I'm experimenting with various Azure features and currently want to retrieve a secret from KeyVault.
Straight to the case:
I'm using this nuget package to interact with my azure resources.
I've developed a simple .NET Core console app and run it locally.
I have a KeyVault resource with one secret defined which is active and not expired.
I've registered an App in AAD so my locally shipped .NET Core console app has an identity within AAD.
Than I've created a "client secret" within this registered app in AAD to use it to authenticate myself as an app.
After that I've added access policy in my KeyVault resource to allow GET operation for secrets for this registered app:
Then I've developed a small piece of code which should retrieve the desired secret:
public class AzureAuthentication
{
public async Task<string> GetAdminPasswordFromKeyVault()
{
const string clientId = "--my-client-id--";
const string tenantId = "--my-tenant-id--";
const string clientSecret = "--my-client-secret--";
var credentials = new ClientSecretCredential(tenantId, clientId, clientSecret);
var client = new SecretClient(new Uri("https://mykeyvaultresource.vault.azure.net"), credentials);
var secret = await client.GetSecretAsync("admincreds");
return secret.Value.Value;
}
}
However when I'm trying to do this I'm getting an AccessDenied error:
Am I missing something painfully obvious here? Or there is some latency (>30 min for this moment) for which changes from Access policies screen in KeyVault resource are applied?
I test your code and Get permission, it works fine.
From your screenshot, it looks you didn't add the correct service principal related to the AD App to the Access policies.
If you add the service principal related to the AD App, it will appear as APPLICATION, not COMPOUND IDENTITY.
So when you add it, you could search for the client Id(i.e. application Id) or the name of your App Registration directly, make sure you add the correct one.
Make sure your AD App(service principal) has the correct permission in your keyvault -> Access policies
Related
I'm trying to develop a web app on an Azure VM that uses Azure Key Vault. Later this app will also be deployed to Azure. As far as I know, the most straight forward way to make the app work, both locally and deployed, with the key vault, is to use the DefaultAzureCredential class. The code would be like this:
string kvUri = "https://" + keyvaultName + ".vault.azure.net";
SecretClient client = new SecretClient(new Uri(kvUri), new DefaultAzureCredential());
KeyVaultSecret secret = await client.GetSecretAsync(secretName);
At runtime, the provider will try different credential types in order.
This sounds exactly what I want:
When developing locally (on the Azure VM, though), I want to use my user credential (user identity added to the key vault's permission) without any configuration, since I have already logged into the Visual Studio using the same user credential.
Once deployed to Azure, I want to use the app registration credential (also added to the key vault's permission).
But when running the app locally, I'm getting a 403 error The user, group or application .... does not have secrets get permission on key vault ...
After looking up the object id in the error message, I realize it's the dev machine Azure VM's credential that the application uses, not my user credential.
Is there a way to change this behavior?
To prevent the Azure VM from getting a token, you can exclude the ManagedIdentityCredential in your Development environment and only enable it in a Non-Development environment.
if (environment.IsDevelopment())
{
var credentials = new DefaultAzureCredential(new DefaultAzureCredentialOptions
{
ExcludeManagedIdentityCredential = true,
ExcludeAzureCliCredential = true
});
}
else
{
var credentials = new DefaultAzureCredential(new DefaultAzureCredentialOptions
{
ExcludeVisualStudioCodeCredential = true,
ExcludeVisualStudioCredential = true
});
}
Once deployed to Azure, I want to use the app registration credential (also added to the key vault's permission).
An Azure App Service can use a managed identity as well. There is no need for a separate App Registration.
See https://learn.microsoft.com/en-us/dotnet/api/overview/azure/identity-readme#key-concepts for more information.
Create and identity if you wish to use (default identity)
appservice -> select you application -> identity->enable it ->should give you a Id
and than add it to key Vault Access policy
alternatively app registration can be used with tenantId,clientId,secret to connect to keyvault
I need to read the list of users in the Azure active directory. The client has created a Graph API application but they do not want to share the client secret of the application, instead they asked us to use the Key vault. How to access from the node.js application the key to retrieve the list of users?
I tried the below one but gave error and I am not sure how to authenticate.
const { DefaultAzureCredential } = require("#azure/identity");
const { SecretClient } = require("#azure/keyvault-secrets");
const credential = new DefaultAzureCredential();
const vaultName = "lsm-keyvault";
const url = `https://${vaultName}.vault.azure.net`;
const client = new SecretClient(url, credential);
const secretName = "Demo";
async function main() {
const result = await client.setSecret(secretName, "MySecretValue", {
enabled: false
});
console.log(result)
}
Well, if you run the code in local, the DefaultAzureCredential will use the environmental variables automatically.
So in your case, you need to register an application with Azure AD, and get the tenant id, client id(i.e. application id), client secret(i.e. application secret), set the environmental variables, AZURE_CLIENT_ID, AZURE_CLIENT_SECRET, and AZURE_TENANT_ID.
For the 403 error you got, I notice you said It added as a compound entity, based on my experience, you did not add the correct service principal related to the AD App correctly to the Access policies of the keyvault. If you add it correctly, it will appear as APPLICATION, not COMPOUND IDENTITY.
So when you add it, you could search for the client Id(i.e. application Id) or the name of your App Registration directly, make sure you add the correct one. I gave the details in this similar issue, you could refer to it.
To retrieve the secret, the Get permission is enough, the code should be
const retrievedSecret = await client.getSecret(secretName);
I notice you use client.setSecret in your code, it is used to save a secret, to use it, you may need the Set permission.
For more details, see Quickstart: Azure Key Vault client library for Node.js (v4).
Update:
I have to eventually need to deploy this but not in azure but in another environment. How do I set the environment variables and access it.
If so, you need to change your code to authenticate, use the three values directly in the code.
Change the lines
const { DefaultAzureCredential } = require("#azure/identity");
const credential = new DefaultAzureCredential();
To
const { ClientSecretCredential } = require("#azure/identity");
const credential = new ClientSecretCredential(tenantId, clientId, clientSecret);
See - https://www.npmjs.com/package/#azure/identity/v/1.0.3#authenticating-as-a-service-principal
All you need to do is follow the below steps:
Create an App in the Azure Active Directory (Service Principal) from App Registrations.
Go to Key Vault resource, Access Policy blade, assign read access to this Azure AD App (Service Principal) that we created in the above step.
Set these 3 Environment variables AZURE_CLIENT_ID, AZURE_TENANT_ID, and AZURE_CLIENT_SECRET in your App Service. Get the values of these variables from the app that we created in step 1.
Use DefaultAzureCredential that we are already using now. This will automatically pick the credentials from the environment variables that we defined in App Service for the authentication.
Another way is to obtain Key Vault token dynamically and use that token to get the secrets from the Key Vault - https://learn.microsoft.com/en-us/samples/azure-samples/app-service-msi-keyvault-node/app-service-msi-keyvault-node/
Helpful Reference:
https://www.rahulpnath.com/blog/defaultazurecredential_from_azure_sdk/
I'm working with Azure Key Vault and I'm testing the "Managed Identities" for Azure Resource. Long story short: with this feature we can easily access to a KeyVault secrets from (e.g.) VM, App Service... I wrote this simple code:
private void GetKeyVaultSecrets()
{
AzureServiceTokenProvider azureServiceTokenProvider = new AzureServiceTokenProvider();
var akvCallback = new KeyVaultClient.AuthenticationCallback(azureServiceTokenProvider.KeyVaultTokenCallback);
var keyVaultClient = new KeyVaultClient(akvCallback);
var secret = keyVaultClient.GetSecretAsync("https://mykeyvault.vault.azure.net/secrets/mySecret").GetAwaiter().GetResult();
string superSecret = secret.Value;
}
And I'm able to access my "Secret" without any kind of Authorization. Is it safe? Am I missing something? It looks so strange that with those 7 lines of code you have access to all your secrets. Thanks for your attention.
If you are running this on a service with a system-assigned Managed Identity, here's what actually happens (example for App Service, VM is slightly different):
Your app reads IDENTITY_ENDPOINT and IDENTITY_HEADER environment variables
HTTP call to IDENTITY_ENDPOINT using the IDENTITY_HEADER as authentication
This endpoint cannot be called from the outside, only from within the instance.
Its port is also random
In the call, your app specifies it wants a token for Key Vault (resource https://vault.azure.net)
The Managed Identity endpoint uses the certificate it has created to authenticate to Azure Active Directory with the Client Credentials flow
Azure AD verifies the request and issues a token
Managed Identity endpoint returns the token to your app
KeyVaultClient uses the token to authorize the call to Key Vault
On Virtual Machines, the Instance Metadata Service is used to get tokens.
The main thing to understand is that any process running on the instance itself is capable of getting tokens from the Managed Identity.
Though if you were to get malicious code running on your instance,
other approaches could be in trouble as well :)
If you run that code locally, it can work as well.
AzureServiceTokenProvider also attempts Visual Studio authentication as well as Azure CLI authentication.
So if you are logged in to e.g. AZ CLI, it is able to get an access token for your user to Azure Key Vault and access it.
Reference: https://learn.microsoft.com/en-us/azure/app-service/overview-managed-identity?context=azure%2Factive-directory%2Fmanaged-identities-azure-resources%2Fcontext%2Fmsi-context&tabs=dotnet#rest-protocol-examples
Example request done in VMs: https://learn.microsoft.com/en-us/azure/active-directory/managed-identities-azure-resources/tutorial-windows-vm-access-nonaad#access-data
Summary: I have a REST API that I use for functional testing. I only allow people or groups in a specific "Tester" role to hit the API. I want to trigger this functional testing during an Azure DevOps Release Pipeline automatically, but I can't figure out how to authorize the machine account to hit the API.
Details:
I have this API secured with [Authorize(Roles = "Tester")]
[Route("quotas/developers")]
[HttpGet]
[Authorize(Roles = "Tester")]
[SwaggerResponse(HttpStatusCode.OK, "Successful operation", Type = typeof(DeveloperQuota[]))]
public async Task<List<DeveloperQuota>> GetDeveloperQuota([FromUri]string developerUpn)
To set this up, I have an Enterprise Application registered in Azure Active Directory. In the manifest, I declare the role.
And then in the Enterprise Application I add some users and groups which are assigned the role "Tester."
This works fine for running my functional tests by hand. I run the tests, it pops up an oauth dialog for me to enter my credentials, it grabs my Bearer token from the successful auth request then passes it along to the APIs.
private string GetActiveDirectoryToken()
{
string authority = this.configuration.ActiveDirectoryAuthority;
string resource = this.configuration.ActiveDirectoryAudience;
string keyVaultUri = this.configuration.KeyVaultUri;
IKeyVaultAdapterFactory keyVaultAdapterFactory = new KeyVaultAdapterFactory();
var keyVaultAdapter = keyVaultAdapterFactory.CreateInstance(KeyVaultServicePrincipal.PowerShellAppId);
SecureString clientIdSecure = keyVaultAdapter.GetAzureKeyVaultSecretSecure(keyVaultUri, "GasCallbackRegistrationClientID", null).Result;
SecureString redirectUriSecure = keyVaultAdapter.GetAzureKeyVaultSecretSecure(keyVaultUri, "GasCallbackRegistrationClientIDRedirectUri", null).Result;
var authContext = new AuthenticationContext(authority);
var result = authContext.AcquireTokenAsync(
resource,
SecureStringUtilities.DecryptSecureString(clientIdSecure),
new Uri(SecureStringUtilities.DecryptSecureString(redirectUriSecure)),
new PlatformParameters(PromptBehavior.Auto)).Result;
return result.AccessToken;
}
Of course, if I'm running this during automation, there will be nothing to fill in the dialog with creds, nor do I want to be storing a copy of these creds, especially since these creds roll on a schedule which are maintained elsewhere.
My thought was that I could create an Azure Service Principal, associate a cert with the service principal, install the cert on my deployment machine, login as the Service Principal if the cert was available, and then put that Service Principal in the "Tester" role. The problem is I can't add a Service Principal as a user in the Enterprise Application. It only appears to allow me to add "Users and groups." I similarly can't add a service principal to a group.
Any thoughts on how I can authorize my deployment box to hit these APIs?
Roles published for applications are treated as application permissions and not assignable to other apps via the "Users and Groups" assignment screen.
To assign the app permissions to a client app, go to the client app's registration page, click on Api Permissions and then Add a Permission. Select the My Api tab, search for your application that published the app roles and you'd see the app role listed in the list below. Select that, save and then grant admin consent.
I would like to use an Azure Key Vault secret from an on-premise web application.
I created a Key Vault with a Secret, but in Access Policies I should specify an Authorized Application and in the samples is used an Azure WebApp.
I want instead use the Secret from on-premise MVC web app: shoud i specify nothing and it works ? i specified the Azure Vault and as Principal myself but i'm not sure if this is correct.
Well, something will need to authenticate to access the secret.
Either the current user, or you can use a service principal.
Since we are talking about an MVC app, the service principal is probably easier.
You will need to register a new app in Azure Active Directory via the Azure Portal.
Find Azure AD, and register a new app via App registrations.
The name and URLs don't really matter, but it needs to be of type Web app/API.
The sign-on URL can be https://localhost for example.
Then add a key in the Keys blade to the app (click Settings after the app is created, then Keys).
Copy the client id (application id) and the key somewhere.
Now you can go to your Key Vault, and create a new access policy, and choose the app you created as the principal.
Give it the rights you want, like Secrets -> Get.
Then you can save the policy.
In your app, you can then use the Key Vault library + ADAL like so:
var kvClient = new KeyVaultClient(async (authority, resource, scope) =>
{
var context = new AuthenticationContext(authority);
var credential = new ClientCredential("client-id-here", "key-here");
AuthenticationResult result = await context.AcquireTokenAsync(resource, credential);
return result.AccessToken;
});
SecretBundle secret = await kvClient.GetSecretAsync("https://yourvault.vault.azure.net/", "secret-name");
string secretValue = secret.Value;