To all AWS experts:
Error : Policy has invalid action
Trying to Deny access to a IAM user via bucket policy. AWS document shows as an example but its not working. Am I doing something wrong?
Bucket Policy JSON:
{
"Id": "Policy1630065308389",
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Stmt1630065306314",
"Action": [
"s3:DeleteBucket",
"s3:GetObject"
],
"Effect": "Deny",
"Resource": "arn:aws:s3:::mybucketv11/*",
"Principal": {
"AWS": "arn:aws:iam::673863497215:user/mom-tester"
}
}
]
}
The s3:DeleteBucket action is a bucket-level action so you cannot apply it to the resource "arn:aws:s3:::mybucketv11/*", which is an object-level resource.
Your bucket policy would look more like this:
{
"Id": "Policy1630065308389",
"Version": "2012-10-17",
"Statement": [
{
"Sid": "s1",
"Action": ["s3:GetObject"],
"Effect": "Deny",
"Resource": "arn:aws:s3:::mybucketv11/*",
"Principal": {
"AWS": "arn:aws:iam::673863497215:user/mom-tester"
}
},
{
"Sid": "s2",
"Action": ["s3:DeleteBucket"],
"Effect": "Deny",
"Resource": "arn:aws:s3:::mybucketv11",
"Principal": {
"AWS": "arn:aws:iam::673863497215:user/mom-tester"
}
}
]
}
That said, why are you using an S3 bucket policy to deny access to the IAM user? Why not simply modify the permissions/roles of the IAM user so as not to allow access to this bucket?
Related
So far my S3 Bucket policy looks like this which I have got from the Generator Policy, I included my Account ID as the Principle to generate the policy but when I go to add this within my Load Balancer attributes it says that "Access Denied for bucket: bucket2. Please check S3bucket permission" What is denying access and how could I fix it?
{
"Version": "2012-10-17",
"Id": "Policy1630018580759",
"Statement": [
{
"Sid": "Stmt1630018536294",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::615298492481:root"
},
"Action": "s3:*",
"Resource": "arn:aws:s3:::elb-bkt/logs/AWSLogs/615298492481/*"
}
]
}
I'm trying to allow a set of users in a group access to a role through which they can upload objects to an s3 bucket.
The group as the policy:
{
"Version": "2012-10-17",
"Statement": {
"Effect": "Allow",
"Action": "sts:AssumeRole",
"Resource": "arn:aws:iam::ACCOUNTID:role/Clinic_Sync"
}
}
The role "Clinic_Sync" has the policy:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "SyncReqs",
"Effect": "Allow",
"Action": [
"s3:PutObject",
"s3:GetObject",
"s3:DeleteObject",
"s3:PutObjectAcl"
],
"Resource": "arn:aws:s3:::*/*"
},
{
"Sid": "SyncReqs2",
"Effect": "Allow",
"Action": [
"s3:ListBucket",
"s3:GetBucketLocation"
],
"Resource": "arn:aws:s3:::*"
}
]
}
The bucket has the policy:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::ACCOUNTID:role/Clinic_Sync"
},
"Action": "s3:ListBucket",
"Resource": "arn:aws:s3:::mydata"
},
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::ACCOUNTID:role/Clinic_Sync"
},
"Action": [
"s3:GetObject",
"s3:PutObject",
"s3:DeleteObject"
],
"Resource": "arn:aws:s3:::mydata/*"
},
{
"Effect": "Deny",
"Principal": "*",
"Action": "s3:*",
"Resource": [
"arn:aws:s3:::mydata",
"arn:aws:s3:::mydata/*"
],
"Condition": {
"StringNotLike": {
"aws:userId": [
"ADMINUSERID:*",
"ACCOUNTNO"
]
}
}
}
]
}
The idea being that no one can access the bucket except through assuming this role (other than the admin). I have created the credentials files as follows:
[default]
aws_access_key_id = ACCESSID1
aws_secret_access_key = SECRETKEY1
[csync]
role_arn = arn:aws:iam::ACCOUNTID:role/Clinic_Sync
source_profile = default
And the config file:
[default]
output = json
region = eu-west-2
[profile csync]
role_arn = arn:aws:iam::ACCOUNTID:role/Clinic_Sync
source_profile = default
The bucket policy seems to work, as running the command "aws s3 cp hello.txt s3://mydata" gives the error: Upload failed. An error occured when calling the PutObject operation: Access Denied.
But when I try to use the role, using the command "aws s3 cp hello.txt s3://run3d-data --profile csync", it gives this error:
upload failed: .\hello.txt to s3://mydata/hello.txt An error occurred (AccessDenied) when calling the AssumeRole operation: User: arn:aws:iam::ACCOUNTID:user/TestAcc2 is not authorized to perform: sts:AssumeRole on resource: arn:aws:iam::ACCOUNTID:role/Clinic_Sync
I've been searching the web for an answer for ages and can't find any answers. The aws documentation is frankly unintelligible to me. If anyone can help me find a solution to this I'd be much appreciated as I'm tearing my hair out here.
To reiterate, I just want the users in a particular group to have access to a role that grants them permission to use an s3 bucket, but block all other access to the bucket.
Your bucket policy seems to say: "Deny access to the bucket unless aws:userId is a given Admin User ID or Account Number. It does not reference the Role.
Therefore, accessing the bucket via the Role will be denied. This is because Deny always overrides Allow.
Writing policies with Deny can be quite difficult, as seen in this situation.
If you really want to keep a bucket secure, it is easier to put the bucket in a separate AWS Account and only grant cross-account access to the entities that should have access. This way, no Deny policy is required.
If you receive a not authorised to perform sts:AssumeRole error, make sure the Trust Policy grants access to users by selecting the Another AWS account option when creating the role. The policy should look similar to:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::111111111111:root"
},
"Action": "sts:AssumeRole",
"Condition": {}
}
]
}
I created an s3 bucket and gave the following bucket policy to it
{
"Version": "2012-10-17",
"Id": "Policy1586942250763",
"Statement": [
{
"Sid": "Stmt1586942249918",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::accID:user/username1”
},
"Action": "s3:*",
"Resource": "arn:aws:s3:::bucket-name"
}
]
}
Obviously this would give access only to the user username1. Now username1 was deleted from IAM. Is there any way to recover access to this bucket. I have an IAM account with admin privileges but aws s3api delete-bucket-policy111 seems to be not working.
Only root user can do anything on that bucket now.
I need to give external users access to a single Amazon S3 bucket folder. I have their ARN information but I am having an issue granting access.
{
"Version": "2012-10-17",
"Id": "S3AccessPolicy",
"Statement": [
{
"Sid": "TestAccess",
"Effect": "Allow",
"Principal": {
"AWS": "<external ARN>"
},
"Action": [
"s3:GetObject",
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::rootlevelbucket",
"arn:aws:s3:::rootlevelbucket/specificfolder/*"
]
}
]
}
There is 2 sides to cross account access. You have the first part with the bucket policy, but the admin for the external account needs to grant the user access to the S3 with a IAM policy like below. You can use the s3:* on the IAM policy because you bucket policy will restrict to just the commands you list.
AWS Documentation
IAM Policy for external user:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "RootlevelbucketAccess",
"Effect": "Allow",
"Action": [
"s3:*"
],
"Resource": [
"arn:aws:s3:::rootlevelbucket",
"arn:aws:s3:::rootlevelbucket/specificfolder/*"
]
}
]
}
I have the following policy on an S3 bucket created with the AWS policy generator to allow a lambda, running with a specific role, access to the files in the bucket. However, when I execute the Lambda, I get 403 permission denied:
"errorMessage": "Access Denied (Service: Amazon S3; Status Code: 403; Error Code: AccessDenied; Request ID: <requestId>)",
"errorType": "com.amazonaws.services.s3.model.AmazonS3Exception",
The Policy on the S3 bucket:
{
"Version": "2012-10-17",
"Id": "Policy<number>",
"Statement": [
{
"Sid": "Stmt<number>",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::<account>:role/<roleName>"
},
"Action": "s3:*",
"Resource": "arn:aws:s3:::<bucketName>/*"
}
]
}
What is wrong with the policy? The Lamba is running with the role configured in the policy.
A role assigned to an AWS Lambda function should be created with an AWS Lambda role (that is selected when creating a Role in the IAM console).
Roles do not have a Principal since the permissions are assigned to whichever service (in this case, Lambda function) is using the role.
Also, you should assign permissions on the bucket itself (e.g. to list contents) and on the contents of the bucket (e.g. to GetObject).
It would be something like this:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "AllowS3Access",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::123XXX:role/service-role/LAMBDA_ROLE_NAME"
},
"Action": [
"s3:*"
],
"Resource": [
"arn:aws:s3:::my-bucket",
"arn:aws:s3:::my-bucket/*"
]
}
]
}
After looping for I while i could make it work, the process is:
create the s3 bucket.
create the IAM policy (bucket name needed)
Create IAM role (IAM policy needed)
Create lambda Function (IAM Role needed)
Create s3 bucket policy (lambda function name needed)
IAM Policy:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Stmt*******",
"Effect": "Allow",
"Action": [
"s3:PutObject",
"s3:PutObjectAcl",
"s3:PutObjectTagging",
"s3:PutObjectVersionAcl",
"s3:PutObjectVersionTagging"
],
"Resource": [
"arn:aws:s3:::<bucket-name>"
]
}
]
}
and I use this policy on the s3 Bucket
{
"Id": "Policy************",
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Stmt********",
"Action": [
"s3:PutObject",
"s3:PutObjectAcl",
"s3:PutObjectTagging",
"s3:PutObjectVersionAcl",
"s3:PutObjectVersionTagging"
],
"Effect": "Allow",
"Resource": "arn:aws:s3:::<bucket-name>/*",
"Principal": {
"AWS": [
"arn:aws:iam::*********:role/<lambda-function-name>"
]
}
}
]
}