添加 github.com/pion/dtls 代码

2025-08-08 11:10:14 +08:00 · 2021-05-21 19:03:00 +08:00
parent 54a0cb7928
commit 28b5119f50
380 changed files with 16870 additions and 0 deletions
--- a/dtls-2.0.9/flight0handler.go
+++ b/dtls-2.0.9/flight0handler.go
@@ -0,0 +1,102 @@
+package dtls
+
+import (
+	"context"
+	"crypto/rand"
+
+	"github.com/pion/dtls/v2/pkg/crypto/elliptic"
+	"github.com/pion/dtls/v2/pkg/protocol"
+	"github.com/pion/dtls/v2/pkg/protocol/alert"
+	"github.com/pion/dtls/v2/pkg/protocol/extension"
+	"github.com/pion/dtls/v2/pkg/protocol/handshake"
+)
+
+func flight0Parse(ctx context.Context, c flightConn, state *State, cache *handshakeCache, cfg *handshakeConfig) (flightVal, *alert.Alert, error) {
+	seq, msgs, ok := cache.fullPullMap(0,
+		handshakeCachePullRule{handshake.TypeClientHello, cfg.initialEpoch, true, false},
+	)
+	if !ok {
+		// No valid message received. Keep reading
+		return 0, nil, nil
+	}
+	state.handshakeRecvSequence = seq
+
+	var clientHello *handshake.MessageClientHello
+
+	// Validate type
+	if clientHello, ok = msgs[handshake.TypeClientHello].(*handshake.MessageClientHello); !ok {
+		return 0, &alert.Alert{Level: alert.Fatal, Description: alert.InternalError}, nil
+	}
+
+	if !clientHello.Version.Equal(protocol.Version1_2) {
+		return 0, &alert.Alert{Level: alert.Fatal, Description: alert.ProtocolVersion}, errUnsupportedProtocolVersion
+	}
+
+	state.remoteRandom = clientHello.Random
+
+	cipherSuites := []CipherSuite{}
+	for _, id := range clientHello.CipherSuiteIDs {
+		if c := cipherSuiteForID(CipherSuiteID(id), cfg.customCipherSuites); c != nil {
+			cipherSuites = append(cipherSuites, c)
+		}
+	}
+
+	if state.cipherSuite, ok = findMatchingCipherSuite(cipherSuites, cfg.localCipherSuites); !ok {
+		return 0, &alert.Alert{Level: alert.Fatal, Description: alert.InsufficientSecurity}, errCipherSuiteNoIntersection
+	}
+
+	for _, val := range clientHello.Extensions {
+		switch e := val.(type) {
+		case *extension.SupportedEllipticCurves:
+			if len(e.EllipticCurves) == 0 {
+				return 0, &alert.Alert{Level: alert.Fatal, Description: alert.InsufficientSecurity}, errNoSupportedEllipticCurves
+			}
+			state.namedCurve = e.EllipticCurves[0]
+		case *extension.UseSRTP:
+			profile, ok := findMatchingSRTPProfile(e.ProtectionProfiles, cfg.localSRTPProtectionProfiles)
+			if !ok {
+				return 0, &alert.Alert{Level: alert.Fatal, Description: alert.InsufficientSecurity}, errServerNoMatchingSRTPProfile
+			}
+			state.srtpProtectionProfile = profile
+		case *extension.UseExtendedMasterSecret:
+			if cfg.extendedMasterSecret != DisableExtendedMasterSecret {
+				state.extendedMasterSecret = true
+			}
+		case *extension.ServerName:
+			state.serverName = e.ServerName // remote server name
+		}
+	}
+
+	if cfg.extendedMasterSecret == RequireExtendedMasterSecret && !state.extendedMasterSecret {
+		return 0, &alert.Alert{Level: alert.Fatal, Description: alert.InsufficientSecurity}, errServerRequiredButNoClientEMS
+	}
+
+	if state.localKeypair == nil {
+		var err error
+		state.localKeypair, err = elliptic.GenerateKeypair(state.namedCurve)
+		if err != nil {
+			return 0, &alert.Alert{Level: alert.Fatal, Description: alert.IllegalParameter}, err
+		}
+	}
+
+	return flight2, nil, nil
+}
+
+func flight0Generate(c flightConn, state *State, cache *handshakeCache, cfg *handshakeConfig) ([]*packet, *alert.Alert, error) {
+	// Initialize
+	state.cookie = make([]byte, cookieLength)
+	if _, err := rand.Read(state.cookie); err != nil {
+		return nil, nil, err
+	}
+
+	var zeroEpoch uint16
+	state.localEpoch.Store(zeroEpoch)
+	state.remoteEpoch.Store(zeroEpoch)
+	state.namedCurve = defaultNamedCurve
+
+	if err := state.localRandom.Populate(); err != nil {
+		return nil, nil, err
+	}
+
+	return nil, nil, nil
+}