Using C#, I am able to download files from the bucket just by knowing the bucket name and the file key (filename).
The file and bucket are set up to not be accessible publicly.
Once I do
GetObjectRequest request = new GetObjectRequest
{
BucketName = bucketName,
Key = keyName
};
Even though I have not provided access key or the secret key, I still have access to the file content.
Is there a way to not allow this?
#akiva is partially correct.
If you are running this on an ec2 instance, if that instance has a 'IAM role' associated with it, and if that role has access to the bucket, the application can access the bucket without the application providing credentials.
On a regular machine, or even on an ec2 instance that does not have an associated IAM role, credentials are often stored in the users .aws subdirectory in a credentials file.
if you're connecting from an EC2 server it sometimes has a configuration file that stores the credentials globally for you
If your code is on EC2 machine, it fetches the access key and secret key stored in the hidden .aws directory. Also, if this EC2 instance has an IAM role with suitable permissions, it can fetch the contents from your S3 bucket very well.
You might need to check the role associated with your EC2 instance in order to prevent the accessibility to your S3 bucket.
Related
We are able to put objects into our S3 Bucket.
But now we have a requirement that we need to put these Object directly to an S3 Bucket which belongs to a different account and different region.
Here we have few questions:
Is this possible?
If possible what changes we need to do for this?
They have provided us Access Key, Secret Key, Region, and Bucket details.
Any comments and suggestions will be appreciated.
IAM credentials are associated with a single AWS Account.
When you launch your own Amazon EC2 instance with an assigned IAM Role, it will receive access credentials that are associated with your account.
To write to another account's Amazon S3 bucket, you have two options:
Option 1: Your credentials + Bucket Policy
The owner of the destination Amazon S3 bucket can add a Bucket Policy on the bucket that permits access by your IAM Role. This way, you can just use the normal credentials available on the EC2 instance.
Option 2: Their credentials
It appears that you have been given access credentials for their account. You can use these credentials to access their Amazon S3 bucket.
As detailed on Working with AWS Credentials - AWS SDK for Java, you can provide these credentials in several ways. However, if you are using BOTH the credentials provided by the IAM Role AND the credentials that have been given to you, it can be difficult to 'switch between' them. (I'm not sure if there is a way to tell the Credentials Provider to switch between a profile stored in the ~/.aws/credentials file and those provided via instance metadata.)
Thus, the easiest way is to specify the Access Key and Secret Key when creating the S3 client:
BasicAWSCredentials awsCreds = new BasicAWSCredentials("access_key_id", "secret_key_id");
AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
.withCredentials(new AWSStaticCredentialsProvider(awsCreds))
.build();
It is generally not a good idea to put credentials in your code. You should load them from a configuration file.
Yes, it's possible. You need to allow cross account S3 put operation in bucket's policy.
Here is a blog by AWS. It should help you in setting up cross account put action.
As far as I can tell the only way to mount an s3 bucket with s3fs is to use an accesskey:secretkey specified in a file with various file locations supported.
However, if I'm an ec2 instance, in the local s3 account, with an instance profile, I just want to use the instance profile credentials that are available. Does anyone know of a way to use an instance profile, and not have to set credentials in the local file system? If not, is anyone working on supporting this feature going forward?
Thanks
Once/if you have a role that is attached to the EC2 instance, you can then add the following entry in /etc/fstab to automatically mount the S3 bucket on boot:
s3fs#bucketname /PATHtoLocalMount fuse _netdev,iam_role=nameofiamrolenoquotes
Naturally, you have to have s3fs installed (as you do judging from the question), and the role policy must grant the appropriate (probably full) access to the S3 bucket. This is great in the sense that no IAM credentials need to be stored on the instance (=safer, because the role access cannot be used outside the instance attached to the role, while the IAM credentials can).
I am trying to connect to s3 bucket from the EC2 instance. The logging into ec2 instance is using private key, generated from pem file. Ideally I should have been able access the s3 bucket from here directly without passing access key and secret. But when i try to connect it is asking for above 2 things rahter than directly connecting and listing the contents.
The SSH key you generated from the pem file, and the AWS IAM account access key and secret key are two completely different things. The SSH key is used for initiating SSH connections with your EC2 server. The access key and secret key are from an AWS IAM account and are used for accessing the AWS API.
If you are trying to access S3 from your EC2 server the the prefered way is to assign an IAM role to the EC2 instance with the appropriate permissions, so that you don't have to deal with the IAM key credentials.
I have this snippet to upload a file on S3
s3 = boto3.resource('s3')
s3.Object('bucketname', timestamped_filename).put(Body=open(FILE_SAVE_PATH, 'rb'))
my bucket has a delete/upload permission for everyone, so it does work on my Windows machine.
However, when I try to run the same code on my Mac it throws
botocore.exeptions.NoCredentialsError: Unable to locate credentials
Is this behavior normal?
And what kind of credentials I can possibly provide if I'm accessing a public bucket?
Thank you.
When making an API call to AWS, valid credentials must be provided. These credentials are associated with an IAM User and grant access to AWS services.
When making API calls (or using the AWS Command-Line Interface (CLI)) from an Amazon EC2 instance, these credentials can be granted to the EC2 instance by assigning an IAM Role to the instance at launch time.
When making calls from a non-EC2 computer, credentials must be provided via a configuration file or environment variables.
It appears that your Windows machine is either an EC2 instance with a role, or it has a local configuration file with valid credentials; and it appears that your Mac has neither of these.
See: boto3 Credentials documentation
I am mounting an AWS S3 bucket as a filesystem using s3fs-fuse. It requires a file which contains AWS Access Key Id and AWS Secret Access Key.
How do I avoid the access using this file? And instead use AWS IAM roles?
As per Fuse Over Amazon document, you can specify the credentials using 4 methods. If you don't want to use a file, then you can set AWSACCESSKEYID and AWSSECRETACCESSKEY environment variables.
Also, if your goal is to use AWS IAM instance profile, then you need to run your s3fs-fuse from an EC2 instance. In that case, you don't have to set these credential files/environment variables. This is because while creating the instance, if you attach the instance role and policy, the EC2 instance will get the credentials at boot time. Please see the section 'Using Instance Profiles' in page 190 of AWS IAM User Guide
there is an argument -o iam_role=--- which helps you to avoid AccessKey and SecretAccessKey
The Full steps to configure this is given below
https://www.nxtcloud.io/mount-s3-bucket-on-ec2-using-s3fs-and-iam-role/