Native [DTLS 1.2][rfc6347] implementation in the Go programming language.
A long term goal is a professional security review, and maybe an inclusion in stdlib.
[rfc6347]: https://tools.ietf.org/html/rfc6347
### Goals/Progress
This will only be targeting DTLS 1.2, and the most modern/common cipher suites.
We would love contributions that fall under the 'Planned Features' and any bug fixes!
#### Current features
* DTLS 1.2 Client/Server
* Key Exchange via ECDHE(curve25519, nistp256, nistp384) and PSK
* Packet loss and re-ordering is handled during handshaking
* Key export ([RFC 5705][rfc5705])
* Serialization and Resumption of sessions
* Extended Master Secret extension ([RFC 7627][rfc7627])
* ALPN extension ([RFC 7301][rfc7301])
[rfc5705]: https://tools.ietf.org/html/rfc5705
[rfc7627]: https://tools.ietf.org/html/rfc7627
[rfc7301]: https://tools.ietf.org/html/rfc7301
#### Supported ciphers
##### ECDHE
* TLS_ECDHE_ECDSA_WITH_AES_128_CCM ([RFC 6655][rfc6655])
* TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 ([RFC 6655][rfc6655])
* TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 ([RFC 5289][rfc5289])
* TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 ([RFC 5289][rfc5289])
* TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 ([RFC 5289][rfc5289])
* TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 ([RFC 5289][rfc5289])
* TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA ([RFC 8422][rfc8422])
* TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA ([RFC 8422][rfc8422])
##### PSK
* TLS_PSK_WITH_AES_128_CCM ([RFC 6655][rfc6655])
* TLS_PSK_WITH_AES_128_CCM_8 ([RFC 6655][rfc6655])
* TLS_PSK_WITH_AES_128_GCM_SHA256 ([RFC 5487][rfc5487])
* TLS_PSK_WITH_AES_128_CBC_SHA256 ([RFC 5487][rfc5487])
[rfc5289]: https://tools.ietf.org/html/rfc5289
[rfc8422]: https://tools.ietf.org/html/rfc8422
[rfc6655]: https://tools.ietf.org/html/rfc6655
[rfc5487]: https://tools.ietf.org/html/rfc5487
#### Planned Features
* Chacha20Poly1305
#### Excluded Features
* DTLS 1.0
* Renegotiation
* Compression
### Using
This library needs at least Go 1.13, and you should have [Go modules
enabled](https://github.com/golang/go/wiki/Modules).
#### Pion DTLS
For a DTLS 1.2 Server that listens on 127.0.0.1:4444
```sh
go run examples/listen/selfsign/main.go
```
For a DTLS 1.2 Client that connects to 127.0.0.1:4444
```sh
go run examples/dial/selfsign/main.go
```
#### OpenSSL
Pion DTLS can connect to itself and OpenSSL.
```
// Generate a certificate
openssl ecparam -out key.pem -name prime256v1 -genkey
openssl req -new -sha256 -key key.pem -out server.csr
openssl x509 -req -sha256 -days 365 -in server.csr -signkey key.pem -out cert.pem
// Use with examples/dial/selfsign/main.go
openssl s_server -dtls1_2 -cert cert.pem -key key.pem -accept 4444
// Use with examples/listen/selfsign/main.go
openssl s_client -dtls1_2 -connect 127.0.0.1:4444 -debug -cert cert.pem -key key.pem
```
### Using with PSK
Pion DTLS also comes with examples that do key exchange via PSK
#### Pion DTLS
```sh
go run examples/listen/psk/main.go
```
```sh
go run examples/dial/psk/main.go
```
#### OpenSSL
```
// Use with examples/dial/psk/main.go
openssl s_server -dtls1_2 -accept 4444 -nocert -psk abc123 -cipher PSK-AES128-CCM8
// Use with examples/listen/psk/main.go
openssl s_client -dtls1_2 -connect 127.0.0.1:4444 -psk abc123 -cipher PSK-AES128-CCM8
```
### Contributing
Check out the **[contributing wiki](https://github.com/pion/webrtc/wiki/Contributing)** to join the group of amazing people making this project possible:
### License
MIT License - see [LICENSE](LICENSE) for full text