Building a Managed SFTP Server with AWS Transfer Family - S3 Integration and User Management
Learn how to build SFTP/FTPS servers with Transfer Family, integrate with S3, and configure custom authentication.
Overview of Transfer Family
Transfer Family is a service that provides managed servers supporting four protocols - SFTP, FTPS, FTP, and AS2 - capable of handling up to thousands of concurrent connections. If you use SFTP for file exchange with trading partners, you can build an SFTP server with Transfer Family and set S3 as the transfer destination, freeing you from file storage management. Existing SFTP clients and scripts can be migrated simply by changing the connection hostname.
Authentication and Workflows
User authentication can be configured using one of three methods: service-managed (managed within Transfer Family), custom (Lambda authorizer), or AWS Directory Service. Custom authentication lets you implement authentication logic in a Lambda function and integrate with existing LDAP or Active Directory. Managed workflows are processing chains that run automatically after file uploads, allowing you to define file copying, tagging, PGP decryption, and custom Lambda processing.
AS2 Protocol and Automation
The AS2 (Applicability Statement 2) protocol is widely used for B2B file exchange, providing message encryption, signing, and delivery receipts (MDN). Transfer Family's AS2 connector lets you set up automated file exchange with partners using S3 as storage. Managed workflows execute automated processing (copying, tagging, Lambda invocation) after file uploads, building file processing pipelines. CloudWatch Logs records transfer logs for auditing file send and receive activity. For detailed information about Transfer Family, you can also find related books on Amazon.
Transfer Family Pricing
Transfer Family pricing consists of protocol endpoint hours (approximately $0.30 per hour, approximately $216 per month) and data transfer volume (approximately $0.04 per GB for uploads, approximately $0.04 per GB for downloads). Since the always-on endpoint cost is the primary expense, evaluate cost efficiency in advance if transfer frequency is low. S3 storage costs are billed separately. Selecting the VPC endpoint type provides fixed IP addresses via Elastic IP, accommodating partner firewall configurations.
Summary
Transfer Family provides managed servers for SFTP, FTPS, FTP, and AS2 protocols, simplifying file storage management through S3 integration. Custom authentication uses Lambda authorizers to integrate with existing identity providers. Managed workflows automate post-upload processing, and AS2 connectors automate B2B file exchange.