Start TLS_PSK_WITH_AES_128_CCM8

[Sean-Der]

@daenney This works 100% !OpenSSL <-> Pion and Pion <-> Pion

I am going on vacation on Tuesday, mind helping me catch corner cases etc...? Would love to get this merged and tagged :)

[codecov-io]

Codecov Report

Merging #76 into master will increase coverage by 0.74%.
The diff coverage is 78.67%.

@@            Coverage Diff             @@
##           master      #76      +/-   ##
==========================================
+ Coverage   69.67%   70.42%   +0.74%     
==========================================
  Files          48       50       +2     
  Lines        2681     2847     +166     
==========================================
+ Hits         1868     2005     +137     
- Misses        579      600      +21     
- Partials      234      242       +8

Impacted Files	Coverage Δ
handshake_message_server_hello.go	52.83% <0%> (ø)	⬆️
prf.go	62.83% <100%> (+2.08%)	⬆️
crypto_gcm.go	62.5% <100%> (-7.5%)	⬇️
crypto.go	61.11% <100%> (+5.55%)	⬆️
cipher_suite.go	97.01% <100%> (+0.09%)	⬆️
crypto_ccm.go	62.5% <62.5%> (ø)
client_handlers.go	81.25% <68%> (+1.39%)	⬆️
handshake_message_client_key_exchange.go	72.72% <71.42%> (+6.06%)	⬆️
conn.go	76.68% <72.72%> (+0.64%)	⬆️
cipher_suite_tls_psk_with_aes_128_ccm8.go	75% <75%> (ø)
... and 8 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b1c2af3...d3da74b. Read the comment docs.

[Sean-Der]

@daenney @igolaizola

I am happy with this w/e I can get a review I would really appreciate it!

[daenney]

This is awesome, thank you so much! I'm currently also on vacay but I have access to the IoT equipment at home, so I'll try to test this today.

[igolaizola]

Nice job!

[daenney]

I'm happy to say I've just managed to ping my IKEA Tradfri gateway with this! So this has been validated in protoduction 😄.

If anyone's looking on and would like to try it, here's the sample code:

package main

import (
	"fmt"
	"net"

	"github.com/dustin/go-coap"
	"github.com/pion/dtls"
)

func main() {
	addr := &net.UDPAddr{IP: net.ParseIP("gateway-ip"), Port: 5684}
	config := &dtls.Config{
		PSK: func(_ []byte) ([]byte, error) {
			return []byte("psk-on-bottom-of-gateway"), nil
		},
		PSKIdentityHint: []byte("Client_identity"), // For Tradfri Gateway the IdentityHint MUST be Client_identity
		CipherSuites:    []dtls.CipherSuiteID{dtls.TLS_PSK_WITH_AES_128_CCM8},
	}

	dtlsConn, err := dtls.Dial("udp", addr, config)
	if err != nil {
		panic(err)
	}
	defer dtlsConn.Close()

	req := coap.Message{
		Type:      coap.Confirmable,
		Code:      coap.GET,
		MessageID: 1,
		Token:     []byte{},
		Payload:   []byte{},
	} // This is a CoAP Ping, empty confirmable message

	data, err := req.MarshalBinary()
	if err != nil {
		panic(err)
	}

	_, err = dtlsConn.Write(data)
	if err != nil {
		panic(err)
	}

	resp := make([]byte, 2048)
	dtlsConn.Read(resp)
	msg, err := coap.ParseMessage(resp)
	if err != nil {
		panic(err)
	}
	fmt.Println(msg.MessageID)
	fmt.Println(msg.Type)
	fmt.Println(msg.Code)
	fmt.Println(msg.Token)
	fmt.Println(string(msg.Payload))

}

It'll output:

1
Acknowledgement
NotFound
[]
Not Found

[Sean-Der]

@daenney that is awesome! So glad it works :)

Thanks for doing half the work, really glad we did this. I am hoping we can get pion/dtls good enough so it can get wide adoption/get the community around one Go implementation.