Power Platform Community Forum Thread Details

The current SFTP-SSH connector in Power Automate is lagging behind modern security standards, and it is actively blocking enterprise integrations with secure environments like AWS GovCloud.

Currently, the connector relies on an outdated version of the SSH.NET library that does not support Encrypt-then-MAC (EtM) algorithms—specifically hmac-sha2-256-etm and hmac-sha2-512-etm.

Modern SFTP servers, including AWS Transfer Family’s default security policies, have deprecated the older MAC algorithms and strictly enforce EtM. Because of this, Power Automate cannot complete the handshake and drops the connection with the error: Server HMAC algorithm not found.

Any workarounds?

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Using connectors