM credentials  
           V
+---------------------------+
| SecureCart S3 Storage UI  |
+---------------------------+
           |
           | (4) User accesses designated S3 folder  
           V
+---------------------------+
| Amazon S3                 |
+---------------------------+

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📌 Key Differences Between This Flow & IAM Identity Center Approach

Feature	Without IAM Identity Center	With IAM Identity Center
User Management	Handled by external IdP (Okta, ADFS, OneLogin)	IAM Identity Center manages users & groups
Access Control	IAM roles & policies directly manage access	IAM Identity Center assigns permission sets
Federation Setup	Direct SAML/OIDC federation to AWS IAM	Federation through IAM Identity Center
Use Case Fit	Best for single AWS account setups	Best for multi-account AWS Organizations

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📌 Summary

✅ SecureCart employees authenticate using SSO via Okta, ADFS, or another IdP. ✅ IAM roles & policies dynamically enforce access controls—no need for IAM users. ✅ AWS STS issues temporary credentials for enhanced security. ✅ S3 bucket policies & IAM permissions ensure least privilege access. ✅ Session expiration & renewal enforces security best practices.