What are the details for the AWS Transfer Family SFTP server?

Question

*What are the details for the AWS Transfer Family SFTP server?*

I want to better understand the security of the provided SFTP server.

I can get good information based on the security policy [here](https://docs.aws.amazon.com/transfer/latest/userguide/security-policies.html), but that does not provide all the information I need.

- Which protocol draft is supported? I am guessing either [SFTP v3](https://datatracker.ietf.org/doc/html/draft-ietf-secsh-filexfer-02) or [SFTP v4](https://datatracker.ietf.org/doc/html/draft-ietf-secsh-filexfer-04) or something else.
- Does this SFTP break the moved files into packets and perform a checksum on each packet to ensure transmission file integrity, failing the transmission when one or more packets are fail?
- Is there documentation specific to the hosted SFTP server and its protocol implementation?

hayao-k · Answer

*  The debug output looks like this
   ```
   debug1: Remote protocol version 2.0, remote software version AWS_SFTP_1.1
   ```
* Verified by MD5 checksum  
  https://aws.amazon.com/aws-transfer-family/faqs/?nc1=h_ls#Security_and_compliance
  > **Q: How does the service ensure integrity of uploaded files?**  
  > A: Files uploaded through services are verified by comparing the file’s pre- and post-upload MD5 checksum.

* No such documentation appears to be publicly available

What are the details for the AWS Transfer Family SFTP server?

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