I want to create a policy to allow everyone to read my S3 bucket, this is the policy that I have created (I am following this guide):
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"s3:GetObject"
],
"Resource": "arn:aws:s3:::my-s3-bucket/*",
"Principal": "*"
}
]
}
I cannot create this policy, this is the error that I am getting:
This policy contains the following error: Has prohibited field
Principal For more information about the IAM policy grammar, see AWS
IAM Policies
The problem was, I was creating the new Policy in IAM. I had to add the policy in S3, as a bucket Policy:
Select S3 Bucket -> Permissions -> Bucket Policy: paste the policy here
Note: If you want to grant read permission to anonymous user at the bucket level, then you need to turn off the following two settings.
I have generated the policy which you want using the Policy Generator.
{
"Id": "Policy1567210887639",
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Stmt1567210883302",
"Action": [
"s3:GetObject"
],
"Effect": "Allow",
"Resource": "arn:aws:s3:::my-s3-bucket/*",
"Principal": "*"
}
]
}
Check if this works for you.
Related
I'm trying to add this as an inline policy, with arn for user (principle) and arn for bucket (resource).
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::00000000:user/name"
},
"Action": ”s3:ListBucket”
"Resource": "arn:aws:s3:::bucket name"
}
]
}
error: Unsupported Principal: The policy type IDENTITY_POLICY does not support the Principal element. Remove the Principal element
tried adding this snippet as an inline policy but I have to find another way due to error Unsupported Principal: The policy type IDENTITY_POLICY does not support the Principal element. Remove the Principal element
Just remove the principal element.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": ”s3:ListBucket”
"Resource": "arn:aws:s3:::bucket name"
}
]
}
This should be working for you, just replace the user with correct AWS user.
{
"Id": "Policy1673568063233",
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Stmt1673568062150",
"Action": [
"s3:ListBucket"
],
"Effect": "Allow",
"Resource": "arn:aws:s3:::bucket name",
"Principal": {
"AWS": [
"arn:aws:iam::00000000:user/name"
]
}
}
]
}
AWS policy generator is always a great place for dealing with policy generation
https://awspolicygen.s3.amazonaws.com/policygen.html
There are two places you might place such a policy:
Bucket Policy
Policy on an IAM User
If you are creating a Bucket Policy, it will require a Principal.
However, if you are wanting to assign rules to a specific IAM User, then it is better to create a policy on the IAM User themselves. When doing this, there should not be a Principal because this is inferred by the IAM User on which the policy is placed.
Having some issues with AWS permissions and policies for grafana to be able to upload images. First off I tried with a custom policy attached to my user based on the requirements here https://grafana.com/docs/installation/configuration/#access-key.
Here's the policy:
custom policy with locked down permissions and bucket name
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"s3:PutObject",
"s3:PutObjectAcl"
],
"Resource": "arn:aws:s3:::myclient-grafana-images"
}
]
}
This unfortunately didn't work and can see an access denied error in my grafana logs. The user is trying to write an image to the bucket and ended up adding the AWS predefined policy for s3 full access. This managed to get it working
s3 full access policy
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "s3:*",
"Resource": "*"
}
]
}
The question is trying to lock the policy down just to the bucket that I need. I've tried creating a new policy with the full access policy and updated the wildcard to reference the s3 arn but that didn't work either.
Any suggestions on the best way to lock down the policies.
The PutObject and PutObjectAcl actions work on objects, not buckets.
This means that your Resource key should represent objects. ARN for objects start with the bucket name but are followed by a / and a path.
You should adapt your policy in the following way if you want to be able to put any object in your bucket (note the /*):
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"s3:PutObject",
"s3:PutObjectAcl"
],
"Resource": "arn:aws:s3:::myclient-grafana-images/*"
}
]
}
I have an AWS account with read/write permissions as shown below:
I'd like to make it so that an IAM user can download files from an S3 bucket but I'm getting access denied when executing aws s3 sync s3://<bucket_name> . I have tried various things, but not to avail. Some steps that I did:
Created a user called s3-full-access
Executed aws configure in my CLI and entered the generated access key id and secret access key for the above user
Created a bucket policy (shown below) that I'd hoped grants access for my user created in first step.
My bucket has a folder name AffectivaLogs in which files were being added anonymously by various users, and it seems like though the bucket is public, the folder inside it is not and I am not even able to make it public, and it leads to following error.
Following are the public access settings:
Update: I updated the bucket policy as follows, but it doesn't work.
To test the situation, I did the following:
Created an IAM User with no attached policies
Created an Amazon S3 bucket
Turned off S3 block public access settings:
Block new public bucket policies
Block public and cross-account access if bucket has public policies
Added a Bucket Policy granting s3:* access to the contents of the bucket for the IAM User
I then ran aws s3 sync and got Access Denied.
I then modified the policy to also permit access to the bucket itself:
{
"Id": "Policy",
"Version": "2012-10-17",
"Statement": [
{
"Sid": "statement",
"Action": "s3:*",
"Effect": "Allow",
"Resource": [
"arn:aws:s3:::my-bucket/*",
"arn:aws:s3:::my-bucket"
],
"Principal": {
"AWS": [
"arn:aws:iam::123456789012:user/stack-user"
]
}
}
]
}
This worked.
Bottom line: Also add permissions to access the bucket, in addition to the contents of the bucket. (I suspect it is because aws s3 sync requires listing of bucket contents, in addition to accessing the objects themselves.)
If you use KMS encryption enabled on bucket you should also add policy that allows you to decrypt data using KMS key.
You can configure the S3 policy with the required principal
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "ListBucket",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::accountId:user/*
},
"Action": "s3:ListBucket",
"Resource": "arn:aws:s3:::bucket"
},
{
"Sid": "GetObjects",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::accountId:user/*
},
"Action": "s3:GetObject",
"Resource": "arn:aws:s3:::bucket/*"
}
]
}
Or you can create IAM policy and attached it to the role
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "ListBucket",
"Effect": "Allow",
"Action": [
"s3:ListBucket"
],
"Resource": "arn:aws:s3:::bucket"
},
{
"Sid": "GetObject",
"Effect": "Allow",
"Action": [
"s3:GetObject"
],
"Resource": "arn:aws:s3:::bucket/*"
}
]
}
I have two accounts, account ACCOUNTAAAA, and ACCOUNTBBBB. A bucket (BUCKETAAAA) exists in account ACCOUNTAAAA and an instance with a role (ROLEBBBB) in ACCOUNTBBBB needs to be able to read from it.
I have adding the following permissions to the bucket:
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::ACCOUNTBBBB:role/ROLEBBBB"
},
"Action": [
"s3:*"
],
"Resource": "arn:aws:s3:::BUCKETAAAA/*"
}
I have the following permissions on the role in ACOUNTBBBB:
"Sid": "",
"Effect": "Allow",
"Action": [
"s3:*"
],
"Resource": [
"arn:aws:s3:::BUCKETAAAA/",
"arn:aws:s3:::BUCKETAAAA/*"
]
}
My assumption is I should be able to run aws s3 ls s3://BUCKETAAAA on the EC2 instance with the IAM role attached, and see the contants of BUCKETAAAA. When I try this, I get An error occurred (AccessDenied) when calling the ListObjects operation: Access Denied.
What am I missing here?
To reproduce your situation, I did the following:
Created Role-B in Account-B with EC2 as the Trusted Entity ("Allows EC2 instances to call AWS services on your behalf") and a policy granting access to Bucket-A
Created Bucket-A in Account-A
Added a Bucket Policy to Bucket-A, which grants access to Role-B
Assigned Role-B to an Amazon EC2 instance
The Bucket Policy on Bucket-A was:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "AddPerm",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::<account>:role/role-b"
},
"Action": [
"s3:*"
],
"Resource": [
"arn:aws:s3:::bucket-a",
"arn:aws:s3:::bucket-a/*"
]
}
]
}
The permissions on Role-B were:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "BucketA",
"Effect": "Allow",
"Action": "s3:*",
"Resource": [
"arn:aws:s3:::bucket-a",
"arn:aws:s3:::bucket-a/*"
]
}
]
}
I was able to successfully use aws s3 ls s3://bucket-a and was able to copy files to Bucket-A.
The main difference I see with your attempt was that your Bucket Policy only granted permissions for:
"Resource": "arn:aws:s3:::BUCKETAAAA/*"
This means "anything within Bucket-A" but does not include Bucket-A itself. The command aws s3 ls s3://BUCKETAAAA operates on the bucket, for which the role has no permissions.
Thus, you should also add permissions for the bucket itself:
"Resource": [
"arn:aws:s3:::BUCKETAAAA",
"arn:aws:s3:::BUCKETAAAA/*"
I am trying to connect Amazon S3 to other services through Bucket policy.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {"arn:aws:iam::ACCOUNT-ID:user/augmen",
}
"Action": [
"s3:ListBucket",
"s3:GetBucketLocation",
"s3:GetObject"
],
"Resource": ["arn:aws:s3:::rajatv.input",
"arn:aws:s3:::rajatv.input/*"]
}
]
}
Still getting errors like:
This policy contains invalid Json
Invalid Bucket syntax
No Resources
It appears that you are wanting to give bucket access to a specific IAM User. If so, the best way is to put a policy on the IAM User themselves, so that the permissions apply only to them.
This policy would grant bucket access to whichever user has it as an IAM policy. To add it, go to the user, Add Inline Policy:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "PermitBucketAccess",
"Effect": "Allow",
"Action": [
"s3:ListBucket",
"s3:GetBucketLocation",
"s3:GetObject"
],
"Resource": [
"arn:aws:s3:::rajatv.input",
"arn:aws:s3:::rajatv.input/*"
]
}
]
}
Bucket Policies, which are applied to the bucket itself, are best used to grant access to everyone, whereas an IAM policy is best for granting permissions to specific IAM Users, Groups and Roles.
Principal needs to have this format:
"Principal": {"AWS": ["arn:aws:iam::ACCOUNT-ID-WITHOUT-HYPHENS:root"]},