IAM Policy is not giving access to the accesspoint - amazon-s3

With this policy:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"s3:ListStorageLensConfigurations",
"s3:ListAccessPointsForObjectLambda",
"s3:GetAccessPoint",
"s3:PutAccountPublicAccessBlock",
"s3:GetAccountPublicAccessBlock",
"s3:ListAllMyBuckets",
"s3:ListAccessPoints",
"s3:ListJobs",
"s3:PutStorageLensConfiguration",
"s3:CreateJob"
],
"Resource": "*"
},
{
"Sid": "VisualEditor1",
"Effect": "Allow",
"Action": "s3:*",
"Resource": "*"
}
]
}
I am allowed to access a specific s3 accesspoint. However, when I try using a more specific access which only gives s3:* actions to a specific accesspoint:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"s3:ListStorageLensConfigurations",
"s3:ListAccessPointsForObjectLambda",
"s3:GetAccessPoint",
"s3:PutAccountPublicAccessBlock",
"s3:GetAccountPublicAccessBlock",
"s3:ListAllMyBuckets",
"s3:ListAccessPoints",
"s3:ListJobs",
"s3:PutStorageLensConfiguration",
"s3:CreateJob"
],
"Resource": "*"
},
{
"Sid": "VisualEditor1",
"Effect": "Allow",
"Action": "s3:*",
"Resource": "arn:aws:s3:eu-west-1:598276570227:accesspoint/accesspointname"
}
]
}
This does not work, and the EC2 with this role stops being able to access the s3 access point (just copying a file using the AWS CLI)
First why is this happening? The role still should have access to all the actions on that accesspoint by my reckoning (which must be wrong in some way!).
Secondly, I am trying to make it such that an s3 bucket is only accessible from a certain IAM role. I tried setting this from the access policy from the access point itself. This had the opposite problem that it was too permissive and everything could still access it. What is the correct way of doing this - putting an IAM policy on the accesspoint to restrict access to the IAM role or making an IAM Role which has access to this s3 access point?

I got this working by using this:]
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"s3:ListStorageLensConfigurations",
"s3:ListAccessPointsForObjectLambda",
"s3:GetAccessPoint",
"s3:PutAccountPublicAccessBlock",
"s3:GetAccountPublicAccessBlock",
"s3:ListAllMyBuckets",
"s3:ListAccessPoints",
"s3:ListJobs",
"s3:PutStorageLensConfiguration",
"s3:CreateJob"
],
"Resource": "*"
},
{
"Sid": "VisualEditor1",
"Effect": "Allow",
"Action": "s3:*",
"Resource": "*",
"Condition": {
"StringLike": {
"s3:DataAccessPointArn": "arn:aws:s3:eu-west-1:598276570227:accesspoint/accesspointname"
}
}
}
]
}

Related

How to restrict the S3 buckets listing in the Visual Studio AWS explorer

I am setting up the AWS toolkit in the Visual Studio. I have created an IAM user which will be used for development.
But for the IAM user I have configured I am seeing that it cannot see the S3 buckets in the explorer. It gives "Access denied".
This is the custom role assigned to the IAM user:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "AllowListing",
"Effect": "Allow",
"Action": [
"s3:ListBucket"
],
"Resource": "arn:aws:s3:::dev-buckets"
},
{
"Sid": "AllowReadWriteDel",
"Effect": "Allow",
"Action": [
"s3:PutObject",
"s3:GetObject",
"s3:DeleteObject"
],
"Resource": "arn:aws:s3:::dev-buckets/*"
}
]
}
The only way I can get it working is by adding "AmazonS3FullAccess" policy to the IAM user. But then it exposes all the buckets in the account. Not just the buckets meant for the developers.
Is it possible to do using a custom policy? I am a beginner.
You cannot only list specific bucket when trying to list buckets.
I think the following policy should help you out:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"s3:GetBucketLocation",
"s3:ListAllMyBuckets"
],
"Resource": "arn:aws:s3:::*"
},
{
"Effect": "Allow",
"Action": "s3:*",
"Resource": [
"arn:aws:s3:::dev-buckets",
"arn:aws:s3:::dev-buckets/*"
]
}
]
}

Cannot put object to Amazon S3 bucket

I'm fighting with it for the last couple of days and I'm hopeless.
I use Zend S3 lib to access my S3 via IAM account.
I'm able to list and create my buckets, but I cannot put any object nor read info ($s3->getInfo()) of a sample file I uploaded via console.
I set to my IAM account to full access: AmazonS3FullAccess, also added my own:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"s3:GetAccessPoint",
"s3:PutAccountPublicAccessBlock",
"s3:GetAccountPublicAccessBlock",
"s3:ListAllMyBuckets",
"s3:ListAccessPoints",
"s3:ListJobs",
"s3:CreateJob",
"s3:HeadBucket"
],
"Resource": "*"
},
{
"Sid": "VisualEditor1",
"Effect": "Allow",
"Action": "s3:*",
"Resource": [
"arn:aws:s3:::*",
"arn:aws:s3:*:*:accesspoint/*",
"arn:aws:s3:*:*:job/*"
]
},
{
"Sid": "VisualEditor2",
"Effect": "Allow",
"Action": "s3:*",
"Resource": "arn:aws:s3:::*/*"
}
]
}
This is my PHP code:
$amazonKey = AWS_ACCESS_KEY;
$amazonSecret = AWS_SECRET_ACCESS_KEY;
$s3 = new Zend_Service_Amazon_S3($amazonKey, $amazonSecret);
//Avaliable buckets this code works:
$this->view->content.="-----------Avaliable buckets:-------------<br>";
foreach($s3->getBuckets() as $bucket)
$this->view->content.=$bucket."<br>";
//this doesn't work
$amazonBucket='map-markers';
$object=$amazonBucket."/myobject";
$result=$s3->putObject($object, "somedata");
if ($result===false) $this->view->content.="putObject: '.$object.' FAIL!";
else
$this->view->content.="putObject: ".print_r($result)."<br>";
Also I tried C++ builder lib for AWS TAmazonStorageService: `
if (s3->UploadObject(BUCKET_NAME,OBJ_NAME,AnsiString("test").BytesOf()),true,0, amzbaPrivate, amzrNotSpecified, ResponseInfo) {
TVarRec args[1] = {ResponseInfo->StatusMessage};
Console("UploadObject:Upload to "+AnsiString(BUCKET_NAME)+" "+OBJ_NAME+" OK!");
}
else
{
TVarRec args[1] = {ResponseInfo->StatusMessage};
Console(Format(AnsiString("UploadObject Failure! %s"), args, 0));
}
S3->UploadObject returns true along with "HTTP 200" in ResponseInfo but the object is not created.
Bucket permissions are like this :
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "S3Permissions",
"Effect": "Allow",
"Principal": "*",
"Action": "s3:*",
"Resource": [
"arn:aws:s3:::map-markers/*",
"arn:aws:s3:::map-markers"
]
}
]
}
Additionally I unblocked all public access to the bucket.
I have no Idea what else could I do?
best regards
Tom
`

AWS restrict access to subfolder in s3

I am trying to restrict an IAM role to only be able to access a specific subfolder (key prefix) in an S3 bucket. Here's the policy JSON I'm using, but currently the user can still access other folders in the bucket:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor1",
"Effect": "Allow",
"Action": [
"s3:*"
],
"Resource": [
"arn:aws:s3:::somebucket",
"arn:aws:s3:::somebucket/*"
]
},
{
"Sid": "VisualEditor2",
"Effect": "Allow",
"Action": [
"s3:ListBucketVersions",
"s3:ListBucketByTags",
"s3:GetBucketAcl"
],
"Resource": [
"arn:aws:s3:::mybucket"
]
},
{
"Sid": "VisualEditor3",
"Effect": "Allow",
"Action": [
"s3:GetObjectAcl",
"s3:GetObject",
"s3:GetObjectVersion"
],
"Resource": [
"arn:aws:s3:::mybucket/datasets/company1/*"
]
}
]
}
Currently, using this role I can still do, e.g.
aws s3 cp s3://mybucket/datasets/company2/dataset.csv
and download the dataset. What am I doing wrong?
When I try and simulate the policy it seems to be correct (trying to getObject on mybucket/datasets/company2/dataset.csv fails implicitly, but this does not happen in practice. There are no other policies attached to this user.

Amazon S3 : How to allow access to a specific path, only for a specific referer?

I have a Amazon S3 bucket mybucket and only want to enable access to content in a specific nested folder (or in S3 terms, with a specific "prefix").
I tried the following S3 bucket policy but it doesn't work. After adding the condition I started getting access denied errors in the browser.
{
"Version": "2012-10-17",
"Id": "Policy for mybucket",
"Statement": [
{
"Sid": "Allow access to public content only from my.domain.com",
"Effect": "Allow",
"Principal": "*",
"Action": "s3:GetObject",
"Resource": "arn:aws:s3:::mybucket/public/content/*",
"Condition": {
"StringLike": {
"aws:Referer": [
"http://my.domain.com/*"
]
}
}
}
]
}
What should the policy look like to achieve this?
You need to split the policy in to two statements. One to allow access to the folder (prefix), and one to deny access when the referer is not one of the white listed domains:
{
"Version": "2012-10-17",
"Id": "Policy for mybucket",
"Statement": [
{
"Sid": "Allow access to public content",
"Effect": "Allow",
"Principal": "*",
"Action": "s3:GetObject",
"Resource": "arn:aws:s3:::mybucket/public/content/*"
},
{
"Sid": "Deny access to public content when not on my.domain.com",
"Effect": "Deny",
"Principal": "*",
"Action": "s3:GetObject",
"Resource": "arn:aws:s3:::mybucket/public/content/*",
"Condition": {
"StringNotLike": {
"aws:Referer": [
"http://my.domain.com/*"
]
}
}
}
]
}

How can I set a policy for an s3 bucket that allows authenticated users to list the bucket or get any file from the bucket

I have set a permission on the bucket that allows "Authenticated Users" to list, upload, and delete from a bucket I created. This seems to allow me to upload files to the bucket, but it appears that downloading files from the bucket is not covered by this permission, and I instead need to define a policy for the bucket. It's not clear to me how to set such a policy. I tried the policy generator with my best guesses at what I should fill in, but the result was not a valid policy when I pasted it in as a new policy for the bucket (it failed with the message Action does not apply to any resource(s) in statement - Action "s3:ListBucket" in Statement "Stmt-some-number"). Can someone explain what is wrong with the following policy and how to set it correctly to allow authenticated users to retrieve files from the bucket?
{
"Id": "Policy-some-number",
"Statement": [
{
"Sid": "Stmt-some-number",
"Action": [
"s3:GetObject",
"s3:ListBucket"
],
"Effect": "Allow",
"Resource": "arn:aws:s3:::my-bucket/*",
"Principal": {
"AWS": [
"*"
]
}
}
]
}
s3:GetObject applies to the objects in the bucket so the Resource is correct: "Resource": "arn:aws:s3:::my-bucket/*".
s3:ListBucket applies to the Bucket itself and so the Resource should be "Resource": "arn:aws:s3:::my-bucket"
your resulting policy should resemble:
{
"Id": "Policy-some-number",
"Statement": [
{
"Sid": "Stmt-some-number",
"Action": [
"s3:GetObject"
],
"Effect": "Allow",
"Resource": "arn:aws:s3:::my-bucket/*",
"Principal": {
"AWS": [
"*"
]
}
},
{
"Sid": "Stmt-some-other-number",
"Action": [
"s3:ListBucket"
],
"Effect": "Allow",
"Resource": "arn:aws:s3:::my-bucket",
"Principal": {
"AWS": [
"*"
]
}
}
]
}
Just to compliment #c4urself answer. the answer help solve my issue as well, but there is some indication from AWS documentation, which you can add more than one resource, just use [] to make them a list.
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-endpoints.html#vpc-endpoints-s3-bucket-policies
{
"Statement": [
{
"Sid": "Access-to-specific-bucket-only",
"Principal": "*",
"Action": [
"s3:ListBucket",
"s3:GetObject",
"s3:PutObject"
],
"Effect": "Allow",
"Resource": ["arn:aws:s3:::my_secure_bucket",
"arn:aws:s3:::my_secure_bucket/*"]
}
]
}
Update Bucket policy as below
{
"Version": "2012-10-17",
"Id": "Policy1546023103427",
"Statement": [
{
"Sid": "Stmt1546023101836",
"Effect": "Allow",
"Principal": "*",
"Action": [
"s3:ListBucket",
"s3:GetObject"
],
"Resource": [
"arn:aws:s3:::usagereports-atul",
"arn:aws:s3:::usagereports-atul/*"
]
}
]
}
Just make the resource and array/list of resources and add an item to the list with /* as s3:GetObject applies to arn:aws:s3:::my_secure_bucket/*. See below
"Resource": ["arn:aws:s3:::my_secure_bucket",
"arn:aws:s3:::my_secure_bucket/*"