SecureCart's Journey

Step 1: Define Access Requirements

Identify User & Service Access Needs

• Who needs access?

  • Developers → Need access to deploy and troubleshoot services.

  • Security Team → Requires full visibility but limited write permissions.

  • Application Services → Require controlled access to AWS resources (S3, RDS, etc.).

  • Third-Party Vendors → Need temporary, scoped access.

• What AWS resources need access control?

  • Compute (ECS, Lambda, EC2)

  • Storage (S3, EBS)

  • Databases (RDS, DynamoDB)

  • IAM & Security Controls (CloudTrail, GuardDuty, Config)

• Multi-Account Structure in AWS Organizations

  • Management Account → Governance & Security Controls.

  • Workload Accounts → Separate accounts for Dev, Staging, Production.

  • Security & Logging Account → Centralized logging, IAM monitoring, and threat detection.

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Step 2: Establish Identity and Access Management (IAM) Best Practices

Centralizing Identity with AWS Identity Center (SSO)

• AWS Identity Center (formerly SSO) for centralized user management.

• Federated access via Azure AD/Okta using SAML 2.0 or OIDC.

• Role-Based Access Control (RBAC) using IAM roles mapped to Identity Center permissions.

• Enforce MFA for all users with Identity Center policies.

Implementing IAM Role-Based Access

• No IAM users → Use IAM roles with temporary credentials.

• Principle of Least Privilege (PoLP) → Define custom IAM policies with only required permissions.

• IAM permission boundaries to restrict max permissions developers can grant themselves.

• IAM Access Analyzer to monitor unintended public access.

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Step 3: Enforcing Governance with AWS Organizations & SCPs

Structuring AWS Organizations for Security & Governance

• Organizational Units (OUs) for different environments:

  • SecurityOU: Security & compliance enforcement.

  • WorkloadsOU: Dev, Staging, Production workload accounts.

  • SharedServicesOU: Centralized CI/CD, logging, networking.

Applying Service Control Policies (SCPs)

• Prevent root user access with an SCP.

• Restrict usage of specific services (e.g., disallow Internet Gateway creation outside networking accounts).

• Enforce encryption for S3, RDS, and EBS with SCPs.

• Restrict AWS Region usage to comply with data residency laws.

Example SCP: Block Non-Compliant S3 Buckets

jsonCopyEdit{
    "Effect": "Deny",
    "Action": "s3:PutBucketPolicy",
    "Resource": "*",
    "Condition": {
        "StringNotEquals": {
            "s3:x-amz-server-side-encryption": "AES256"
        }
    }
}

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Step 4: Implement Secure Multi-Account Access with STS & Federated Roles

Using AWS Security Token Service (STS) for Temporary Access

• IAM Roles with STS assume-role instead of IAM users.

• Short-lived, auto-expiring credentials instead of static API keys.

• Cross-account role assumption for accessing shared services.

Configuring Cross-Account Access for SecureCart Teams

• Developers assume DeveloperRole in Staging & Dev accounts.

• Security Engineers assume SecurityAuditRole across all accounts.

• CI/CD pipelines assume a DeploymentRole with minimal permissions.

📌 Example IAM Role Trust Policy for Cross-Account Access

jsonCopyEdit{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "AWS": "arn:aws:iam::111122223333:root"
            },
            "Action": "sts:AssumeRole"
        }
    ]
}

(Allows the account 111122223333 to assume the IAM role for cross-account access.)