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 .
AWS provides SDKs that consist of libraries and sample code for various programming languages and platforms (Java, Ruby, .Net, macOS, 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 (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. You can also 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 - This topic provides general information about the types of credentials used for accessing AWS.
Temporary Security Credentials - This section of the IAM User Guide describes how to create and use temporary security credentials.
Signature Version 4 Signing Process - This set of topics walks you through the process of signing a request using an access key ID and a secret access key.
Commonly Used API Operations
Of the API operations discussed in this guide, the following will prove the most useful for most applications. You will likely perform operations other than these, such as creating keys and assigning policies, by using the console.
Encrypt
Decrypt
GenerateDataKey
GenerateDataKeyWithoutPlaintext
Summary
Functions
-
cancel_key_deletion(Client, Input)
Cancels the deletion of a customer master key (CMK).
- cancel_key_deletion(Client, Input, Options)
-
connect_custom_key_store(Client, Input)
Connects or reconnects a custom key store to its associated AWS CloudHSM cluster.
- connect_custom_key_store(Client, Input, Options)
-
create_alias(Client, Input)
Creates a friendly name for a customer master key (CMK).
- create_alias(Client, Input, Options)
-
create_custom_key_store(Client, Input)
Creates a custom key store that is associated with an AWS CloudHSM cluster that you own and manage.
- create_custom_key_store(Client, Input, Options)
-
create_grant(Client, Input)
Adds a grant to a customer master key (CMK).
- create_grant(Client, Input, Options)
-
create_key(Client, Input)
Creates a unique customer managed customer master key (CMK) in your AWS account and Region.
- create_key(Client, Input, Options)
-
decrypt(Client, Input)
Decrypts ciphertext that was encrypted by a AWS KMS customer master key (CMK) using any of the following operations:.
- decrypt(Client, Input, Options)
-
delete_alias(Client, Input)
Deletes the specified alias.
- delete_alias(Client, Input, Options)
-
delete_custom_key_store(Client, Input)
Deletes a custom key store.
- delete_custom_key_store(Client, Input, Options)
-
delete_imported_key_material(Client, Input)
Deletes key material that you previously imported.
- delete_imported_key_material(Client, Input, Options)
-
describe_custom_key_stores(Client, Input)
Gets information about custom key stores in the account and region.
- describe_custom_key_stores(Client, Input, Options)
-
describe_key(Client, Input)
Provides detailed information about a customer master key (CMK).
- describe_key(Client, Input, Options)
-
disable_key(Client, Input)
Sets the state of a customer master key (CMK) to disabled.
- disable_key(Client, Input, Options)
-
disable_key_rotation(Client, Input)
Disables automatic rotation of the key material for the specified symmetric customer master key (CMK).
- disable_key_rotation(Client, Input, Options)
-
disconnect_custom_key_store(Client, Input)
Disconnects the custom key store from its associated AWS CloudHSM cluster.
- disconnect_custom_key_store(Client, Input, Options)
-
enable_key(Client, Input)
Sets the key state of a customer master key (CMK) to enabled.
- enable_key(Client, Input, Options)
-
enable_key_rotation(Client, Input)
Enables automatic rotation of the key material for the specified symmetric customer master key (CMK).
- enable_key_rotation(Client, Input, Options)
-
encrypt(Client, Input)
Encrypts plaintext into ciphertext by using a customer master key (CMK).
- encrypt(Client, Input, Options)
-
generate_data_key(Client, Input)
Generates a unique symmetric data key for client-side encryption.
- generate_data_key(Client, Input, Options)
-
generate_data_key_pair(Client, Input)
Generates a unique asymmetric data key pair.
- generate_data_key_pair(Client, Input, Options)
-
generate_data_key_pair_without_plaintext(Client, Input)
Generates a unique asymmetric data key pair.
- generate_data_key_pair_without_plaintext(Client, Input, Options)
-
generate_data_key_without_plaintext(Client, Input)
Generates a unique symmetric data key.
- generate_data_key_without_plaintext(Client, Input, Options)
-
generate_random(Client, Input)
Returns a random byte string that is cryptographically secure.
- generate_random(Client, Input, Options)
-
get_key_policy(Client, Input)
Gets a key policy attached to the specified customer master key (CMK).
- get_key_policy(Client, Input, Options)
-
get_key_rotation_status(Client, Input)
Gets a Boolean value that indicates whether automatic rotation of the key material is enabled for the specified customer master key (CMK).
- get_key_rotation_status(Client, Input, Options)
-
get_parameters_for_import(Client, Input)
Returns the items you need to import key material into a symmetric, customer managed customer master key (CMK).
- get_parameters_for_import(Client, Input, Options)
-
get_public_key(Client, Input)
Returns the public key of an asymmetric CMK.
- get_public_key(Client, Input, Options)
-
import_key_material(Client, Input)
Imports key material into an existing symmetric AWS KMS customer master key (CMK) that was created without key material.
- import_key_material(Client, Input, Options)
-
list_aliases(Client, Input)
Gets a list of aliases in the caller's AWS account and region.
- list_aliases(Client, Input, Options)
-
list_grants(Client, Input)
Gets a list of all grants for the specified customer master key (CMK).
- list_grants(Client, Input, Options)
-
list_key_policies(Client, Input)
Gets the names of the key policies that are attached to a customer master key (CMK).
- list_key_policies(Client, Input, Options)
-
list_keys(Client, Input)
Gets a list of all customer master keys (CMKs) in the caller's AWS account and Region.
- list_keys(Client, Input, Options)
-
list_resource_tags(Client, Input)
Returns all tags on the specified customer master key (CMK).
- list_resource_tags(Client, Input, Options)
-
list_retirable_grants(Client, Input)
Returns all grants in which the specified principal is the
RetiringPrincipal
in the grant. - list_retirable_grants(Client, Input, Options)
-
put_key_policy(Client, Input)
Attaches a key policy to the specified customer master key (CMK).
- put_key_policy(Client, Input, Options)
-
re_encrypt(Client, Input)
Decrypts ciphertext and then reencrypts it entirely within AWS KMS.
- re_encrypt(Client, Input, Options)
-
retire_grant(Client, Input)
Retires a grant.
- retire_grant(Client, Input, Options)
-
revoke_grant(Client, Input)
Revokes the specified grant for the specified customer master key (CMK).
- revoke_grant(Client, Input, Options)
-
schedule_key_deletion(Client, Input)
Schedules the deletion of a customer master key (CMK).
- schedule_key_deletion(Client, Input, Options)
-
sign(Client, Input)
Creates a digital signature for a message or message digest by using the private key in an asymmetric CMK.
- sign(Client, Input, Options)
-
tag_resource(Client, Input)
Adds or edits tags on a customer managed CMK.
- tag_resource(Client, Input, Options)
-
untag_resource(Client, Input)
Deletes tags from a customer managed CMK.
- untag_resource(Client, Input, Options)
-
update_alias(Client, Input)
Associates an existing AWS KMS alias with a different customer master key (CMK).
- update_alias(Client, Input, Options)
-
update_custom_key_store(Client, Input)
Changes the properties of a custom key store.
- update_custom_key_store(Client, Input, Options)
-
update_key_description(Client, Input)
Updates the description of a customer master key (CMK).
- update_key_description(Client, Input, Options)
-
verify(Client, Input)
Verifies a digital signature that was generated by the
Sign
operation. - verify(Client, Input, Options)
Functions
cancel_key_deletion(Client, Input)
Cancels the deletion of a customer master key (CMK).
When this operation succeeds, the key state of the CMK is Disabled
. To
enable the 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.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:CancelKeyDeletion (key policy)
Related operations:ScheduleKeyDeletion
cancel_key_deletion(Client, Input, Options)
connect_custom_key_store(Client, Input)
Connects or reconnects a custom key store to its associated AWS CloudHSM cluster.
The custom key store must be connected before you can create customer master keys (CMKs) in the key store or use the CMKs it contains. You can disconnect and reconnect a custom key store at any time.
To connect a custom key store, its associated AWS CloudHSM cluster must
have at least one active HSM. To get the number of active HSMs in a
cluster, use the DescribeClusters operation. To add HSMs to the cluster,
use the CreateHsm operation. Also, the kmsuser
crypto user (CU) must not
be logged into the cluster. This prevents AWS KMS from using this account
to log in.
The connection process can take an extended amount of time to complete; up
to 20 minutes. This operation starts the connection process, but it does
not wait for it to complete. When it succeeds, this operation quickly
returns an HTTP 200 response and a JSON object with no properties.
However, this response does not indicate that the custom key store is
connected. To get the connection state of the custom key store, use the
DescribeCustomKeyStores
operation.
During the connection process, AWS KMS finds the AWS CloudHSM cluster that
is associated with the custom key store, creates the connection
infrastructure, connects to the cluster, logs into the AWS CloudHSM client
as the kmsuser
CU, and rotates its password.
The ConnectCustomKeyStore
operation might fail for various reasons. To
find the reason, use the DescribeCustomKeyStores
operation and see the
ConnectionErrorCode
in the response. For help interpreting the
ConnectionErrorCode
, see CustomKeyStoresListEntry
.
To fix the failure, use the DisconnectCustomKeyStore
operation to
disconnect the custom key store, correct the error, use the
UpdateCustomKeyStore
operation if necessary, and then use
ConnectCustomKeyStore
again.
If you are having trouble connecting or disconnecting a custom key store, see Troubleshooting a Custom Key Store in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a custom key store in a different AWS account.
Required permissions: kms:ConnectCustomKeyStore (IAM policy)
Related operations
CreateCustomKeyStore
DeleteCustomKeyStore
DescribeCustomKeyStores
DisconnectCustomKeyStore
UpdateCustomKeyStore
connect_custom_key_store(Client, Input, Options)
create_alias(Client, Input)
Creates a friendly name for a customer master key (CMK).
You can use an alias to identify a CMK in the AWS KMS console, in the
DescribeKey
operation and in cryptographic operations, such as Encrypt
and GenerateDataKey
.
You can also change the CMK that's associated with the alias
(UpdateAlias
) or delete the alias (DeleteAlias
) at any time. These
operations don't affect the underlying CMK.
You can associate the alias with any customer managed CMK in the same AWS Region. Each alias is associated with only on CMK at a time, but a CMK can have multiple aliases. A valid CMK is required. You can't create an alias without a CMK.
The alias must be unique in the account and Region, but you can have aliases with the same name in different Regions. For detailed information about aliases, see Using aliases in the AWS Key Management Service Developer Guide.
This operation does not return a response. To get the alias that you
created, use the ListAliases
operation.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on an alias in a different AWS account.
Required permissions
kms:CreateAlias on the alias (IAM policy).
kms:CreateAlias on the CMK (key policy).
For details, see Controlling access to aliases in the AWS Key Management Service Developer Guide.
Related operations:
DeleteAlias
ListAliases
UpdateAlias
create_alias(Client, Input, Options)
create_custom_key_store(Client, Input)
Creates a custom key store that is associated with an AWS CloudHSM cluster that you own and manage.
This operation is part of the Custom Key Store feature feature in AWS KMS, which combines the convenience and extensive integration of AWS KMS with the isolation and control of a single-tenant key store.
Before you create the custom key store, you must assemble the required elements, including an AWS CloudHSM cluster that fulfills the requirements for a custom key store. For details about the required elements, see Assemble the Prerequisites in the AWS Key Management Service Developer Guide.
When the operation completes successfully, it returns the ID of the new
custom key store. Before you can use your new custom key store, you need
to use the ConnectCustomKeyStore
operation to connect the new key store
to its AWS CloudHSM cluster. Even if you are not going to use your custom
key store immediately, you might want to connect it to verify that all
settings are correct and then disconnect it until you are ready to use it.
For help with failures, see Troubleshooting a Custom Key Store in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a custom key store in a different AWS account.
Required permissions: kms:CreateCustomKeyStore (IAM policy).
Related operations:
ConnectCustomKeyStore
DeleteCustomKeyStore
DescribeCustomKeyStores
DisconnectCustomKeyStore
UpdateCustomKeyStore
create_custom_key_store(Client, Input, Options)
create_grant(Client, Input)
Adds a grant to a customer master key (CMK).
The grant allows the grantee principal to use the CMK when the conditions specified in the grant are met. When setting permissions, grants are an alternative to key policies.
To create a grant that allows a cryptographic operation only when the
request includes a particular encryption context, use the Constraints
parameter. For details, see GrantConstraints
.
You can create grants on symmetric and asymmetric CMKs. However, if the
grant allows an operation that the CMK does not support, CreateGrant
fails with a ValidationException
.
Grants for symmetric CMKs cannot allow operations that are not supported for symmetric CMKs, including
Sign
,Verify
, andGetPublicKey
. (There are limited exceptions to this rule for legacy operations, but you should not create a grant for an operation that AWS KMS does not support.)Grants for asymmetric CMKs cannot allow operations that are not supported for asymmetric CMKs, including operations that generate data keys or data key pairs, or operations related to automatic key rotation, imported key material, or CMKs in custom key stores.
Grants for asymmetric CMKs with a
KeyUsage
ofENCRYPT_DECRYPT
cannot allow theSign
orVerify
operations. Grants for asymmetric CMKs with aKeyUsage
ofSIGN_VERIFY
cannot allow theEncrypt
orDecrypt
operations.Grants for asymmetric CMKs cannot include an encryption context grant constraint. An encryption context is not supported on asymmetric CMKs.
For information about symmetric and asymmetric CMKs, see Using Symmetric and Asymmetric CMKs in the AWS Key Management Service Developer Guide. For more information about grants, see Grants in the AWS Key Management Service Developer Guide .
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: Yes. To perform this operation on a CMK in a different
AWS account, specify the key ARN in the value of the KeyId
parameter.
Required permissions: kms:CreateGrant (key policy)
Related operations:
ListGrants
ListRetirableGrants
RetireGrant
RevokeGrant
create_grant(Client, Input, Options)
create_key(Client, Input)
Creates a unique customer managed customer master key (CMK) in your AWS account and Region.
You can use the CreateKey
operation to create symmetric or asymmetric
CMKs.
Symmetric CMKs contain a 256-bit symmetric key that never leaves AWS KMS unencrypted. To use the CMK, you must call AWS KMS. You can use a symmetric CMK to encrypt and decrypt small amounts of data, but they are typically used to generate data keys and data keys pairs. For details, see
GenerateDataKey
andGenerateDataKeyPair
.Asymmetric CMKs can contain an RSA key pair or an Elliptic Curve (ECC) key pair. The private key in an asymmetric CMK never leaves AWS KMS unencrypted. However, you can use the
GetPublicKey
operation to download the public key so it can be used outside of AWS KMS. CMKs with RSA key pairs can be used to encrypt or decrypt data or sign and verify messages (but not both). CMKs with ECC key pairs can be used only to sign and verify messages.
For information about symmetric and asymmetric CMKs, see Using Symmetric and Asymmetric CMKs in the AWS Key Management Service Developer Guide.
To create different types of CMKs, use the following guidance:
- Asymmetric CMKs
To create an asymmetric CMK, use the
CustomerMasterKeySpec
parameter to specify the type of key material in the CMK. Then, use theKeyUsage
parameter to determine whether the CMK will be used to encrypt and decrypt or sign and verify. You can't change these properties after the CMK is created.- Symmetric CMKs
When creating a symmetric CMK, you don't need to specify the
CustomerMasterKeySpec
orKeyUsage
parameters. The default value forCustomerMasterKeySpec
,SYMMETRIC_DEFAULT
, and the default value forKeyUsage
,ENCRYPT_DECRYPT
, are the only valid values for symmetric CMKs.- Imported Key Material
To import your own key material, begin by creating a symmetric CMK with no key material. To do this, use the
Origin
parameter ofCreateKey
with a value ofEXTERNAL
. Next, useGetParametersForImport
operation to get a public key and import token, and use the public key to encrypt your key material. Then, useImportKeyMaterial
with your import token to import the key material. For step-by-step instructions, see Importing Key Material in the AWS Key Management Service Developer Guide . You cannot import the key material into an asymmetric CMK.- Custom Key Stores
To create a symmetric CMK in a custom key store, use the
CustomKeyStoreId
parameter to specify the custom key store. You must also use theOrigin
parameter with a value ofAWS_CLOUDHSM
. The AWS CloudHSM cluster that is associated with the custom key store must have at least two active HSMs in different Availability Zones in the AWS Region.You cannot create an asymmetric CMK in a custom key store. For information about custom key stores in AWS KMS see Using Custom Key Stores in the AWS Key Management Service Developer Guide .
Cross-account use: No. You cannot use this operation to create a CMK in a different AWS account.
Required permissions: kms:CreateKey (IAM policy). To use the Tags
parameter, kms:TagResource (IAM policy). For examples and information
about related permissions, see Allow a user to create CMKs in the AWS Key
Management Service Developer Guide.
Related operations:
DescribeKey
ListKeys
ScheduleKeyDeletion
create_key(Client, Input, Options)
decrypt(Client, Input)
Decrypts ciphertext that was encrypted by a AWS KMS customer master key (CMK) using any of the following operations:
Encrypt
GenerateDataKey
GenerateDataKeyPair
GenerateDataKeyWithoutPlaintext
GenerateDataKeyPairWithoutPlaintext
You can use this operation to decrypt ciphertext that was encrypted under a symmetric or asymmetric CMK.
When the CMK is asymmetric, you must specify the CMK and the encryption algorithm that was used to encrypt the ciphertext. For information about symmetric and asymmetric CMKs, see Using Symmetric and Asymmetric CMKs in the AWS Key Management Service Developer Guide.
The Decrypt operation also decrypts ciphertext that was encrypted outside of AWS KMS by the public key in an AWS KMS asymmetric CMK. However, it cannot decrypt ciphertext produced by other libraries, such as the AWS Encryption SDK or Amazon S3 client-side encryption. These libraries return a ciphertext format that is incompatible with AWS KMS.
If the ciphertext was encrypted under a symmetric CMK, the KeyId
parameter is optional. AWS KMS can get this information from metadata that
it adds to the symmetric ciphertext blob. This feature adds durability to
your implementation by ensuring that authorized users can decrypt
ciphertext decades after it was encrypted, even if they've lost track of
the CMK ID. However, specifying the CMK is always recommended as a best
practice. When you use the KeyId
parameter to specify a CMK, AWS KMS
only uses the CMK you specify. If the ciphertext was encrypted under a
different CMK, the Decrypt
operation fails. This practice ensures that
you use the CMK that you intend.
Whenever possible, use key policies to give users permission to call the
Decrypt
operation on a particular CMK, instead of using IAM policies.
Otherwise, you might create an IAM user policy that gives the user
Decrypt
permission on all CMKs. This user could decrypt ciphertext that
was encrypted by CMKs in other accounts if the key policy for the
cross-account CMK permits it. If you must use an IAM policy for Decrypt
permissions, limit the user to particular CMKs or particular trusted
accounts. For details, see Best practices for IAM policies in the AWS Key
Management Service Developer Guide.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: Yes. You can decrypt a ciphertext using a CMK in a different AWS account.
Required permissions: kms:Decrypt (key policy)
Related operations:
Encrypt
GenerateDataKey
GenerateDataKeyPair
ReEncrypt
decrypt(Client, Input, Options)
delete_alias(Client, Input)
Deletes the specified alias.
Because an alias is not a property of a CMK, you can delete and change the
aliases of a CMK without affecting the CMK. Also, aliases do not appear in
the response from the DescribeKey
operation. To get the aliases of all
CMKs, use the ListAliases
operation.
Each CMK can have multiple aliases. To change the alias of a CMK, use
DeleteAlias
to delete the current alias and CreateAlias
to create a
new alias. To associate an existing alias with a different customer master
key (CMK), call UpdateAlias
.
Cross-account use: No. You cannot perform this operation on an alias in a different AWS account.
Required permissions
kms:DeleteAlias on the alias (IAM policy).
kms:DeleteAlias on the CMK (key policy).
For details, see Controlling access to aliases in the AWS Key Management Service Developer Guide.
Related operations:
CreateAlias
ListAliases
UpdateAlias
delete_alias(Client, Input, Options)
delete_custom_key_store(Client, Input)
Deletes a custom key store.
This operation does not delete the AWS CloudHSM cluster that is associated with the custom key store, or affect any users or keys in the cluster.
The custom key store that you delete cannot contain any AWS KMS customer
master keys (CMKs). Before deleting the key store, verify that you will
never need to use any of the CMKs in the key store for any cryptographic
operations. Then, use ScheduleKeyDeletion
to delete the AWS KMS customer
master keys (CMKs) from the key store. When the scheduled waiting period
expires, the ScheduleKeyDeletion
operation deletes the CMKs. Then it
makes a best effort to delete the key material from the associated
cluster. However, you might need to manually delete the orphaned key
material from the cluster and its backups.
After all CMKs are deleted from AWS KMS, use DisconnectCustomKeyStore
to
disconnect the key store from AWS KMS. Then, you can delete the custom key
store.
Instead of deleting the custom key store, consider using
DisconnectCustomKeyStore
to disconnect it from AWS KMS. While the key
store is disconnected, you cannot create or use the CMKs in the key store.
But, you do not need to delete CMKs and you can reconnect a disconnected
custom key store at any time.
If the operation succeeds, it returns a JSON object with no properties.
This operation is part of the Custom Key Store feature feature in AWS KMS, which combines the convenience and extensive integration of AWS KMS with the isolation and control of a single-tenant key store.
Cross-account use: No. You cannot perform this operation on a custom key store in a different AWS account.
Required permissions: kms:DeleteCustomKeyStore (IAM policy)
Related operations:
ConnectCustomKeyStore
CreateCustomKeyStore
DescribeCustomKeyStores
DisconnectCustomKeyStore
UpdateCustomKeyStore
delete_custom_key_store(Client, Input, Options)
delete_imported_key_material(Client, Input)
Deletes key material that you previously imported.
This operation 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.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:DeleteImportedKeyMaterial (key policy)
Related operations:
GetParametersForImport
ImportKeyMaterial
delete_imported_key_material(Client, Input, Options)
describe_custom_key_stores(Client, Input)
Gets information about custom key stores in the account and region.
This operation is part of the Custom Key Store feature feature in AWS KMS, which combines the convenience and extensive integration of AWS KMS with the isolation and control of a single-tenant key store.
By default, this operation returns information about all custom key stores
in the account and region. To get only information about a particular
custom key store, use either the CustomKeyStoreName
or
CustomKeyStoreId
parameter (but not both).
To determine whether the custom key store is connected to its AWS CloudHSM
cluster, use the ConnectionState
element in the response. If an attempt
to connect the custom key store failed, the ConnectionState
value is
FAILED
and the ConnectionErrorCode
element in the response indicates
the cause of the failure. For help interpreting the ConnectionErrorCode
,
see CustomKeyStoresListEntry
.
Custom key stores have a DISCONNECTED
connection state if the key store
has never been connected or you use the DisconnectCustomKeyStore
operation to disconnect it. If your custom key store state is CONNECTED
but you are having trouble using it, make sure that its associated AWS
CloudHSM cluster is active and contains the minimum number of HSMs
required for the operation, if any.
For help repairing your custom key store, see the Troubleshooting Custom Key Stores topic in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a custom key store in a different AWS account.
Required permissions: kms:DescribeCustomKeyStores (IAM policy)
Related operations:
ConnectCustomKeyStore
CreateCustomKeyStore
DeleteCustomKeyStore
DisconnectCustomKeyStore
UpdateCustomKeyStore
describe_custom_key_stores(Client, Input, Options)
describe_key(Client, Input)
Provides detailed information about a customer master key (CMK).
You can run DescribeKey
on a customer managed CMK or an AWS managed CMK.
This detailed information includes the key ARN, creation date (and
deletion date, if applicable), the key state, and the origin and
expiration date (if any) of the key material. For CMKs in custom key
stores, it includes information about the custom key store, such as the
key store ID and the AWS CloudHSM cluster ID. It includes fields, like
KeySpec
, that help you distinguish symmetric from asymmetric CMKs. It
also provides information that is particularly important to asymmetric
CMKs, such as the key usage (encryption or signing) and the encryption
algorithms or signing algorithms that the CMK supports.
DescribeKey
does not return the following information:
Aliases associated with the CMK. To get this information, use
ListAliases
.Whether automatic key rotation is enabled on the CMK. To get this information, use
GetKeyRotationStatus
. Also, some key states prevent a CMK from being automatically rotated. For details, see How Automatic Key Rotation Works in AWS Key Management Service Developer Guide.Tags on the CMK. To get this information, use
ListResourceTags
.Key policies and grants on the CMK. To get this information, use
GetKeyPolicy
andListGrants
.
If you call the DescribeKey
operation on a predefined AWS
alias, that is, an AWS alias with no key ID, AWS KMS creates an AWS
managed CMK. Then, it associates the alias with the new CMK, and returns
the KeyId
and Arn
of the new CMK in the response.
Cross-account use: Yes. To perform this operation with a CMK in a
different AWS account, specify the key ARN or alias ARN in the value of
the KeyId
parameter.
Required permissions: kms:DescribeKey (key policy)
Related operations:
GetKeyPolicy
GetKeyRotationStatus
ListAliases
ListGrants
ListKeys
ListResourceTags
ListRetirableGrants
describe_key(Client, Input, Options)
disable_key(Client, Input)
Sets the state of a customer master key (CMK) to disabled.
This change temporarily prevents use of the CMK 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 .
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:DisableKey (key policy)
Related operations:EnableKey
disable_key(Client, Input, Options)
disable_key_rotation(Client, Input)
Disables automatic rotation of the key material for the specified symmetric customer master key (CMK).
You cannot enable automatic rotation of asymmetric CMKs, CMKs with imported key material, or CMKs in a custom key store.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:DisableKeyRotation (key policy)
Related operations:
EnableKeyRotation
GetKeyRotationStatus
disable_key_rotation(Client, Input, Options)
disconnect_custom_key_store(Client, Input)
Disconnects the custom key store from its associated AWS CloudHSM cluster.
While a custom key store is disconnected, you can manage the custom key store and its customer master keys (CMKs), but you cannot create or use CMKs in the custom key store. You can reconnect the custom key store at any time.
While a custom key store is disconnected, all attempts to create customer master keys (CMKs) in the custom key store or to use existing CMKs in cryptographic operations will fail. This action can prevent users from storing and accessing sensitive data.
To find the connection state of a custom key store, use the
DescribeCustomKeyStores
operation. To reconnect a custom key store, use
the ConnectCustomKeyStore
operation.
If the operation succeeds, it returns a JSON object with no properties.
This operation is part of the Custom Key Store feature feature in AWS KMS, which combines the convenience and extensive integration of AWS KMS with the isolation and control of a single-tenant key store.
Cross-account use: No. You cannot perform this operation on a custom key store in a different AWS account.
Required permissions: kms:DisconnectCustomKeyStore (IAM policy)
Related operations:
ConnectCustomKeyStore
CreateCustomKeyStore
DeleteCustomKeyStore
DescribeCustomKeyStores
UpdateCustomKeyStore
disconnect_custom_key_store(Client, Input, Options)
enable_key(Client, Input)
Sets the key state of a customer master key (CMK) to enabled.
This allows you to use the CMK for cryptographic operations.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:EnableKey (key policy)
Related operations:DisableKey
enable_key(Client, Input, Options)
enable_key_rotation(Client, Input)
Enables automatic rotation of the key material for the specified symmetric customer master key (CMK).
You cannot enable automatic rotation of asymmetric CMKs, CMKs with imported key material, or CMKs in a custom key store.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:EnableKeyRotation (key policy)
Related operations:
DisableKeyRotation
GetKeyRotationStatus
enable_key_rotation(Client, Input, Options)
encrypt(Client, Input)
Encrypts plaintext into ciphertext by using a customer master key (CMK).
The Encrypt
operation has two primary use cases:
You can encrypt small amounts of arbitrary data, such as a personal identifier or database password, or other sensitive information.
You can use the
Encrypt
operation to move encrypted data from one AWS Region to another. For example, in Region A, generate a data key and use the plaintext key to encrypt your data. Then, in Region A, use theEncrypt
operation to encrypt the plaintext data key under a CMK in Region B. Now, you can move the encrypted data and the encrypted data key to Region B. When necessary, you can decrypt the encrypted data key and the encrypted data entirely within in Region B.
You don't need to use the Encrypt
operation to encrypt a
data key. The GenerateDataKey
and GenerateDataKeyPair
operations
return a plaintext data key and an encrypted copy of that data key.
When you encrypt data, you must specify a symmetric or asymmetric CMK to
use in the encryption operation. The CMK must have a KeyUsage
value of
ENCRYPT_DECRYPT.
To find the KeyUsage
of a CMK, use the DescribeKey
operation.
If you use a symmetric CMK, you can use an encryption context to add
additional security to your encryption operation. If you specify an
EncryptionContext
when encrypting data, you must specify the same
encryption context (a case-sensitive exact match) when decrypting the
data. Otherwise, the request to decrypt fails with an
InvalidCiphertextException
. For more information, see Encryption Context
in the AWS Key Management Service Developer Guide.
If you specify an asymmetric CMK, you must also specify the encryption algorithm. The algorithm must be compatible with the CMK type.
When you use an asymmetric CMK to encrypt or reencrypt data, be sure to record the CMK and encryption algorithm that you choose. You will be required to provide the same CMK and encryption algorithm when you decrypt the data. If the CMK and algorithm do not match the values used to encrypt the data, the decrypt operation fails.
You are not required to supply the CMK ID and encryption algorithm when you decrypt with symmetric CMKs because AWS KMS stores this information in the ciphertext blob. AWS KMS cannot store metadata in ciphertext generated with asymmetric keys. The standard format for asymmetric key ciphertext does not include configurable fields.
The maximum size of the data that you can encrypt varies with the type of CMK and the encryption algorithm that you choose.
Symmetric CMKs
SYMMETRIC_DEFAULT
: 4096 bytes
RSA_2048
RSAES_OAEP_SHA_1
: 214 bytesRSAES_OAEP_SHA_256
: 190 bytes
RSA_3072
RSAES_OAEP_SHA_1
: 342 bytesRSAES_OAEP_SHA_256
: 318 bytes
RSA_4096
RSAES_OAEP_SHA_1
: 470 bytesRSAES_OAEP_SHA_256
: 446 bytes
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: Yes. To perform this operation with a CMK in a
different AWS account, specify the key ARN or alias ARN in the value of
the KeyId
parameter.
Required permissions: kms:Encrypt (key policy)
Related operations:
Decrypt
GenerateDataKey
GenerateDataKeyPair
encrypt(Client, Input, Options)
generate_data_key(Client, Input)
Generates a unique symmetric data key for client-side encryption.
This operation returns a plaintext copy of the data key and a copy that is encrypted under a customer master key (CMK) that you specify. You can use the plaintext key to encrypt your data outside of AWS KMS and store the encrypted data key with the encrypted data.
GenerateDataKey
returns a unique data key for each request. The bytes in
the plaintext key are not related to the caller or the CMK.
To generate a data key, specify the symmetric CMK that will be used to
encrypt the data key. You cannot use an asymmetric CMK to generate data
keys. To get the type of your CMK, use the DescribeKey
operation. You
must also specify the length of the data key. Use either the KeySpec
or
NumberOfBytes
parameters (but not both). For 128-bit and 256-bit data
keys, use the KeySpec
parameter.
To get only an encrypted copy of the data key, use
GenerateDataKeyWithoutPlaintext
. To generate an asymmetric data key
pair, use the GenerateDataKeyPair
or
GenerateDataKeyPairWithoutPlaintext
operation. To get a
cryptographically secure random byte string, use GenerateRandom
.
You can use the optional encryption context to add additional security to
the encryption operation. If you specify an EncryptionContext
, you must
specify the same encryption context (a case-sensitive exact match) when
decrypting the encrypted data key. Otherwise, the request to decrypt fails
with an InvalidCiphertextException
. For more information, see Encryption
Context in the AWS Key Management Service Developer Guide.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
How to use your data key
We recommend that you use the following pattern to encrypt data locally in your application. You can write your own code or use a client-side encryption library, such as the AWS Encryption SDK, the Amazon DynamoDB Encryption Client, or Amazon S3 client-side encryption to do these tasks for you.
To encrypt data outside of AWS KMS:
Use the
GenerateDataKey
operation to get a data key.Use the plaintext data key (in the
Plaintext
field of the response) to encrypt your data outside of AWS KMS. Then erase the plaintext data key from memory.Store the encrypted data key (in the
CiphertextBlob
field of the response) with the encrypted data.
To decrypt data outside of AWS KMS:
Use the
Decrypt
operation to decrypt the encrypted data key. The operation returns a plaintext copy of the data key.Use the plaintext data key to decrypt data outside of AWS KMS, then erase the plaintext data key from memory.
Cross-account use: Yes. To perform this operation with a CMK
in a different AWS account, specify the key ARN or alias ARN in the value
of the KeyId
parameter.
Required permissions: kms:GenerateDataKey (key policy)
Related operations:
Decrypt
Encrypt
GenerateDataKeyPair
GenerateDataKeyPairWithoutPlaintext
GenerateDataKeyWithoutPlaintext
generate_data_key(Client, Input, Options)
generate_data_key_pair(Client, Input)
Generates a unique asymmetric data key pair.
The GenerateDataKeyPair
operation returns a plaintext public key, a
plaintext private key, and a copy of the private key that is encrypted
under the symmetric CMK you specify. You can use the data key pair to
perform asymmetric cryptography outside of AWS KMS.
GenerateDataKeyPair
returns a unique data key pair for each request. The
bytes in the keys are not related to the caller or the CMK that is used to
encrypt the private key.
You can use the public key that GenerateDataKeyPair
returns to encrypt
data or verify a signature outside of AWS KMS. Then, store the encrypted
private key with the data. When you are ready to decrypt data or sign a
message, you can use the Decrypt
operation to decrypt the encrypted
private key.
To generate a data key pair, you must specify a symmetric customer master
key (CMK) to encrypt the private key in a data key pair. You cannot use an
asymmetric CMK or a CMK in a custom key store. To get the type and origin
of your CMK, use the DescribeKey
operation.
If you are using the data key pair to encrypt data, or for any operation
where you don't immediately need a private key, consider using the
GenerateDataKeyPairWithoutPlaintext
operation.
GenerateDataKeyPairWithoutPlaintext
returns a plaintext public key and
an encrypted private key, but omits the plaintext private key that you
need only to decrypt ciphertext or sign a message. Later, when you need to
decrypt the data or sign a message, use the Decrypt
operation to decrypt
the encrypted private key in the data key pair.
You can use the optional encryption context to add additional security to
the encryption operation. If you specify an EncryptionContext
, you must
specify the same encryption context (a case-sensitive exact match) when
decrypting the encrypted data key. Otherwise, the request to decrypt fails
with an InvalidCiphertextException
. For more information, see Encryption
Context in the AWS Key Management Service Developer Guide.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: Yes. To perform this operation with a CMK in a
different AWS account, specify the key ARN or alias ARN in the value of
the KeyId
parameter.
Required permissions: kms:GenerateDataKeyPair (key policy)
Related operations:
Decrypt
Encrypt
GenerateDataKey
GenerateDataKeyPairWithoutPlaintext
GenerateDataKeyWithoutPlaintext
generate_data_key_pair(Client, Input, Options)
generate_data_key_pair_without_plaintext(Client, Input)
Generates a unique asymmetric data key pair.
The GenerateDataKeyPairWithoutPlaintext
operation returns a plaintext
public key and a copy of the private key that is encrypted under the
symmetric CMK you specify. Unlike GenerateDataKeyPair
, this operation
does not return a plaintext private key.
To generate a data key pair, you must specify a symmetric customer master
key (CMK) to encrypt the private key in the data key pair. You cannot use
an asymmetric CMK or a CMK in a custom key store. To get the type and
origin of your CMK, use the KeySpec
field in the DescribeKey
response.
You can use the public key that GenerateDataKeyPairWithoutPlaintext
returns to encrypt data or verify a signature outside of AWS KMS. Then,
store the encrypted private key with the data. When you are ready to
decrypt data or sign a message, you can use the Decrypt
operation to
decrypt the encrypted private key.
GenerateDataKeyPairWithoutPlaintext
returns a unique data key pair for
each request. The bytes in the key are not related to the caller or CMK
that is used to encrypt the private key.
You can use the optional encryption context to add additional security to
the encryption operation. If you specify an EncryptionContext
, you must
specify the same encryption context (a case-sensitive exact match) when
decrypting the encrypted data key. Otherwise, the request to decrypt fails
with an InvalidCiphertextException
. For more information, see Encryption
Context in the AWS Key Management Service Developer Guide.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: Yes. To perform this operation with a CMK in a
different AWS account, specify the key ARN or alias ARN in the value of
the KeyId
parameter.
Required permissions: kms:GenerateDataKeyPairWithoutPlaintext (key policy)
Related operations:
Decrypt
Encrypt
GenerateDataKey
GenerateDataKeyPair
GenerateDataKeyWithoutPlaintext
generate_data_key_pair_without_plaintext(Client, Input, Options)
generate_data_key_without_plaintext(Client, Input)
Generates a unique symmetric data key.
This operation returns a data key that is encrypted under a customer
master key (CMK) that you specify. To request an asymmetric data key pair,
use the GenerateDataKeyPair
or GenerateDataKeyPairWithoutPlaintext
operations.
GenerateDataKeyWithoutPlaintext
is identical to the GenerateDataKey
operation except that returns only the encrypted copy of the data key.
This operation is useful for systems that need to encrypt data at some
point, but not immediately. When you need to encrypt the data, you call
the Decrypt
operation on the encrypted copy of the key.
It's also useful in distributed systems with different levels of trust. For example, you might store encrypted data in containers. One component of your system creates new containers and stores an encrypted data key with each container. Then, a different component puts the data into the containers. That component first decrypts the data key, uses the plaintext data key to encrypt data, puts the encrypted data into the container, and then destroys the plaintext data key. In this system, the component that creates the containers never sees the plaintext data key.
GenerateDataKeyWithoutPlaintext
returns a unique data key for each
request. The bytes in the keys are not related to the caller or CMK that
is used to encrypt the private key.
To generate a data key, you must specify the symmetric customer master key
(CMK) that is used to encrypt the data key. You cannot use an asymmetric
CMK to generate a data key. To get the type of your CMK, use the
DescribeKey
operation.
If the operation succeeds, you will find the encrypted copy of the data
key in the CiphertextBlob
field.
You can use the optional encryption context to add additional security to
the encryption operation. If you specify an EncryptionContext
, you must
specify the same encryption context (a case-sensitive exact match) when
decrypting the encrypted data key. Otherwise, the request to decrypt fails
with an InvalidCiphertextException
. For more information, see Encryption
Context in the AWS Key Management Service Developer Guide.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: Yes. To perform this operation with a CMK in a
different AWS account, specify the key ARN or alias ARN in the value of
the KeyId
parameter.
Required permissions: kms:GenerateDataKeyWithoutPlaintext (key policy)
Related operations:
Decrypt
Encrypt
GenerateDataKey
GenerateDataKeyPair
GenerateDataKeyPairWithoutPlaintext
generate_data_key_without_plaintext(Client, Input, Options)
generate_random(Client, Input)
Returns a random byte string that is cryptographically secure.
By default, the random byte string is generated in AWS KMS. To generate the byte string in the AWS CloudHSM cluster that is associated with a custom key store, specify the custom key store ID.
For more information about entropy and random number generation, see the AWS Key Management Service Cryptographic Details whitepaper.
Required permissions: kms:GenerateRandom (IAM policy)generate_random(Client, Input, Options)
get_key_policy(Client, Input)
Gets a key policy attached to the specified customer master key (CMK).
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:GetKeyPolicy (key policy)
Related operations:PutKeyPolicy
get_key_policy(Client, Input, Options)
get_key_rotation_status(Client, Input)
Gets a Boolean value that indicates whether automatic rotation of the key material is enabled for the specified customer master key (CMK).
You cannot enable automatic rotation of asymmetric CMKs, CMKs with
imported key material, or CMKs in a custom key store. The key rotation
status for these CMKs is always false
.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Disabled: The key rotation status does not change when you disable a CMK. However, while the CMK is disabled, AWS KMS does not rotate the backing key.
Pending deletion: While a CMK is pending deletion, its key rotation status is
false
and AWS KMS does not rotate the backing key. If you cancel the deletion, the original key rotation status is restored.
Cross-account use: Yes. To perform this operation on a CMK in
a different AWS account, specify the key ARN in the value of the KeyId
parameter.
Required permissions: kms:GetKeyRotationStatus (key policy)
Related operations:
DisableKeyRotation
EnableKeyRotation
get_key_rotation_status(Client, Input, Options)
get_parameters_for_import(Client, Input)
Returns the items you need to import key material into a symmetric, customer managed customer master key (CMK).
For more information about importing key material into AWS KMS, see Importing Key Material in the AWS Key Management Service Developer Guide.
This operation returns a public key and an import token. Use the public
key to encrypt the symmetric key material. Store the import token to send
with a subsequent ImportKeyMaterial
request.
You must specify the key ID of the symmetric 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. You cannot perform this
operation on an asymmetric CMK or on any CMK in a different AWS account.
To import key material, you must use the public key and import token from
the same response. These items are valid for 24 hours. The expiration date
and time appear in the GetParametersForImport
response. You cannot use
an expired token in an ImportKeyMaterial
request. If your key and token
expire, send another GetParametersForImport
request.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:GetParametersForImport (key policy)
Related operations:
ImportKeyMaterial
DeleteImportedKeyMaterial
get_parameters_for_import(Client, Input, Options)
get_public_key(Client, Input)
Returns the public key of an asymmetric CMK.
Unlike the private key of a asymmetric CMK, which never leaves AWS KMS
unencrypted, callers with kms:GetPublicKey
permission can download the
public key of an asymmetric CMK. You can share the public key to allow
others to encrypt messages and verify signatures outside of AWS KMS. For
information about symmetric and asymmetric CMKs, see Using Symmetric and
Asymmetric CMKs in the AWS Key Management Service Developer Guide.
You do not need to download the public key. Instead, you can use the
public key within AWS KMS by calling the Encrypt
, ReEncrypt
, or
Verify
operations with the identifier of an asymmetric CMK. When you use
the public key within AWS KMS, you benefit from the authentication,
authorization, and logging that are part of every AWS KMS operation. You
also reduce of risk of encrypting data that cannot be decrypted. These
features are not effective outside of AWS KMS. For details, see Special
Considerations for Downloading Public Keys.
To help you use the public key safely outside of AWS KMS, GetPublicKey
returns important information about the public key in the response,
including:
CustomerMasterKeySpec: The type of key material in the public key, such as
RSA_4096
orECC_NIST_P521
.KeyUsage: Whether the key is used for encryption or signing.
EncryptionAlgorithms or SigningAlgorithms: A list of the encryption algorithms or the signing algorithms for the key.
Although AWS KMS cannot enforce these restrictions on external operations, it is crucial that you use this information to prevent the public key from being used improperly. For example, you can prevent a public signing key from being used encrypt data, or prevent a public key from being used with an encryption algorithm that is not supported by AWS KMS. You can also avoid errors, such as using the wrong signing algorithm in a verification operation.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: Yes. To perform this operation with a CMK in a
different AWS account, specify the key ARN or alias ARN in the value of
the KeyId
parameter.
Required permissions: kms:GetPublicKey (key policy)
Related operations:CreateKey
get_public_key(Client, Input, Options)
import_key_material(Client, Input)
Imports key material into an existing symmetric AWS KMS customer master key (CMK) that was created without key material.
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.
You cannot perform this operation on an asymmetric CMK or on any CMK in a different AWS account. For more information about creating CMKs with no key material and then importing key material, see Importing Key Material in the AWS Key Management Service Developer Guide.
Before using this operation, call GetParametersForImport
. Its response
includes a public key and an import token. Use the public key to encrypt
the key material. Then, submit the import token from the same
GetParametersForImport
response.
When calling this operation, you must specify the following values:
The key ID or key ARN of a CMK with no key material. Its
Origin
must beEXTERNAL
.To create a CMK with no key material, call
CreateKey
and set the value of itsOrigin
parameter toEXTERNAL
. To get theOrigin
of a CMK, callDescribeKey
.)The encrypted key material. To get the public key to encrypt the key material, call
GetParametersForImport
.The import token that
GetParametersForImport
returned. You must use a public key and token from the sameGetParametersForImport
response.Whether the key material expires and if so, when. If you set an expiration date, AWS KMS deletes the key material from the CMK on the specified date, and the CMK becomes unusable. To use the CMK again, you must reimport the same key material. The only way to change an expiration date is by reimporting the same key material and specifying a new expiration date.
When this operation is successful, the key state of the CMK
changes from PendingImport
to Enabled
, and you can use the CMK.
If this operation fails, use the exception to help determine the problem.
If the error is related to the key material, the import token, or wrapping
key, use GetParametersForImport
to get a new public key and import token
for the CMK and repeat the import procedure. For help, see How To Import
Key Material in the AWS Key Management Service Developer Guide.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:ImportKeyMaterial (key policy)
Related operations:
DeleteImportedKeyMaterial
GetParametersForImport
import_key_material(Client, Input, Options)
list_aliases(Client, Input)
Gets a list of aliases in the caller's AWS account and region.
For more information about aliases, see CreateAlias
.
By default, the ListAliases
operation returns all aliases in the account
and region. To get only the aliases associated with a particular customer
master key (CMK), use the KeyId
parameter.
The ListAliases
response can include aliases that you created and
associated with your customer managed CMKs, and aliases that AWS created
and associated with AWS managed CMKs in your account. You can recognize
AWS aliases because their names have the format aws/
, such
as aws/dynamodb
.
The response might also include aliases that have no TargetKeyId
field.
These are predefined aliases that AWS has created but has not yet
associated with a CMK. Aliases that AWS creates in your account, including
predefined aliases, do not count against your AWS KMS aliases quota.
Cross-account use: No. ListAliases
does not return aliases in other AWS
accounts.
Required permissions: kms:ListAliases (IAM policy)
For details, see Controlling access to aliases in the AWS Key Management Service Developer Guide.
Related operations:
CreateAlias
DeleteAlias
UpdateAlias
list_aliases(Client, Input, Options)
list_grants(Client, Input)
Gets a list of all grants for the specified customer master key (CMK).
You must specify the CMK in all requests. You can filter the grant list by grant ID or grantee principal.
The GranteePrincipal
field in the ListGrants
response usually contains
the user or role designated as the grantee principal in the grant.
However, when the grantee principal in the grant is an AWS service, the
GranteePrincipal
field contains the service principal, which might
represent several different grantee principals.
Cross-account use: Yes. To perform this operation on a CMK in a different
AWS account, specify the key ARN in the value of the KeyId
parameter.
Required permissions: kms:ListGrants (key policy)
Related operations:
CreateGrant
ListRetirableGrants
RetireGrant
RevokeGrant
list_grants(Client, Input, Options)
list_key_policies(Client, Input)
Gets the names of the key policies that are attached to a customer master key (CMK).
This operation is designed to get policy names that you can use in a
GetKeyPolicy
operation. However, the only valid policy name is
default
.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:ListKeyPolicies (key policy)
Related operations:
GetKeyPolicy
PutKeyPolicy
list_key_policies(Client, Input, Options)
list_keys(Client, Input)
Gets a list of all customer master keys (CMKs) in the caller's AWS account and Region.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:ListKeys (IAM policy)
Related operations:
CreateKey
DescribeKey
ListAliases
ListResourceTags
list_keys(Client, Input, Options)
list_resource_tags(Client, Input)
Returns all tags on the specified customer master key (CMK).
For general information about tags, including the format and syntax, see Tagging AWS resources in the Amazon Web Services General Reference. For information about using tags in AWS KMS, see Tagging keys.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:ListResourceTags (key policy)
Related operations:
TagResource
UntagResource
list_resource_tags(Client, Input, Options)
list_retirable_grants(Client, Input)
Returns all grants in which the specified principal is the
RetiringPrincipal
in the grant.
You can specify any principal in your AWS account. The grants that are returned include grants for CMKs in your AWS account and other AWS accounts.
You might use this operation to determine which grants you may retire. To
retire a grant, use the RetireGrant
operation.
Cross-account use: You must specify a principal in your AWS account.
However, this operation can return grants in any AWS account. You do not
need kms:ListRetirableGrants
permission (or any other additional
permission) in any AWS account other than your own.
Required permissions: kms:ListRetirableGrants (IAM policy) in your AWS account.
Related operations:
CreateGrant
ListGrants
RetireGrant
RevokeGrant
list_retirable_grants(Client, Input, Options)
put_key_policy(Client, Input)
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. For help writing and formatting a JSON policy document, see the IAM JSON Policy Reference in the IAM User Guide . For examples of adding a key policy in multiple programming languages, see Setting a key policy in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:PutKeyPolicy (key policy)
Related operations:GetKeyPolicy
put_key_policy(Client, Input, Options)
re_encrypt(Client, Input)
Decrypts ciphertext and then reencrypts it entirely within AWS KMS.
You can use this operation to change the customer master key (CMK) under which data is encrypted, such as when you manually rotate a CMK or change the CMK that protects a ciphertext. You can also use it to reencrypt ciphertext under the same CMK, such as to change the encryption context of a ciphertext.
The ReEncrypt
operation can decrypt ciphertext that was encrypted by
using an AWS KMS CMK in an AWS KMS operation, such as Encrypt
or
GenerateDataKey
. It can also decrypt ciphertext that was encrypted by
using the public key of an asymmetric CMK outside of AWS KMS. However, it
cannot decrypt ciphertext produced by other libraries, such as the AWS
Encryption SDK or Amazon S3 client-side encryption. These libraries return
a ciphertext format that is incompatible with AWS KMS.
When you use the ReEncrypt
operation, you need to provide information
for the decrypt operation and the subsequent encrypt operation.
If your ciphertext was encrypted under an asymmetric CMK, you must use the
SourceKeyId
parameter to identify the CMK that encrypted the ciphertext. You must also supply the encryption algorithm that was used. This information is required to decrypt the data.If your ciphertext was encrypted under a symmetric CMK, the
SourceKeyId
parameter is optional. AWS KMS can get this information from metadata that it adds to the symmetric ciphertext blob. This feature adds durability to your implementation by ensuring that authorized users can decrypt ciphertext decades after it was encrypted, even if they've lost track of the CMK ID. However, specifying the source CMK is always recommended as a best practice. When you use theSourceKeyId
parameter to specify a CMK, AWS KMS uses only the CMK you specify. If the ciphertext was encrypted under a different CMK, theReEncrypt
operation fails. This practice ensures that you use the CMK that you intend.To reencrypt the data, you must use the
DestinationKeyId
parameter specify the CMK that re-encrypts the data after it is decrypted. You can select a symmetric or asymmetric CMK. If the destination CMK is an asymmetric CMK, you must also provide the encryption algorithm. The algorithm that you choose must be compatible with the CMK.When you use an asymmetric CMK to encrypt or reencrypt data, be sure to record the CMK and encryption algorithm that you choose. You will be required to provide the same CMK and encryption algorithm when you decrypt the data. If the CMK and algorithm do not match the values used to encrypt the data, the decrypt operation fails.
You are not required to supply the CMK ID and encryption algorithm when you decrypt with symmetric CMKs because AWS KMS stores this information in the ciphertext blob. AWS KMS cannot store metadata in ciphertext generated with asymmetric keys. The standard format for asymmetric key ciphertext does not include configurable fields.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: Yes. The source CMK and destination CMK can be in different AWS accounts. Either or both CMKs can be in a different account than the caller.
Required permissions:
kms:ReEncryptFrom permission on the source CMK (key policy)
kms:ReEncryptTo permission on the destination CMK (key policy)
To permit reencryption from or to a CMK, include the
"kms:ReEncrypt*"
permission in your key policy. This permission is
automatically included in the key policy when you use the console to
create a CMK. But you must include it manually when you create a CMK
programmatically or when you use the PutKeyPolicy
operation to set a key
policy.
Related operations:
Decrypt
Encrypt
GenerateDataKey
GenerateDataKeyPair
re_encrypt(Client, Input, Options)
retire_grant(Client, Input)
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 grantThe
GranteePrincipal
, ifRetireGrant
is an operation specified in the grant
You must identify the grant to retire by its grant token or by
a combination of the grant ID and the Amazon Resource Name (ARN) of the
customer master key (CMK). A grant token is a unique variable-length
base64-encoded string. A grant ID is a 64 character unique identifier of a
grant. The CreateGrant
operation returns both.
Cross-account use: Yes. You can retire a grant on a CMK in a different AWS account.
Required permissions:: Permission to retire a grant is specified in the grant. You cannot control access to this operation in a policy. For more information, see Using grants in the AWS Key Management Service Developer Guide.
Related operations:
CreateGrant
ListGrants
ListRetirableGrants
RevokeGrant
retire_grant(Client, Input, Options)
revoke_grant(Client, Input)
Revokes the specified grant for the specified customer master key (CMK).
You can revoke a grant to actively deny operations that depend on it.
Cross-account use: Yes. To perform this operation on a CMK in a different
AWS account, specify the key ARN in the value of the KeyId
parameter.
Required permissions: kms:RevokeGrant (key policy)
Related operations:
CreateGrant
ListGrants
ListRetirableGrants
RetireGrant
revoke_grant(Client, Input, Options)
schedule_key_deletion(Client, Input)
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 key 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 a CMK is a destructive and potentially dangerous operation. When
a CMK is deleted, all data that was encrypted under the CMK is
unrecoverable. To prevent the use of a CMK without deleting it, use
DisableKey
.
If you schedule deletion of a CMK from a custom key store, when the
waiting period expires, ScheduleKeyDeletion
deletes the CMK from AWS
KMS. Then AWS KMS makes a best effort to delete the key material from the
associated AWS CloudHSM cluster. However, you might need to manually
delete the orphaned key material from the cluster and its backups.
For more information about scheduling a CMK for deletion, see Deleting Customer Master Keys in the AWS Key Management Service Developer Guide.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:ScheduleKeyDeletion (key policy)
Related operations
CancelKeyDeletion
DisableKey
schedule_key_deletion(Client, Input, Options)
sign(Client, Input)
Creates a digital signature for a message or message digest by using the private key in an asymmetric CMK.
To verify the signature, use the Verify
operation, or use the public key
in the same asymmetric CMK outside of AWS KMS. For information about
symmetric and asymmetric CMKs, see Using Symmetric and Asymmetric CMKs in
the AWS Key Management Service Developer Guide.
Digital signatures are generated and verified by using asymmetric key pair, such as an RSA or ECC pair that is represented by an asymmetric customer master key (CMK). The key owner (or an authorized user) uses their private key to sign a message. Anyone with the public key can verify that the message was signed with that particular private key and that the message hasn't changed since it was signed.
To use the Sign
operation, provide the following information:
Use the
KeyId
parameter to identify an asymmetric CMK with aKeyUsage
value ofSIGN_VERIFY
. To get theKeyUsage
value of a CMK, use theDescribeKey
operation. The caller must havekms:Sign
permission on the CMK.Use the
Message
parameter to specify the message or message digest to sign. You can submit messages of up to 4096 bytes. To sign a larger message, generate a hash digest of the message, and then provide the hash digest in theMessage
parameter. To indicate whether the message is a full message or a digest, use theMessageType
parameter.Choose a signing algorithm that is compatible with the CMK.
When signing a message, be sure to record the CMK and the signing algorithm. This information is required to verify the signature.
To verify the signature that this operation generates, use the Verify
operation. Or use the GetPublicKey
operation to download the public key
and then use the public key to verify the signature outside of AWS KMS.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: Yes. To perform this operation with a CMK in a
different AWS account, specify the key ARN or alias ARN in the value of
the KeyId
parameter.
Required permissions: kms:Sign (key policy)
Related operations:Verify
sign(Client, Input, Options)
tag_resource(Client, Input)
Adds or edits tags on a customer managed CMK.
Each tag consists of a tag key and a tag value, both of which are case-sensitive strings. The tag value can be an empty (null) string.
To add a tag, specify a new tag key and a tag value. To edit a tag, specify an existing tag key and a new tag value.
You can use this operation to tag a customer managed CMK, but you cannot tag an AWS managed CMK, an AWS owned CMK, or an alias.
For general information about tags, including the format and syntax, see Tagging AWS resources in the Amazon Web Services General Reference. For information about using tags in AWS KMS, see Tagging keys.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:TagResource (key policy)
Related operations
UntagResource
ListResourceTags
tag_resource(Client, Input, Options)
untag_resource(Client, Input)
Deletes tags from a customer managed CMK.
To delete a tag, specify the tag key and the CMK.
When it succeeds, the UntagResource
operation doesn't return any output.
Also, if the specified tag key isn't found on the CMK, it doesn't throw an
exception or return a response. To confirm that the operation worked, use
the ListResourceTags
operation.
For general information about tags, including the format and syntax, see Tagging AWS resources in the Amazon Web Services General Reference. For information about using tags in AWS KMS, see Tagging keys.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:UntagResource (key policy)
Related operations
TagResource
ListResourceTags
untag_resource(Client, Input, Options)
update_alias(Client, Input)
Associates an existing AWS KMS alias with a different customer master key (CMK).
Each alias is associated with only one CMK at a time, although a CMK can have multiple aliases. The alias and the CMK must be in the same AWS account and region.
The current and new CMK must be the same type (both symmetric or both
asymmetric), and they must have the same key usage (ENCRYPT_DECRYPT
or
SIGN_VERIFY
). This restriction prevents errors in code that uses
aliases. If you must assign an alias to a different type of CMK, use
DeleteAlias
to delete the old alias and CreateAlias
to create a new
alias.
You cannot use UpdateAlias
to change an alias name. To change an alias
name, use DeleteAlias
to delete the old alias and CreateAlias
to
create a new alias.
Because an alias is not a property of a CMK, you can create, update, and
delete the aliases of a CMK without affecting the CMK. Also, aliases do
not appear in the response from the DescribeKey
operation. To get the
aliases of all CMKs in the account, use the ListAliases
operation.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions
kms:UpdateAlias on the alias (IAM policy).
kms:UpdateAlias on the current CMK (key policy).
kms:UpdateAlias on the new CMK (key policy).
For details, see Controlling access to aliases in the AWS Key Management Service Developer Guide.
Related operations:
CreateAlias
DeleteAlias
ListAliases
update_alias(Client, Input, Options)
update_custom_key_store(Client, Input)
Changes the properties of a custom key store.
Use the CustomKeyStoreId
parameter to identify the custom key store you
want to edit. Use the remaining parameters to change the properties of the
custom key store.
You can only update a custom key store that is disconnected. To disconnect
the custom key store, use DisconnectCustomKeyStore
. To reconnect the
custom key store after the update completes, use ConnectCustomKeyStore
.
To find the connection state of a custom key store, use the
DescribeCustomKeyStores
operation.
Use the parameters of UpdateCustomKeyStore
to edit your keystore
settings.
Use the NewCustomKeyStoreName parameter to change the friendly name of the custom key store to the value that you specify.
Use the KeyStorePassword parameter tell AWS KMS the current password of the
kmsuser
crypto user (CU) in the associated AWS CloudHSM cluster. You can use this parameter to fix connection failures that occur when AWS KMS cannot log into the associated cluster because thekmsuser
password has changed. This value does not change the password in the AWS CloudHSM cluster.Use the CloudHsmClusterId parameter to associate the custom key store with a different, but related, AWS CloudHSM cluster. You can use this parameter to repair a custom key store if its AWS CloudHSM cluster becomes corrupted or is deleted, or when you need to create or restore a cluster from a backup.
If the operation succeeds, it returns a JSON object with no properties.
This operation is part of the Custom Key Store feature feature in AWS KMS, which combines the convenience and extensive integration of AWS KMS with the isolation and control of a single-tenant key store.
Cross-account use: No. You cannot perform this operation on a custom key store in a different AWS account.
Required permissions: kms:UpdateCustomKeyStore (IAM policy)
Related operations:
ConnectCustomKeyStore
CreateCustomKeyStore
DeleteCustomKeyStore
DescribeCustomKeyStores
DisconnectCustomKeyStore
update_custom_key_store(Client, Input, Options)
update_key_description(Client, Input)
Updates the description of a customer master key (CMK).
To see the description of a CMK, use DescribeKey
.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: No. You cannot perform this operation on a CMK in a different AWS account.
Required permissions: kms:UpdateKeyDescription (key policy)
Related operations
CreateKey
DescribeKey
update_key_description(Client, Input, Options)
verify(Client, Input)
Verifies a digital signature that was generated by the Sign
operation.
Verification confirms that an authorized user signed the message with the
specified CMK and signing algorithm, and the message hasn't changed since
it was signed. If the signature is verified, the value of the
SignatureValid
field in the response is True
. If the signature
verification fails, the Verify
operation fails with an
KMSInvalidSignatureException
exception.
A digital signature is generated by using the private key in an asymmetric CMK. The signature is verified by using the public key in the same asymmetric CMK. For information about symmetric and asymmetric CMKs, see Using Symmetric and Asymmetric CMKs in the AWS Key Management Service Developer Guide.
To verify a digital signature, you can use the Verify
operation. Specify
the same asymmetric CMK, message, and signing algorithm that were used to
produce the signature.
You can also verify the digital signature by using the public key of the
CMK outside of AWS KMS. Use the GetPublicKey
operation to download the
public key in the asymmetric CMK and then use the public key to verify the
signature outside of AWS KMS. The advantage of using the Verify
operation is that it is performed within AWS KMS. As a result, it's easy
to call, the operation is performed within the FIPS boundary, it is logged
in AWS CloudTrail, and you can use key policy and IAM policy to determine
who is authorized to use the CMK to verify signatures.
The CMK that you use for this operation must be in a compatible key state. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
Cross-account use: Yes. To perform this operation with a CMK in a
different AWS account, specify the key ARN or alias ARN in the value of
the KeyId
parameter.
Required permissions: kms:Verify (key policy)
Related operations:Sign