What is the certificate required for? - c#

I understand very well the purpose of certificates: both in a general case and in the specific usage for token creation under IDS. When I wire up my IDP like this:
.AddSigningCredential(new X509Certificate2(path, pass));
or this:
I get it to work (both dev creds and sign creds work). Accidentally, I commented out both of them, effectively applying the following config.
I had been expecting no tokens, invalid tokens, crashes, exceptions and what not. Instead, everything works smoothly and I see no evident problems.
Now, that can't be right, obviously. What am I missing and what bad thing have I caused by omitting the credentials to be present?!

What happens, I think, is that the built-in automatic key manager kicks in and generates the keys for you.
You can verify this because this module creates a subfolder in ~/keys directory.
See the documentation here about the Automatic Key Management.
It can be disabled here:
AddSigningCredential is used to add a custom signing key and AddDeveloperSigningCredential is used to let IdentityServer generate a test key for development.


Are the data protection keys necessary for docker container?

I am getting the following error in my logs when running my application on a docker container.
[08:20:54 WRN] Storing keys in a directory '/root/.aspnet/DataProtection-Keys' that may not be persisted outside of the container. Protected data will be unavailable when container is destroyed. <s:Microsoft.AspNetCore.DataProtection.Repositories.FileSystemXmlRepository>
[08:20:54 WRN] No XML encryptor configured. Key {<some-id} may be persisted to storage in unencrypted form. <s:Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager>
I was reading into data protection keys, especially from this article https://www.edument.se/post/storing-the-asp-net-core-data-protection-key-ring-in-azure-key-vault?lang=en and it seems to be something that might be really important when deploying an app. However, what I don't understand is what is it being used for? I am not using identity or session cookies. And for the technologies I am using, I create my own keys to encrypt the information.(For example for JWT or for encrypting some text).
I do use cookies to set my jwt token by using the set-token header with HTTPonly flag. Could that be what the key is being created for?
I want to know in order to define if we should take action to make the keys persistent or if can just ignore it. I would appreciate it a lot if someone has some insight into this that is willing to share.
Here a screenshot of the file where the keys are being stored
Actually, the section What happens if I don’t configure the data protection service in ASP.NET Core? of the referenced post gives a great explanation of what it is used for.
And yes, setting HttpOnly=true means encrypting the cookie's value with the Key Ring. You can do a simple test: run your service locally in a docker container, perform the flow that sets the cookie on your browser, then remove the container and create a new one. Now try to perform the action that requires the cookie, and it will fail because your service can't longer decrypt the cookie's value.

C# and ASP.NET Core 6 : authentication and user details in "session"

I'm going to get so many "okay grandpa" comments for this one.
I've read a dozen articles and every SO question I could find on this subject.
I must have been away too long or missed something completely, because I swear that user authentication used to be very simple. I seem to recall built-in methods and a session on the server simply knowing who the user was via a cookie or similar, with the ability to store information "in session". I don't recall even setting up authentication in years past, it was just built-in to new applications.
Instead, the most succinct guide I could find is very involved. I think I need a token authorization/authentication setup because there may be consumers (like apps) who don't have a typical cookie pattern these days. In my head, the token works like a cookie except it's manually held on the user end and passed via header with each request?
To its credit, the guide worked, at least for logging in and correctly utilizing the simple Authorize attribute in controllers. However, User.Identity.Name is always empty, even when User.Identity.IsAuthenticated is true, which is perplexing.
How I think auth is working:
User request hits API with username/password
Service checks the combination, and returns an encrypted JWT to the user
The user sends the JWT back with every request
The server decrypts this JWT to identify the user - this is probably where I'm wrong
So here is where my question comes in:
I need more data about the user, like access to the entire UserModel with every request, but I don't want to go to the database to find it every time. This is where I think there should just be a session object in memory, but that doesn't appear to be the case with token authentication.
Where do I put user-specific, short-term ("session") information for consumption in future requests where a user is identified with a JWT in the Authorization header instead of a cookie?
Session state isn't right, because it's hard-wired to a cookie
HttpContext.Items aren't right, because it's just for the one request
Cache storage isn't right, because it's not user/session specific. I could potentially create a session-like user-keyed storage here but that seems way, way over-engineered for this.
Basically anything where I'm passing all the data (not just a user identifier) to the client then relying on the client to pass it back seems wrong? But feel free to correct me.
The server decrypts this JWT to identify the user This is probably
where I'm wrong
The JWT token is not encrypted, its signed so you can't alter it. You can open it if you look at jwt.io for example.
Where do I put user-specific, short-term ("session") information for
consumption in future requests where a user is identified with a JWT
in the Authorization header instead of a cookie?
You put it in the principle claims of the token. In the guide you linked it wrote:
var claims = new List<Claim>
new Claim(JwtRegisteredClaimNames.NameId, user.UserName)
So you add whatever you want to the claims to store it on the token and later you can access this data via:
var claim = _contextAccessor.HttpContext.User?.Claims.FirstOrDefault(d =>
d.Type == ClaimTypes.NameIdentifier);
You also can't use any of these other examples that you listed like HttpContext.Items because those are not signed. If the token is altered in any way the system identifies this and returns a 401

CookieTempDataProvider causes CryptographicException

I have an ASP.NET Core app (1.1 targeting full framework) that uses TempDataProvider to store some metadata about the currently logged-in user, such as their "display name" and some other preferences for the app. In my Startup.cs ConfigureServices method I have added the line
services.AddSingleton<ITempDataProvider, CookieTempDataProvider>();
which is populated after login using (for example)
TempData["DisplayName"] = login.DisplayName;
This works well, creating an encrypted, chunked session cookie for the user named .AspNetCore.Mvc.CookieTempDataProvider. I can "peek" and clear on logout, etc. as I expect. However after some interval - perhaps the app pool going idle, but the browser session remaining active - I receive a CryptographicException:
System.Security.Cryptography.CryptographicException: The key {guid} was not found in the key ring
It appears that the browser session cookie is still good, but the server has lost its ability to decrypt and use it. Currently the only way to resolve is to manually clear the cookie and let the app create a new one.
Is there any way to protect against this behavior? I do want the contents of the cookie to be difficult/impossible to forge, and this seemed like a valid mechanism to achieve that.

C# GMAIL API Service Account Modify - unauthorized_client

I am just starting out with the c# Google.Apis.Gmail.V1 classes and using a service account to read a mailbox.
My code works fine when I use the following snippet
ServiceAccountCredential credential = new ServiceAccountCredential(
new ServiceAccountCredential.Initializer(ServiceAccountEmailAddress)
User = "abc#test.domain.com",
Scopes = new[] { "https://www.googleapis.com/auth/gmail.readonly" }
With that code I can call the following successfully
if (credential.RequestAccessTokenAsync(CancellationToken.None).Result)
But I need to modify the email messages so I changed the scope from
I now get an exception when requesting the access token
{"Error:\"unauthorized_client\", Description:\"Unauthorized client or scope in request.\", Uri:\"\""}
I have checked the service account (*.iam.gserviceaccount.com) in the Google Developers Console and I have tried all options for permissions including OWNER which should give me Full access to all resources but no joy.
I think I am just missing a simple step but I am unsure of where to look next.
I would read through this, but here is the short version. I know this is an older post, but hopefully it finds you!
If you have not updated/white-listed the service account's privileges/scopes in the Google Admin Console you will need to do that, make sure the domain has API access enabled, make sure the service account is setup properly, when creating the "certificate" object be aware its parameters so that it is being instantiated correctly, check the permissions on the account being impersonated and finally make sure you've made an appropriate Google Apps service account key (could have easily made an inappropriate key type.)
White-listing Google APIs in the Admin Console
This gives the Google Apps service account the abilityto use whatever scopes you provide in your Google Apps domain.
Login to the Google Apps Admin Console by using the following link.
The Google Apps user account must have sufficient privileges to modify domain related settings. It does not have to be the account used to create the Google Apps project in the developer console. If the account does not have privilege you will be directed to a completely different screen with no options to click on varying domain controlling web apps like "Security", "Roles", "Support", "Groups" and etc. Instead you'll dumped onto a page that shows things like "Gmail", "Drive", "Docs" and etc. that is typical user apps. The current link it drops you at is https://apps.google.com/user/hub
Click “Security.”
Click “Show more” option at the bottom of the security options list.
Click “Advanced Settings” to get the more options.
Select the “Manage API client access” link.
Now certain API scopes must be white-listed for the desired service account. In the “Client Name” text box provide the service account’s client ID. The client ID is obtained in the developer console. In the “One or more API scopes” add the desired scopes; comma delimited.
Note, if there are existing scopes they will be removed so be sure to re-add any that will be needed.
Enable Domain Wide API Access
Login to the Google Apps Admin Console by using the following link.
Go to the “Security” page.
Under “API reference” section
Make sure that “Enable API access” is enabled.
Creating an Appropriate Google Apps Service Account Key (Probably this)
Go to the Google Developer Console. Login as the Google Apps user that created the Google Apps project/service account. https://console.developers.google.com/
Navigate to the particular project with which you created the service account.
Click the "Service Account" button on the left of the project's page to bring up a page with all of the project's service accounts.
Click the vertical ellipse widget all the way to the right of the desired service account's row. Select “Create Key.”
Select .p12 key as it looks like this is what you're trying to use. Click "Create." Be sure to protect this key.
I have found that if the key is not created this way then it leaves open the possiblity for making either an API key or an OAuth 2.0 client/user key. These are the wrong types of keys to use in this case you would need to have created a service account key. The way outlined above forces you to create a service account key.
Modifying the Existing Google Apps Service Account's Settings
I'm not going over how to setup the actual service account, one thing you may need in your case is to make sure that the service account has domain wide delegation enabled. This is toggled in the Google Developer Console. Should be pretty easy to find.
You do not provide your entire code base for creating the token, so just want to add a few things you might be doing improperly.
Make sure when you create the certificate that the secret you provide is the default "notasecret" string. This secret is currently the default value provided by all keys distributed by Google and is immutable during key creation. I had a link to prove this, but have since lost it.
X509Certificate2 certificate = new X509Certificate2(certificateFilePath, "notasecret", X509KeyStorageFlags.Exportable);
Just trying to advocate proper coding. While I have found some bugs in the past with Google's constant values that required additional string manipulation (adding additional slashes.) You should really be using the string constants that they provide in place of literals. I only say to use these because it provides a layer of abstraction, who is to say Google will never change the literal; unlikely.
In your case the new scope is:
While the old scope was:
Otherwise, everything code wise looks good to me.
Another thing to try would be to make sure that the actual Google Apps user account being impersonated by the service account has sufficient privileges. I would suspect a different error if this were the case, would be getting a 403 in the response instead. Anyway, in your case this is the "abc#test.domain.com" account. Once again you would go to the Google Admin Console, check its roles make sure it has sufficient roles checked for whatever it is you're trying to do. I don't know what specifically you'll need in this case, best bet would be to give it the same permissions as the "Super Admin" role then remove permissions as you go to see what it might actually need. Otherwise, if possible just give it "Super Admin."
If I was a gambler I would put my money on an inappropriately created service account key. I just recently ran into this and it was the only thing that produced the same exact error you're receiving. Other things would get me the same "Description" value in the response token, but not the same "Error" value. I'm not really even sure how the culprit key was made, because I didn't make it. I just know the fix was to recreate a new key with the steps above and that fixed the issue.

Web service lifetime against authentication list

What I have
I'm making a web service using C#.
In order to authenticate users, they have to send their name plus their encrypted password, in order to check if exists in a database.
Then, If it's found, I create a string token, which is a 10 char string randomly generated in order to send it the next times while the session is alive, avoiding to have to send the original credentials anymore.
What is my problem
Using this approach, my problem appears due to the service lifetime.
It's known that web services are not initialized each time a request arrives, but nor is infinite. So there will be a moment, when it'll be destroyed and initialized again.
At this point, my token list would be erased, as well as all the alive connections with it, as this is its function.
So I'm stuck at this point. I'm not sure about how to proceed, maybe I'm just fooling around and there's a simpler way to authenticate users? Or maybe you've and idea about how to don't loose all these alive sessions without having to write them at a DB.
Thank you in advance
My goal
I aim to create a personal Web Service, just build for me and some friends. Not inside a company nor anything like this. Not in the same LAN neither.
I want to add a bit of security to this service, so I wanted to add authentication to the WS, mainly in order to avoid people pretending to be another and this kind of stuff. So I created User+Password system.
Then, in order to avoid to send them both in each WS Request, I started to write the "token" approach described above.
Notice that I'm using token word because it's similarity with token systems for these cases, but it's a completely created from 0 system, nothing proffesional, so do not assume anything complex about it if I've not said that.
How my system works (or try to)
User -> Auth (user, pass_encrypted) -> WS -> DB (exist? OK)
WS -> token (randomly generated, 10char string) -> User
After that, at each WS request, User sends the token instead of credentials.
After receiving it, WS looks for the token at a List<structureToken>, so it obtains the user which is doing the call, and (for example) the access level, in order to know if the user has rights to run this call.
Your current problem is that you want same list to be persisted through restarts and not persisted to any physical media at the same time. You have to pick one of the choices and live with it: not persisted - just ignore the fact you can have list in memory and make sure token can be validated by itself, if persisting - pick storage and save you list of random numbers.
Since you are building simple system without actual need to have proven verifiable security you can get some ideas from existing systems (like STS and the way it creates token). Basically STS signs information about user (indeed after validation) and than encrypts it with public key of receiving party. So particular server that supposed to get the token can decrypt it (as it has private key part), everyone else may still use it but have to treat as non-verifiable black box token.
Simplest version of this would be no encryption of information, just basic signing. Proper signing requires private/public pair (so external party can validate signature), but since in your case both parties are the same service - you can just SHA256. To prevent external callers to fake you signature you need to have some private information included in hash to "salt" value before hashing. Random number hardcoded into server code (or read from settings) would be good enough. You may also want to include expiration as part of signed value.
So your "token" could look like:
Name,expiration,Base64 of SHA256 of {Name + expiration + secret value}
Since your server code have "secret value" you can always re-compute hash to verify if it is indeed the correct token.
do not use it for any real services. Use an existing authentication and make sure to review all security comments related to proper usage of it.
this approach gives you chance to learn a some other concepts - i.e. key update (when your "secret value" need to change, or in real systems signing/encryption certs).