aws-cdk-lib.aws_kms.Key

class Key (construct)

LanguageType name
.NETAmazon.CDK.AWS.KMS.Key
Gogithub.com/aws/aws-cdk-go/awscdk/v2/awskms#Key
Javasoftware.amazon.awscdk.services.kms.Key
Pythonaws_cdk.aws_kms.Key
TypeScript (source)aws-cdk-lib » aws_kms » Key

Implements IConstruct, IDependable, IResource, IKey

Defines a KMS key.

Example

import * as kms from 'aws-cdk-lib/aws-kms';

const encryptionKey = new kms.Key(this, 'Key', {
  enableKeyRotation: true,
});
const table = new dynamodb.Table(this, 'MyTable', {
  partitionKey: { name: 'id', type: dynamodb.AttributeType.STRING },
  encryption: dynamodb.TableEncryption.CUSTOMER_MANAGED,
  encryptionKey, // This will be exposed as table.encryptionKey
});

Initializer

new Key(scope: Construct, id: string, props?: KeyProps)

Parameters

  • scope Construct
  • id string
  • props KeyProps

Construct Props

NameTypeDescription
admins?IPrincipal[]A list of principals to add as key administrators to the key policy.
alias?stringInitial alias to add to the key.
description?stringA description of the key.
enableKeyRotation?booleanIndicates whether AWS KMS rotates the key.
enabled?booleanIndicates whether the key is available for use.
keySpec?KeySpecThe cryptographic configuration of the key. The valid value depends on usage of the key.
keyUsage?KeyUsageThe cryptographic operations for which the key can be used.
pendingWindow?DurationSpecifies the number of days in the waiting period before AWS KMS deletes a CMK that has been removed from a CloudFormation stack.
policy?PolicyDocumentCustom policy document to attach to the KMS key.
removalPolicy?RemovalPolicyWhether the encryption key should be retained when it is removed from the Stack.

admins?

Type: IPrincipal[] (optional, default: [])

A list of principals to add as key administrators to the key policy.

Key administrators have permissions to manage the key (e.g., change permissions, revoke), but do not have permissions to use the key in cryptographic operations (e.g., encrypt, decrypt).

These principals will be added to the default key policy (if none specified), or to the specified policy (if provided).


alias?

Type: string (optional, default: No alias is added for the key.)

Initial alias to add to the key.

More aliases can be added later by calling addAlias.


description?

Type: string (optional, default: No description.)

A description of the key.

Use a description that helps your users decide whether the key is appropriate for a particular task.


enableKeyRotation?

Type: boolean (optional, default: false)

Indicates whether AWS KMS rotates the key.


enabled?

Type: boolean (optional, default: Key is enabled.)

Indicates whether the key is available for use.


keySpec?

Type: KeySpec (optional, default: KeySpec.SYMMETRIC_DEFAULT)

The cryptographic configuration of the key. The valid value depends on usage of the key.

IMPORTANT: If you change this property of an existing key, the existing key is scheduled for deletion and a new key is created with the specified value.


keyUsage?

Type: KeyUsage (optional, default: KeyUsage.ENCRYPT_DECRYPT)

The cryptographic operations for which the key can be used.

IMPORTANT: If you change this property of an existing key, the existing key is scheduled for deletion and a new key is created with the specified value.


pendingWindow?

Type: Duration (optional, default: 30 days)

Specifies the number of days in the waiting period before AWS KMS deletes a CMK that has been removed from a CloudFormation stack.

When you remove a customer master key (CMK) from a CloudFormation stack, AWS KMS schedules the CMK for deletion and starts the mandatory waiting period. The PendingWindowInDays property determines the length of waiting period. During the waiting period, the key state of CMK is Pending Deletion, which prevents the CMK from being used in cryptographic operations. When the waiting period expires, AWS KMS permanently deletes the CMK.

Enter a value between 7 and 30 days.

See also: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-kms-key.html#cfn-kms-key-pendingwindowindays


policy?

Type: PolicyDocument (optional, default: A policy document with permissions for the account root to administer the key will be created.)

Custom policy document to attach to the KMS key.

NOTE - If the @aws-cdk/aws-kms:defaultKeyPolicies feature flag is set (the default for new projects), this policy will override the default key policy and become the only key policy for the key. If the feature flag is not set, this policy will be appended to the default key policy.


removalPolicy?

Type: RemovalPolicy (optional, default: RemovalPolicy.Retain)

Whether the encryption key should be retained when it is removed from the Stack.

This is useful when one wants to retain access to data that was encrypted with a key that is being retired.

Properties

NameTypeDescription
envResourceEnvironmentThe environment this resource belongs to.
keyArnstringThe ARN of the key.
keyIdstringThe ID of the key (the part that looks something like: 1234abcd-12ab-34cd-56ef-1234567890ab).
nodeNodeThe tree node.
stackStackThe stack in which this resource is defined.
trustAccountIdentitiesbooleanOptional property to control trusting account identities.
policy?PolicyDocumentOptional policy document that represents the resource policy of this key.

env

Type: ResourceEnvironment

The environment this resource belongs to.

For resources that are created and managed by the CDK (generally, those created by creating new class instances like Role, Bucket, etc.), this is always the same as the environment of the stack they belong to; however, for imported resources (those obtained from static methods like fromRoleArn, fromBucketName, etc.), that might be different than the stack they were imported into.


keyArn

Type: string

The ARN of the key.


keyId

Type: string

The ID of the key (the part that looks something like: 1234abcd-12ab-34cd-56ef-1234567890ab).


node

Type: Node

The tree node.


stack

Type: Stack

The stack in which this resource is defined.


trustAccountIdentities

Type: boolean

Optional property to control trusting account identities.

If specified, grants will default identity policies instead of to both resource and identity policies. This matches the default behavior when creating KMS keys via the API or console.


policy?

Type: PolicyDocument (optional)

Optional policy document that represents the resource policy of this key.

If specified, addToResourcePolicy can be used to edit this policy. Otherwise this method will no-op.

Methods

NameDescription
addAlias(aliasName)Defines a new alias for the key.
addToResourcePolicy(statement, allowNoOp?)Adds a statement to the KMS key resource policy.
applyRemovalPolicy(policy)Apply the given removal policy to this resource.
grant(grantee, ...actions)Grant the indicated permissions on this key to the given principal.
grantAdmin(grantee)Grant admins permissions using this key to the given principal.
grantDecrypt(grantee)Grant decryption permissions using this key to the given principal.
grantEncrypt(grantee)Grant encryption permissions using this key to the given principal.
grantEncryptDecrypt(grantee)Grant encryption and decryption permissions using this key to the given principal.
grantGenerateMac(grantee)Grant permissions to generating MACs to the given principal.
grantVerifyMac(grantee)Grant permissions to verifying MACs to the given principal.
toString()Returns a string representation of this construct.
static fromCfnKey(cfnKey)Create a mutable IKey based on a low-level CfnKey.
static fromKeyArn(scope, id, keyArn)Import an externally defined KMS Key using its ARN.
static fromLookup(scope, id, options)Import an existing Key by querying the AWS environment this stack is deployed to.

addAlias(aliasName)

public addAlias(aliasName: string): Alias

Parameters

  • aliasName string

Returns

  • Alias

Defines a new alias for the key.


addToResourcePolicy(statement, allowNoOp?)

public addToResourcePolicy(statement: PolicyStatement, allowNoOp?: boolean): AddToResourcePolicyResult

Parameters

  • statement PolicyStatement — The policy statement to add.
  • allowNoOp boolean — If this is set to false and there is no policy defined (i.e. external key), the operation will fail. Otherwise, it will no-op.

Returns

  • AddToResourcePolicyResult

Adds a statement to the KMS key resource policy.


applyRemovalPolicy(policy)

public applyRemovalPolicy(policy: RemovalPolicy): void

Parameters

  • policy RemovalPolicy

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).


grant(grantee, ...actions)

public grant(grantee: IGrantable, ...actions: string[]): Grant

Parameters

  • grantee IGrantable
  • actions string

Returns

  • Grant

Grant the indicated permissions on this key to the given principal.

This modifies both the principal's policy as well as the resource policy, since the default CloudFormation setup for KMS keys is that the policy must not be empty and so default grants won't work.


grantAdmin(grantee)

public grantAdmin(grantee: IGrantable): Grant

Parameters

  • grantee IGrantable

Returns

  • Grant

Grant admins permissions using this key to the given principal.

Key administrators have permissions to manage the key (e.g., change permissions, revoke), but do not have permissions to use the key in cryptographic operations (e.g., encrypt, decrypt).


grantDecrypt(grantee)

public grantDecrypt(grantee: IGrantable): Grant

Parameters

  • grantee IGrantable

Returns

  • Grant

Grant decryption permissions using this key to the given principal.


grantEncrypt(grantee)

public grantEncrypt(grantee: IGrantable): Grant

Parameters

  • grantee IGrantable

Returns

  • Grant

Grant encryption permissions using this key to the given principal.


grantEncryptDecrypt(grantee)

public grantEncryptDecrypt(grantee: IGrantable): Grant

Parameters

  • grantee IGrantable

Returns

  • Grant

Grant encryption and decryption permissions using this key to the given principal.


grantGenerateMac(grantee)

public grantGenerateMac(grantee: IGrantable): Grant

Parameters

  • grantee IGrantable

Returns

  • Grant

Grant permissions to generating MACs to the given principal.


grantVerifyMac(grantee)

public grantVerifyMac(grantee: IGrantable): Grant

Parameters

  • grantee IGrantable

Returns

  • Grant

Grant permissions to verifying MACs to the given principal.


toString()

public toString(): string

Returns

  • string

Returns a string representation of this construct.


static fromCfnKey(cfnKey)

public static fromCfnKey(cfnKey: CfnKey): IKey

Parameters

  • cfnKey CfnKey

Returns

  • IKey

Create a mutable IKey based on a low-level CfnKey.

This is most useful when combined with the cloudformation-include module. This method is different than fromKeyArn() because the IKey returned from this method is mutable; meaning, calling any mutating methods on it, like IKey.addToResourcePolicy(), will actually be reflected in the resulting template, as opposed to the object returned from fromKeyArn(), on which calling those methods would have no effect.


static fromKeyArn(scope, id, keyArn)

public static fromKeyArn(scope: Construct, id: string, keyArn: string): IKey

Parameters

  • scope Construct — the construct that will "own" the imported key.
  • id string — the id of the imported key in the construct tree.
  • keyArn string — the ARN of an existing KMS key.

Returns

  • IKey

Import an externally defined KMS Key using its ARN.


static fromLookup(scope, id, options)

public static fromLookup(scope: Construct, id: string, options: KeyLookupOptions): IKey

Parameters

  • scope Construct
  • id string
  • options KeyLookupOptions

Returns

  • IKey

Import an existing Key by querying the AWS environment this stack is deployed to.

This function only needs to be used to use Keys not defined in your CDK application. If you are looking to share a Key between stacks, you can pass the Key object between stacks and use it as normal. In addition, it's not necessary to use this method if an interface accepts an IKey. In this case, Alias.fromAliasName() can be used which returns an alias that extends IKey.

Calling this method will lead to a lookup when the CDK CLI is executed. You can therefore not use any values that will only be available at CloudFormation execution time (i.e., Tokens).

The Key information will be cached in cdk.context.json and the same Key will be used on future runs. To refresh the lookup, you will have to evict the value from the cache using the cdk context command. See https://docs.aws.amazon.com/cdk/latest/guide/context.html for more information.