How to control view for each user or team? - amazon-web-services

Let's say I've 10 API's under my account and 10 users. Each user is responsible for their own API.
Is there way to configure in a way that when each user login and go to API gateway they do not see 10 API's and only see the one they're responsible for it?

You can achieve it by giving resource level permission to each IAM user. As below example, Under the Resource array, you can specify the API ARN for each IAM.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"apigateway:GET"
],
"Resource": [
"arn:aws:apigateway:us-east-1::/restapis/a123456789/*"
]
}
]
}
Please look into the below document for more details.
https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-iam-policy-examples.html

Related

How to revoke a user session when using AWS SSO?

I'm currently managing a AWS SSO solution using it with AzureAD. For our use case we need to be able to revoke access/session of a user.
In AzureAD it's pretty simple, go to the user, block him, revoke its session. It's done, user needs to relog but he won't be able to do so.
In AWS SSO, it looks a bit harder, I can't seem to find a way to instantly revoke a session. I can disable its access, but once he has a session, even deleting the user/group from AWS SSO will not terminate the session.
This causes quite a problem as this is compliant to my security standards.
Any ideas?
Thanks people
An option is to put in place a temporary SCP on the AWS account to deny all actions for the Role session of the user as shown below:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "UserRestrictions",
"Effect": "Deny",
"Action": "*",
"Resource": [
"*"
],
"Condition": {
"StringEquals": {
"aws:userId": [
"AROAEXAMPLEROLEID:alice#example.com"
]
}
}
}
]}
After a day or so (or the max role duration) you could remove the SCP. This is useful if you only have a single role session but in the scenario of an AWS SSO user, the user probably has access to multiple Roles across multiple AWS accounts. Rather than adding multiple SCPs you could add a SCP higher up in the organizational hierarchy that denies actions for all Role sessions for the user as shown below:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "UserRestrictions",
"Effect": "Deny",
"Action": "*",
"Resource": [
"*"
],
"Condition": {
"StringLike": {
"aws:userId": [
"*:alice#example.com"
]
}
}
}
]}

AWS IAM Policy grant permissions for some EC2 instances

I want to restrict access for a specific user to see just few EC2 instances. I created a new user in IAM Roles and I attached a new Policy to it. The content of that Policy is attached below. I tried to look over documentation and to do it myself like this:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "ec2:*",
"Resource": [
"arn:aws:ec2:eu-west-1:ACCOUNT_ID:instance/i-INSTANCE_ID1",
"arn:aws:ec2:eu-west-1:ACCOUNT_ID:instance/i-INSTANCE_ID2"
]
}
]
}
I placed my region,ACCOUNT_ID(the owner id, not of the new user created) and instance-id, but when I connect with that user and I go to list all Instances I got this An error occurred fetching instance data: You are not authorized to perform this operation..
After I placed the code in JSON editor, in Policy Review step I got this message:
This policy defines some actions, resources, or conditions that do not
provide permissions. To grant access, policies must have an action
that has an applicable resource or condition. For details, choose Show
remaining Learn more
The AWS documentation mention exactly the same configuration or these examples.
I assume you connect as that user in the console (but it would be the same with CLI) Here is what I think is happening:
To list all the instances, the console most probably calls the DescribeInstances API. As per the list of action/resources/tags that can be used in IAM policy, this API does not support the resource filter in IAM.
This means your user has no authorization to list instances and they will not be shown in the console. You can validate this theory by using the CLI to request the details of a specific instance id, if my hypothesis is correct, it will be authorized.
As DescribeInstances can not be restricted by resource or tags, I don't think it is possible to filter the instance list for a user.
To have the console working, you'll need to add the following statement in your IAM policy
"Statement": [
{ your existing statement },
{
"Effect": "Allow",
"Action": "ec2:DescribeInstances",
"Resource": "*"
}
]
Please report if I was right :-) The example you mentioned in your question shows exactly that : Resources = * on DescribeInstances and Resources specific InstanceId on other operations.
The previous answer is wrong, you can Conditionally allow access to ec2:DescribeInstances by tag names. It's an AWS best practice as well. Also explicitly deny access to the ec2:CreateTags and ec2:DeleteTags actions to prevent users from creating or deleting tags to take control of the instance.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "ec2:DescribeInstances",
"Resource": "*",
"Condition": {
"StringEquals": {
"ec2:ResourceTag/UserName": "${aws:username}"
}
}
},
{
"Effect": "Deny",
"Action": [
"ec2:CreateTags",
"ec2:DeleteTags"
],
"Resource": "*"
}
]
}
DescribeInstances action does not support condition.
https://docs.aws.amazon.com/service-authorization/latest/reference/list_amazonec2.html

How to only allow AWS IoT subscriptions to topics under Cognito user id (sub)?

I want my backend to be able to directly send messages to authenticated users. Which means I need to limit the users to only subscribe on topics under their own identifiers. Ideally, to my currently limited understanding, I would have a policy that has the user sub as a variable:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"iot:Connect",
"iot:Publish",
"iot:Receive",
"iot:GetThingShadow",
"iot:UpdateThingShadow",
"iot:DeleteThingShadow"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"iot:Subscribe"
],
"Resource": "arn:aws:iot:us-east-1:949960872797:topicfilter/user/${cognitoUserSub}/someTopic"
}
]
}
If ultimately the cognito identifier is not an option for this policy, please advise me of what other identifier i would provide. Whichever it is, i need to be able to somehow obtain it based on the user's cognito identifier (the sub).
Note that my knowledge in this regard is very limited, so I understand that I might be off by quite a bit.
Answered on AWS forum https://forums.aws.amazon.com/thread.jspa?threadID=268115
For details on how to use cognito with AWS IoT also check https://forums.aws.amazon.com/thread.jspa?threadID=224268

AWS IAM SSM - Restrict Documents that Instances can run

Is there a way to restrict the IAM policy for an EC2 instance s.t. it can only run a short list of Documents - I tried restricting access to ssm:GetDocument like this:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"ssm:GetDocument"
],
"Resource": [
"arn:aws:ssm:ap-southeast-2:*:document/MyCommand"
]
}
]}
But I can run any command on the instance still including the AWS-RunPowershellScript document.
This link shows how users can be restricted with respect to ssm:sendCommand:
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/delegate-commands.html
I have not found a way to restrict SendCommand based on document. If a user does not have access, you get an error like this:
User: arn:aws:iam::123456789012:user/username is not authorized to perform: ssm:SendCommand on resource: arn:aws:ec2:us-east-1:123456789012:instance/i-01234567890abcdef
This indicates that the Resource in SendCommand can be limited based on instance ids. It would be nice if one of the Conditions was a Document ARN, but so far I haven't found any way to do it (it's not a condition in the policy generator wizard).
Update: I posted this question on the AWS forums, hopefully I'll get a response: https://forums.aws.amazon.com/thread.jspa?threadID=249039
Update 2: I got a response and the solution is that to accomplish this you must use Resource to specify both what instances you allow commands to be run on, and what document the user is allowed to run. For example, this is what I ended up with:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"ssm:SendCommand"
],
"Resource": [
"arn:aws:ec2:*:123456789012:instance/*",
"arn:aws:ssm:*:123456789012:document/RestartServices"
]
}
]
}

aws policy variable ${aws:username} returning error not authorized

I have followed the docs at aws http://docs.aws.amazon.com/IAM/latest/UserGuide/PolicyVariables.html
and the question at Can an aws IAM policy dynamically refer to the logged in username?
to create a policy for a user to list his own credentials under web console/users so he can generate his own keys.
user/Alpha
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action":["iam:*"],
"Resource":["arn:aws:iam::{myacctnumber}:user/${aws:username}"]
}
]
}
when I attach the the policy to user/Alpha, then open a new browser and log in as user Alpha > console > users, I get the error message
We encountered the following errors while processing your request
X User: arn:aws:iam::{myacctnumber}:user/Alpha is not authorized to perform: iam ListUsers on resource: arn:aws:iam::{myacctnumber}:user/
note the user/ is not displaying the friendly name as would be expected from ${aws:username}.
I have also tried changing the policy to
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action":["iam:*"],
"Resource":["arn:aws:iam::{myacctnumber}:user/Alpha"]
}
]
}
but the same error displays.
If I make one further change to the resource and make it a wildcard,
"Resource":["arn:aws:iam::{myacctnumber}:user/*"]
the full user list is displayed to to the user Alpha
Do I need extra permissions to allow a user to see only themselves?
thx
Art
The console, when displaying a list of users, uses the iam:ListUsers API call. This call cannot be restricted by resource.
Therefore, the console will function correctly if you provide a policies that permits the ListUsers call, eg:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"iam:ListUsers"
],
"Resource": [
"*"
]
}
]
}
The only other way for the user to update their own settings would be via the AWS Command-Line Interface (CLI) or an API call, since they can avoid the need to call ListUsers.