# TrustStore

A new Trust Store.

Extends: Construct › Resource › TrustStore
Implements: IResource, ITrustStore, IEnvironmentAware, ITrustStoreRef, IConstruct, IDependable

- CloudFormation: [`AWS::ElasticLoadBalancingV2::TrustStore`](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-resource-elasticloadbalancingv2-truststore.html)
- L1 type: [`CfnTrustStore`](/cdk/api/v2/docs/aws-cdk-lib.aws_elasticloadbalancingv2.CfnTrustStore.html)
- Source: [`aws-elasticloadbalancingv2/lib/alb/trust-store.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/aws-elasticloadbalancingv2/lib/alb/trust-store.ts#L63)
- Type last changed: v2.234.0 · 8 Jan 2026

## Example

```ts
import * as acm from 'aws-cdk-lib/aws-certificatemanager';

declare const certificate: acm.Certificate;
declare const lb: elbv2.ApplicationLoadBalancer;
declare const bucket: s3.Bucket;

const trustStore = new elbv2.TrustStore(this, 'Store', {
  bucket,
  key: 'rootCA_cert.pem',
});

lb.addListener('Listener', {
  port: 443,
  protocol: elbv2.ApplicationProtocol.HTTPS,
  certificates: [certificate],
  // mTLS settings
  mutualAuthentication: {
    advertiseTrustStoreCaNames: true,
    ignoreClientCertificateExpiry: false,
    mutualAuthenticationMode: elbv2.MutualAuthenticationMode.VERIFY,
    trustStore,
  },
  defaultAction: elbv2.ListenerAction.fixedResponse(200,
    { contentType: 'text/plain', messageBody: 'Success mTLS' }),
});
```

## Initializer

```ts
new TrustStore(scope: Construct, id: string, props: TrustStoreProps)
```

## Construct Props

- `bucket`: [IBucketRef](/cdk/api/v2/docs/aws-cdk-lib.interfaces.aws_s3.IBucketRef.html) (required) — The bucket that the trust store is hosted in.

- `key`: string (required) — The key in S3 to look at for the trust store.

- `trustStoreName`: string — The name of the trust store.

  **Default:** Auto generated

- `version`: string — The version of the S3 object that contains your truststore.

  **Default:** latest version

  To specify a version, you must have versioning enabled for the S3 bucket.

## Properties

- `env`: [ResourceEnvironment](/cdk/api/v2/docs/aws-cdk-lib.interfaces.ResourceEnvironment.html) — The environment this resource belongs to.

  For resources that are created and managed in a Stack (those created by
  creating new class instances like `new Role()`, `new Bucket()`, etc.), this
  is always the same as the environment of the stack they belong to.

  For referenced resources (those obtained from referencing methods like
  `Role.fromRoleArn()`, `Bucket.fromBucketName()`, etc.), they might be
  different than the stack they were imported into.

- `node`: [Node](/cdk/api/v2/docs/constructs.Node.html) — The tree node.

- `numberOfCaCertificates`: number — The number of CA certificates in the trust store.

- `PROPERTY_INJECTION_ID`: string (static) — Uniquely identifies this class.

- `stack`: [Stack](/cdk/api/v2/docs/aws-cdk-lib.Stack.html) — The stack in which this resource is defined.

- `status`: string — The status of the trust store.

- `trustStoreArn`: string — The ARN of the trust store.

- `trustStoreName`: string — The name of the trust store.

- `trustStoreRef`: [TrustStoreReference](/cdk/api/v2/docs/aws-cdk-lib.interfaces.aws_elasticloadbalancingv2.TrustStoreReference.html) — A reference to this trust store.

## Methods

- `applyCrossStackReferenceStrength(strength: ReferenceStrength): void` — Override the cross-stack reference strength for this resource.

  When set, any cross-stack reference to this resource will use the specified
  mechanism instead of the global default determined by the
  `@aws-cdk/core:defaultCrossStackReferences` context key. This is useful for
  selectively weakening specific references to avoid the "deadly embrace" problem
  without changing the app-wide default.

  **Parameters**

  - `strength` — - The reference strength to use for this resource.

- `applyRemovalPolicy(policy: RemovalPolicy): void` — Apply the given removal policy to this resource.

  The Removal Policy controls what happens to this resource when it stops
  being managed by CloudFormation, either because you've removed it from the
  CDK application or because you've made a change that requires the resource
  to be replaced.

  The resource can be deleted (`RemovalPolicy.DESTROY`), or left in your AWS
  account for data recovery and cleanup later (`RemovalPolicy.RETAIN`).

- `fromTrustStoreArn(scope: Construct, id: string, trustStoreArn: string): ITrustStore` (static) — Import from ARN.

- `isConstruct(x: any): boolean` (static) — Checks if `x` is a construct.

  Use this method instead of `instanceof` to properly detect `Construct`
  instances, even when the construct library is symlinked.

  Explanation: in JavaScript, multiple copies of the `constructs` library on
  disk are seen as independent, completely different libraries. As a
  consequence, the class `Construct` in each copy of the `constructs` library
  is seen as a different class, and an instance of one class will not test as
  `instanceof` the other class. `npm install` will not create installations
  like this, but users may manually symlink construct libraries together or
  use a monorepo tool: in those cases, multiple copies of the `constructs`
  library can be accidentally installed, and `instanceof` will behave
  unpredictably. It is safest to avoid using `instanceof`, and using
  this type-testing method instead.

  **Parameters**

  - `x` — Any object.

  **Returns:** true if `x` is an object created from a class which extends `Construct`.

- `isOwnedResource(construct: IConstruct): boolean` (static) — Returns true if the construct was created by CDK, and false otherwise.

- `isResource(construct: IConstruct): boolean` (static) — Check whether the given construct is a Resource.

- `toString(): string` — Returns a string representation of this construct.

- `with(...mixins: IMixin[]): IConstruct` — Applies one or more mixins to this construct.

  Mixins are applied in order. The list of constructs is captured at the
  start of the call, so constructs added by a mixin will not be visited.
  Use multiple `with()` calls if subsequent mixins should apply to added
  constructs.