I have seen many examples of how to use RBAC and request a bearer token using a registered app for which you give access to your blob storage account or container.
What I need instead is to give access to a specific group of users in an AzureAD group and now request an access token as an individual user, without any application (clietn_id) in between.
Would someone help/guide me to achieving that with a tool like postman for example.
Thanks a lot in advance!
Azure AD tokens are requested trough registered or enterprise apps. You will need a client id in between.
If you want to authenticate a user programmatically you will need to implement the ROPC flow. Click here for the Postman request. Keep in mind ROPC is not recommended, do not support personal accounts or passwordless logins, MFA and others.
Remember to Grant your registered app permissions to Azure Storage and set the scope parameter to https://storage.azure.com/user_impersonation in Postman.
Related
I want to create an Azure Function that accesses Cosmos DB Containers and Key Vault Scopes. Function calls require Active Directory sign in and users are granted access to resources via Groups.
Azure resources should be accessed or denied based on the signed in user's permissions or group memberships.
How can the Azure Function access other Azure Resources on behalf of the authenticated caller?
It's pretty complex unfortunately, you'd need to have a new OAuth2 access token scoped to cosmosdb resource to be able to access it.
Please check OAuth2 On-Behalf-Of flow:
https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-on-behalf-of-flow
When I used it 2 years ago, there was no SDK support for this flow, I simply used http request against https://login.microsoftonline.com/{tenant_id}/oauth2/v2.0/token
In your case, you would also have to add https://cosmos.azure.com/user_impersonation delegated API permission to your app registration and users will be asked for a consent when they try to access your API.
i'm new in Azure. And if the question is stupid don't punish me.
I made an App in Azure to get access to storage blob and key vault.
I used Azure AD tenant(with AD users) and user_impersonation scopes like https://storage.azure.com/user_impersonation and https://vault.azure.net/user_impersonation
All I need from that App is:
Upload file to Blob
Download file from Blob
Delete file from Blob
Generate SAS
Get value of secret from Key Vault.
In Azure AD tenant it works fine. I can request to login.microsoftonline.com enter credentials and get token to my back-end to do all this things listed above.But later customer desided to use custom UX(to hide Microsoft login page) and only one way to get this is to use B2C and local accounts.
I made a B2C tenant like here tutorial-create-tenant
Registered App like here tutorial-register-applications and add Api permissions to Azure Storage from APIs my organization uses tab
Created user-flows like here user-flows
All local users in one group with Owner policy
Using this request i got a token
https:/<domain_name>.b2clogin.com/<domain_name>.onmicrosoft.com/oauth2/v2.0/authorize?
p=B2C_1_signin&
client_id=<App_ID>&
nonce=defaultNonce&
redirect_uri=https%3A%2F%2Fjwt.ms%2F& // https://jwt.ms/
scope=https%3A%2F%2Fstorage.azure.com%2Fuser_impersonation& // https://storage.azure.com/user_impersonation
response_type=token&
prompt=login
In decoded token claim "aud" has id the same as Azure Storage API from APIs my organization uses tab when I register App, "scp" is "user_impersonation". But using this token i can't get access to storage using Postman (I use it as Bearer token)
For example GET request to https://.blob.core.windows.net/?comp=list must return json with list of containers(and in Azure AD it work) but with this token got an error
<Error>
<Code>AuthenticationFailed</Code>
<Message>Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature.
RequestId:49873755-401e-0065-0dd0-386211000000
Time:2020-06-02T11:24:57.3079213Z</Message>
<AuthenticationErrorDetail>Signature validation failed. Signature key not found.</AuthenticationErrorDetail>
</Error>
May be I need to add additional Api access to Storage app some how?
What should I set up yet?
Or maybe there is a way to connect Ad B2C tenant to AD tenant?
Will appreciate any help.
Upd: as #juunas noiced I had differernt subscriptions for B2C tenant and Storage account. Now b2c and storage in one sub(i created new b2c, link subscription and move it inside b2c tenant, after that i made a storage account in moved subscription)
But the problem still exist.
I tried to change scope in request. On Api Permissions page in Azure Storage user_impersonation option you can see link like
https://*.dfs.core.windows.net/user_impersonation
when I used this link as a scope I've got an error
AADB2C90117: The scope
'https://*.dfs.core.windows.net/user_impersonation'
provided in the request is not supported.
After replacing of asterisk by name of storage account in link I've got the next message
AADB2C90205: This application does not have sufficient permissions
against this web resource to perform the operation.
It looks like I need to get additional permissions for App?
Does it make sense? Or trying to get access to particular storage account is wrong?
I am trying to find security best practice on App permissions in the context of azure resource management.
Currently, there is only one permission listed for management.azure.com and it is
management.azure.com/user_impersonation (preview). This delegated user impersonation can be a serious problem and it can led to account takeover by malicious app.
Think about a scenario where a user with global administrator role consent and authorize an access token to the app. App can use the token and do whatever it wants with the azure tenant.
Another scenario where a privileged user assigned contributor role to multiple subscriptions. Token authorized by this user can be misused by app to modify resources in any of the subscriptions.
Unlike graph (graph.microsoft.com) api where you can handpick the permission (user.read), resource management api has only one option - user_impersonation!
You may argue why would a privileged user authorize the action but people make mistakes. Our job is to stop or minimize such risk by design. So, what's the best way to allow app to manage resources in azure and minimize the security risk?
Thanks to #juunas for outline and tips. Thanks to #Gaurav for attempting to address my question. I was able to modify azure resources on a subscription without having to grant user_impersonation on management.azure.com api. Here are the steps-
1) Register an app (TestPermissions in my case)
2) Add API Permissions (optional). You don't need to add management.azure.com.
3) Go the Azure resource (subscription, resource group or management group level based on your requirement) and add IAM/RBAC role to the registered app. I assigned Contributor role to TestPermissions app at the subscription level.
4) Request a oauth2 access token following client credential grant flow. You can provide client_id and client_secret in the body of the POST request or you can provide it as Authorization Basic base64 encoded header (that's what I did). Save the access token for future use (until it expires).
Note: I could not add multiple audience (scope) at the same time. If you would like to get a token for graph api, you can request a separate token by changing the scope to http://graph.microsoft.com/.default
5) Use the access token captured in the previous step to interact with azure resource manager. You will need to add the jwt bearer token in the Authorization header (not shown here) on every request to https://management.azure.com. In this example, I am creating a new resource group named TestCreateRG003 to one of my Pay-as-you-go subscription.
6) Let's validate/verify that the resource is created or updated in Azure. Bingo, there they are! App can read/modify (based on RBAC) azure resources w/o having to grant impersonation permission.
It is true that by granting that permission you are allowing the app to act as you, with all the permissions that brings.
The main way I've seen used when limitations are desired is that you:
Register an app in your Azure AD
Grant the service principal the necessary roles (e.g. Reader on specific resources)
Set the tenant id, client id, client secret etc. in the app
This of course requires that the app itself supports this approach.
If it only allows usage through impersonation, then you'll need to either trust or not use it.
Let me see if I can answer this question.
When a user requests a token for management.azure.com, all is done at that time is that the user has permission to execute Azure ARM API. That doesn't mean that they can do everything that's possible with Azure ARM API.
The things that they can do is controlled by Azure Role Based Access Control (RBAC). So if a user is in the Reader role, the token got on behalf of the user can only read information about resources in their Azure Subscription. They will not be allowed to create, update or delete resources in their Azure Subscription.
What you will need to do is grant users appropriate RBAC role to minimize the risks of misuse.
We are working on WEB APIs and want to integrate Azure AD for AuthN and AuthZ. We have successfully integrated the same. We have created enterprise applications, custom roles, assigned users for the same.
Now we need to allow access to APIs with AWS like keys (Secret / Access keys). Individual user can generate their own keys and store those in Azure AD so that when those keys are used, user can be authenticated.
I didn't find any way to achieve this using Azure AD. Any suggestions around same are welcome.
Meanwhile I have gone through custom store for keys. Please refer link : https://www.codeproject.com/Articles/1228892/Securing-ASP-NET-CORE-Web-API-using-Custom-API-Key
Thanks in advance.
Azure AD authentication uses tokens.
So any app wishing to call your API must authenticate with AAD and acquire a token for the API.
If these users are making apps within your organisation, then they can register their app in your AAD and require access to your API. They will create and manage their own keys.
If on the other hand these users are making an app for another organisation, you'll have to make your API a multi-tenant app.
And you'll need to have an on-boarding page in your API through which you will redirect their admin/user to the AAD login page, where they will consent to any permissions your API requires.
After this a service principal is created in their tenant.
Then they can register their client apps and require access to your API.
They will have full control which permissions they want to assign to each app, what roles to give to users etc. But of course the tokens will contain their tenant id so you can filter access on that.
I am trying to gather metrics info of azure resources. For that i need an access token to authorize. But to get an access token i have to give client id, client secret, subscription id, tenant id.I was wondering if i could get this access token without giving so many details except username and password of my azure account.
Basically you need the parameters. Azure's APIs are protected by Azure AD so you have to authenticate against it first. If you want to make calls as the user, you still need to authenticate with one of the few ways available. The password grant (as shown in #4c74356b41 answer) is one option, though it is not really recommended. The reason is that if the user's password has expired or has MFA enabled, it won't work.
What you usually do is request the user to login via Azure AD sign-in page (via redirect or web view), and then exchange the resulting authorization code for an access token and refresh token. Then you can make calls against the APIs as the user.
Another option is to register your app in Azure AD and grant its service principal some roles in your Azure subscriptions/resource groups/resources. Then it can authenticate with client credentials (using only its client id and secret + your Azure AD tenant id).
it is possible, but it is considered not safe. And you would still need a lot of parameters:
Name Description
grant_type The OAuth 2 grant type: password
resource The app to consume the token, such as Microsoft Graph, Azure AD Graph or your own Restful service
client_id The Client Id of a registered application in Azure AD
username The user account in Azure AD
password The password of the user account
scope optional, such as openid to get Id Token
Reference:
https://blogs.msdn.microsoft.com/wushuai/2016/09/25/resource-owner-password-credentials-grant-in-azure-ad-oauth/
ps. Don't mind Walter, he is wrong like 50% of the time in his answers.
It really depends on your need and if you want this fully automated or not.
If you want to have a token for a ServicePrincipal, the answer of 4c74356b41 is a great way to do it.
However if you would want to obtain a bearer token for a user (you or another AAD user) that is already authenticated in a PowerShell session, you could do this very easily if you use this piece of code that I wrote.
https://gallery.technet.microsoft.com/scriptcenter/Easily-obtain-AccessToken-3ba6e593
Basically what it does, it fetch the current token from the token cache and return it to you. This way you don't have to deal with clientId, cliendSecret or certificate. I use this all the time when I need to call the Azure REST API on a Just In Time fashion.