Wireshark showing no encryption in OpenVPN

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bonzi200x
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Wireshark showing no encryption in OpenVPN

Post by bonzi200x » Thu Mar 10, 2011 10:03 pm

I have cipher BF-CBC uncommented in both server and client and wireshark is listening to tap0 but it is not showing any encryption. Am I doing something wrong here?

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Bebop
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Re: Wireshark showing no encryption in OpenVPN

Post by Bebop » Thu Mar 10, 2011 11:13 pm

bonzi200x wrote:I have cipher BF-CBC uncommented in both server and client and wireshark is listening to tap0 but it is not showing any encryption. Am I doing something wrong here?
Depending on your setup. More detail required.

Do you mean that you have Wireshark on your server end-point TAP device?

If yes, then the data is decrypted at the end point, and data is seen as plain text.

Think about it more for a second. If the data were not decrypted at each end, then how would the data ever be used?

The data will be encrypted at all locations between you and the endpoint, but not at the endpoint itself.

At least thats how it is for TUN. Assuming TAP is no different.
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janjust
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Re: Wireshark showing no encryption in OpenVPN

Post by janjust » Fri Mar 11, 2011 4:45 pm

the 'tap0' interface is *inside* the tunnel and hence should not be encrypted.
If you want to see encrypted traffic listen on the 'eth0' interface (or whichever i/f OpenVPN is configured over).

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