Configure Sequence Mitigation
You can use Sequence Rules to establish a set of known behavior for API clients.
For example, you may expect that API requests made during a bank funds transfer could conform to the following order in time:
| Order | Method | Path | Description |
|---|---|---|---|
| 1 | GET | /api/v1/users/{user_id}/accounts | user_id is the active user. |
| 2 | GET | /api/v1/accounts/{account_id}/balance | account_id is one of the user’s accounts. |
| 3 | GET | /api/v1/accounts/{account_id}/balance | account_id is a different account belonging to the user. |
| 4 | POST | /api/v1/transferFunds | This contains a request body detailing an account to transfer funds from, an account to transfer funds to, and an amount of money to transfer. |
You may want to enforce that an API user requests GET /api/v1/users/{user_id}/accounts before GET /api/v1/accounts/{account_id}/balance and that you request GET /api/v1/accounts/{account_id}/balance before POST /api/v1/transferFunds.
Using Sequence Mitigation, you can enforce that request pattern with two new Sequence Mitigation rules.
You can also set up a negative security model with Sequence Mitigation. See Configuration to understand how to distinguish between rule types using the kind field.
Configure
Configuring Sequence Mitigation is currently available only via API.
Example of a rule object{ "id": "d4909253-390f-4956-89fd-92a5b0cd86d8", "title": "<RULE_TITLE>", "kind": "allow", "action": "block", "sequence": [ "0d9bf70c-92e1-4bb3-9411-34a3bcc59003", "b704ab4d-5be0-46e0-9875-b2b3d1ab42f9" ], "priority": 0, "last_updated": "2023-07-24T12:06:51.796286Z", "created_at": "2023-07-24T12:06:51.796286Z"
}
This rule enforces that a request to endpoint 0d9bf70c-92e1-4bb3-9411-34a3bcc59003 must come before a request to endpoint b704ab4d-5be0-46e0-9875-b2b3d1ab42f9.
Otherwise, the request to endpoint b704ab4d-5be0-46e0-9875-b2b3d1ab42f9 is blocked.
Fields
Field name | Description | Possible Values | Example |
|---|---|---|---|
id | An opaque identifier that identifies a rule. | A UUID | "d4909253-390f-4956-89fd-92a5b0cd86d8" |
title | A string that helps to identify the rule. | A value between 1 and 50 characters | "Allow checkout sequence" |
kind | Defines the semantics of this rule. Block rules have a negative security model and allow to explicitly deny a sequence. Allow rules have a positive security model and deny everything but the configured sequence. | block, allow | "block" |
action | What firewall action should we do when the rule matches. | block,log | "log" |
sequence | Denotes the operations (from Endpoint Management) that make up the sequence for this rule. We currently only support sequences of length two. The first operation will be the starting endpoint and the second operation will be the ending endpoint. | An array with two valid operation IDs from Endpoint Management | ["0d9bf70c-92e1-4bb3-9411-34a3bcc59003", "b704ab4d-5be0-46e0-9875-b2b3d1ab42f9"] |
priority | Denotes the precedence of this rule in relation to all other rules. Rules with a higher priority value are evaluated before those with a lower value. If two rules have the same priority, they are evaluated in the order in which they were added. | A valid integer | 10 |
last_updated | When this rule was last changed. | A date string | 2023-05-02T12:06:51.796286Z |
created_at | When this rule was created. | A date string | 2023-05-02T12:06:51.796286Z |
You can find an endpoint’s operation ID by exporting the schema in Endpoint Management or via the API.
List sequence rules
Use the GET command to list rules.
cURL commandcurl "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/seqrules"
Add a single sequence rule
Use the POST command to create a single rule.
This adds a single rule to all existing rules. Priority can be used to place the rule between, before, or after another rule.
The response will reflect the rule that has been written with its ID. In case something is not right with the rule, an appropriate error message with a json path pointing towards the issue will be provided.
Example using cURLcurl POST "https://api.cloudflare.com/client/v4/zones/{zoneID}/api_gateway/seqrules/rules" \
--header "Content-Type: application/json" \
--data '{ "title": "string", "kind": "block", "action": "block", "sequence": [ "0d9bf70c-92e1-4bb3-9411-34a3bcc59003", "b704ab4d-5be0-46e0-9875-b2b3d1ab42f9" ], "priority": 0}'
Add multiple sequence rules
Use the PUT command to set up new rules in bulk.
This will overwrite any existing rules and replace them with the rules specified in the body. Setting an empty array for the rules removes all rules.
The response will reflect the rules that have been written with their IDs in case something is not right with the rules, an appropriate error message with a json path pointing towards the issue will be provided.
Example using cURLcurl --request PUT "https://api.cloudflare.com/client/v4/zones/{zoneID}/api_gateway/seqrules" \
--header "Content-Type: application/json" \
--data '{ "rules": [ { "title": "<RULE_TITLE>", "kind": "block", "action": "block", "sequence": [ "0d9bf70c-92e1-4bb3-9411-34a3bcc59003", "b704ab4d-5be0-46e0-9875-b2b3d1ab42f9" ], "priority": 0 } ]}'
Delete a rule
Use the DELETE command with its rule ID to delete a rule.
cURL commandcurl --request DELETE "https://api.cloudflare.com/client/v4/zones/{zone_id}/api_gateway/seqrules/rules/d4909253-390f-4956-89fd-92a5b0cd86d8"