API Selection Filters

This section describes the conditions that act as selection criteria for choosing APIs that are eligible for a particular test. It also filters out APIs that are not eligible.

Example:

Example of API Selection filter

# THIS IS API SELECTION FILTER
api_selection_filters:
  response_code:
    gte: 200
    lt: 300
  url:
    belongs_to_collections:
      - payment
      - checkout
      - juiceshop.akto.io
    contains_either:
      - login
      - signin
      - sign-in
      - log-in
  request_payload:
    for_one:
      key: 
        contains_either:
          - password
          - pwd
          - pass
          - passwd
  request_headers:
    for_one:
      key:
        contains_either: cookie
        extract: header_key

Syntax

1. Parent Operators

2. Data Operators

3. Collection Operators

4. Combining Conditions using Boolean Operators

Parent Operators

Each condition block begins with a parent operator. Parent Operators indicate the property of the API you are testing. All the conditions will apply to these parent operators. Parent Operators can have the following values:

Parent Operator	Description
response_code	This denotes that the conditions will be applied on response code of the api
method	This denotes that the conditions will be applied on http method of the api
url	This denotes that the conditions will be applied on http url of the api
request_payload	This denotes that the conditions will be applied on request payload of the api
response_payload	This denotes that the conditions will be applied on response payload of the api
request_headers	This denotes that the condition will be applied on request headers of the api
response_headers	This denotes that the condition will be applied on response headers of the api
query_param	This denotes that the condition will be applied on query params of the api

Data Operators

Each Parent Operator should contain one or more Data Operators that describe the exact condition to be applied to the Parent Property. Data Operators can have the following values:

Data Operator	Expected Arguments	Description
belongs_to_collections	List	Checks whether the parent property belongs to one of the specified collections in the list. The API must be part of at least one of the collections specified to satisfy this condition.
contains_either	List/Non List	Checks whether the parent property contains the specified input. If input is an array, any one of the input element should satisfy this condition.
contains_all	List/Non List	Checks whether the parent property contains the specified input. If input is an array, all of the input element should satisfy this condition.
regex	List/Non List	Checks whether the parent property contains a match for the regex specified in the specified input. If input is an array, one of the regex input should have a match
eq	Non List	Checks whether the parent property is equal to the specified input.
neq	Non List	Checks whether the parent property is not equal equal to the specified input.
gt	Non List	Checks whether the parent property is greater than to the specified input.
gte	Non List	Checks whether the parent property is greater than equal to the specified input.
lt	Non List	Checks whether the parent property is lesser than the specified input.
lte	Non List	Checks whether the parent property is lesser than equal to to the specified input.
not_contains	List/Non List	Checks whether the parent property does not contain the specified input. If input is an array, all of the input element should satisfy this condition.
not_contains_either	List/Non List	Checks whether the parent property does not contain the specified input. If input is an array, any one of the input element should satisfy this condition.
contains_jwt	boolean	Checks whether the parent property contains/not contains a jwt token
cookie_expire_filter	boolean	Checks if the cookie expires in next 30 days

belongs_to_collections

Checks whether the parent property belongs to one of the specified collections in the list. The API must be part of at least one of the collections specified to satisfy this condition.

Example 1

Example of belongs_to_collections

url:
  belongs_to_collections:
    - payment
    - checkout

# APIs that belong to either the payment or checkout collection would match the above condition.
# Match Example - An API categorized as part of the payment collection
# Invalid Example - An API that belongs only to the auth collection

contains_either

Checks whether the parent property contains the specified input. If input is an array, any one of the input element should satisfy this condition.

Example 1

Example of contains_either

url:
	contains_either: login
# Endpoints that contain login substring would match the above condition.
# Match Example - https://xyz.com/user/login
# Invalid Example - https://xyz.com/user/register

Example 2

Example of contains_either

url:
	contains_either:
			- https
			- login
# Endpoints that contain either https or login substring would match the above condition.
# Match Examples - https://xyz.com/user/login | https://xyz.com/user/register
# Invalid Example - http://xyz.com/user/data

👉🏻 In simple language: The above yaml syntax is filtering APIs with url containing the keywords ‘https’ or ‘login’

contains_all

Checks whether the parent property contains the specified input. If input is an array, all of the input mlelement should satisfy this condition.

Example 1

Example 1

url:
	contains_all: login
# Endpoints that contain login substring would match the above condition.
# Match Example - https://xyz.com/user/login 
# Invalid Example - https://xyz.com/user/register

Example 2

Example for contains_all

url:
	contains_all:
			- https
			- login
# Endpoints that contain both https and login substring would match the above condition.
# Match Example - https://xyz.com/user/login 
# Invalid Example - http://xyz.com/user/login | https://xyz.com/user/register

👉🏻 In simple language: The above yaml syntax is filtering APIs with url containing the keywords ‘https’ and ‘login’

regex

Checks whether the parent property contains a match for the regex specified in the specified input. If input is an array, one of the regex input should have a match.

Example 1

Example for regex

request_payload:
	contains_either: .*user*.
# If any part of request payload matches the above regex, it would be considered a match.
# Match Example - {”id”: 123, “data”:{”userName”: “abc”}} - userName is a valid match for above regex
# Invalid Example - {”id”: 123, “data”:{”name”: “abc”}} - no part of the request payload matches the above regex

eq

Checks whether the parent property is equal to the specified input.

Example 1

Example for eq

method:
	eq: POST
# All the Post Endpoints will match the above condition.
# Match Example - POST https://xyz.com/getById
# Invalid Example - GET https://xyz.com/getById

gt

Checks whether the parent property is greater than the specified input.

Example 1

Example for gt

response_code:
	gt: 204
# Endpoints with response greater than 204 will match the above condition.
# Match Example - Response codes like 205, 302
# Invalid Example - Response codes like 200, 201

gte

Checks whether the parent property is greater than or equal to the specified input.

Example 1

Example for gte

response_code:
	gte: 204
# Endpoints with response greater than or equal to 204 will match the above condition.
# Match Example - Response codes like 204, 302
# Invalid Example - Response codes like 200, 201

lt

Checks whether the parent property is lesser than the specified input.

Example 1

Example for lt

response_code:
	lt: 204
# Endpoints with response less than 204 will match the above condition.
# Match Example - Response codes like 200, 201
# Invalid Example - Response codes like 204, 205

lte

Checks whether the parent property is lesser than or equal to the specified input.

Example 1

response_code:
	lte: 204
# Endpoints with response less than or equal to 204 will match the above condition.
# Match Example - Response codes like 200, 204
# Invalid Example - Response codes like 205, 302

not_contains

Checks whether the parent property does not contain the specified input. If input is an array, all of the input element should satisfy this condition.

Example 1

Example of not_contains

response_payload:
	not_contains: 
		- "normal_user"
		- "new"
# Response Payloads not containing strings ("normal_user", "new") will match the above condition.

Match Example for above

{"id": 100, "userdata": {"name": "xyz", "status": "admin", "identifier": "old"}}

Invalid Example for above

1. {"id": 100, "userdata": {"name": "xyz", "status": "normal_user", "identifier": "old"}}

2. {"id": 100, "userdata": {"name": "xyz", "status": "admin", "identifier": "new"}}

3. {"id": 100, "userdata": {"name": "xyz", "status": "normal_user", "identifier": "new"}}

not_contains_either

Checks whether the parent property does not contain the specified input. If input is an array, any one of the input element should satisfy this condition.

Example 1

Example of not_contains_either

response_payload:
	not_contains_either: 
		- "normal_user"
		- "new"
# Response Payloads which does not contain either ("normal_user") or ("new") will match the above condition.


# Match Example - 
1. {"id": 100, "userdata": {"name": "xyz", "status": "admin",
	    "identifier": "old"}}
2. {"id": 100, "userdata": {"name": "xyz", "status": "normal_user",
	    "identifier": "old"}}
3. {"id": 100, "userdata": {"name": "xyz", "status": "admin",
	    "identifier": "new"}}
# Invalid Example - 
1. {"id": 100, "userdata": {"name": "xyz", "status": "normal_user",
	    "identifier": "new"}}

contains_jwt

Checks whether the parent property contains/not contains a JWT token.

Example 1

Example of contains_jwt

request_headers:
	for_one:
		value:
			contains_jwt: true 

# Request Headers which contain jwt token will match the above condition.
# Match Example - 
	1. Headers - 
			Content-Type: application/json
			Authorization: <Bearer-Token>
# Invalid Example - 
	1. Headers -
			Content-Type: application/json
			Authorization: 23sdf234r3aaa

Collection Operators

These operators are useful for queries that involve individual keys and values in payloads and headers, rather than applying the condition to the entire payload as a string. To achieve the desired result, they must be combined with a data operator.

for_one

This collection operator is used to imply that either of key or value in the entire payload should satisfy the condition.

Example 1

Request Payload {”id”: 123, “data”:{”Username”: “abc”}}

Let’s say we want to check if there is a key present in request payload which contains name. We can represent that in the following yaml syntax -

Example of for_one

api_selection_filters:
	request_payload:
		for_one:
			key:
				contains_either: name

# ”for_one” here specified that the condition is applied on key. 
# Data operand 'contains_either' checks whether any key in the request payload contains string (”name”)

👉🏻 In simple language: The above yaml syntax is filtering APIs with any key of the request payload containing the keyword ‘name’

Example 2

Request Payload {”id”: 123, ”status”: “admin”, “createdAt”: 1688364964}

Let’s say we want to check if there is a key present in request payload which is equal to status, and contains a value like (admin). We can represent that in the following yaml syntax -

Example of for_one

api_selection_filters:
	request_payload:
		for_one:
			key:
				eq: status
			value:
				regex: .*admin.*
# ”for_one” here specified that the condition is applied on both key and value. 
# Data operand 'eq' checks whether any key in the request payload is exactly equalt to (”status”).
# Data operand 'regex' checks whether any value in the status key matches the provided regex.

👉🏻 In simple language: The above yaml syntax is filtering APIs with any key of the request payload equal to ‘status’ and the same key having value which matches specified regex.

Matching Payloads

1. {”id”: 123, ”status”: “admin”, “createdAt”: 1688364964}

2. {”status”: “administrator”, “active”: true}

3. {”userInfo”: {”name”: “testUser”, “status”: “admin”}, “lastLoginTs”: 1688364964}

Invalid Examples

1. {”id”: 123, “createdAt”: 1688364964}

2. {”id”: 123, ”status”: “normal”, “createdAt”: 1688364964}

3. {”id”: 123, ”access”: “admin”, “status”: “active”} Here key is named status, and a value matches regex .*admin*., but there is no single key value pair which satisfies both conditions.

Body Operators

These operators are useful for applying conditions specifically on request payload, response payload strings. To achieve the desired result, they must be combined with a data operator. Currently there are 2 types of body operators -

length

Length operator is used for applying conditions on the request/response payload length. Let’s explore this more through the below example

Examples of length

#Example 1
request_payload:
	length:
		gt: 0

# Here we want to apply a condition, where api's should have a non-empty request payload.
# We use length operator, and combine it with data operator(gt), where we specify length to be greater than 0
 
#Example 2
response_payload:
	length:
		gte: 10

# Here we want to apply a condition, where api's should have a non-empty response payload.
# We use length operator, and combine it with data operator(gt), where we specify length to be greater than equal to 10 

Extract Operators

extract

These operators can be used to save parent entity’s value into a variable at any point during the api_selection_filters phase, which can be used later on in the test template yaml using ${} notation. Let’s see it in action in the below example -

Example of extract

#Example 1
url:
  contains_either: https
  extract: urlVar

# Here we have defined an extract operator, which will copy the complete url into a new variable named urlVar, in case the contains_either operand satisfies the condition

#Example 2
method:
  extract: methodVar
  

# Here we have defined an extract operator, which will copy the http method values into a new variable named methodVar

We can also extract an individual key/value inside the parent entities like (request_payload, response_payload, request_headers, response_headers, query_params).

Example 1:

Request Payload** {”id”: 123, “data”:{”Username”: “abc”, "userStatus": "admin"}}

Example of extract

#request_payload:
  for_one;
    key:
      contains_either: status
      extract: keyVar

# Here we have defined an extract operator, which will copy the key("userStatus") into a new variable named keyVar, since ("userStatus") satisfies the contains_either operand. In simple words - keyVar = userStatus

Example 2

Request Payload** {”id”: 123, “data”:{”Username”: “abc”, "userStatus": "admin"}}

Example of extract

request_payload:
  for_one;
    key:
      contains_either: status
      extract: keyVar
    value:
      extract: valVar

# Here we have defined an extract operator, which will copy the key("userStatus") into a new variable named keyVar, since ("userStatus") satisfies the contains_either operand.
# We also defined a second extract operator inside value operand, which will copy the value associated with the matching key("userStatus") into the variable, i.e. ("admin").
# In other words - keyVar = userStatus, valVar = admin  

How to use extracted variables in YAML

You can use ${<VAR_NAME>} to refer the extracted value. Eg. you can use extracted urlVar do the following -

#Here we append /debug/vars to the URL to check if debug variables are exposed. 

api_selection_filters:
  url:
    extract: urlVar

execute:
  type: single
  requests:
    - req:
      - modify_url: ${urlVar}/debug/vars

validate:
  ...

extractMultiple

This is similar to extract, except it can extract a list of values. For example, if you need a list of all keys in the API request JSON, you can use extractMultiple operator. Using extract will just extract the first key. #Example 1

#Example of extractMultiple

api_selection_filters:
  request_payload:
    for_one:
      key:
        regex: .*
        extractMultiple: payloadKeys # Here we extract list of all keys in the payload

execute:
  type: single
  requests:
  - req:
    - add_body_param:
      ${payloadKeys}: '\0' #Here we replace all values by null terminated string

Combining conditions using Boolean Operators

Security tests can be complex in nature. Often, a specific test requires multiple filter conditions to evaluate whether a given endpoint is eligible for the test.

Default Behavior

For a test to consider an endpoint valid, all conditions specified in the YAML template must be satisfied. By default, yaml considers and operator for all conditions. However, you can easily override this behavior using other boolean operators.

Boolean Operators

Boolean operators are of 2 types:

and

The and operator requires all of the specified conditions to be satisfied, which is also the default behavior. It can be applied on top of any operator, including data, collection, and parent operands.

Example 1

Example of and

#Test Description - 
# condition 1: Consider only post endpoints.
# condition 2: Status code must be between 200-205(including both)
# condition 3: Request Headers should contain a header named origin.
# All conditions are mandatory.

api_selection_filters:
  and:
    - method:
        eq: POST
    - response_code:
        and:
          - gte: 200
          - lte: 205
    - request_headers:
        for_one:
          key:
            eq: origin 

Since applying and operator is default behaviour, we don’t need to explicitly write and operator. See below

Example of and

# removed 'AND' as it is default behavior

api_selection_filters:
  method:
    eq: POST
  response_code:
    gte: 200
    lte: 205
  request_headers:
    for_one:
      key:
        eq: origin

or

The OR operator requires that at least one of the specified conditions is satisfied. It can be applied to any operator, including data, collection, and parent operands.

Example 1

Example of or

# Test Description 
# condition 1: Status code must be equal to either 200 or 302
# condition 2: Request Headers should contain a header named origin.
# An endpoint should either satisfy either of the above two conditions

api_selection_filters:
  or:
    - response_code:
        or:
          - eq: 200
          - eq: 302
    - request_headers:
        for_one:
          key:
            eq: origin