Which Encryption Method Is Being Used in My OpenVPN server?

Solution 1:

There is two differents things here :

SHA1

The Secure Hash Algorithm (SHA) is used to authenticate data and SSL/TLS connections. In this process, a unique fingerprint is created to validate the TLS certificate – that is, to check you’re connecting to the server you’re supposed to be. Without this, a hacker could re-route your traffic to their own server instead of your VPN provider’s

The cipher

Encryption ciphers are at the heart of VPN technology. They help determine how the secure tunnel is formed. Each cipher offers a different solution to secure, private and anonymous browsing.

Warnings

Be carefull using SHA1, because the algorythm is not enought secure now. You should use a better algo, like SHA512 for the handshake.

Conclusion

Your VPN encryption's algo is DHE-RSA-AES256-SHA

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