Use CreateGrant com um AWS SDK ou CLI

        public static async Task Main()
        {
            var client = new AmazonKeyManagementServiceClient();

            // The identity that is given permission to perform the operations
            // specified in the grant.
            var grantee = "arn:aws:iam::111122223333:role/ExampleRole";

            // The identifier of the AWS KMS key to which the grant applies. You
            // can use the key ID or the Amazon Resource Name (ARN) of the KMS key.
            var keyId = "7c9eccc2-38cb-4c4f-9db3-766ee8dd3ad4";

            var request = new CreateGrantRequest
            {
                GranteePrincipal = grantee,
                KeyId = keyId,

                // A list of operations that the grant allows.
                Operations = new List<string>
                {
                    "Encrypt",
                    "Decrypt",
                },
            };

            var response = await client.CreateGrantAsync(request);

            string grantId = response.GrantId; // The unique identifier of the grant.
            string grantToken = response.GrantToken; // The grant token.

            Console.WriteLine($"Id: {grantId}, Token: {grantToken}");
        }
    }

Como criar uma concessão

O exemplo de create-grant a seguir cria uma concessão que permite que o usuário exampleUser use o comando decrypt na chave do KMS 1234abcd-12ab-34cd-56ef-1234567890ab de exemplo. A entidade principal descontinuada é o perfil adminRole. A concessão usa a restrição de concessão EncryptionContextSubset para conceder essa permissão apenas quando o contexto de criptografia na solicitação decrypt incluir o par de chave/valor "Department": "IT".

aws kms create-grant \
    --key-id 1234abcd-12ab-34cd-56ef-1234567890ab \
    --grantee-principal arn:aws:iam::123456789012:user/exampleUser \
    --operations Decrypt \
    --constraints EncryptionContextSubset={Department=IT} \
    --retiring-principal arn:aws:iam::123456789012:role/adminRole

Saída:

{
    "GrantId": "1a2b3c4d2f5e69f440bae30eaec9570bb1fb7358824f9ddfa1aa5a0dab1a59b2",
    "GrantToken": "<grant token here>"
}

Use o list-grants comando para visualizar informações detalhadas sobre a concessão.

Para obter mais informações, consulte Concessões no AWS KMS no Guia do desenvolvedor do AWS Key Management Service.

    /**
     * Grants permissions to a specified principal on a customer master key (CMK) asynchronously.
     *
     * @param keyId             The unique identifier for the customer master key (CMK) that the grant applies to.
     * @param granteePrincipal  The principal that is given permission to perform the operations that the grant permits on the CMK.
     * @return A {@link CompletableFuture} that, when completed, contains the ID of the created grant.
     * @throws RuntimeException If an error occurs during the grant creation process.
     */
    public CompletableFuture<String> grantKeyAsync(String keyId, String granteePrincipal) {
        List<GrantOperation> grantPermissions = List.of(
            GrantOperation.ENCRYPT,
            GrantOperation.DECRYPT,
            GrantOperation.DESCRIBE_KEY
        );

        CreateGrantRequest grantRequest = CreateGrantRequest.builder()
            .keyId(keyId)
            .name("grant1")
            .granteePrincipal(granteePrincipal)
            .operations(grantPermissions)
            .build();

        CompletableFuture<CreateGrantResponse> responseFuture = getAsyncClient().createGrant(grantRequest);
        responseFuture.whenComplete((response, ex) -> {
            if (ex == null) {
                logger.info("Grant created successfully with ID: " + response.grantId());
            } else {
                if (ex instanceof KmsException kmsEx) {
                    throw new RuntimeException("Failed to create grant: " + kmsEx.getMessage(), kmsEx);
                } else {
                    throw new RuntimeException("An unexpected error occurred: " + ex.getMessage(), ex);
                }
            }
        });

        return responseFuture.thenApply(CreateGrantResponse::grantId);
    }

suspend fun createNewGrant(
    keyIdVal: String?,
    granteePrincipalVal: String?,
    operation: String,
): String? {
    val operationOb = GrantOperation.fromValue(operation)
    val grantOperationList = ArrayList<GrantOperation>()
    grantOperationList.add(operationOb)

    val request =
        CreateGrantRequest {
            keyId = keyIdVal
            granteePrincipal = granteePrincipalVal
            operations = grantOperationList
        }

    KmsClient { region = "us-west-2" }.use { kmsClient ->
        val response = kmsClient.createGrant(request)
        return response.grantId
    }
}

    /***
     * @param string $keyId
     * @param string $granteePrincipal
     * @param array $operations
     * @param array $grantTokens
     * @return Result
     */
    public function createGrant(string $keyId, string $granteePrincipal, array $operations, array $grantTokens = [])
    {
        $args = [
            'KeyId' => $keyId,
            'GranteePrincipal' => $granteePrincipal,
            'Operations' => $operations,
        ];
        if($grantTokens){
            $args['GrantTokens'] = $grantTokens;
        }
        try{
            return $this->client->createGrant($args);
        }catch(KmsException $caught){
            if($caught->getAwsErrorMessage() == "InvalidGrantTokenException"){
                echo "The request was rejected because the specified grant token is not valid.\n";
            }
            throw $caught;
        }
    }

class GrantManager:
    def __init__(self, kms_client):
        self.kms_client = kms_client

    @classmethod
    def from_client(cls) -> "GrantManager":
        """
        Creates a GrantManager instance with a default KMS client.

        :return: An instance of GrantManager initialized with the default KMS client.
        """
        kms_client = boto3.client("kms")
        return cls(kms_client)


    def create_grant(
        self, key_id: str, principal: str, operations: [str]
    ) -> dict[str, str]:
        """
        Creates a grant for a key that lets a principal generate a symmetric data
        encryption key.

        :param key_id: The ARN or ID of the key.
        :param principal: The principal to grant permission to.
        :param operations: The operations to grant permission for.
        :return: The grant that is created.
        """
        try:
            return self.kms_client.create_grant(
                KeyId=key_id,
                GranteePrincipal=principal,
                Operations=operations,
            )
        except ClientError as err:
            logger.error(
                "Couldn't create a grant on key %s. Here's why: %s",
                key_id,
                err.response["Error"]["Message"],
            )
            raise