seahaven-org-baseline/lib/account-baseline-stack.ts
Adam Moussa 77d9d6c574
[INFRA-96] CMK-encrypt sensitive CloudWatch log groups (M-24) (#20)
* [INFRA-96] CMK-encrypt sensitive CloudWatch log groups (M-24)

Add a dedicated customer-managed CMK (alias/seahaven-logs) for encrypting
the sensitive CloudWatch Logs groups (CloudTrail + finance/PII Lambdas).

- lib/logs-key.ts: LogsKey construct. Key policy grants the CloudWatch Logs
  service principal (logs.us-east-1.amazonaws.com) Encrypt*/Decrypt*/
  ReEncrypt*/GenerateDataKey*/DescribeKey, scoped by the
  kms:EncryptionContext:aws:logs:arn condition (REQUIRED per AWS docs or log
  delivery breaks). Cross-reviewed (GPT-4.1): tightened Describe* -> DescribeKey;
  CreateGrant omitted (not needed for plain log-group encryption).
- account-baseline-stack.ts: instantiate LogsKey and set KmsKeyId on the L2
  Trail's CloudWatch log group in place (escape hatch on the existing
  AWS::Logs::LogGroup) so it keeps the same logical id + physical name -
  additive, no replacement, CIS Section-4 metric filters (which import the
  group by name) keep working, live audit trail not disrupted. Gated by
  context `encryptTrailLogGroup` so the CMK can be smoke-tested on a low-risk
  Lambda group before the most-sensitive CloudTrail group.

Finance/PII Lambda log groups (exec-aide-*, payments-*, po-email-processor,
vendor-reply-processor) are owned by other stacks and associated to this CMK
via the CLI for now; codifying KmsKeyId in those repos is tracked as drift.

* [INFRA-96] Document sensitive-logs CMK (M-24) in README
2026-06-08 19:04:36 -04:00

240 lines
11 KiB
TypeScript

import * as cdk from "aws-cdk-lib";
import * as s3 from "aws-cdk-lib/aws-s3";
import * as kms from "aws-cdk-lib/aws-kms";
import * as iam from "aws-cdk-lib/aws-iam";
import * as logs from "aws-cdk-lib/aws-logs";
import * as cloudtrail from "aws-cdk-lib/aws-cloudtrail";
import { Construct } from "constructs";
import { LogsKey } from "./logs-key";
import { DetectiveControls } from "./detective-controls";
import { GovernanceToggles } from "./governance-toggles";
import { BedrockLogging } from "./bedrock-logging";
import { CisMonitoring } from "./cis-monitoring";
import { FlowLogs } from "./flow-logs";
import { SesMonitoring } from "./ses-monitoring";
import { AppWebAcl } from "./web-acl";
/**
* Account-level security baseline for Sea Haven (account 328440206208).
*
* First resident: a multi-region CloudTrail with log-file validation, KMS
* encryption, an Object-Lock'd S3 log bucket, and CloudWatch Logs delivery.
* Closes audit finding C-1 and CIS 3.1/3.2/3.4/3.6/3.7 (+3.8 via key rotation),
* and provides the CloudWatch Logs group that the CIS Section 4 metric filters
* (H-1) attach to.
*
* Future residents (same stack): AWS Config (H-2), GuardDuty (H-3),
* Security Hub (H-4), IAM Access Analyzer (M-5), Inspector2 (M-6).
*/
export interface AccountBaselineStackProps extends cdk.StackProps {
/** Monthly cost budget ceiling in USD (M-10). */
readonly monthlyBudgetUsd: number;
/** Email for budget threshold alerts (M-10). */
readonly budgetAlertEmail: string;
}
export class AccountBaselineStack extends cdk.Stack {
constructor(scope: Construct, id: string, props: AccountBaselineStackProps) {
super(scope, id, props);
const trailName = "seahaven-org-trail";
// AWS Organizations org id (o-9kufuzz6b4). CloudTrail org trusted-access is
// already enabled on the management account; promoting this trail to an org
// trail (INFRA-73) makes it collect member-account events into this bucket.
const orgId = "o-9kufuzz6b4";
// Static trail ARN (built from name, not trail.trailArn) so the key policy
// does not create a circular dependency with the Trail resource.
const trailArn = cdk.Arn.format(
{ service: "cloudtrail", resource: "trail", resourceName: trailName },
this
);
// ── KMS CMK ── encrypts CloudTrail log files (CIS 3.7); rotation = CIS 3.8.
const trailKey = new kms.Key(this, "TrailKey", {
alias: "cloudtrail-logs",
description: "Encrypts CloudTrail log files for the account-wide trail",
enableKeyRotation: true,
removalPolicy: cdk.RemovalPolicy.RETAIN,
});
// The L2 Trail construct does NOT grant the CloudTrail service principal use
// of a customer-provided key, so delivery of encrypted logs would fail.
// Grant it explicitly, scoped to this account's trail via SourceArn and the
// CloudTrail encryption context. (Caught by cross-review 2026-05-29.)
trailKey.addToResourcePolicy(
new iam.PolicyStatement({
sid: "AllowCloudTrailEncrypt",
effect: iam.Effect.ALLOW,
principals: [new iam.ServicePrincipal("cloudtrail.amazonaws.com")],
actions: ["kms:GenerateDataKey*"],
resources: ["*"],
conditions: {
StringEquals: { "aws:SourceArn": trailArn },
StringLike: {
"kms:EncryptionContext:aws:cloudtrail:arn": `arn:${this.partition}:cloudtrail:*:${this.account}:trail/*`,
},
},
})
);
// INFRA-73 (org trail): member accounts deliver their CloudTrail events to
// this CMK-encrypted bucket, so the CloudTrail service principal must be able
// to GenerateDataKey using each member trail's own encryption context.
//
// Cross-review BLOCK (GPT-4.1): the SourceArn must NOT be pinned to the
// management account 328440206208 — org-trail shadow trails in member
// accounts present their OWN account id in both the SourceArn and the
// encryption-context arn, so pinning to the management account would silently
// block all member-account delivery. Both are wildcarded across accounts and
// the statement is org-scoped by aws:PrincipalOrgID so only accounts in
// o-9kufuzz6b4 — not arbitrary CloudTrail principals — can use the key.
trailKey.addToResourcePolicy(
new iam.PolicyStatement({
sid: "AllowOrgMemberCloudTrailEncrypt",
effect: iam.Effect.ALLOW,
principals: [new iam.ServicePrincipal("cloudtrail.amazonaws.com")],
actions: ["kms:GenerateDataKey*", "kms:DescribeKey"],
resources: ["*"],
conditions: {
StringEquals: { "aws:PrincipalOrgID": orgId },
StringLike: {
"kms:EncryptionContext:aws:cloudtrail:arn": `arn:${this.partition}:cloudtrail:*:*:trail/*`,
"aws:SourceArn": `arn:${this.partition}:cloudtrail:*:*:trail/*`,
},
},
})
);
trailKey.addToResourcePolicy(
new iam.PolicyStatement({
sid: "AllowCloudTrailDescribeKey",
effect: iam.Effect.ALLOW,
principals: [new iam.ServicePrincipal("cloudtrail.amazonaws.com")],
actions: ["kms:DescribeKey"],
resources: ["*"],
})
);
// Central, pre-existing access-logs bucket (manually created, imported
// read-only) — receives S3 server access logs for the trail bucket (CIS 3.6).
const accessLogsBucket = s3.Bucket.fromBucketName(
this,
"AccessLogsBucket",
"seahaven-s3-access-logs"
);
// ── Hardened, tamper-resistant log bucket ──
// Private (BPA all on), KMS-encrypted, versioned, TLS-only, Object-Lock
// GOVERNANCE 365d so logs cannot be silently deleted/overwritten.
const logBucket = new s3.Bucket(this, "TrailLogBucket", {
bucketName: `seahaven-cloudtrail-logs-${this.account}`,
encryption: s3.BucketEncryption.KMS,
encryptionKey: trailKey,
bucketKeyEnabled: true,
blockPublicAccess: s3.BlockPublicAccess.BLOCK_ALL,
enforceSSL: true,
versioned: true,
objectLockEnabled: true,
objectLockDefaultRetention: s3.ObjectLockRetention.governance(
cdk.Duration.days(365)
),
serverAccessLogsBucket: accessLogsBucket,
serverAccessLogsPrefix: "cloudtrail-bucket-access/",
lifecycleRules: [
{
id: "transition-and-expire",
transitions: [
{
storageClass: s3.StorageClass.GLACIER,
transitionAfter: cdk.Duration.days(90),
},
],
expiration: cdk.Duration.days(365),
abortIncompleteMultipartUploadAfter: cdk.Duration.days(7),
},
],
removalPolicy: cdk.RemovalPolicy.RETAIN,
});
// ── Multi-region trail ──
// Management events (read + write), log-file validation, global service
// events, delivered to the KMS-encrypted bucket and to CloudWatch Logs.
// Data events (CIS 3.10/3.11) intentionally deferred — management events
// only for now to control cost (see README).
const trail = new cloudtrail.Trail(this, "Trail", {
trailName,
bucket: logBucket,
encryptionKey: trailKey,
isMultiRegionTrail: true,
// INFRA-73: promote to an organization trail. CloudTrail org
// trusted-access is already enabled on the management account; this makes
// the trail collect every member account's events into this bucket.
// Passing orgId lets the L2 construct auto-attach the AWSLogs/<orgId>/*
// bucket-policy PutObject statement (scoped to this trail's SourceArn).
isOrganizationTrail: true,
orgId,
includeGlobalServiceEvents: true,
enableFileValidation: true,
sendToCloudWatchLogs: true,
cloudWatchLogsRetention: logs.RetentionDays.ONE_YEAR,
managementEvents: cloudtrail.ReadWriteType.ALL,
});
// ── Sensitive CloudWatch Logs CMK (M-24 / INFRA-96) ──
// Dedicated key for encrypting the CloudTrail CW log group and the
// finance/PII Lambda log groups (those live in other stacks and are
// associated via CLI until codified in their owning repos — see README).
const logsKey = new LogsKey(this, "LogsKey");
// CMK-encrypt the Trail's CloudWatch Logs group in place. The L2 Trail
// construct owns this group (path Trail/LogGroup) and does not expose an
// encryptionKey prop for it, so we set KmsKeyId via escape hatch. This keeps
// the same logical ID and physical name, so it is additive (no replacement)
// and the CIS Section 4 metric filters that import the group by name (H-1)
// keep working, and the live audit trail is never disrupted.
//
// Gated by context `encryptTrailLogGroup` (default true) so the CMK can be
// rolled out and smoke-tested on a low-risk Lambda log group first, before
// applying it to the most-sensitive CloudTrail group (INFRA-96 step 3).
const encryptTrailLogGroup =
this.node.tryGetContext("encryptTrailLogGroup") !== "false";
if (encryptTrailLogGroup && trail.logGroup) {
const cfnTrailLogGroup = trail.logGroup.node
.defaultChild as logs.CfnLogGroup;
cfnTrailLogGroup.kmsKeyId = logsKey.key.keyArn;
}
// ── Day 1 detective layer + governance toggles ──
// Config (H-2), GuardDuty (H-3), Security Hub (H-4), Access Analyzer (M-5).
new DetectiveControls(this, "DetectiveControls");
// Monthly cost budget (M-10). Other governance toggles are CLI + documented.
new GovernanceToggles(this, "GovernanceToggles", {
monthlyLimitUsd: props.monthlyBudgetUsd,
alertEmail: props.budgetAlertEmail,
});
// ── Day 2 monitoring + logging ──
// CIS Section 4 metric filters/alarms (H-1), VPC flow logs (H-14),
// SES bounce/complaint config set (M-13).
new CisMonitoring(this, "CisMonitoring", {
alarmEmail: props.budgetAlertEmail,
});
new FlowLogs(this, "FlowLogs");
new SesMonitoring(this, "SesMonitoring");
// Shared CloudFront WAF WebACL (M-17); ARN published to SSM for app stacks.
new AppWebAcl(this, "AppWebAcl");
// ── Day 5 AI governance ──
// Bedrock model invocation logging destinations + delivery role (H-20).
// The account-level logging configuration itself has no CFN resource type;
// applied via CLI post-deploy (see lib/bedrock-logging.ts header).
new BedrockLogging(this, "BedrockLogging");
cdk.Tags.of(this).add("Project", "account-baseline");
cdk.Tags.of(this).add("Owner", "adam@seahavenind.com");
cdk.Tags.of(this).add("Environment", "prod");
cdk.Tags.of(this).add("ManagedBy", "cdk");
new cdk.CfnOutput(this, "TrailArn", { value: trail.trailArn });
new cdk.CfnOutput(this, "LogBucketName", { value: logBucket.bucketName });
new cdk.CfnOutput(this, "TrailKmsKeyArn", { value: trailKey.keyArn });
}
}