Capture/Log WCF Binding/Serialization/Deserialization Error - wcf

I've class which has a set of attributes.
I'm trying to call WebService from custom Billing device (based on proprietary HW/SW). The problem is that in the application in some cases the required field (an integer in this case) is sent as null. WebService just rejects that.
Is there any way to log such errors in the Server as "return false" prompts the App to resend again (which will fail as the value is still null). Idea is to write to database the errors (with device details and the actual error, integer column is null in this case) and the Application/Web Admin can get in touch with user of the device to take appropriate action.

For debugging, you can use Fiddler2 easily to capture any web traffic, including the full xml of a SOAP request/response (and it even handles SSL easily, unlike Wireshark)
For logging... I wish I knew. Sorry.
Also, dupe of In C#, How to look at the actual SOAP request/response in C#

Related

What information is logged by IdentityModel when ShowPii is set to true?

IdentityModelEventSource has a property called ShowPII that means that Personally Identifiable Information will be added to the logs (in relation to security). This value is used to decide when to log some OAuth2 sensitive data.
I am trying to understand what kind of Personally Identifiable Information will be logged:
Client ID? (aka Client Key, Consumer Key)
Client Secret? (aka Consumer Secret)
Json Web Tokens? (aka JWT)
Access Tokens?
Refresh Tokens?
Kerberos Tickets?
PKCE Values?
Authorization Codes?
I know it cannot get access to usernames and passwords because they are only exchanged directly with the IDP.
But but I need to know if I need to find a way to lock down my log files because it will have data that constitutes a security vulnerability.
This is possible log messages of IdentityModel: LogMessages.cs
About
I am trying to understand what kind of Personally Identifiable Information will be logged
I won't copy-paste log messages from there (especially, as they can change at any moment). You can check them yourself and decide what should be considered as the PII.
But here's an interesting example:
"IDX10615: Encryption failed. No support for: Algorithm: '{0}', SecurityKey: '{1}'."
and this is how it's used:
throw LogHelper.LogExceptionMessage(new SecurityTokenEncryptionFailedException(LogHelper.FormatInvariant(TokenLogMessages.IDX10615, encryptingCredentials.Enc, encryptingCredentials.Key)));
If you'll follow the track you'll find out that encryptingCredentials.Key will be logged if ShowPII = true and won't be logged if ShowPII = false.
Of course, depending on your use case, this particular message may never appear in your logs. And not all messages so outrageously leaky. But you never know:
your use case may change
you may be mistaken about the set of messages IdentityModel can emit for your use case
IdentityModel code may change, and you may forget to check if messages' set is still secure
So about
if I need to find a way to lock down my log files
Yes, you definitely need to.
Or better yet - don't use ShowPII = true in production for monitoring, use it only in development environment for debugging purposes.
Looking at the source, it appears that when ShowPII is on - it will do two things:
Replace all parameters passed to library-specific exceptions with their data type names
For all system exceptions - replace inner message with exception type name
In this context "library-specific" is an exception that is of type Exception and its full type name starts with "Microsoft.IdentityModel." (library defines a few)
Depending on your use case you'd see a variety of parameters that can be logged with custom exceptions. A quick search for FormatInvariant yields quite a few for your consideration.
Again, depending on how you use it, you might get a better idea of what the error messages are by looking through relevant LogMessages.cs file on your specific namespace.
P.S.: on a side note, it appears that default ShowPII setting is GDPR-compliant

Can someone clarify IOS Safari Service Worker Support

Looking at the MDN documentation IOS/Safari fully supports ServiceWorkerGlobalScope.onfetch but when you look at the FetchEvent specification it says it is not supported at all by Safari.
In particular, I would like to store some state for each client and was hoping to use the fetchEvent.clientId property of the event to index it. Of course I presume I also have access to the fetchEvent.request object otherwise I can't see how a service worker can do anything useful and I could simulate clientID from a passed in parameter in the url. But the docs don't really tell me what IOS/Safari supports and doesn't so I don't know which way to go.
Can someone please tell me precisely what does IOS/Safari pass when it calls the defined onfetch function.
I found the answer to my question by using https://jakearchibald.github.io/isserviceworkerready/demos/fetchevent/
connecting my iPad to my Macbook and debugging my iPad. I was eventually able to open the web inspector for the Service worker for that page, and the console.log showed the event passed in.
FetchEvent.clientID is present but a zero length string. As it happens I did the same thing on my (linux) Desktop using Chrome and its also a zero length string, BUT it has another parameter resultingClientId with what looks like a UUID in it. That parameter is not there in Safari.
The FetchEvent.request is there, and in particular the URL. So I can generate my own client id in the client (I am using Date.now().toString() as that is good enough for my purposes) for use in the service worker. In fact my site without a service worker was using the in the URLs I need to intercept already, so I am happy that I have a solution.

Rest API and UUID

One of the reasons, and probably the main one, to use UUID is to avoid having a "centralized" point responsible for creating and assigning ids to resources.
That means that, for REST APIs, the clients could (and should) be able to generate, and give the UUID for a certain resource when they POST that specific resource for the first time. That would minimize problems related with successfully posting a resource for the first time but not getting the ID back as response (connectivity problems for example). That can result in a new post for some of the clients, generating duplicated resources.
My question are:
Having UUID generated by clients and being exposed in the REST API is a best practice?
Are there any other alternatives to that?
REST does not really care if the UUID is generated by the server or by the client. It just needs a unique resource-identifier in form of an URI.
What form the URI has, is not important to clients and servers - only that they are unique and may be obtained by clients (HATEOAS). You need of course also a resource on the server side which is able to create the sub-resource for you and understands that you want to provide the UUID instead of generating an own one. Instead of a UUID you could f.e. also use a url-encoded title of a blog-post or like this question a combination of hash-value and question-title 31584303/rest-api-and-uuid to uniquely identify a resource.
Generating a UUID by a client is in my opinion not used that ofen in practice, but I may be wrong on this matter. The actual question is rather, why should a client really provide an own UUID instead of letting the server create one? The client is, IMO, only interested in getting the data to the server and having some way to retrieve it at some later point, which will be provided through the location header returned in the response of a POST request.
If connection issues are an actual concern, you could let the client send an empty POST to create a resource and send back the location within the header. The content is than added via a PUT request.
There still can be some connection issues involved:
request does not reach the server
response does not reach the client
While the primer one is no issue for the client as well as for the server as no operation is executed and the request can simply be resent, the latter one will actually create a resource at the server side, though the link never reaches the client. Therefore the actual resource is in an unreferencable state unless you provide a way to iterate over all resources, which contains also the empty ones.
A server can have a cleanup thread in the back which removes empty resources after a given amount of time. If a client sends a further empty POST request but this time also receives the URI of the created resource, he can update the state of the resource via PUT. PUT is idempotent. If the server did not receive the request, the client can simply resent it. PUT has the semantic of updating existing or creating a new resource if it is not yet available. So, the server can create the resource in that case with the provided content. If the request did reach the server, a further update does not change the state of the resource.
one advantage of client-generated UUID is: the client knows the resource key even before creating the resource. no need to read the response of the POST/PUT except for errors

The use of HTTP status to communicate application circumstances

Suppose I ask a question to an criminal register: http://server/demographics/party/{partyId} and that person is not known on that system.
Is that an error? Isn't it a good thing?
When returning 404, it is an error code, Restlet has implemented it as a specific URL cannot be resolved to a route to a server-resource (a handling class), an erroneous situation.
In my opinion, if a system understands a call, and is able to process it without errors, it should return 200 (HTTP-ok), and it should return the information: "We don't know this person".
What is the best thing to do?
There's nothing wrong in returning a 404 status code. It simply means "you asked for a resource, and it doesn't exist". If it did return 200, it would have to somehow return an additional status code telling you that everything went fine, but the resource couldn't be found. That's unnecessary, because 404 already means exactly that.
A status 500 is normally returned to mean "something went wrong, I can't tell you if the resource exists or not". Now if you returned a 404 to mean that, this would be a mistake.
Whether it's a good thing or not is not doesn't have anything to do with HTTP or REST. And BTW, if the register was a file containing the survivors of a disaster, you would probably find it bad to not find the person you looked for, unless maybe if the person is your mother in law, unless you actually love your mother in law. (this is meant as a joke, for those who don't find it obvious).
A web service could be implemented in a way that produces either kind of response.
If it is being implemented in a way that is truer to HTTP/Rest, then '404 not found' would be the appropriate response for not finding something. This is what the 404 status is for.
It may help to think of your request as saying 'I assume this record exists, and I want to see it', and the 404 response as saying 'You are in error that record does not exist'.
If this URL is going to be used by code (rather than be displayed in a browser), then if you don't make a distinction in the response status then you will have to add extra information to the response body to make the difference obvious.
If this URL is going to be displayed to a user in a browser, then the server is still able to display content in the response body for a 404.
Please read: http://archive.oreilly.com/pub/post/restful_error_handling.html#__federated=1
Quoting:
Conclusion:
Human Readable Error Messages: Part of the major appeal of REST based web services is that you can open any browser, type in the right URL, and see an immediate response -- no special tools needed. However, HTTP error codes do not always provide enough information. For example, if we take option 1 above, and request and invalid book ID, we get back a 404 Error Code. From the developer perspective, have we actually typed in the wrong host name, or an invalid book ID? It's not immediately clear. In Option 3 (DAS), we get back a blank page with no information. To view the actual error code, you need to run a network sniffer, or point your browser through a proxy. For all these reasons, I think Option 4 has a lot to offer. It significantly lowers the barrier for new developers, and enables all information related to a web service to be directly viewable within a web browser.
Application Specific Errors: Option 1 has the disadvantage of not being directly viewable within a browser. It also has the additional disadvantage of mapping all HTTP error codes to application specific error codes. HTTP status codes are specific to document retrieval and posting, and these may not map directly to your application domain. For example, one of the DAS error codes relates to invalid genomic coordinates (sequence coordinate is out of bounds/invalid). What HTTP error code would we map to in this case?
Machine Readable Error Codes: As a third criteria, error codes should be easily readable by other applications. For example, the XooMLe application returns back only human readable error messages, e.g. "Invalid Google API key supplied". An application parsing a XooMLe response would have to search for this specific error message, and this can be notoriously brittle -- for example, the XooMLe server might simply change the message to "Invalid Key Supplied". Error codes, such as those provided by DAS are important for programmatic control, and easy creation of exceptions. For example, if XooMLe returned a 1001 error code, a client application could do a quick lookup and immediately throw an InvalidKeyException.
Based on these three criteria, here's my vote for best error handling option:
Use HTTP Status Codes for problems specifically related to HTTP, and not specifically related to your web service.
When an error occurs, always return an XML document detailing the error.
Make sure the XML error document contains both an error code, and a human readable error message. For example:
1001
Invalid Google API key supplied
By following these three simple practices, you can make it significantly easier for others to interface with your service, and react when things go wrong. New developers can easily see valid and invalid requests via a simple web browser, and programs can easily (and more robustly) extract error codes and act appropriately.
The Amazon.com web services API follows the approach of returned XML document can specify an ErrorMsg element.
XooMLe also follows this approach. (XooMLe provides a RESTful API wrapper to the existing SOAP based Google API).
Another approach is by DAS ( Distributed Annotation System) which always returns 200 if there was no HTTP-error and has error information in the HTTP-header, which is less favorable, because it is not human readable, as a browser does not display the HTTP-header.

What is RACRoute in Mainframe?

What is RACRoute in Mainframe? While checking th event viewer I get an error "RACRoute AUTH failed" while trying to transfer a file to a Mainframe system. Can this be explained?
RACROUTE is a rather large topic. The simplest answer is that you are probably not authorized by RACF to perform the action you are attempting. If there is an error message identifier (RACF messages begin with ICF followed by a 3 digit number and then a letter) you might have some luck looking that up in the references I've provided. There is likely an ICH message in the mainframe SYSLOG or OPERLOG that corresponds to what you are seeing in your event log.
RACROUTE is the basic macro for authorisation checks via the SAF interface. (IBM's RACF and (I presume) Computer Associates' ACF2 and Top Secret security products respond to authorisation requests made this way.)