Condition building: comparing 2 variables' string values

[jonesfloyd]

I'm trying to trigger a fault rule if the value of one variable is Like the string value of another variable.

Use case: In the new SOAP passthrough proxy functionality (as of cloud release 160727), all operations are sent to the proxy base path "/" rather than to individual resources, such as /GetCityWeatherByZIP. That creates a challenge for protecting calls using an API product, because there are no specific resources to configure in the product. So I'm trying a technique of using product custom attributes. For example, I've configured my product like this:

attribute: allowedOperations

values: GetCityForecastByZIP,GetCityWeatherByZIP

If I send a GetWeatherInformation call (not one of my attribute values), I want to throw an error.

I'm getting operation from an Extract Variables policy (with XPath), and I'm getting the product custom attribute values from a Verify API Key policy variable (the multiple values are not an array).

Here's my Raise Fault configuration:

<Step>
  <Name>Raise-Fault-Product</Name>
  <Condition>(operation !~ "{verifyapikey.Verify-API-Key-1.apiproduct.allowedOperations}")</Condition>
</Step>

I also tried:

!(operation ~ "{verifyapikey.Verify-API-Key-1.apiproduct.allowedOperations}")

But it's not quite working as expected. For example, the fault gets triggered when I simply use ~ without any !.

!~ seems to not be supported, since it's not listed in our Conditions reference.

Any ideas? Use JavaScript instead?

I'm attaching my proxy (weather-api-key.zip).

[#2 · Accepted solution]

I would recommend using the regex match instead of the like match for negative conditions i have had better results that way

[jonesfloyd]

Thanks, @srichardson. Now I'm trying to figure out how to include the expression variable value as a string. When I do this:

<Condition>!(verifyapikey.Verify-API-Key-1.apiproduct.allowedOperations ~~ "{operation}")</Condition> 

I get this error in the UI:

Invalid condition: !(verifyapikey.Verify-API-Key-1.apiproduct.allowedOperations ~~ "{operation}") in policy Raise-Fault-Product. Reason: Invalid pattern specified : Illegal repetition {operation}.

Any ideas on how to do this?

[#4]

verifyapikey.Verify-API-Key-1.apiproduct.allowedOperations ~~ ^((?!{operation}).)*$

[jonesfloyd]

You rock! Since this still doesn't work in the condition (UI still complains), I like your follow-up suggestion of handling the comparison in JavaScript and triggering Raise Fault on the return value of the JS (such as true or false). Thanks again, Steve!