wip: ipmi-pcap-decrypt command

[oliverpool]

See #44 for background on this command.

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To run:

export IPMI_PASSWORD="secret"
go run . ipmidump.pcap

This worked fine for our usecase, but it is quite limited since it only prints the raw deciphered payload bytes (without decoding them into proper packets).

I don't know how to achieve this with gopacket.

cmd/ipmi-pcap-decrypt/authenticator.go is copy/paste authenticator.go (can surely be optimized, by exporting the right methods/structs).

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Since the bug has been identified in our case, we (currently) don't need this tool anymore. However I would be happy to provide feedback if needed!

[oliverpool]

instead of printing to stdout, another approach would be to decrypt the payload and write a new .pcap file (so that wireshark can display it fully).