# KeyLookupOptions

Properties for looking up an existing Key.

- Source: [`aws-kms/lib/key-lookup.ts`](https://github.com/aws/aws-cdk/blob/v2.274.0/packages/aws-cdk-lib/aws-kms/lib/key-lookup.ts#L4)
- Type last changed: v2.163.0 · 22 Oct 2024

## Example

```ts
const myKeyLookup = kms.Key.fromLookup(this, 'MyKeyLookup', {
  aliasName: 'alias/KeyAlias',
});

const role = new iam.Role(this, 'MyRole', {
  assumedBy: new iam.ServicePrincipal('lambda.amazonaws.com'),
});
myKeyLookup.grantEncryptDecrypt(role);
```

## Properties

- `aliasName`: string (required) — The alias name of the Key.

  Must be in the format `alias/<AliasName>`.

- `returnDummyKeyOnMissing`: boolean = false — Whether to return a dummy key if the key was not found.

  If it is set to `true` and the key was not found, a dummy
  key with a key id '1234abcd-12ab-34cd-56ef-1234567890ab'
  will be returned. The value of the dummy key id can also
  be referenced using the `Key.DEFAULT_DUMMY_KEY_ID` variable,
  and you can check if the key is a dummy key by using the
  `Key.isLookupDummy()` method.