Pion DTLS AECDH-AES128-SHA Example

README.md

• openssl s_server -dtls -cipher "AECDH-AES128-SHA:@SECLEVEL=0" -state -accept 127.0.0.1:4444 -nocert -msg
• openssl s_client -dtls -cipher "AECDH-AES128-SHA:@SECLEVEL=0" -state -connect 127.0.0.1:4444

dial.go

package main

import (
	"context"
	"net"
	"time"

	"github.com/pion/dtls/v2"
)

func dial() {
	// Prepare the IP to connect to
	addr := &net.UDPAddr{IP: net.ParseIP("127.0.0.1"), Port: 4444}

	// Connect to a DTLS server
	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()
	_, err := dtls.DialWithContext(ctx, "udp", addr, &dtls.Config{
		CustomCipherSuites: func() []dtls.CipherSuite { return []dtls.CipherSuite{&TLSAecdhAes128Sha{}} },
		CipherSuites:       []dtls.CipherSuiteID{},
	})
	if err != nil {
		panic(err)

	}

}

listener.go

package main

import (
	"net"

	"github.com/pion/dtls/v2"
)

func listener() {
	// Prepare the IP to listen on
	addr := &net.UDPAddr{IP: net.ParseIP("0.0.0.0"), Port: 4444}

	// Prepare the configuration of the DTLS connection
	config := &dtls.Config{
		CustomCipherSuites: func() []dtls.CipherSuite { return []dtls.CipherSuite{&TLSAecdhAes128Sha{}} },
		CipherSuites:       []dtls.CipherSuiteID{},
	}

	// Connect to a DTLS server
	listener, err := dtls.Listen("udp", addr, config)
	if err != nil {
		panic(err)
	}

	_, err = listener.Accept()
	if err != nil {
		panic(err)

	}
}

main.go

package main

import (
	"crypto/sha1"
	"crypto/sha256"
	"fmt"
	"hash"
	"sync/atomic"

	"github.com/pion/dtls/v2"
	"github.com/pion/dtls/v2/pkg/crypto/ciphersuite"
	"github.com/pion/dtls/v2/pkg/crypto/clientcertificate"
	"github.com/pion/dtls/v2/pkg/crypto/prf"
	"github.com/pion/dtls/v2/pkg/protocol/recordlayer"
)

func main() {
	dial()

	if false {
		listener()

	}
}

// TLSAecdhAes128Sha implements the TLS_ADH_AES128_SHA CipherSuite
type TLSAecdhAes128Sha struct {
	cbc atomic.Value // *cryptoCBC
}

// CertificateType returns what type of certificate this CipherSuite exchanges
func (c *TLSAecdhAes128Sha) CertificateType() clientcertificate.Type {
	return clientcertificate.Type(0)
}

// ID returns the ID of the CipherSuite
func (c *TLSAecdhAes128Sha) ID() dtls.CipherSuiteID {
	return 0xC018
}

func (c *TLSAecdhAes128Sha) String() string {
	return "AECDH-AES128-SHA"
}

// HashFunc returns the hashing func for this CipherSuite
func (c *TLSAecdhAes128Sha) HashFunc() func() hash.Hash {
	return sha256.New
}

// AuthenticationType controls what authentication method is using during the handshake
func (c *TLSAecdhAes128Sha) AuthenticationType() dtls.CipherSuiteAuthenticationType {
	return dtls.CipherSuiteAuthenticationTypeAnonymous
}

// IsInitialized returns if the CipherSuite has keying material and can
// encrypt/decrypt packets
func (c *TLSAecdhAes128Sha) IsInitialized() bool {
	return c.cbc.Load() != nil
}

// Init initializes the internal Cipher with keying material
func (c *TLSAecdhAes128Sha) Init(masterSecret, clientRandom, serverRandom []byte, isClient bool) error {
	const (
		prfMacLen = 20
		prfKeyLen = 16
		prfIvLen  = 16
	)

	keys, err := prf.GenerateEncryptionKeys(masterSecret, clientRandom, serverRandom, prfMacLen, prfKeyLen, prfIvLen, c.HashFunc())
	if err != nil {
		return err
	}

	var cbc *ciphersuite.CBC
	if isClient {
		cbc, err = ciphersuite.NewCBC(
			keys.ClientWriteKey, keys.ClientWriteIV, keys.ClientMACKey,
			keys.ServerWriteKey, keys.ServerWriteIV, keys.ServerMACKey,
			sha1.New,
		)
	} else {
		cbc, err = ciphersuite.NewCBC(
			keys.ServerWriteKey, keys.ServerWriteIV, keys.ServerMACKey,
			keys.ClientWriteKey, keys.ClientWriteIV, keys.ClientMACKey,
			sha1.New,
		)
	}
	c.cbc.Store(cbc)

	return err
}

// Encrypt encrypts a single TLS RecordLayer
func (c *TLSAecdhAes128Sha) Encrypt(pkt *recordlayer.RecordLayer, raw []byte) ([]byte, error) {
	cbc := c.cbc.Load()
	if cbc == nil {
		return nil, fmt.Errorf("CipherSuite is not ready, unable to encrypt")
	}

	return cbc.(*ciphersuite.CBC).Encrypt(pkt, raw)
}

// Decrypt decrypts a single TLS RecordLayer
func (c *TLSAecdhAes128Sha) Decrypt(raw []byte) ([]byte, error) {
	cbc := c.cbc.Load()
	if cbc == nil { // !c.isInitialized()
		return nil, fmt.Errorf("CipherSuite is not ready, unable to decrypt")
	}

	return cbc.(*ciphersuite.CBC).Decrypt(raw)
}