Define access policies using access levels

This page explains how to define Context-Aware Access policies using access levels.

An access level is a set of attributes assigned to requests based on their origin. Using information such as device type, IP address, and user identity, you can designate what level of access to grant. For example, you might assign a High_Trust level to connections from within your corporate network and a Medium_Trust level to external devices running approved operating systems.

An access policy is a container for all of your Access Context Manager resources, such as access levels and service perimeters.

For more information about access levels and access policies, see the Access Context Manager overview.

Limitations

When defining an access level, the following limitations apply:

  • You can't use an IP address as an attribute for Docker connections, nor can you use private IP addresses when connecting to private clusters using kubectl or a managed Looker instance.
  • Data Studio is always allowed unrestricted access to the Google Cloud APIs, regardless of Access Context Manager policies.
  • Device attributes aren't available for non-Google OAuth client applications.
  • You can't use a scoped access level.

Define your policy using access levels

Console

Create a basic access level:

  1. In the Google Cloud console, open the Access Context Manager page.

    Go to the Access Context Manager page

  2. If you are prompted, select a project.

  3. On the Access Context Manager page, click New.

  4. In the New Access Level pane, do the following:

    1. In the Access level title field, enter a title for the access level. The title must be at most 50 characters, start with a letter, and can contain only numbers, letters, underscores, and spaces.

    2. In the Conditions section, click the add button for the type of attribute you want to add, and then provide the values you want applied to that attribute.

      For a complete list of the attributes that you can add, see access level attributes.

      For example, if you want the access level to consider where a request is coming from within your network, you would select the IP Subnetworks attribute.

      Repeat this step to add multiple attributes to the same condition. When a condition has multiple attributes, all of the attributes must be met by the access request.

      An access level condition can include one of each type of attribute. Some attributes include additional options, such as the Device Policy attribute.

      Access levels support conditions based on user identity. However, to add identities to a condition, you must create or update the access level using the gcloud CLI or the API.

    3. Use the When condition is met, return option to specify whether you want the condition to require that a request meet all specified attributes (TRUE) or whether the request must meet anything but those attributes (FALSE).

      For example, if you want to deny requests from a certain IP address range of your network, specify the IP address range using the IP Subnetworks attribute and then set the condition to FALSE.

    4. Optionally, click Add another condition to add an additional condition to your access level and then repeat the previous two steps.

      For example, if you want to deny access to a subset of IP addresses within a broader IP address range, create a new condition, specify the subset IP address range for the IP Subnetworks attribute, and set the condition to return FALSE.

      Repeat this step to add multiple conditions to the same access level.

    5. If you created more than one condition, use Combine condition with to specify whether you want the access level to require a request to meet at least one of the conditions (OR), or all of the conditions (AND).

    6. Click Save.

gcloud

If you don't have an access policy for your organization, create one before continuing.

Use the gcloud access-context-manager levels create command to create an access level:

gcloud access-context-manager levels create LEVEL_NAME OPTIONS \
    --policy=POLICY

Replace the following:

  • LEVEL_NAME: The unique name for the access level. It must begin with a letter and include only letters, numbers, and underscores. The name can be a maximum of 50 characters.

  • OPTIONS: The required options from the following table.

    Options
    basic-level-spec

    A YAML file that specifies one or more conditions for the access level.

    title

    A short title for the access level. The access level's title is displayed in the Google Cloud console.

    combine-function

    (Optional) Determines how conditions are combined.

    Valid values: AND, OR

    description

    (Optional) A long-form description of the access level.

  • POLICY: The ID of your organization's access policy. If you have a default policy set, this parameter is optional.

Optionally, you can include any of the gcloud flags.

basic-level-spec YAML file

When you use the gcloud CLI to create an access level, you must provide a YAML file for the basic-level-spec option. The YAML file defines one or more conditions for the access level. Conditions must contain at least one attribute. When a condition contains more than one attribute, they are combined as either an AND operation (all must be true) or as a NAND operation (none can be true), depending on whether the negate attribute is included in the condition.

For a complete list of the attributes that you can include in your YAML file, see access level attributes.

For more information about access levels and YAML, refer to the example YAML for an access level.

Example command

gcloud access-context-manager levels create Device_Trust \
    --basic-level-spec=corpdevspec.yaml \
    --combine-function=AND \
    --description='Access level that conforms to corporate spec.' \
    --title='Device_Trust Extended' \
    --policy=1521580097614100

API

If you don't have an access policy for your organization, create one before continuing.

To create an access level, call accessLevels.create.

POST https://accesscontextmanager.googleapis.com/v1/accessPolicies/POLICY/accessLevels

POLICY is the ID of your organization's access policy.

Request body

The request body must include an AccessLevel resource that specifies the conditions you want for the new access level. Each Condition has one or more attributes that are evaluated as an AND operation (all must be true) or as a NAND operation (none can be true) depending on whether the negate field is set to true. The resulting evaluation determines whether the condition is met or not.

Response body

If successful, the response body for the call contains an Operation resource that provides details about the POST operation.

Common policy configurations

The following examples cover a few of the practical ways your organization might want to implement access levels. The examples assume your organization already has an access policy.

Limit access on a corporate network

This example describes how to create an access level condition that allows access only from a specified range of IP addresses (for example, those within a corporate network).

By restricting the range of IP addresses that are granted access, you can make exfiltrating data more difficult for an attacker that is inside or outside your organization.

For this example, assume you want to create an access level that will allow a group of internal auditors to access the Cloud Logging service for a project named sensitive-data. All of the devices for the auditors are assigned IPs on a subnet ranging between 203.0.113.0 and 203.0.113.127. You know there won't be any devices assigned to that subnet other than those used by the auditors.

If you want to use a private IP address range (for example, 192.168.0.0/16 or 172.16.0.0/12), see Allow access to protected resources from an internal IP address for additional information and an example implementation using VPC Service Controls.

Console

  1. In the Google Cloud console, open the Access Context Manager.

    Go to the Access Context Manager page

  2. If you are prompted, select project.

  3. At the top of the Access Context Manager page, click New.

  4. In the New Access Level pane, in the Conditions section, click Add attribute and then click IP Subnetworks.

  5. In the IP Subnetworks box, select either Public IP or Private IP.

    • If you select Public IP, enter one or more IPv4 or IPv6 ranges formatted as CIDR blocks.

      In this example, to limit access to only the auditors, enter 203.0.113.0/25 in the IP Subnetworks box.

    • If you select Private IP, click Select VPC networks. You can specify VPC networks using one of the three options available in the Import options list.

      • Option 1:

        1. Select Browse for VPC networks in your organization and select the VPC networks.

        2. Click Add selected VPC networks.

        3. Click Select IP subnets and select the subnets.

        4. Click Add IP subnets.

      • Option 2:

        1. Select Manually enter VPC network address and enter one or more VPC networks.

        2. Click Add VPC network.

        3. Click Select IP subnets and select the subnets.

        4. Click Add IP subnets.

      • Option 3:

        1. Select Upload CSV file (overwrites existing networks).

          If you use a CSV file to add VPC networks and subnets to an access level, Access Context Manager overwrites the previously selected VPC networks and subnets.

        2. Click Browse and upload the CSV file. In the CSV file, you must specify the VPC networks and subnets in the following format:

          VPC_NETWORK_NAME_1       | IP_RANGE_1       | IP_RANGE_2       | ...
VPC_NETWORK_NAME_2       | .                | .                | ...
.                        | .                | .                | ...
.                        | .                | .                | ...

        3. Click Import networks.

          Using the CSV file, Access Context Manager populates the VPC network names and subnet information in the VPC network address and IP subnetworks boxes respectively.

      For information about the VPC network name and private IP address format, see Use internal IP address in access levels.

  6. Click Save.

gcloud

  1. Create a YAML file for an access level that includes one or more IPv4 or IPv6 ranges formatted as CIDR blocks.

    In this example, to limit access to only the auditors, you would enter the following into the YAML file:

    - ipSubnetworks:
  - 203.0.113.0/25

    If you want to use a private IP address, you need to enter the following information in the YAML file:

    - vpcNetworkSources:
  - vpcSubnetwork:
      network: VPC_NETWORK_NAME
      vpcIpSubnetworks:
      - IP_RANGE

    Replace VPC_NETWORK_NAME and IP_RANGE with the values described in the Use internal IP address in access levels section.