AWS Transfer for SFTP was launched on November 2018 as a fully managed service that enables the transfer of files directly into and out of Amazon S3 using the Secure File Transfer Protocol (SFTP).
Today, we are happy to announce the expansion of the service to add support for FTPS and FTP, which makes it easy to migrate and securely run File Transfer Protocol over SSL (FTPS) and FTP workloads in AWS, in addition to the existing AWS Transfer for SFTP service. Supporting SFTP-, FTPS-, and FTP-based transfers for Amazon S3, we are also announcing the “AWS Transfer Family,” which is the aggregated name of AWS Transfer for SFTP, FTPS, and FTP.
Some software archiving and scientific research applications use FTP to distribute software artifacts or public datasets, and CRM, ERP, and supply chain applications use FTPS for transferring sensitive data. Many of their existing applications cannot switch from FTP or FTPS to SFTP because this requires changing existing applications and processes – especially those involving third-parties – and is often impractical or infeasible. Customers are looking for an easy and secure way to migrate their file transfers without disrupting their existing integrations and end users. For these reasons, we are launching AWS Transfer for FTPS and AWS Transfer for FTP.
Basic difference between SFTP and FTPS/FTP
Let’s talk a bit about the differences among SFTP and FTPS/FTP before we start a walk through. These are actually different protocols, but they work similar to “File Transfer.”
- Secure File Transfer Protocol (SFTP) – Defined by the Internet Engineering Task Force (IETF) as an extended version of SSH 2.0, allowing file transfer over SSH and for use with Transport Layer Security (TLS) and VPN applications.
- File Transfer Protocol (FTP) – Defined by RFC114 originally, and replaced by RFC765 and RFC959 for TCP/IP basis.
- File Transfer Protocol over SSL/TLS (FTPS) – Used to encrypt FTP communication by SSL/TLS.
Until now, customers with multiple protocol needs were using the service for SFTP or were waiting for this launch. With this announcement, customers who use either of the three protocols can migrate and leverage AWS services for their end to end file transfer needs. Availability of these new protocols increases accessibility to your data, while the same options that were available for SFTP can be used for FTPS and FTP to secure access. Access control features available include using use of IAM Roles and policies, Logical directories for S3 and Security Groups.
This walk through provides a step-by-step guide for creating a fully managed FTP Server. FTP servers are only accessible inside your VPC, including AWS Direct Connect or VPN. You can use FTPS if you need access via the internet.
You will see a new AWS console page when you access the AWS Transfer Family console. Click Create server to begin.
For this example, let’s start the walk through by selecting FTP. Click the FTP check box, and uncheck the SFTP check box. We can assign both protocols at the same time, but we are creating a FTP server as the new feature for this step.
We now need to assign an Identity provider. The identity provider is used for authentication when logging on to the FTP server. Only Custom which is provided by Amazon API Gateway is supported for FTPS and FTP. To be able to invoke the API, we need to create an Invocation URL, which is an API Gateway endpoint, and also an IAM role. Here are guidelines for how to create an Invocation URL using CloudFormation with a yaml template. For servers enabled for SFTP only, you can also choose Service Managed authentication to store and manage identities within the service.
Click Next, and an Endpoint configuration dialog comes up.
We can only choose VPC as a VPC hosted endpoint for FTP. If we need access from the internet, we need to choose FTPS instead of FTP for security reasons. Then, we choose an appropriate VPC and its subnet to host the endpoint.
Click Next, and the next dialog comes up. The next step is optional. We can enable CloudWatch logging by assigning an IAM role. The CloudFormation template above created an IAM role that we can use, or we can use a different role.
We skip the Server Host key section because this is for SFTP.
Assign the appropriate tags and click Next. Then, click Create server. The FTP server is created.
Click Server ID, and we see the detail of the FTP server.
It is time to test the FTP server!
From Action, let’s select Test. Type “myuser” as Username and “MySuperSecretPassword” as Password.
Status code of HTTP 200 is returned if your FTP server is successfully integrated with your identity provider.
Now that we know your identity provider is all integrated correctly, let’s test using a ftp client.
We can now perform cd/ls/put/get/rm operations using a FTP client against an existing Amazon S3 bucket(s). We use Amazon EC2 for this walk through. Create an instance if we do not have it in the subnet specified above, and Install lftp client.
To connect to the server, we will need its endpoint URL of the FTP server. We need to access the VPC Endpoint console to obtain it. If you were using an internet facing SFTP and/or FTPS server, you could get this information directly from the AWS Transfer Family Console. If we access the Endpoint from another subnet or other VPC, please be sure that Security Groups allows TCP port 21 and port 8192-8200.
Then, we can try to login to the FTP server by below command;
Username and Password for test is specified in the source code inside the Lambda function created by CloudFormation as guided.
The blog article “Enable password authentication for AWS Transfer for SFTP using AWS Secrets Manager” is a good way to start to learn more about managing an authentication data, and this CloudFormation template is used for creating API Gateway and Lambda functions with AWS Secrets Manager.
- Only Passive mode is supported. Our service does not make outbound connections.
- Only Explicit mode for FTPS is supported. Our service does not support implicit mode.
- Renaming file name is supported, but renaming directory (S3 BucketName) is not supported, and also append operations are not supported
AWS Transfer for FTPS and FTP are available in all Regions where AWS Transfer for SFTP is currently available. Take a look at the product page and the documentation to learn more. You can also check this video for a demo.