I store my Lambda zip files in an S3 bucket in Account A. In Account B I have my Lambda. I am trying to have my Lambda use the zip file in Account A's bucket but I keep getting:
Your access has been denied by S3, please make sure your request credentials have permission to GetObject for bucket/code.zip. S3 Error Code: AccessDenied. S3 Error Message: Access Denied
I have followed guides I have found online but I am still facing issues.
Here is my current config:
Account A's S3 Bucket Policy:
{
"Version": "2012-10-17",
"Id": "ExamplePolicy",
"Statement": [
{
"Sid": "ExampleStmt",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::AccountBID:role/MyLambdaRole"
},
"Action": [
"s3:GetObject",
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::bucket",
"arn:aws:s3:::bucket/*"
]
}
]
}
Account B's Lambda Execution Role Policy:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"s3:GetObject",
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::bucket/*",
"arn:aws:s3:::bucket"
]
}
]
}
The principal in your bucket policy is the role that AWS Lambda uses during execution, which is not used when deploying your function. You could easily just allow the entire B account principal in the bucket policy and then use IAM policies in account B to allow access to the bucket that way.
A bucket policy allowing an entire account looks like this:
{
"Version": "2008-10-17",
"Statement": [
{
"Sid": "ProductAccountAccess",
"Effect": "Allow",
"Principal": {
"AWS": [
"arn:aws:iam::XXXX-account-number:root"
]
},
"Action": [
"s3:Get*",
"s3:List*"
],
"Resource": [
"arn:aws:s3:::bucket",
"arn:aws:s3:::bucket/*"
]
}
]
}
This means that the IAM policies in account B depend on how you do your deployment. Meaning that whatever credentials are used for the deployment need to have S3 permissions for that bucket.
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 have a bucket with empty bucket policy, block public access turned ON (ACLs and Bucket) and trying to list buckets using IAM policy tied to user using STS AssumeRole with following attached policy.
{
"Version": "2012-10-17",
"Statement": [
{
"Action": [
"s3:GetObject",
"s3:GetBucket*",
"s3:ListBucket*",
"s3:ListAllMyBuckets"
],
"Effect": "Allow",
"Resource": [
"arn:aws:s3:::my-test-bucket/*"
]
}
]
}
The assumed role credentials are used during the STS session in python (boto3)
s3c = boto3.client('s3',
aws_access_key_id=credentials['AccessKeyId'],
aws_secret_access_key=credentials['SecretAccessKey'],
aws_session_token=credentials['SessionToken'])
s3c.list_buckets()
I get this exception:
botocore.exceptions.ClientError: An error occurred (AccessDenied) when calling the ListBuckets operation: Access Denied
When I tried to use IAM Policy simulator, it indicates "Implicitly denied". Im thinking if I need to access a bucket policy for this user? My understanding has been if both IAM and Bucket policy, it is an intersection. If either is not present, the other takes precedence.
Calling list_buckets() uses the s3:ListAllMyBuckets permission.
This permission cannot be restricted to a specific bucket. A user can either list all of the buckets in the account, or none of them.
Calling operations on a bucket (ListBucket, GetBucket*) requires permission for the bucket itself.
Operations on objects requires permission for the objects (or /* after the bucket name to permit actions on all objects).
Therefore, you can change your policy to:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "s3:ListAllMyBuckets",
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"s3:ListBucket",
"s3:GetBucket*"
],
"Resource": "arn:aws:s3:::my-test-bucket"
},
{
"Effect": "Allow",
"Action": "s3:GetObject",
"Resource": "arn:aws:s3:::my-test-bucket/*"
}
]
}
This is a pretty common issue because people tend to miss the difference between a "bucket" resource and an "object" resource. A bucket ends in the name of the bucket (arn:aws:s3:::my-test-bucket) whereas an object includes the bucket and key, and is often granted with a star after the initial slash. So, just change your policy to the following.
{
"Version": "2012-10-17",
"Statement": [
{
"Action": [
"s3:ListAllMyBuckets"
],
"Effect": "Allow",
"Resource": [
"arn:aws:s3:::my-test-bucket"
]
},
{
"Action": [
"s3:GetObject",
"s3:GetBucket*",
"s3:ListBucket*"
],
"Effect": "Allow",
"Resource": [
"arn:aws:s3:::my-test-bucket/*"
]
}
]
}
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.