ExAws.KMS.Core
AWS Key Management Service
AWS Key Management Service
AWS Key Management Service (KMS) is an encryption and key management web service. This guide describes the KMS actions that you can call programmatically. For general information about KMS, see the AWS Key Management Service Developer Guide
Note: AWS provides SDKs that consist of libraries and sample code for various programming languages and platforms (Java, Ruby, .Net, iOS, Android, etc.). The SDKs provide a convenient way to create programmatic access to KMS and AWS. 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 KMS.
Clients must support TLS (Transport Layer Security) 1.0. We recommend TLS 1.2. Clients must also support cipher suites with Perfect Forward Secrecy (PFS) such as Ephemeral Diffie-Hellman (DHE) or Elliptic Curve Ephemeral Diffie-Hellman (ECDHE). Most modern systems such as Java 7 and later support these modes.
Signing Requests
Requests must be signed by using an access key ID and a secret access key. We strongly recommend that you do not use your AWS account access key ID and secret key for everyday work with 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 KMS operations require Signature Version 4.
Recording API Requests
KMS supports AWS CloudTrail, a service that records 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 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.
AWS Security Token Service. This guide describes how to create and use temporary security credentials.
- Signing AWS API Requests. 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 APIs
Of the APIs discussed in this guide, the following will prove the most useful for most applications. You will likely perform actions other than these, such as creating keys and assigning policies, by using the console.
Encrypt
Decrypt
GenerateDataKey
GenerateDataKeyWithoutPlaintext
Summary↑
Types ↑
key_list :: [key_list_entry]
kms_internal_exception :: [{:message, error_message_type}]
description_type :: binary
dependency_timeout_exception :: [{:message, error_message_type}]
data_key_spec :: binary
create_grant_response :: [grant_id: grant_id_type, grant_token: grant_token_type]
list_grants_request :: [key_id: key_id_type, limit: limit_type, marker: marker_type]
invalid_ciphertext_exception :: [{:message, error_message_type}]
re_encrypt_request :: [ciphertext_blob: ciphertext_type, destination_encryption_context: encryption_context_type, destination_key_id: key_id_type, grant_tokens: grant_token_list, source_encryption_context: encryption_context_type]
aws_account_id_type :: binary
policy_name_type :: binary
invalid_key_usage_exception :: [{:message, error_message_type}]
retire_grant_request :: [grant_id: grant_id_type, grant_token: grant_token_type, key_id: key_id_type]
disabled_exception :: [{:message, error_message_type}]
delete_alias_request :: [{:alias_name, alias_name_type}]
get_key_policy_response :: [{:policy, policy_type}]
grant_token_type :: binary
disable_key_request :: [{:key_id, key_id_type}]
generate_data_key_request :: [encryption_context: encryption_context_type, grant_tokens: grant_token_list, key_id: key_id_type, key_spec: data_key_spec, number_of_bytes: number_of_bytes_type]
grant_id_type :: binary
decrypt_response :: [key_id: key_id_type, plaintext: plaintext_type]
key_metadata :: [aws_account_id: aws_account_id_type, arn: arn_type, creation_date: date_type, description: description_type, enabled: boolean_type, key_id: key_id_type, key_usage: key_usage_type]
create_key_response :: [{:key_metadata, key_metadata}]
malformed_policy_document_exception :: [{:message, error_message_type}]
get_key_rotation_status_request :: [{:key_id, key_id_type}]
list_aliases_response :: [aliases: alias_list, next_marker: marker_type, truncated: boolean_type]
already_exists_exception :: [{:message, error_message_type}]
list_aliases_request :: [limit: limit_type, marker: marker_type]
ciphertext_type :: binary
list_keys_request :: [limit: limit_type, marker: marker_type]
generate_data_key_without_plaintext_request :: [encryption_context: encryption_context_type, grant_tokens: grant_token_list, key_id: key_id_type, key_spec: data_key_spec, number_of_bytes: number_of_bytes_type]
generate_data_key_without_plaintext_response :: [ciphertext_blob: ciphertext_type, key_id: key_id_type]
generate_data_key_response :: [ciphertext_blob: ciphertext_type, key_id: key_id_type, plaintext: plaintext_type]
list_grants_response :: [grants: grant_list, next_marker: marker_type, truncated: boolean_type]
describe_key_response :: [{:key_metadata, key_metadata}]
not_found_exception :: [{:message, error_message_type}]
get_key_policy_request :: [key_id: key_id_type, policy_name: policy_name_type]
disable_key_rotation_request :: [{:key_id, key_id_type}]
unsupported_operation_exception :: [{:message, error_message_type}]
invalid_marker_exception :: [{:message, error_message_type}]
grant_operation :: binary
list_key_policies_response :: [next_marker: marker_type, policy_names: policy_name_list, truncated: boolean_type]
encrypt_response :: [ciphertext_blob: ciphertext_type, key_id: key_id_type]
key_list_entry :: [key_arn: arn_type, key_id: key_id_type]
grant_constraints :: [encryption_context_equals: encryption_context_type, encryption_context_subset: encryption_context_type]
decrypt_request :: [ciphertext_blob: ciphertext_type, encryption_context: encryption_context_type, grant_tokens: grant_token_list]
encryption_context_key :: binary
get_key_rotation_status_response :: [{:key_rotation_enabled, boolean_type}]
key_id_type :: binary
enable_key_rotation_request :: [{:key_id, key_id_type}]
limit_exceeded_exception :: [{:message, error_message_type}]
invalid_alias_name_exception :: [{:message, error_message_type}]
generate_random_request :: [{:number_of_bytes, number_of_bytes_type}]
limit_type :: integer
update_alias_request :: [alias_name: alias_name_type, target_key_id: key_id_type]
list_keys_response :: [keys: key_list, next_marker: marker_type, truncated: boolean_type]
re_encrypt_response :: [ciphertext_blob: ciphertext_type, key_id: key_id_type, source_key_id: key_id_type]
date_type :: integer
key_usage_type :: binary
grant_list_entry :: [constraints: grant_constraints, grant_id: grant_id_type, grantee_principal: principal_id_type, issuing_account: principal_id_type, operations: grant_operation_list, retiring_principal: principal_id_type]
invalid_arn_exception :: [{:message, error_message_type}]
update_key_description_request :: [description: description_type, key_id: key_id_type]
generate_random_response :: [{:plaintext, plaintext_type}]
boolean_type :: boolean
list_key_policies_request :: [key_id: key_id_type, limit: limit_type, marker: marker_type]
create_key_request :: [description: description_type, key_usage: key_usage_type, policy: policy_type]
create_grant_request :: [constraints: grant_constraints, grant_tokens: grant_token_list, grantee_principal: principal_id_type, key_id: key_id_type, operations: grant_operation_list, retiring_principal: principal_id_type]
create_alias_request :: [alias_name: alias_name_type, target_key_id: key_id_type]
arn_type :: binary
invalid_grant_token_exception :: [{:message, error_message_type}]
number_of_bytes_type :: integer
error_message_type :: binary
enable_key_request :: [{:key_id, key_id_type}]
put_key_policy_request :: [key_id: key_id_type, policy: policy_type, policy_name: policy_name_type]
describe_key_request :: [{:key_id, key_id_type}]
revoke_grant_request :: [grant_id: grant_id_type, key_id: key_id_type]
alias_name_type :: binary
encryption_context_value :: binary
alias_list_entry :: [alias_arn: arn_type, alias_name: alias_name_type, target_key_id: key_id_type]
marker_type :: binary
encrypt_request :: [encryption_context: encryption_context_type, grant_tokens: grant_token_list, key_id: key_id_type, plaintext: plaintext_type]
policy_type :: binary
principal_id_type :: binary
plaintext_type :: binary
Functions
Specs:
- create_alias(client :: ExAws.KMS.t, input :: create_alias_request) :: ExAws.Request.JSON.response_t
CreateAlias
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).
To associate an alias with a different key, call UpdateAlias
.
Note that you cannot create or update an alias that represents a key in another account.
Specs:
- create_alias!(client :: ExAws.KMS.t, input :: create_alias_request) :: ExAws.Request.JSON.success_t | no_return
Same as create_alias/2
but raise on error.
Specs:
- create_grant(client :: ExAws.KMS.t, input :: create_grant_request) :: ExAws.Request.JSON.response_t
CreateGrant
Adds a grant to a key to specify who can access the key and under what conditions. Grants are alternate permission mechanisms to key policies. For more information about grants, see Grants in the developer guide. If a grant is absent, access to the key is evaluated based on IAM policies attached to the user.
ListGrants
RetireGrant
RevokeGrant
Specs:
- create_grant!(client :: ExAws.KMS.t, input :: create_grant_request) :: ExAws.Request.JSON.success_t | no_return
Same as create_grant/2
but raise on error.
Specs:
- create_key(client :: ExAws.KMS.t, input :: create_key_request) :: ExAws.Request.JSON.response_t
CreateKey
Creates a customer master key. Customer master keys can be used to encrypt
small amounts of data (less than 4K) directly, but they are most commonly
used to encrypt or envelope data keys that are then used to encrypt
customer data. For more information about data keys, see GenerateDataKey
and GenerateDataKeyWithoutPlaintext
.
Specs:
- create_key!(client :: ExAws.KMS.t, input :: create_key_request) :: ExAws.Request.JSON.success_t | no_return
Same as create_key/2
but raise on error.
Specs:
- decrypt(client :: ExAws.KMS.t, input :: decrypt_request) :: ExAws.Request.JSON.response_t
Decrypt
Decrypts ciphertext. Ciphertext is plaintext that has been previously encrypted by using any of the following functions:
GenerateDataKey
GenerateDataKeyWithoutPlaintext
Encrypt
Note that if a caller has been granted access permissions to all keys
(through, for example, IAM user policies that grant Decrypt
permission on
all resources), then ciphertext encrypted by using keys in other accounts
where the key grants access to the caller can be decrypted. To remedy this,
we recommend that you do not grant Decrypt
access in an IAM user policy.
Instead grant Decrypt
access only in key policies. If you must grant
Decrypt
access in an IAM user policy, you should scope the resource to
specific keys or to specific trusted accounts.
Specs:
- decrypt!(client :: ExAws.KMS.t, input :: decrypt_request) :: ExAws.Request.JSON.success_t | no_return
Same as decrypt/2
but raise on error.
Specs:
- delete_alias(client :: ExAws.KMS.t, input :: delete_alias_request) :: ExAws.Request.JSON.response_t
DeleteAlias
Deletes the specified alias. To associate an alias with a different key,
call UpdateAlias
.
Specs:
- delete_alias!(client :: ExAws.KMS.t, input :: delete_alias_request) :: ExAws.Request.JSON.success_t | no_return
Same as delete_alias/2
but raise on error.
Specs:
- describe_key(client :: ExAws.KMS.t, input :: describe_key_request) :: ExAws.Request.JSON.response_t
DescribeKey
Provides detailed information about the specified customer master key.
Specs:
- describe_key!(client :: ExAws.KMS.t, input :: describe_key_request) :: ExAws.Request.JSON.success_t | no_return
Same as describe_key/2
but raise on error.
Specs:
- disable_key(client :: ExAws.KMS.t, input :: disable_key_request) :: ExAws.Request.JSON.response_t
DisableKey
Marks a key as disabled, thereby preventing its use.
Specs:
- disable_key!(client :: ExAws.KMS.t, input :: disable_key_request) :: ExAws.Request.JSON.success_t | no_return
Same as disable_key/2
but raise on error.
Specs:
- disable_key_rotation(client :: ExAws.KMS.t, input :: disable_key_rotation_request) :: ExAws.Request.JSON.response_t
DisableKeyRotation
Disables rotation of the specified key.
Specs:
- disable_key_rotation!(client :: ExAws.KMS.t, input :: disable_key_rotation_request) :: ExAws.Request.JSON.success_t | no_return
Same as disable_key_rotation/2
but raise on error.
Specs:
- enable_key(client :: ExAws.KMS.t, input :: enable_key_request) :: ExAws.Request.JSON.response_t
EnableKey
Marks a key as enabled, thereby permitting its use. You can have up to 25 enabled keys at one time.
Specs:
- enable_key!(client :: ExAws.KMS.t, input :: enable_key_request) :: ExAws.Request.JSON.success_t | no_return
Same as enable_key/2
but raise on error.
Specs:
- enable_key_rotation(client :: ExAws.KMS.t, input :: enable_key_rotation_request) :: ExAws.Request.JSON.response_t
EnableKeyRotation
Enables rotation of the specified customer master key.
Specs:
- enable_key_rotation!(client :: ExAws.KMS.t, input :: enable_key_rotation_request) :: ExAws.Request.JSON.success_t | no_return
Same as enable_key_rotation/2
but raise on error.
Specs:
- encrypt(client :: ExAws.KMS.t, input :: encrypt_request) :: ExAws.Request.JSON.response_t
Encrypt
Encrypts plaintext into ciphertext by using a customer master key. The
Encrypt
function has two primary use cases:
You can encrypt up to 4 KB of arbitrary data such as an RSA key, a database password, or other sensitive customer information.
- If you are moving encrypted data from one region to another, you can use this API to encrypt in the new region the plaintext data key that was used to encrypt the data in the original region. This provides you with an encrypted copy of the data key that can be decrypted in the new region and used there to decrypt the encrypted data.
Unless you are moving encrypted data from one region to another, you don’t
use this function to encrypt a generated data key within a region. You
retrieve data keys already encrypted by calling the GenerateDataKey
or
GenerateDataKeyWithoutPlaintext
function. Data keys don’t need to be
encrypted again by calling Encrypt
.
If you want to encrypt data locally in your application, you can use the
GenerateDataKey
function to return a plaintext data encryption key and a
copy of the key encrypted under the customer master key (CMK) of your
choosing.
Specs:
- encrypt!(client :: ExAws.KMS.t, input :: encrypt_request) :: ExAws.Request.JSON.success_t | no_return
Same as encrypt/2
but raise on error.
Specs:
- generate_data_key(client :: ExAws.KMS.t, input :: generate_data_key_request) :: ExAws.Request.JSON.response_t
GenerateDataKey
Generates a data key that you can use in your application to locally
encrypt data. This call returns a plaintext version of the key in the
Plaintext
field of the response object and an encrypted copy of the key
in the CiphertextBlob
field. The key is encrypted by using the master key
specified by the KeyId
field. To decrypt the encrypted key, pass it to
the Decrypt
API.
We recommend that you use the following pattern to locally encrypt data:
call the GenerateDataKey
API, use the key returned in the Plaintext
response field to locally encrypt data, and then erase the plaintext data
key from memory. Store the encrypted data key (contained in the
CiphertextBlob
field) alongside of the locally encrypted data.
Note:You should not call the Encrypt
function to re-encrypt your data
keys within a region. GenerateDataKey
always returns the data key
encrypted and tied to the customer master key that will be used to decrypt
it. There is no need to decrypt it twice. If you decide to use the optional
EncryptionContext
parameter, you must also store the context in full or
at least store enough information along with the encrypted data to be able
to reconstruct the context when submitting the ciphertext to the Decrypt
API. It is a good practice to choose a context that you can reconstruct on
the fly to better secure the ciphertext. For more information about how
this parameter is used, see Encryption
Context.
To decrypt data, pass the encrypted data key to the Decrypt
API.
Decrypt
uses the associated master key to decrypt the encrypted data key
and returns it as plaintext. Use the plaintext data key to locally decrypt
your data and then erase the key from memory. You must specify the
encryption context, if any, that you specified when you generated the key.
The encryption context is logged by CloudTrail, and you can use this log to
help track the use of particular data.
Specs:
- generate_data_key!(client :: ExAws.KMS.t, input :: generate_data_key_request) :: ExAws.Request.JSON.success_t | no_return
Same as generate_data_key/2
but raise on error.
Specs:
- generate_data_key_without_plaintext(client :: ExAws.KMS.t, input :: generate_data_key_without_plaintext_request) :: ExAws.Request.JSON.response_t
GenerateDataKeyWithoutPlaintext
Returns a data key encrypted by a customer master key without the plaintext
copy of that key. Otherwise, this API functions exactly like
GenerateDataKey
. You can use this API to, for example, satisfy an audit
requirement that an encrypted key be made available without exposing the
plaintext copy of that key.
Specs:
- generate_data_key_without_plaintext!(client :: ExAws.KMS.t, input :: generate_data_key_without_plaintext_request) :: ExAws.Request.JSON.success_t | no_return
Same as generate_data_key_without_plaintext/2
but raise on error.
Specs:
- generate_random(client :: ExAws.KMS.t, input :: generate_random_request) :: ExAws.Request.JSON.response_t
GenerateRandom
Generates an unpredictable byte string.
Specs:
- generate_random!(client :: ExAws.KMS.t, input :: generate_random_request) :: ExAws.Request.JSON.success_t | no_return
Same as generate_random/2
but raise on error.
Specs:
- get_key_policy(client :: ExAws.KMS.t, input :: get_key_policy_request) :: ExAws.Request.JSON.response_t
GetKeyPolicy
Retrieves a policy attached to the specified key.
Specs:
- get_key_policy!(client :: ExAws.KMS.t, input :: get_key_policy_request) :: ExAws.Request.JSON.success_t | no_return
Same as get_key_policy/2
but raise on error.
Specs:
- get_key_rotation_status(client :: ExAws.KMS.t, input :: get_key_rotation_status_request) :: ExAws.Request.JSON.response_t
GetKeyRotationStatus
Retrieves a Boolean value that indicates whether key rotation is enabled for the specified key.
Specs:
- get_key_rotation_status!(client :: ExAws.KMS.t, input :: get_key_rotation_status_request) :: ExAws.Request.JSON.success_t | no_return
Same as get_key_rotation_status/2
but raise on error.
Specs:
- list_aliases(client :: ExAws.KMS.t, input :: list_aliases_request) :: ExAws.Request.JSON.response_t
ListAliases
Lists all of the key aliases in the account.
Specs:
- list_aliases!(client :: ExAws.KMS.t, input :: list_aliases_request) :: ExAws.Request.JSON.success_t | no_return
Same as list_aliases/2
but raise on error.
Specs:
- list_grants(client :: ExAws.KMS.t, input :: list_grants_request) :: ExAws.Request.JSON.response_t
ListGrants
List the grants for a specified key.
Specs:
- list_grants!(client :: ExAws.KMS.t, input :: list_grants_request) :: ExAws.Request.JSON.success_t | no_return
Same as list_grants/2
but raise on error.
Specs:
- list_key_policies(client :: ExAws.KMS.t, input :: list_key_policies_request) :: ExAws.Request.JSON.response_t
ListKeyPolicies
Retrieves a list of policies attached to a key.
Specs:
- list_key_policies!(client :: ExAws.KMS.t, input :: list_key_policies_request) :: ExAws.Request.JSON.success_t | no_return
Same as list_key_policies/2
but raise on error.
Specs:
- list_keys(client :: ExAws.KMS.t, input :: list_keys_request) :: ExAws.Request.JSON.response_t
ListKeys
Lists the customer master keys.
Specs:
- list_keys!(client :: ExAws.KMS.t, input :: list_keys_request) :: ExAws.Request.JSON.success_t | no_return
Same as list_keys/2
but raise on error.
Specs:
- put_key_policy(client :: ExAws.KMS.t, input :: put_key_policy_request) :: ExAws.Request.JSON.response_t
PutKeyPolicy
Attaches a policy to the specified key.
Specs:
- put_key_policy!(client :: ExAws.KMS.t, input :: put_key_policy_request) :: ExAws.Request.JSON.success_t | no_return
Same as put_key_policy/2
but raise on error.
Specs:
- re_encrypt(client :: ExAws.KMS.t, input :: re_encrypt_request) :: ExAws.Request.JSON.response_t
ReEncrypt
Encrypts data on the server side with a new customer master key without exposing the plaintext of the data on the client side. The data is first decrypted and then encrypted. This operation can also be used to change the encryption context of a ciphertext.
Unlike other actions, ReEncrypt
is authorized twice - once as
ReEncryptFrom
on the source key and once as ReEncryptTo
on the
destination key. We therefore recommend that you include the
"action":"kms:ReEncrypt*"
statement in your key policies to permit
re-encryption from or to the key. The statement is included automatically
when you authorize use of the key through the console but must be included
manually when you set a policy by using the PutKeyPolicy
function.
Specs:
- re_encrypt!(client :: ExAws.KMS.t, input :: re_encrypt_request) :: ExAws.Request.JSON.success_t | no_return
Same as re_encrypt/2
but raise on error.
Specs:
- retire_grant(client :: ExAws.KMS.t, input :: retire_grant_request) :: ExAws.Request.JSON.response_t
RetireGrant
Retires a grant. You can retire a grant when you’re done using it to clean up. You should revoke a grant when you intend to actively deny operations that depend on it. The following are permitted to call this API:
The account that created the grant
The
RetiringPrincipal
, if present- The
GranteePrincipal
, ifRetireGrant
is a grantee operation
The grant to retire must be identified by its grant token or by a
combination of the key ARN and the grant ID. A grant token is a unique
variable-length base64-encoded string. A grant ID is a 64 character unique
identifier of a grant. Both are returned by the CreateGrant
function.
Specs:
- retire_grant!(client :: ExAws.KMS.t, input :: retire_grant_request) :: ExAws.Request.JSON.success_t | no_return
Same as retire_grant/2
but raise on error.
Specs:
- revoke_grant(client :: ExAws.KMS.t, input :: revoke_grant_request) :: ExAws.Request.JSON.response_t
RevokeGrant
Revokes a grant. You can revoke a grant to actively deny operations that depend on it.
Specs:
- revoke_grant!(client :: ExAws.KMS.t, input :: revoke_grant_request) :: ExAws.Request.JSON.success_t | no_return
Same as revoke_grant/2
but raise on error.
Specs:
- update_alias(client :: ExAws.KMS.t, input :: update_alias_request) :: ExAws.Request.JSON.response_t
UpdateAlias
Updates an alias to associate it with a different 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).
An alias is not a property of a key. Therefore, an alias can be associated with and disassociated from an existing key without changing the properties of the key.
Note that you cannot create or update an alias that represents a key in another account.
Specs:
- update_alias!(client :: ExAws.KMS.t, input :: update_alias_request) :: ExAws.Request.JSON.success_t | no_return
Same as update_alias/2
but raise on error.
Specs:
- update_key_description(client :: ExAws.KMS.t, input :: update_key_description_request) :: ExAws.Request.JSON.response_t
UpdateKeyDescription
Updates the description of a key.
Specs:
- update_key_description!(client :: ExAws.KMS.t, input :: update_key_description_request) :: ExAws.Request.JSON.success_t | no_return
Same as update_key_description/2
but raise on error.