AWS SDK Version 2 for .NET
API Reference

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.NET Framework 4.5
 
Interface for accessing KeyManagementService AWS Key Management Service

AWS Key Management Service (AWS KMS) is an encryption and key management web service. This guide describes the AWS KMS operations that you can call programmatically. For general information about AWS KMS, see the AWS Key Management Service Developer Guide.

AWS provides SDKs that consist of libraries and sample code for various programming languages and platforms (Java, Ruby, .Net, iOS, Android, etc.). The SDKs provide a convenient way to create programmatic access to AWS KMS and other AWS services. For example, the SDKs take care of tasks such as signing requests (see below), managing errors, and retrying requests automatically. For more information about the AWS SDKs, including how to download and install them, see Tools for Amazon Web Services.

We recommend that you use the AWS SDKs to make programmatic API calls to AWS KMS.

Clients must support TLS (Transport Layer Security) 1.0. We recommend TLS 1.2. Clients must also support cipher suites with Perfect Forward Secrecy (PFS) such as Ephemeral Diffie-Hellman (DHE) or Elliptic Curve Ephemeral Diffie-Hellman (ECDHE). Most modern systems such as Java 7 and later support these modes.

Signing Requests

Requests must be signed by using an access key ID and a secret access key. We strongly recommend that you do not use your AWS account access key ID and secret key for everyday work with AWS KMS. Instead, use the access key ID and secret access key for an IAM user, or you can use the AWS Security Token Service to generate temporary security credentials that you can use to sign requests.

All AWS KMS operations require Signature Version 4.

Logging API Requests

AWS KMS supports AWS CloudTrail, a service that logs AWS API calls and related events for your AWS account and delivers them to an Amazon S3 bucket that you specify. By using the information collected by CloudTrail, you can determine what requests were made to AWS KMS, who made the request, when it was made, and so on. To learn more about CloudTrail, including how to turn it on and find your log files, see the AWS CloudTrail User Guide.

Additional Resources

For more information about credentials and request signing, see the following:

Commonly Used APIs

Of the APIs discussed in this guide, the following will prove the most useful for most applications. You will likely perform actions other than these, such as creating keys and assigning policies, by using the console.

Inheritance Hierarchy

Amazon.KeyManagementService.IAmazonKeyManagementService

Namespace: Amazon.KeyManagementService
Assembly: AWSSDK.dll
Version: (assembly version)

Syntax

C#
public interface IAmazonKeyManagementService
         IDisposable

The IAmazonKeyManagementService type exposes the following members

Methods

NameDescription
Public Method CancelKeyDeletion(string) Cancels the deletion of a customer master key (CMK). When this operation is successful, the CMK is set to the Disabled state. To enable a CMK, use EnableKey.

For more information about scheduling and canceling deletion of a CMK, go to Deleting Customer Master Keys in the AWS Key Management Service Developer Guide.

Public Method CancelKeyDeletion(CancelKeyDeletionRequest) Cancels the deletion of a customer master key (CMK). When this operation is successful, the CMK is set to the Disabled state. To enable a CMK, use EnableKey.

For more information about scheduling and canceling deletion of a CMK, go to Deleting Customer Master Keys in the AWS Key Management Service Developer Guide.

Public Method CancelKeyDeletionAsync(CancelKeyDeletionRequest, CancellationToken) Initiates the asynchronous execution of the CancelKeyDeletion operation.
Public Method CreateAlias(string, string) Creates a display name for a customer master key. An alias can be used to identify a key and should be unique. The console enforces a one-to-one mapping between the alias and a key. An alias name can contain only alphanumeric characters, forward slashes (/), underscores (_), and dashes (-). An alias must start with the word "alias" followed by a forward slash (alias/). An alias that begins with "aws" after the forward slash (alias/aws...) is reserved by Amazon Web Services (AWS).

The alias and the key it is mapped to must be in the same AWS account and the same region.

To map an alias to a different key, call UpdateAlias.

Public Method CreateAlias(CreateAliasRequest) Creates a display name for a customer master key. An alias can be used to identify a key and should be unique. The console enforces a one-to-one mapping between the alias and a key. An alias name can contain only alphanumeric characters, forward slashes (/), underscores (_), and dashes (-). An alias must start with the word "alias" followed by a forward slash (alias/). An alias that begins with "aws" after the forward slash (alias/aws...) is reserved by Amazon Web Services (AWS).

The alias and the key it is mapped to must be in the same AWS account and the same region.

To map an alias to a different key, call UpdateAlias.

Public Method CreateAliasAsync(CreateAliasRequest, CancellationToken) Initiates the asynchronous execution of the CreateAlias operation.
Public Method CreateGrant(CreateGrantRequest) Adds a grant to a key to specify who can use the key and under what conditions. Grants are alternate permission mechanisms to key policies.

For more information about grants, see Grants in the AWS Key Management Service Developer Guide.

Public Method CreateGrantAsync(CreateGrantRequest, CancellationToken) Initiates the asynchronous execution of the CreateGrant operation.
Public Method CreateKey(CreateKeyRequest) Creates a customer master key. Customer master keys can be used to encrypt small amounts of data (less than 4K) directly, but they are most commonly used to encrypt or envelope data keys that are then used to encrypt customer data. For more information about data keys, see GenerateDataKey and GenerateDataKeyWithoutPlaintext.
Public Method CreateKeyAsync(CreateKeyRequest, CancellationToken) Initiates the asynchronous execution of the CreateKey operation.
Public Method Decrypt(DecryptRequest) Decrypts ciphertext. Ciphertext is plaintext that has been previously encrypted by using any of the following functions:

Note that if a caller has been granted access permissions to all keys (through, for example, IAM user policies that grant Decrypt permission on all resources), then ciphertext encrypted by using keys in other accounts where the key grants access to the caller can be decrypted. To remedy this, we recommend that you do not grant Decrypt access in an IAM user policy. Instead grant Decrypt access only in key policies. If you must grant Decrypt access in an IAM user policy, you should scope the resource to specific keys or to specific trusted accounts.

Public Method DecryptAsync(DecryptRequest, CancellationToken) Initiates the asynchronous execution of the Decrypt operation.
Public Method DeleteAlias(string) Deletes the specified alias. To map an alias to a different key, call UpdateAlias.
Public Method DeleteAlias(DeleteAliasRequest) Deletes the specified alias. To map an alias to a different key, call UpdateAlias.
Public Method DeleteAliasAsync(DeleteAliasRequest, CancellationToken) Initiates the asynchronous execution of the DeleteAlias operation.
Public Method DescribeKey(string) Provides detailed information about the specified customer master key.
Public Method DescribeKey(DescribeKeyRequest) Provides detailed information about the specified customer master key.
Public Method DescribeKeyAsync(DescribeKeyRequest, CancellationToken) Initiates the asynchronous execution of the DescribeKey operation.
Public Method DisableKey(string) Sets the state of a master key to disabled, thereby preventing its use for cryptographic operations. For more information about how key state affects the use of a master key, go to How Key State Affects the Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Public Method DisableKey(DisableKeyRequest) Sets the state of a master key to disabled, thereby preventing its use for cryptographic operations. For more information about how key state affects the use of a master key, go to How Key State Affects the Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Public Method DisableKeyAsync(DisableKeyRequest, CancellationToken) Initiates the asynchronous execution of the DisableKey operation.
Public Method DisableKeyRotation(string) Disables rotation of the specified key.
Public Method DisableKeyRotation(DisableKeyRotationRequest) Disables rotation of the specified key.
Public Method DisableKeyRotationAsync(DisableKeyRotationRequest, CancellationToken) Initiates the asynchronous execution of the DisableKeyRotation operation.
Public Method EnableKey(string) Marks a key as enabled, thereby permitting its use.
Public Method EnableKey(EnableKeyRequest) Marks a key as enabled, thereby permitting its use.
Public Method EnableKeyAsync(EnableKeyRequest, CancellationToken) Initiates the asynchronous execution of the EnableKey operation.
Public Method EnableKeyRotation(string) Enables rotation of the specified customer master key.
Public Method EnableKeyRotation(EnableKeyRotationRequest) Enables rotation of the specified customer master key.
Public Method EnableKeyRotationAsync(EnableKeyRotationRequest, CancellationToken) Initiates the asynchronous execution of the EnableKeyRotation operation.
Public Method Encrypt(EncryptRequest) Encrypts plaintext into ciphertext by using a customer master key. The Encrypt function has two primary use cases:
  • You can encrypt up to 4 KB of arbitrary data such as an RSA key, a database password, or other sensitive customer information.
  • If you are moving encrypted data from one region to another, you can use this API to encrypt in the new region the plaintext data key that was used to encrypt the data in the original region. This provides you with an encrypted copy of the data key that can be decrypted in the new region and used there to decrypt the encrypted data.

Unless you are moving encrypted data from one region to another, you don't use this function to encrypt a generated data key within a region. You retrieve data keys already encrypted by calling the GenerateDataKey or GenerateDataKeyWithoutPlaintext function. Data keys don't need to be encrypted again by calling Encrypt.

If you want to encrypt data locally in your application, you can use the GenerateDataKey function to return a plaintext data encryption key and a copy of the key encrypted under the customer master key (CMK) of your choosing.

Public Method EncryptAsync(EncryptRequest, CancellationToken) Initiates the asynchronous execution of the Encrypt operation.
Public Method GenerateDataKey(GenerateDataKeyRequest) Generates a data key that you can use in your application to locally encrypt data. This call returns a plaintext version of the key in the Plaintext field of the response object and an encrypted copy of the key in the CiphertextBlob field. The key is encrypted by using the master key specified by the KeyId field. To decrypt the encrypted key, pass it to the Decrypt API.

We recommend that you use the following pattern to locally encrypt data: call the GenerateDataKey API, use the key returned in the Plaintext response field to locally encrypt data, and then erase the plaintext data key from memory. Store the encrypted data key (contained in the CiphertextBlob field) alongside of the locally encrypted data.

You should not call the Encrypt function to re-encrypt your data keys within a region. GenerateDataKey always returns the data key encrypted and tied to the customer master key that will be used to decrypt it. There is no need to decrypt it twice.

If you decide to use the optional EncryptionContext parameter, you must also store the context in full or at least store enough information along with the encrypted data to be able to reconstruct the context when submitting the ciphertext to the Decrypt API. It is a good practice to choose a context that you can reconstruct on the fly to better secure the ciphertext. For more information about how this parameter is used, see Encryption Context.

To decrypt data, pass the encrypted data key to the Decrypt API. Decrypt uses the associated master key to decrypt the encrypted data key and returns it as plaintext. Use the plaintext data key to locally decrypt your data and then erase the key from memory. You must specify the encryption context, if any, that you specified when you generated the key. The encryption context is logged by CloudTrail, and you can use this log to help track the use of particular data.

Public Method GenerateDataKeyAsync(GenerateDataKeyRequest, CancellationToken) Initiates the asynchronous execution of the GenerateDataKey operation.
Public Method GenerateDataKeyWithoutPlaintext(GenerateDataKeyWithoutPlaintextRequest) Returns a data key encrypted by a customer master key without the plaintext copy of that key. Otherwise, this API functions exactly like GenerateDataKey. You can use this API to, for example, satisfy an audit requirement that an encrypted key be made available without exposing the plaintext copy of that key.
Public Method GenerateDataKeyWithoutPlaintextAsync(GenerateDataKeyWithoutPlaintextRequest, CancellationToken) Initiates the asynchronous execution of the GenerateDataKeyWithoutPlaintext operation.
Public Method GenerateRandom(int) Generates an unpredictable byte string.
Public Method GenerateRandom(GenerateRandomRequest) Generates an unpredictable byte string.
Public Method GenerateRandomAsync(GenerateRandomRequest, CancellationToken) Initiates the asynchronous execution of the GenerateRandom operation.
Public Method GetKeyPolicy(string, string) Retrieves a policy attached to the specified key.
Public Method GetKeyPolicy(GetKeyPolicyRequest) Retrieves a policy attached to the specified key.
Public Method GetKeyPolicyAsync(GetKeyPolicyRequest, CancellationToken) Initiates the asynchronous execution of the GetKeyPolicy operation.
Public Method GetKeyRotationStatus(string) Retrieves a Boolean value that indicates whether key rotation is enabled for the specified key.
Public Method GetKeyRotationStatus(GetKeyRotationStatusRequest) Retrieves a Boolean value that indicates whether key rotation is enabled for the specified key.
Public Method GetKeyRotationStatusAsync(GetKeyRotationStatusRequest, CancellationToken) Initiates the asynchronous execution of the GetKeyRotationStatus operation.
Public Method ListAliases(ListAliasesRequest) Lists all of the key aliases in the account.
Public Method ListAliasesAsync(ListAliasesRequest, CancellationToken) Initiates the asynchronous execution of the ListAliases operation.
Public Method ListGrants(ListGrantsRequest) List the grants for a specified key.
Public Method ListGrantsAsync(ListGrantsRequest, CancellationToken) Initiates the asynchronous execution of the ListGrants operation.
Public Method ListKeyPolicies(ListKeyPoliciesRequest) Retrieves a list of policies attached to a key.
Public Method ListKeyPoliciesAsync(ListKeyPoliciesRequest, CancellationToken) Initiates the asynchronous execution of the ListKeyPolicies operation.
Public Method ListKeys(ListKeysRequest) Lists the customer master keys.
Public Method ListKeysAsync(ListKeysRequest, CancellationToken) Initiates the asynchronous execution of the ListKeys operation.
Public Method ListRetirableGrants(string) Returns a list of all grants for which the grant's RetiringPrincipal matches the one specified.

A typical use is to list all grants that you are able to retire. To retire a grant, use RetireGrant.

Public Method ListRetirableGrants() Returns a list of all grants for which the grant's RetiringPrincipal matches the one specified.

A typical use is to list all grants that you are able to retire. To retire a grant, use RetireGrant.

Public Method ListRetirableGrants(ListRetirableGrantsRequest) Returns a list of all grants for which the grant's RetiringPrincipal matches the one specified.

A typical use is to list all grants that you are able to retire. To retire a grant, use RetireGrant.

Public Method ListRetirableGrantsAsync(ListRetirableGrantsRequest, CancellationToken) Initiates the asynchronous execution of the ListRetirableGrants operation.
Public Method PutKeyPolicy(string, string, string) Attaches a policy to the specified key.
Public Method PutKeyPolicy(PutKeyPolicyRequest) Attaches a policy to the specified key.
Public Method PutKeyPolicyAsync(PutKeyPolicyRequest, CancellationToken) Initiates the asynchronous execution of the PutKeyPolicy operation.
Public Method ReEncrypt(ReEncryptRequest) Encrypts data on the server side with a new customer master key without exposing the plaintext of the data on the client side. The data is first decrypted and then encrypted. This operation can also be used to change the encryption context of a ciphertext.

Unlike other actions, ReEncrypt is authorized twice - once as ReEncryptFrom on the source key and once as ReEncryptTo on the destination key. We therefore recommend that you include the "action":"kms:ReEncrypt*" statement in your key policies to permit re-encryption from or to the key. The statement is included automatically when you authorize use of the key through the console but must be included manually when you set a policy by using the PutKeyPolicy function.

Public Method ReEncryptAsync(ReEncryptRequest, CancellationToken) Initiates the asynchronous execution of the ReEncrypt operation.
Public Method RetireGrant(string) Retires a grant. You can retire a grant when you're done using it to clean up. You should revoke a grant when you intend to actively deny operations that depend on it. The following are permitted to call this API:
  • The account that created the grant
  • The RetiringPrincipal, if present
  • The GranteePrincipal, if RetireGrant is a grantee operation
The grant to retire must be identified by its grant token or by a combination of the key ARN and the grant ID. A grant token is a unique variable-length base64-encoded string. A grant ID is a 64 character unique identifier of a grant. Both are returned by the CreateGrant function.
Public Method RetireGrant(RetireGrantRequest) Retires a grant. You can retire a grant when you're done using it to clean up. You should revoke a grant when you intend to actively deny operations that depend on it. The following are permitted to call this API:
  • The account that created the grant
  • The RetiringPrincipal, if present
  • The GranteePrincipal, if RetireGrant is a grantee operation
The grant to retire must be identified by its grant token or by a combination of the key ARN and the grant ID. A grant token is a unique variable-length base64-encoded string. A grant ID is a 64 character unique identifier of a grant. Both are returned by the CreateGrant function.
Public Method RetireGrantAsync(RetireGrantRequest, CancellationToken) Initiates the asynchronous execution of the RetireGrant operation.
Public Method RevokeGrant(string, string) Revokes a grant. You can revoke a grant to actively deny operations that depend on it.
Public Method RevokeGrant(RevokeGrantRequest) Revokes a grant. You can revoke a grant to actively deny operations that depend on it.
Public Method RevokeGrantAsync(RevokeGrantRequest, CancellationToken) Initiates the asynchronous execution of the RevokeGrant operation.
Public Method ScheduleKeyDeletion(string) Schedules the deletion of a customer master key (CMK). You may provide a waiting period, specified in days, before deletion occurs. If you do not provide a waiting period, the default period of 30 days is used. When this operation is successful, the state of the CMK changes to PendingDeletion. Before the waiting period ends, you can use CancelKeyDeletion to cancel the deletion of the CMK. After the waiting period ends, AWS KMS deletes the CMK and all AWS KMS data associated with it, including all aliases that point to it.

Deleting a CMK is a destructive and potentially dangerous operation. When a CMK is deleted, all data that was encrypted under the CMK is rendered unrecoverable. To restrict the use of a CMK without deleting it, use DisableKey.

For more information about scheduling a CMK for deletion, go to Deleting Customer Master Keys in the AWS Key Management Service Developer Guide.

Public Method ScheduleKeyDeletion(string, int) Schedules the deletion of a customer master key (CMK). You may provide a waiting period, specified in days, before deletion occurs. If you do not provide a waiting period, the default period of 30 days is used. When this operation is successful, the state of the CMK changes to PendingDeletion. Before the waiting period ends, you can use CancelKeyDeletion to cancel the deletion of the CMK. After the waiting period ends, AWS KMS deletes the CMK and all AWS KMS data associated with it, including all aliases that point to it.

Deleting a CMK is a destructive and potentially dangerous operation. When a CMK is deleted, all data that was encrypted under the CMK is rendered unrecoverable. To restrict the use of a CMK without deleting it, use DisableKey.

For more information about scheduling a CMK for deletion, go to Deleting Customer Master Keys in the AWS Key Management Service Developer Guide.

Public Method ScheduleKeyDeletion(ScheduleKeyDeletionRequest) Schedules the deletion of a customer master key (CMK). You may provide a waiting period, specified in days, before deletion occurs. If you do not provide a waiting period, the default period of 30 days is used. When this operation is successful, the state of the CMK changes to PendingDeletion. Before the waiting period ends, you can use CancelKeyDeletion to cancel the deletion of the CMK. After the waiting period ends, AWS KMS deletes the CMK and all AWS KMS data associated with it, including all aliases that point to it.

Deleting a CMK is a destructive and potentially dangerous operation. When a CMK is deleted, all data that was encrypted under the CMK is rendered unrecoverable. To restrict the use of a CMK without deleting it, use DisableKey.

For more information about scheduling a CMK for deletion, go to Deleting Customer Master Keys in the AWS Key Management Service Developer Guide.

Public Method ScheduleKeyDeletionAsync(ScheduleKeyDeletionRequest, CancellationToken) Initiates the asynchronous execution of the ScheduleKeyDeletion operation.
Public Method UpdateAlias(string, string) Updates an alias to map it to a different key.

An alias is not a property of a key. Therefore, an alias can be mapped to and unmapped from an existing key without changing the properties of the key.

An alias name can contain only alphanumeric characters, forward slashes (/), underscores (_), and dashes (-). An alias must start with the word "alias" followed by a forward slash (alias/). An alias that begins with "aws" after the forward slash (alias/aws...) is reserved by Amazon Web Services (AWS).

The alias and the key it is mapped to must be in the same AWS account and the same region.

Public Method UpdateAlias(UpdateAliasRequest) Updates an alias to map it to a different key.

An alias is not a property of a key. Therefore, an alias can be mapped to and unmapped from an existing key without changing the properties of the key.

An alias name can contain only alphanumeric characters, forward slashes (/), underscores (_), and dashes (-). An alias must start with the word "alias" followed by a forward slash (alias/). An alias that begins with "aws" after the forward slash (alias/aws...) is reserved by Amazon Web Services (AWS).

The alias and the key it is mapped to must be in the same AWS account and the same region.

Public Method UpdateAliasAsync(UpdateAliasRequest, CancellationToken) Initiates the asynchronous execution of the UpdateAlias operation.
Public Method UpdateKeyDescription(string, string) Updates the description of a key.
Public Method UpdateKeyDescription(UpdateKeyDescriptionRequest) Updates the description of a key.
Public Method UpdateKeyDescriptionAsync(UpdateKeyDescriptionRequest, CancellationToken) Initiates the asynchronous execution of the UpdateKeyDescription operation.

Version Information

.NET Framework:
Supported in: 4.5, 4.0, 3.5

.NET for Windows Store apps:
Supported in: Windows 8.1, Windows 8

.NET for Windows Phone:
Supported in: Windows Phone 8.1, Windows Phone 8