iam-credential-report-s3-bucket.yaml

AWSTemplateFormatVersion: '2010-09-09'
Description: Creates the Amazon S3 Bucket for the IAM Credential Report Blog Post
Metadata:
  AWS::CloudFormation::Interface:
    ParameterGroups:
      -
        Label:
          default: IAM Credential Report Delivery S3 Attributes
        Parameters:
          - pIAMCredReportBucketPrefix
          - pIAMCredReportKeyArn
          - pOrganizationId
          - pOrgPrimaryLambdaRoleName
          - pTagKey1
          - pTagValue1

    ParameterLabels:
      pIAMCredReportBucketPrefix:
        default: IAM Credential Report Delivery Bucket Prefix
      pIAMCredReportKeyArn:
        default: IAM Credential Report Delivery KMS Key
      pOrganizationId:
        default: Organization ID
      pOrgPrimaryLambdaRoleName:
        default: Organization Primary Lambda Role Name
      pTagKey1:
        default: Tag Key
      pTagValue1:
        default: Tag Value

Parameters:
  pIAMCredReportBucketPrefix:
    Type: String 
    Description: IAM Credential Report Delivery S3 bucket prefix. The account and region will get added to the end. e.g. iam-credential-report-delivery-123456789012-us-east-1
    Default: iam-credentials-report

  pIAMCredReportKeyArn:
    Type: String 
    Description: KMS Key ARN to use for encrypting IAM Credential Report sent to S3
  
  pOrganizationId:
    Type: String
    Description: AWS Organization ID
    MinLength: 12
    MaxLength: 12
    AllowedPattern: '^o-[a-z0-9]{10,32}$'
    ConstraintDescription: >
      The Organization Id must be a 12 character string starting with o- and followed by 10 lower case
      alphanumeric characters
  
  pOrgPrimaryLambdaRoleName:
    Type: String
    Description: Organization Primary Account Lambda Role Name
    Default: iam-credential-report-lambda-role

  pTagKey1:
    Type: String 
    Description: Tag key
    Default: managed-by
  
  pTagValue1:
    Type: String 
    Description: Tag key value
    Default: credential-cfn
  
Resources:
  rS3Bucket:
    Type: AWS::S3::Bucket
    Metadata:
      cfn_nag:
        rules_to_suppress:
          - id: W35
            reason: S3 access logging covered by CloudTrail S3 data events
    Properties:
      OwnershipControls:
        Rules:
          - ObjectOwnership: BucketOwnerPreferred
      BucketName: !Sub ${pIAMCredReportBucketPrefix}-${AWS::AccountId}-${AWS::Region}-aws
      VersioningConfiguration:
        Status: Enabled
      BucketEncryption:
        ServerSideEncryptionConfiguration:
          - ServerSideEncryptionByDefault:
              KMSMasterKeyID: !Ref pIAMCredReportKeyArn
              SSEAlgorithm: aws:kms
      PublicAccessBlockConfiguration:
        BlockPublicAcls: True
        BlockPublicPolicy: True
        IgnorePublicAcls: True
        RestrictPublicBuckets: True
      Tags:
        - Key: !Ref pTagKey1
          Value: !Ref pTagValue1

  rS3BucketPolicy:
    Type: AWS::S3::BucketPolicy
    Metadata:
      cfn_nag:
        rules_to_suppress:
          - id: F16
            reason: Resource is scoped down by Conditional
    Properties:
      Bucket: !Ref rS3Bucket
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Sid: SecureTransport
            Effect: Deny
            Principal: "*"
            Action: "s3:*"
            Resource: !Sub arn:aws:s3:::${rS3Bucket}
            Condition:
              Bool:
                "aws:SecureTransport": "false"

          - Sid: AWSBucketDelivery
            Effect: Allow
            Principal: "*"
            Action: s3:PutObject
            Resource: !Sub arn:aws:s3:::${rS3Bucket}/*
            Condition:
              StringEquals:
                "aws:PrincipalOrgID": !Ref pOrganizationId
              StringLike:
                aws:PrincipalArn: !Sub arn:${AWS::Partition}:iam::*:role/${pOrgPrimaryLambdaRoleName}

Outputs:
  oIAMCredDeliveryS3Bucket:
    Description: IAM Credential Report Delivery S3 Bucket
    Value: !Ref rS3Bucket
  oIAMCredDeliveryS3BucketArn:
    Description: IAM Credential Report Delivery S3 Bucket Arn
    Value: !GetAtt rS3Bucket.Arn
  oOrgPrimaryLambdaRoleName:
    Description: IAM Credential Report Lambda Execution Role Name
    Value: !Ref pOrgPrimaryLambdaRoleName