aws-elixir v0.4.0 AWS.KMS
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.
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 (root) 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:
- [AWS Security Credentials](http://docs.aws.amazon.com/general/latest/gr/aws-security-credentials.html) - This topic provides general information about the types of credentials used for accessing AWS.
- [Temporary Security Credentials](http://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_temp.html) - This section of the *IAM User Guide* describes how to create and use temporary security credentials.
- [Signature Version 4 Signing Process](http://docs.aws.amazon.com/general/latest/gr/signature-version-4.html) - This set of topics walks you through the process of signing a request using an access key ID and a secret access key.
- `Encrypt`
- `Decrypt`
- `GenerateDataKey`
- `GenerateDataKeyWithoutPlaintext`
Summary
Functions
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
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)
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
Creates a customer master key (CMK)
Decrypts ciphertext. Ciphertext is plaintext that has been previously encrypted by using any of the following functions
Deletes the specified alias. To map an alias to a different key, call
UpdateAlias
Deletes key material that you previously imported and makes the specified customer master key (CMK) unusable. For more information about importing key material into AWS KMS, see Importing Key Material in the AWS Key Management Service Developer Guide
Provides detailed information about the specified customer master key
Sets the state of a customer master key (CMK) to disabled, thereby preventing its use for cryptographic operations. For more information about how key state affects the use of a CMK, see How Key State Affects the Use of a Customer Master Key in the AWS Key Management Service Developer Guide
Disables rotation of the specified key
Marks a key as enabled, thereby permitting its use
Enables rotation of the specified customer master key
Encrypts plaintext into ciphertext by using a customer master key. The
Encrypt
function has two primary use cases
Returns a data encryption key that you can use in your application to encrypt data locally
Returns a data encryption key encrypted under a customer master key (CMK).
This operation is identical to GenerateDataKey
but returns only the
encrypted copy of the data key
Generates an unpredictable byte string
Retrieves a policy attached to the specified key
Retrieves a Boolean value that indicates whether key rotation is enabled for the specified key
Returns the items you need in order to import key material into AWS KMS from your existing key management infrastructure. For more information about importing key material into AWS KMS, see Importing Key Material in the AWS Key Management Service Developer Guide
Imports key material into an AWS KMS customer master key (CMK) from your existing key management infrastructure. For more information about importing key material into AWS KMS, see Importing Key Material in the AWS Key Management Service Developer Guide
Lists all of the key aliases in the account
List the grants for a specified key
Retrieves a list of policies attached to a key
Lists the customer master keys
Returns a list of all tags for the specified customer master key (CMK)
Returns a list of all grants for which the grant’s RetiringPrincipal
matches the one specified
Attaches a key policy to the specified customer master key (CMK)
Encrypts data on the server side with a new customer master key (CMK) without exposing the plaintext of the data on the client side. The data is first decrypted and then reencrypted. You can also use this operation to change the encryption context of a ciphertext
Retires a grant. To clean up, you can retire a grant when you’re done using it. You should revoke a grant when you intend to actively deny operations that depend on it. The following are permitted to call this API
Revokes a grant. You can revoke a grant to actively deny operations that depend on it
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
refer to it
Adds or overwrites one or more tags for the specified customer master key (CMK)
Removes the specified tag or tags from the specified customer master key (CMK)
Updates an alias to map it to a different key
Updates the description of a customer master key (CMK)
Functions
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, see Deleting Customer Master Keys in the AWS Key Management Service Developer Guide.
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
.
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.
Creates a customer master key (CMK).
You can use a CMK to encrypt small amounts of data (4 KiB or less) directly, but CMKs are more commonly used to encrypt data encryption keys (DEKs), which are used to encrypt raw data. For more information about DEKs and the difference between CMKs and DEKs, see the following:
- The `GenerateDataKey` operation
- [AWS Key Management Service Concepts](http://docs.aws.amazon.com/kms/latest/developerguide/concepts.html) in the *AWS Key Management Service Developer Guide*
Decrypts ciphertext. Ciphertext is plaintext that has been previously encrypted by using any of the following functions:
- `GenerateDataKey`
- `GenerateDataKeyWithoutPlaintext`
- `Encrypt`
Deletes the specified alias. To map an alias to a different key, call
UpdateAlias
.
Deletes key material that you previously imported and makes the specified customer master key (CMK) unusable. For more information about importing key material into AWS KMS, see Importing Key Material in the AWS Key Management Service Developer Guide.
When the specified CMK is in the PendingDeletion
state, this operation
does not change the CMK’s state. Otherwise, it changes the CMK’s state to
PendingImport
.
After you delete key material, you can use ImportKeyMaterial
to reimport
the same key material into the CMK.
Provides detailed information about the specified customer master key.
Sets the state of a customer master key (CMK) to disabled, thereby preventing its use for cryptographic operations. For more information about how key state affects the use of a CMK, see How Key State Affects the Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Enables rotation of the specified customer master key.
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.
Returns a data encryption key that you can use in your application to encrypt data locally.
You must specify the customer master key (CMK) under which to generate the
data key. You must also specify the length of the data key using either the
KeySpec
or NumberOfBytes
field. You must specify one field or the
other, but not both. For common key lengths (128-bit and 256-bit symmetric
keys), we recommend that you use KeySpec
.
This operation returns a plaintext copy of the data key in the Plaintext
field of the response, and an encrypted copy of the data key in the
CiphertextBlob
field. The data key is encrypted under the CMK specified
in the KeyId
field of the request.
We recommend that you use the following pattern to encrypt data locally in your application:
- Use this operation (`GenerateDataKey`) to retrieve a data encryption key.
- Use the plaintext data encryption key (returned in the `Plaintext` field of the response) to encrypt data locally, then erase the plaintext data key from memory.
- Store the encrypted data key (returned in the `CiphertextBlob` field of the response) alongside the locally encrypted data.
- Use the `Decrypt` operation to decrypt the encrypted data key into a plaintext copy of the data key.
- Use the plaintext data key to decrypt data locally, then erase the plaintext data key from memory.
Returns a data encryption key encrypted under a customer master key (CMK).
This operation is identical to GenerateDataKey
but returns only the
encrypted copy of the data key.
This operation is useful in a system that has multiple components with
different degrees of trust. For example, consider a system that stores
encrypted data in containers. Each container stores the encrypted data and
an encrypted copy of the data key. One component of the system, called the
control plane, creates new containers. When it creates a new container,
it uses this operation (GenerateDataKeyWithoutPlaintext
) to get an
encrypted data key and then stores it in the container. Later, a different
component of the system, called the data plane, puts encrypted data into
the containers. To do this, it passes the encrypted data key to the
Decrypt
operation, then uses the returned plaintext data key to encrypt
data, and finally stores the encrypted data in the container. In this
system, the control plane never sees the plaintext data key.
Retrieves a Boolean value that indicates whether key rotation is enabled for the specified key.
Returns the items you need in order to import key material into AWS KMS from your existing key management infrastructure. For more information about importing key material into AWS KMS, see Importing Key Material in the AWS Key Management Service Developer Guide.
You must specify the key ID of the customer master key (CMK) into which you
will import key material. This CMK’s Origin
must be EXTERNAL
. You must
also specify the wrapping algorithm and type of wrapping key (public key)
that you will use to encrypt the key material.
This operation returns a public key and an import token. Use the public key
to encrypt the key material. Store the import token to send with a
subsequent ImportKeyMaterial
request. The public key and import token
from the same response must be used together. These items are valid for 24
hours, after which they cannot be used for a subsequent ImportKeyMaterial
request. To retrieve new ones, send another GetParametersForImport
request.
Imports key material into an AWS KMS customer master key (CMK) from your existing key management infrastructure. For more information about importing key material into AWS KMS, see Importing Key Material in the AWS Key Management Service Developer Guide.
You must specify the key ID of the CMK to import the key material into.
This CMK’s Origin
must be EXTERNAL
. You must also send an import token
and the encrypted key material. Send the import token that you received in
the same GetParametersForImport
response that contained the public key
that you used to encrypt the key material. You must also specify whether
the key material expires and if so, when. When the key material expires,
AWS KMS deletes the key material and the CMK becomes unusable. To use the
CMK again, you can reimport the same key material. If you set an expiration
date, you can change it only by reimporting the same key material and
specifying a new expiration date.
When this operation is successful, the specified CMK’s key state changes to
Enabled
, and you can use the CMK.
After you successfully import key material into a CMK, you can reimport the same key material into that CMK, but you cannot import different key material.
Returns a list of all tags for the specified customer master key (CMK).
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
.
Attaches a key policy to the specified customer master key (CMK).
For more information about key policies, see Key Policies in the AWS Key Management Service Developer Guide.
Encrypts data on the server side with a new customer master key (CMK) without exposing the plaintext of the data on the client side. The data is first decrypted and then reencrypted. You can also use this operation to change the encryption context of a ciphertext.
Unlike other operations, ReEncrypt
is authorized twice, once as
ReEncryptFrom
on the source CMK and once as ReEncryptTo
on the
destination CMK. We recommend that you include the "kms:ReEncrypt*"
permission in your key
policies
to permit reencryption from or to the CMK. This permission is automatically
included in the key policy when you create a CMK through the console, but
you must include it manually when you create a CMK programmatically or when
you set a key policy with the PutKeyPolicy
operation.
Retires a grant. To clean up, you can retire a grant when you’re done using it. 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 AWS account (root user) under which the grant was created
- The `RetiringPrincipal`, if present in the grant
- The `GranteePrincipal`, if `RetireGrant` is an operation specified in the grant
Revokes a grant. You can revoke a grant to actively deny operations that depend on it.
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
refer to it.
Deleting Customer Master Keys in the AWS Key Management Service Developer Guide.
Adds or overwrites one or more tags for the specified customer master key (CMK).
Each tag consists of a tag key and a tag value. Tag keys and tag values are both required, but tag values can be empty (null) strings.
You cannot use the same tag key more than once per CMK. For example,
consider a CMK with one tag whose tag key is Purpose
and tag value is
Test
. If you send a TagResource
request for this CMK with a tag key of
Purpose
and a tag value of Prod
, it does not create a second tag.
Instead, the original tag is overwritten with the new tag value.
Removes the specified tag or tags from the specified customer master key (CMK).
To remove a tag, you specify the tag key for each tag to remove. You do not
specify the tag value. To overwrite the tag value for an existing tag, use
TagResource
.
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.