Missing required field Principal - Amazon S3 - Bucket Policy - amazon-web-services

I'm trying to resize hosted images in amazon s3 using AWS Lamba. I followed the following tutorial which is given by Amazon.
Tutorial
however, when I tried to update my bucket policy it always gives an error as "Missing required field Principal"
This is my policy code:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"logs:CreateLogGroup",
"logs:CreateLogStream",
"logs:PutLogEvents"
],
"Resource": "arn:aws:logs:*:*:*",
},
{
"Effect": "Allow",
"Action": "s3:PutObject",
"Resource": "arn:aws:s3:::yyyy",
"Principal":{"AWS":"arn:aws:iam::123456789:user/xxxxx"}
}
]
}
I Couldn't understand why I'm getting the error. What am I doing wrong?

This is actually not an S3 bucket policy, but a policy document that grants permissions to your Lambda function to write logs to CloudWatch and put the objects to your S3 bucket.
Please see how to set up that: https://www.screencast.com/t/SjD72va1Zso

Related

Getting error: "Has prohibited field Principal", when creating policy

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.

AWS IAM Policy Issues writing to s3 bucket for Grafana alerts

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/*"
}
]
}

Code Build Access denied while downloading artifact from S3

My CodeBuild is configured with CodePipeline. S3 is my artifact store. I continue to get an Access denied message despite having attached IAM roles with sufficient access.
Screenshot of the error message
I have already checked the service role associated with Codebuild. It has the following policy attached to it.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Resource": [
"arn:aws:logs:ap-southeast-1:682905754632:log-group:/aws/codebuild/Build",
"arn:aws:logs:ap-southeast-1:682905754632:log-group:/aws/codebuild/Build:*"
],
"Action": [
"logs:CreateLogGroup",
"logs:CreateLogStream",
"logs:PutLogEvents"
]
},
{
"Effect": "Allow",
"Resource": [
"arn:aws:s3:::codepipeline-ap-southeast-1-*"
],
"Action": [
"s3:PutObject",
"s3:GetObject",
"s3:GetObjectVersion"
]
}
]
}
But when I test it using the IAM policy validator I get the following error message.
Based on the accepted answer to this question the policy that I currently have should allow me to get the artifacts from S3 without any problems - AWS Codebuild fails while downloading source. Message: Access Denied
How do I get rid of the access denied message?
This generally happens when you have a CodeBuild project already and you integrate it to a CodePipeline pipeline. When you integrate a Codebuild project with CodePipeline, the project will retrieve it's source from the CodePipeline Source output. Source output will be stored in the artifact store location, which is an S3 bucket, either a default bucket created by CodePipeline or one you specify upon pipeline creation.
So, you will need to provide permissions to the CodeBuild Service role to access the CodePipline bucket in S3. The role will require permissions to put S3 objects in the bucket, as well as get objects.
Policy which i tried and same is working:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "CodeBuildDefaultPolicy",
"Effect": "Allow",
"Action": [
"codebuild:*",
"iam:PassRole"
],
"Resource": "*"
},
{
"Sid": "CloudWatchLogsAccessPolicy",
"Effect": "Allow",
"Action": [
"logs:FilterLogEvents",
"logs:GetLogEvents"
],
"Resource": "*"
},
{
"Sid": "S3AccessPolicy",
"Effect": "Allow",
"Action": [
"s3:CreateBucket",
"s3:GetObject",
"s3:List*",
"s3:PutObject"
],
"Resource": "*"
}
]
}
Policy Simulator
AWS Reference

Amazon S3 Delete Object Policy Not working

we are using Amazon S3 services and bucket for storing our data, now I have a problem, everything is working, but I want to restrict Delete object permissions only on few tables inside bucket, somehow this is not working:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Stmt1448899531000",
"Effect": "Allow",
"Action": [
"s3:Get*",
"s3:Put*",
"s3:List*"
],
"Resource": [
"*"
]
},
{
"Sid": "Stmt1461061827000",
"Effect": "Allow",
"Action": [
"s3:DeleteObject"
],
"Resource": [
"arn:aws:s3:::cf-templates-11e3g59cf34bh-eu-west-1/report_file_html/*",
"arn:aws:s3:::cf-templates-11e3g59cf34bh-eu-west-1/market_intelligence_result_sets/*"
]
}
]
}
I checked the ARN for bucket and it is "arn:aws:s3:::cf-templates-11e3g59cf34bh-eu-west-1" as excpected, market_intelligence and report_file_html tables also exist in the bucket, so I want to limit delete object action only to these tables,but from my PHP app, I get 403 error, permission denied to delete an object.
Using Amazon IAM Policy Validator, these rules validates successfully, but then using aws CLI, I get access denied error when calling DeleteObject.

AccessDenied for ListObjects for S3 bucket when permissions are s3:*

I am getting:
An error occurred (AccessDenied) when calling the ListObjects operation: Access Denied
When I try to get folder from my S3 bucket.
Using this command:
aws s3 cp s3://bucket-name/data/all-data/ . --recursive
The IAM permissions for the bucket look like this:
{
"Version": "version_id",
"Statement": [
{
"Sid": "some_id",
"Effect": "Allow",
"Action": [
"s3:*"
],
"Resource": [
"arn:aws:s3:::bucketname/*"
]
}
] }
What do I need to change to be able to copy and ls successfully?
You have given permission to perform commands on objects inside the S3 bucket, but you have not given permission to perform any actions on the bucket itself.
Slightly modifying your policy would look like this:
{
"Version": "version_id",
"Statement": [
{
"Sid": "some_id",
"Effect": "Allow",
"Action": [
"s3:*"
],
"Resource": [
"arn:aws:s3:::bucketname",
"arn:aws:s3:::bucketname/*"
]
}
]
}
However, that probably gives more permission than is needed. Following the AWS IAM best practice of Granting Least Privilege would look something like this:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::bucketname"
]
},
{
"Effect": "Allow",
"Action": [
"s3:GetObject"
],
"Resource": [
"arn:aws:s3:::bucketname/*"
]
}
]
}
If you wanted to copy all s3 bucket objects using the command "aws s3 cp s3://bucket-name/data/all-data/ . --recursive" as you mentioned, here is a safe and minimal policy to do that:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::bucket-name"
],
"Condition": {
"StringLike": {
"s3:prefix": "data/all-data/*"
}
}
},
{
"Effect": "Allow",
"Action": [
"s3:GetObject"
],
"Resource": [
"arn:aws:s3:::bucket-name/data/all-data/*"
]
}
]
}
The first statement in this policy allows for listing objects inside a specific bucket's sub directory. The resource needs to be the arn of the S3 bucket, and to limit listing to only a sub-directory in that bucket you can edit the "s3:prefix" value.
The second statement in this policy allows for getting objects inside of the bucket at a specific sub-directory. This means that anything inside the "s3://bucket-name/data/all-data/" path you will be able to copy. Be aware that this doesn't allow you to copy from parent paths such as "s3://bucket-name/data/".
This solution is specific to limiting use for AWS CLI commands; if you need to limit S3 access through the AWS console or API, then more policies will be needed. I suggest taking a look here: https://aws.amazon.com/blogs/security/writing-iam-policies-grant-access-to-user-specific-folders-in-an-amazon-s3-bucket/.
A similar issue to this can be found here which led me to the solution I am giving.
https://github.com/aws/aws-cli/issues/2408
Hope this helps!
I got the same error when using policy as below, although i have "s3:ListBucket" for s3:ListObjects operation.
{
"Version": "2012-10-17",
"Statement": [
{
"Action": [
"s3:ListBucket",
"s3:GetObject",
"s3:GetObjectAcl"
],
"Resource": [
"arn:aws:s3:::<bucketname>/*",
"arn:aws:s3:::*-bucket/*"
],
"Effect": "Allow"
}
]
}
Then i fixed it by adding one line
"arn:aws:s3:::bucketname"
{
"Version": "2012-10-17",
"Statement": [
{
"Action": [
"s3:ListBucket",
"s3:GetObject",
"s3:GetObjectAcl"
],
"Resource": [
"arn:aws:s3:::<bucketname>",
"arn:aws:s3:::<bucketname>/*",
"arn:aws:s3:::*-bucket/*"
],
"Effect": "Allow"
}
]
}
I tried the following:
aws s3 ls s3.console.aws.amazon.com/s3/buckets/{bucket name}
This gave me the error:
An error occurred (AccessDenied) when calling the ListObjectsV2 operation: Access Denied
Using this form worked:
aws s3 ls {bucket name}
I was unable to access to S3 because
first I configured key access on the instance (it was impossible to attach role after the launch then)
forgot about it for a few months
attached role to instance
tried to access.
The configured key had higher priority than role, and access was denied because the user wasn't granted with necessary S3 permissions.
Solution: rm -rf .aws/credentials, then aws uses role.
I faced with the same issue. I just added credentials config:
aws_access_key_id = your_aws_access_key_id
aws_secret_access_key = your_aws_secret_access_key
into "~/.aws/credentials" + restart terminal for default profile.
In the case of multi profiles --profile arg needs to be added:
aws s3 sync ./localDir s3://bucketName --profile=${PROFILE_NAME}
where PROFILE_NAME:
.bash_profile ( or .bashrc) -> export PROFILE_NAME="yourProfileName"
More info about how to config credentials and multi profiles can be found here
For Amazon users who have enabled MFA, please use this:
aws s3 ls s3://bucket-name --profile mfa.
And prepare the profile mfa first by running
aws sts get-session-token --serial-number arn:aws:iam::123456789012:mfa/user-name --token-code 928371 --duration 129600. (replace 123456789012, user-name and 928371).
You have to specify Resource for the bucket via "arn:aws:s3:::bucketname" or "arn:aws:3:::bucketname*". The latter is preferred since it allows manipulations on the bucket's objects too. Notice there is no slash!
Listing objects is an operation on Bucket. Therefore, action "s3:ListBucket" is required.
Adding an object to the Bucket is an operation on Object. Therefore, action "s3:PutObject" is needed.
Certainly, you may want to add other actions as you require.
{
"Version": "version_id",
"Statement": [
{
"Sid": "some_id",
"Effect": "Allow",
"Action": [
"s3:ListBucket",
"s3:PutObject"
],
"Resource": [
"arn:aws:s3:::bucketname*"
]
}
]
}
Okay for those who have done all the above and still getting this issue, try this:
Bucket Policy should look like this:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "AllowBucketSync",
"Effect": "Allow",
"Principal": "*",
"Action": [
"s3:PutObject",
"s3:GetObject",
"s3:PutObjectAcl",
"s3:DeleteObject",
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::BUCKET_NAME",
"arn:aws:s3:::BUCKET_NAME/*"
]
}
]
}
Then save and ensure your Instance or Lightsail is connected to the right profile on AWS Configure.
First:
try adding --recursive at the end, any luck? No okay try the one below.
Second:
Okay now try this instead: --no-sign-request
so it should look like this:
sudo aws s3 sync s3://BUCKET_NAME /yourpath/path/folder --no-sign-request
You're welcome 😂
I was thinking the error is due to "s3:ListObjects" action but I had to add the action "s3:ListBucket" to solve the issue "AccessDenied for ListObjects for S3 bucket"
I'm adding an answer with the same direction as the accepted answer but with small (important) differences and adding more details.
Consider the configuration below:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": ["s3:ListBucket"],
"Resource": ["arn:aws:s3:::<Bucket-Name>"]
},
{
"Effect": "Allow",
"Action": [
"s3:PutObject",
"s3:DeleteObject"
],
"Resource": ["arn:aws:s3:::<Bucket-Name>/*"]
}
]
}
The policy grants programmatic write-delete access and is separated into two parts:
The ListBucket action provides permissions on the bucket level and the other PutObject/DeleteObject actions require permissions on the objects inside the bucket.
The first Resource element specifies arn:aws:s3:::<Bucket-Name> for the ListBucket action so that applications can list all objects in the bucket.
The second Resource element specifies arn:aws:s3:::<Bucket-Name>/* for the PutObject, and DeletObject actions so that applications can write or delete any objects in the bucket.
The separation into two different 'arns' is important from security reasons in order to specify bucket-level and object-level fine grained permissions.
Notice that if I would have specified just GetObject in the 2nd block what would happen is that in cases of programmatic access I would receive an error like:
Upload failed: <file-name> to <bucket-name>:<path-in-bucket> An error occurred (AccessDenied) when calling the PutObject operation: Access Denied.
To allow permissions in s3 bucket go to the permissions tab in s3 bucket and in bucket policy change the action to this which will allow all actions to be performed:
"Action":"*"
Here's the policy that worked for me.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": "*",
"Action": [
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::bucket-name"
]
},
{
"Effect": "Allow",
"Principal": "*",
"Action": [
"s3:GetObject"
],
"Resource": [
"arn:aws:s3:::bucket-name/*"
]
}
]
}
I had a similar problem while trying to sync an entire s3 bucket locally. For me MFA (Multi-factor authentication) was enforced on my account, which is required while making commands via AWS CLI.
So the solution for me was - provide mfa credentials using a profile (mfa documentation) while using any AWS CLI commands.
Ran into a similar issues, for me the problem was that I had different AWS keys set in my bash_profile.
I answered a similar question here: https://stackoverflow.com/a/57317494/11871462
If you have conflicting AWS keys in your bash_profile, AWS CLI defaults to these instead.
I had this issue
my requirement i wanted to allow user to write to specific path
{
"Sid": "raspiiotallowspecificBucket",
"Effect": "Allow",
"Action": [
"s3:GetObject",
"s3:PutObject",
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::<bucketname>/scripts",
"arn:aws:s3:::<bucketname>/scripts/*"
]
},
and problem was solved with this change
{
"Sid": "raspiiotallowspecificBucket",
"Effect": "Allow",
"Action": [
"s3:GetObject",
"s3:PutObject",
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::<bucketname>",
"arn:aws:s3:::<bucketname>/*"
]
},
I like this better than any of the previous answers. It shows how to use the YAML format and lets you use a variable to specify the bucket.
- PolicyName: "AllowIncomingBucket"
PolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: "Allow"
Action: "s3:*"
Resource:
- !Ref S3BucketArn
- !Join ["/", [!Ref S3BucketArn, '*']]
My issue was having set
env:
AWS_ACCESS_KEY_ID: {{ secrets.AWS_ACCESS_KEY_ID }}
AWS_SECRET_ACCESS_KEY: {{ secrets.AWS_SECRET_ACCESS_KEY }}
again, under the aws-sync GitHub Action as environment variables. They were coming from my GitHub settings. Though in my case I had assumed a role in the previous step which would set me some new keys into those same name environment variables. So i was overwriting the good assumed keys with the bad GitHub basic keys.
Please take care of this if you're assuming roles.
I had the same issue. I had to provide the right resource and action, resource is your bucket's arn and action in your desired permission. Also please ensure you have your right user arn. Below is my solution.
{
"Version": "2012-10-17",
"Id": "Policy1546414123454",
"Statement": [
{
"Sid": "Stmt1546414471931",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::123456789101:root"
},
"Action": ["s3:ListBucket", "s3:ListBucketVersions"],
"Resource": "arn:aws:s3:::bucket-name"
}
]
}
If you are suddenly getting this error on a new version of minio on buckets that used to work, the reason is that bucket access policy defaults were changed from version 2021 to 2022. Now in version 2022 by default all buckets (both newly created and existing ones) have Access Policy set to Private - it is not sufficient to provide server credentials to access them - you will still get errors such as these (here: returned to the python minio client):
S3Error: S3 operation failed; code: AccessDenied, message: Access Denied., resource: /dicts, request_id: 16FCBE6EC0E70439, host_id: 61486e5a-20be-42fc-bd5b-7f2093494367, bucket_name: dicts
To roll back to the previous security settings in version 2022, the quickest method is to change the bucket access Access Policy back to Public in the MinIO console (or via mc client).
This is not the best practice but this will unblock you.
Make sure for the user that's executing the command, it has the following policy attached to it under it's permission.
A. PowerUserAccess
B. AmazonS3FullAccess
I had faced same error "An error occurred (AccessDenied) when calling the ListObjectsV2 operation: Access Denied"
Note:
Bucket policy not a good solution.
In IAM service create new custom policy attached with respective user would be safer.
Solved by below procedure:
IAM Service > Policies > Create Policy > select JSON >
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"s3:ListBucket",
"s3:GetObject",
"s3:GetObjectAcl",
"s3:ListBucketVersions"
],
"Resource": [
"arn:aws:s3:::<bucket name>"
]
},
{
"Effect": "Allow",
"Action": [
"s3:ListBucket",
"s3:GetObject",
"s3:GetObjectAcl",
"s3:PutObject",
"s3:DeleteObject",
"s3:ListBucketMultipartUploads",
"s3:ListMultipartUploadParts",
"s3:AbortMultipartUpload",
"s3:DeleteObjectVersion",
"s3:GetObjectVersion",
"s3:PutObjectACL",
"s3:ListBucketVersions"
],
"Resource": [
"arn:aws:s3:::<bucketname>/*"
]
}
]
}
Select Next Tag > Review Policy enter and create policy.
Select the newly created policy
Select the tab 'Policy Usage' in edit window of newly created policy window.
Select "Attach" select the user from the list and Save.
Now try in console with bucket name to list the objects, without bucket name it throws same error.
$aws s3 ls
A little late but might be helpful for someone. First thing first I am managing all access to s3 buckets using bucket policy.
My bucket policy to allow access to folder1 to IAM user: user1
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::123456789012:user/user1"
},
"Action": "s3:*",
"Resource": [
"arn:aws:s3:::s3-bucket/folder1",
"arn:aws:s3:::s3-bucket/folder1/*"
]
}
]
}
Now when user1 tries to perform list operation they get an error. It may look weird as the user has s3 full access from the bucket policy.
aws s3 ls s3://s3-bucket/folder1
aws s3 ls s3://s3-bucket/folder1/
aws s3 ls s3://s3-bucket/folder1/*
An error occurred (AccessDenied) when calling the ListObjectsV2
operation: Access Denied
Now let's take a look at the AWS documentation for ListBucket
Grants permission to list some or all of the objects in an Amazon S3
bucket (up to 1000)
To test that try to create a bucket policy and only provide the ListBucket permission for folder1 like this. Observe that you will get an error.
Conclusion
The ListBucket operation is only permitted for buckets and not for prefixes and hence if we want to provide list operation then it must be at the bucket level. Of course this will allow the user to list objects inside all other folders present in the bucket.