Create Grant
kms_create_grant | R Documentation |
Adds a grant to a KMS key¶
Description¶
Adds a grant to a KMS key.
A grant is a policy instrument that allows Amazon Web Services
principals to use KMS keys in cryptographic operations. It also can
allow them to view a KMS key (describe_key
) and create and manage
grants. When authorizing access to a KMS key, grants are considered
along with key policies and IAM policies. Grants are often used for
temporary permissions because you can create one, use its permissions,
and delete it without changing your key policies or IAM policies.
For detailed information about grants, including grant terminology, see Grants in KMS in the Key Management Service Developer Guide . For examples of working with grants in several programming languages, see Programming grants.
The create_grant
operation returns a GrantToken
and a GrantId
.
-
When you create, retire, or revoke a grant, there might be a brief delay, usually less than five minutes, until the grant is available throughout KMS. This state is known as eventual consistency. Once the grant has achieved eventual consistency, the grantee principal can use the permissions in the grant without identifying the grant.
However, to use the permissions in the grant immediately, use the
GrantToken
thatcreate_grant
returns. For details, see Using a grant token in the Key Management Service Developer Guide . -
The
create_grant
operation also returns aGrantId
. You can use theGrantId
and a key identifier to identify the grant in theretire_grant
andrevoke_grant
operations. To find the grant ID, use thelist_grants
orlist_retirable_grants
operations.
The KMS key that you use for this operation must be in a compatible key state. For details, see Key states of KMS keys in the Key Management Service Developer Guide.
Cross-account use: Yes. To perform this operation on a KMS key in a
different Amazon Web Services account, specify the key ARN in the value
of the KeyId
parameter.
Required permissions: kms:CreateGrant (key policy)
Related operations:
-
list_grants
-
list_retirable_grants
-
retire_grant
-
revoke_grant
Eventual consistency: The KMS API follows an eventual consistency model. For more information, see KMS eventual consistency.
Usage¶
kms_create_grant(KeyId, GranteePrincipal, RetiringPrincipal, Operations,
Constraints, GrantTokens, Name, DryRun)
Arguments¶
KeyId
[required] Identifies the KMS key for the grant. The grant gives principals permission to use this KMS key.
Specify the key ID or key ARN of the KMS key. To specify a KMS key in a different Amazon Web Services account, you must use the key ARN.
For example:
Key ID:
1234abcd-12ab-34cd-56ef-1234567890ab
Key ARN:
arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab
To get the key ID and key ARN for a KMS key, use
list_keys
ordescribe_key
.GranteePrincipal
[required] The identity that gets the permissions specified in the grant.
To specify the grantee principal, use the Amazon Resource Name (ARN) of an Amazon Web Services principal. Valid principals include Amazon Web Services accounts, IAM users, IAM roles, federated users, and assumed role users. For help with the ARN syntax for a principal, see IAM ARNs in the Identity and Access Management User Guide .
RetiringPrincipal
The principal that has permission to use the
retire_grant
operation to retire the grant.To specify the principal, use the Amazon Resource Name (ARN) of an Amazon Web Services principal. Valid principals include Amazon Web Services accounts, IAM users, IAM roles, federated users, and assumed role users. For help with the ARN syntax for a principal, see IAM ARNs in the Identity and Access Management User Guide .
The grant determines the retiring principal. Other principals might have permission to retire the grant or revoke the grant. For details, see
revoke_grant
and Retiring and revoking grants in the Key Management Service Developer Guide.Operations
[required] A list of operations that the grant permits.
This list must include only operations that are permitted in a grant. Also, the operation must be supported on the KMS key. For example, you cannot create a grant for a symmetric encryption KMS key that allows the
sign
operation, or a grant for an asymmetric KMS key that allows thegenerate_data_key
operation. If you try, KMS returns aValidationError
exception. For details, see Grant operations in the Key Management Service Developer Guide.Constraints
Specifies a grant constraint.
Do not include confidential or sensitive information in this field. This field may be displayed in plaintext in CloudTrail logs and other output.
KMS supports the
EncryptionContextEquals
andEncryptionContextSubset
grant constraints, which allow the permissions in the grant only when the encryption context in the request matches (EncryptionContextEquals
) or includes (EncryptionContextSubset
) the encryption context specified in the constraint.The encryption context grant constraints are supported only on grant operations that include an
EncryptionContext
parameter, such as cryptographic operations on symmetric encryption KMS keys. Grants with grant constraints can include thedescribe_key
andretire_grant
operations, but the constraint doesn't apply to these operations. If a grant with a grant constraint includes thecreate_grant
operation, the constraint requires that any grants created with thecreate_grant
permission have an equally strict or stricter encryption context constraint.You cannot use an encryption context grant constraint for cryptographic operations with asymmetric KMS keys or HMAC KMS keys. Operations with these keys don't support an encryption context.
Each constraint value can include up to 8 encryption context pairs. The encryption context value in each constraint cannot exceed 384 characters. For information about grant constraints, see Using grant constraints in the Key Management Service Developer Guide. For more information about encryption context, see Encryption context in the Key Management Service Developer Guide .
GrantTokens
A list of grant tokens.
Use a grant token when your permission to call this operation comes from a new grant that has not yet achieved eventual consistency. For more information, see Grant token and Using a grant token in the Key Management Service Developer Guide.
Name
A friendly name for the grant. Use this value to prevent the unintended creation of duplicate grants when retrying this request.
Do not include confidential or sensitive information in this field. This field may be displayed in plaintext in CloudTrail logs and other output.
When this value is absent, all
create_grant
requests result in a new grant with a uniqueGrantId
even if all the supplied parameters are identical. This can result in unintended duplicates when you retry thecreate_grant
request.When this value is present, you can retry a
create_grant
request with identical parameters; if the grant already exists, the originalGrantId
is returned without creating a new grant. Note that the returned grant token is unique with everycreate_grant
request, even when a duplicateGrantId
is returned. All grant tokens for the same grant ID can be used interchangeably.DryRun
Checks if your request will succeed.
DryRun
is an optional parameter.To learn more about how to use this parameter, see Testing your KMS API calls in the Key Management Service Developer Guide.
Value¶
A list with the following syntax:
Request syntax¶
svc$create_grant(
KeyId = "string",
GranteePrincipal = "string",
RetiringPrincipal = "string",
Operations = list(
"Decrypt"|"Encrypt"|"GenerateDataKey"|"GenerateDataKeyWithoutPlaintext"|"ReEncryptFrom"|"ReEncryptTo"|"Sign"|"Verify"|"GetPublicKey"|"CreateGrant"|"RetireGrant"|"DescribeKey"|"GenerateDataKeyPair"|"GenerateDataKeyPairWithoutPlaintext"|"GenerateMac"|"VerifyMac"|"DeriveSharedSecret"
),
Constraints = list(
EncryptionContextSubset = list(
"string"
),
EncryptionContextEquals = list(
"string"
)
),
GrantTokens = list(
"string"
),
Name = "string",
DryRun = TRUE|FALSE
)
Examples¶
## Not run:
# The following example creates a grant that allows the specified IAM role
# to encrypt data with the specified KMS key.
svc$create_grant(
GranteePrincipal = "arn:aws:iam::111122223333:role/ExampleRole",
KeyId = "arn:aws:kms:us-east-2:444455556666:key/1234abcd-12ab-34cd-56ef-1234567890ab",
Operations = list(
"Encrypt",
"Decrypt"
)
)
## End(Not run)