Cloud Access Management Practices

Last updated: 2021-04-12 17:20:54

Overview

Cloud Access Management (CAM) is a Tencent Cloud authentication and authorization service, which helps you manage the access to your Tencent Cloud resources. You can manage authorized objects, resources, and operations, and set policies to control access when granting permissions.

Features

Granting access to resources under the root account

You can grant the access to the resources under your root account to other users, including sub-accounts and other root accounts, without sharing the identity credentials of your root account.

Granular permission management

Different access permissions to different resources can be granted to different users. For example, some sub-accounts can be granted the read access to a COS bucket, while some other sub-accounts or root accounts can own the write access to a COS object. The above-mentioned resources, access permissions and users can all be managed in batch.

Eventual consistency

CAM currently supports data synchronization across Tencent Cloud regions by copying policies. CAM policies can be modified timely, but it may take some time for those policies synced across regions to take effect. Additionally, CAM uses cache (currently valid for one minute) to improve performance, and any policy update does not take effect until cache expires.

Use Cases

Enterprise sub-account access permission management

Enterprises may need to grant the minimal access permission for their cloud resources to all kinds of employees. Assume that an enterprise owns many cloud resources (CVM, VPC instances, CDN instances, COS buckets and objects, etc.) and many employees (developers, testers, OPS personnel, etc.).
The developers need the read and write permissions to the project-related cloud resources on the development servers. Testers need the read and write permissions to the project-related cloud resources on the test servers. OPS personnel are responsible for the purchase and daily operation of the servers. If the duty or project of an employee changes, the corresponding permissions should be terminated.

Cross-enterprise access permission management

There are cases where enterprises may need to share their cloud resources. For example, a company which has many cloud resources wants to focus on product R&D and outsource the operation of its cloud resources to another company. It also need to revoke all permissions that have been granted as soon as the outsourcing service contracts are terminated.

Policy Syntax

A CAM policy consists of several elements and is used to describe specific information about authorization. Core elements include principal, action, resource, condition, and effect. For more information, please see Access Policy Language Overview.

Note：

There is no particular sequence in the description of policy syntax. However, please note that the action element is case-sensitive.

If there are no particular conditions required, the condition element is optional.

You cannot define the principal element in the console, but only through the policy management APIs or policy syntax parameters.

Core elements

Core Element	Description	Required
version	Specifies the version of the policy syntax. Valid value: 2.0	Yes
principal	Describes the entity to be authorized by the policy, including users (developers, sub-accounts, anonymous users), and user groups	This element can only be used in policy management APIs and policy syntax-related parameters
statement	Describes the details on a permission or a permission set defined by other elements including effect, action, resource, and condition. One policy has only one statement.	Yes
action	Describes the action to be allowed or denied. It can be an API operation or a set of API operations. This element is case-sensitive, e.g. `name/cos:GetService`	Yes
resource	Describes the resource to which the permission applies. A resource is described in a six-segment format. Detailed resource definitions vary by product. For more information on how to specify a resource, see the documentation for the product whose resources you are writing a statement for	Yes
condition	Describes the condition for the policy to take effect. A condition consists of operator, action key, and action value. A condition value may be time, IP address, etc. Some services allow you to specify additional values in a condition	No
effect	Describes whether the statement result is "allow" or "deny"	Yes

Policy limits

Limit	Value
Number of user groups in a root account	300
Number of sub-accounts in a root account	1000
Number of roles in a root account	1000
Number of user groups that a sub-account can be added to	10
Number of root accounts with which a collaborator can be associated	10
Number of sub-accounts in a user group	100
Number of custom policies created for a root account	1500
Number of policies associated to a CAM user/user group/role	200
Maximum characters allowed for a policy syntax	4096

Example policy

The policy in this example allows the sub-account with ID 100000000011 under the root account with ID 100000000001 (APPID: 1250000000) to PUT Object and GET Object on the bucket "examplebucket-bj" in Beijing region and the object “exampleobject” in the bucket “examplebucket-gz” in Guangzhou region, on condition that the access IP falls within the IP address range 10.*.*.10/24.

{
    "version": "2.0",
    "principal": {
        "qcs": ["qcs::cam::uin/100000000001:uin/100000000011"]

        
    },
    "statement": [{
            "effect": "allow",
            "action": ["name/cos:PutObject", "name/cos:GetObject"],
            "resource": ["qcs::cos:ap-beijing:uid/1250000000:examplebucket-bj-1250000000/*",
                "qcs::cos:ap-guangzhou:uid/1250000000:examplebucket-gz-1250000000/exampleobject"
            ],
            "condition": {
                "ip_equal": {
                    "qcs:ip": "10.*.*.10/24"
                }
            }
        
    }]
}

Recent Pages

Cloud Access Management Practices

Overview