# ViaServicePrincipal

A principal to allow access to a key if it's being used through another AWS service.

Extends: PrincipalBase › ViaServicePrincipal
Implements: IAssumeRolePrincipal, IComparablePrincipal, IGrantable, IPrincipal

- Source: [`aws-kms/lib/via-service-principal.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/aws-kms/lib/via-service-principal.ts#L6)
- Type last changed: v2.26.0 · 30 May 2022

## Example

```ts
// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
import { aws_iam as iam } from 'aws-cdk-lib';
import { aws_kms as kms } from 'aws-cdk-lib';

declare const principal: iam.IPrincipal;
const viaServicePrincipal = new kms.ViaServicePrincipal('serviceName', /* all optional props */ principal);
```

## Initializer

```ts
new ViaServicePrincipal(serviceName: string, basePrincipal?: IPrincipal)
```

## Properties

- `assumeRoleAction`: string — When this Principal is used in an AssumeRole policy, the action to use.

- `grantPrincipal`: [IPrincipal](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.IPrincipal.html) — The principal to grant permissions to.

- `policyFragment`: [PrincipalPolicyFragment](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.PrincipalPolicyFragment.html) — Return the policy fragment that identifies this principal in a Policy.

- `principalAccount`: string — The AWS account ID of this principal.

  Can be undefined when the account is not known
  (for example, for service principals).
  Can be a Token - in that case,
  it's assumed to be AWS::AccountId.

## Methods

- `addToAssumeRolePolicy(document: PolicyDocument): void` — Add the principal to the AssumeRolePolicyDocument.

  Add the statements to the AssumeRolePolicyDocument necessary to give this principal
  permissions to assume the given role.

- `addToPolicy(statement: PolicyStatement): boolean` — Add to the policy of this principal.

- `addToPrincipalPolicy(_statement: PolicyStatement): AddToPrincipalPolicyResult` — Add to the policy of this principal.

- `dedupeString(): string` — Return whether or not this principal is equal to the given principal.

- `toJSON(): { [key: string]: string[] }` — JSON-ify the principal.

  Used when JSON.stringify() is called

- `toString(): string` — Returns a string representation of an object.

- `withConditions(conditions: { [key: string]: any }): PrincipalBase` — Returns a new PrincipalWithConditions using this principal as the base, with the passed conditions added.

  When there is a value for the same operator and key in both the principal and the
  conditions parameter, the value from the conditions parameter will be used.

  **Returns:** a new PrincipalWithConditions object.

- `withSessionTags(): PrincipalBase` — Returns a new principal using this principal as the base, with session tags enabled.

  **Returns:** a new SessionTagsPrincipal object.