980 lines
25 KiB
Go
980 lines
25 KiB
Go
package dtls
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import (
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"context"
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"errors"
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"fmt"
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"io"
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"net"
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"sync"
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"sync/atomic"
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"time"
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"github.com/pion/dtls/v2/internal/closer"
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"github.com/pion/dtls/v2/pkg/crypto/elliptic"
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"github.com/pion/dtls/v2/pkg/crypto/signaturehash"
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"github.com/pion/dtls/v2/pkg/protocol"
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"github.com/pion/dtls/v2/pkg/protocol/alert"
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"github.com/pion/dtls/v2/pkg/protocol/handshake"
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"github.com/pion/dtls/v2/pkg/protocol/recordlayer"
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"github.com/pion/logging"
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"github.com/pion/transport/connctx"
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"github.com/pion/transport/deadline"
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"github.com/pion/transport/replaydetector"
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)
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const (
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initialTickerInterval = time.Second
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cookieLength = 20
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defaultNamedCurve = elliptic.X25519
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inboundBufferSize = 8192
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// Default replay protection window is specified by RFC 6347 Section 4.1.2.6
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defaultReplayProtectionWindow = 64
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)
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func invalidKeyingLabels() map[string]bool {
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return map[string]bool{
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"client finished": true,
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"server finished": true,
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"master secret": true,
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"key expansion": true,
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}
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}
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// Conn represents a DTLS connection
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type Conn struct {
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lock sync.RWMutex // Internal lock (must not be public)
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nextConn connctx.ConnCtx // Embedded Conn, typically a udpconn we read/write from
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fragmentBuffer *fragmentBuffer // out-of-order and missing fragment handling
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handshakeCache *handshakeCache // caching of handshake messages for verifyData generation
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decrypted chan interface{} // Decrypted Application Data or error, pull by calling `Read`
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state State // Internal state
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maximumTransmissionUnit int
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handshakeCompletedSuccessfully atomic.Value
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encryptedPackets [][]byte
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connectionClosedByUser bool
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closeLock sync.Mutex
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closed *closer.Closer
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handshakeLoopsFinished sync.WaitGroup
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readDeadline *deadline.Deadline
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writeDeadline *deadline.Deadline
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log logging.LeveledLogger
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reading chan struct{}
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handshakeRecv chan chan struct{}
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cancelHandshaker func()
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cancelHandshakeReader func()
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fsm *handshakeFSM
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replayProtectionWindow uint
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}
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func createConn(ctx context.Context, nextConn net.Conn, config *Config, isClient bool, initialState *State) (*Conn, error) {
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err := validateConfig(config)
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if err != nil {
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return nil, err
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}
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if nextConn == nil {
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return nil, errNilNextConn
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}
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cipherSuites, err := parseCipherSuites(config.CipherSuites, config.CustomCipherSuites, config.PSK == nil || len(config.Certificates) > 0, config.PSK != nil)
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if err != nil {
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return nil, err
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}
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signatureSchemes, err := signaturehash.ParseSignatureSchemes(config.SignatureSchemes, config.InsecureHashes)
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if err != nil {
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return nil, err
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}
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workerInterval := initialTickerInterval
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if config.FlightInterval != 0 {
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workerInterval = config.FlightInterval
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}
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loggerFactory := config.LoggerFactory
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if loggerFactory == nil {
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loggerFactory = logging.NewDefaultLoggerFactory()
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}
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logger := loggerFactory.NewLogger("dtls")
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mtu := config.MTU
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if mtu <= 0 {
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mtu = defaultMTU
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}
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replayProtectionWindow := config.ReplayProtectionWindow
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if replayProtectionWindow <= 0 {
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replayProtectionWindow = defaultReplayProtectionWindow
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}
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c := &Conn{
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nextConn: connctx.New(nextConn),
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fragmentBuffer: newFragmentBuffer(),
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handshakeCache: newHandshakeCache(),
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maximumTransmissionUnit: mtu,
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decrypted: make(chan interface{}, 1),
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log: logger,
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readDeadline: deadline.New(),
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writeDeadline: deadline.New(),
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reading: make(chan struct{}, 1),
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handshakeRecv: make(chan chan struct{}),
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closed: closer.NewCloser(),
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cancelHandshaker: func() {},
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replayProtectionWindow: uint(replayProtectionWindow),
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state: State{
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isClient: isClient,
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},
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}
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c.setRemoteEpoch(0)
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c.setLocalEpoch(0)
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serverName := config.ServerName
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// Use host from conn address when serverName is not provided
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if isClient && serverName == "" && nextConn.RemoteAddr() != nil {
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remoteAddr := nextConn.RemoteAddr().String()
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var host string
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host, _, err = net.SplitHostPort(remoteAddr)
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if err != nil {
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serverName = remoteAddr
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} else {
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serverName = host
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}
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}
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hsCfg := &handshakeConfig{
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localPSKCallback: config.PSK,
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localPSKIdentityHint: config.PSKIdentityHint,
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localCiscoCompatCallback: config.CiscoCompat,
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localCipherSuites: cipherSuites,
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localSignatureSchemes: signatureSchemes,
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extendedMasterSecret: config.ExtendedMasterSecret,
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localSRTPProtectionProfiles: config.SRTPProtectionProfiles,
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serverName: serverName,
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clientAuth: config.ClientAuth,
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localCertificates: config.Certificates,
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insecureSkipVerify: config.InsecureSkipVerify,
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verifyPeerCertificate: config.VerifyPeerCertificate,
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rootCAs: config.RootCAs,
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clientCAs: config.ClientCAs,
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customCipherSuites: config.CustomCipherSuites,
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retransmitInterval: workerInterval,
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log: logger,
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initialEpoch: 0,
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keyLogWriter: config.KeyLogWriter,
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}
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var initialFlight flightVal
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var initialFSMState handshakeState
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if initialState != nil {
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if c.state.isClient {
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initialFlight = flight5
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} else {
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initialFlight = flight6
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}
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initialFSMState = handshakeFinished
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c.state = *initialState
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} else {
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if c.state.isClient {
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initialFlight = flight1
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} else {
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initialFlight = flight0
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}
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initialFSMState = handshakePreparing
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}
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// Do handshake
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if err := c.handshake(ctx, hsCfg, initialFlight, initialFSMState); err != nil {
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return nil, err
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}
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c.log.Trace("Handshake Completed")
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return c, nil
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}
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// Dial connects to the given network address and establishes a DTLS connection on top.
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// Connection handshake will timeout using ConnectContextMaker in the Config.
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// If you want to specify the timeout duration, use DialWithContext() instead.
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func Dial(network string, raddr *net.UDPAddr, config *Config) (*Conn, error) {
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ctx, cancel := config.connectContextMaker()
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defer cancel()
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return DialWithContext(ctx, network, raddr, config)
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}
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// Client establishes a DTLS connection over an existing connection.
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// Connection handshake will timeout using ConnectContextMaker in the Config.
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// If you want to specify the timeout duration, use ClientWithContext() instead.
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func Client(conn net.Conn, config *Config) (*Conn, error) {
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ctx, cancel := config.connectContextMaker()
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defer cancel()
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return ClientWithContext(ctx, conn, config)
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}
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// Server listens for incoming DTLS connections.
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// Connection handshake will timeout using ConnectContextMaker in the Config.
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// If you want to specify the timeout duration, use ServerWithContext() instead.
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func Server(conn net.Conn, config *Config) (*Conn, error) {
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ctx, cancel := config.connectContextMaker()
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defer cancel()
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return ServerWithContext(ctx, conn, config)
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}
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// DialWithContext connects to the given network address and establishes a DTLS connection on top.
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func DialWithContext(ctx context.Context, network string, raddr *net.UDPAddr, config *Config) (*Conn, error) {
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pConn, err := net.DialUDP(network, nil, raddr)
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if err != nil {
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return nil, err
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}
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return ClientWithContext(ctx, pConn, config)
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}
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// ClientWithContext establishes a DTLS connection over an existing connection.
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func ClientWithContext(ctx context.Context, conn net.Conn, config *Config) (*Conn, error) {
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switch {
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case config == nil:
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return nil, errNoConfigProvided
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case config.PSK != nil && config.PSKIdentityHint == nil:
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return nil, errPSKAndIdentityMustBeSetForClient
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}
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return createConn(ctx, conn, config, true, nil)
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}
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// ServerWithContext listens for incoming DTLS connections.
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func ServerWithContext(ctx context.Context, conn net.Conn, config *Config) (*Conn, error) {
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if config == nil {
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return nil, errNoConfigProvided
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}
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return createConn(ctx, conn, config, false, nil)
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}
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// Read reads data from the connection.
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func (c *Conn) Read(p []byte) (n int, err error) {
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if !c.isHandshakeCompletedSuccessfully() {
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return 0, errHandshakeInProgress
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}
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select {
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case <-c.readDeadline.Done():
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return 0, errDeadlineExceeded
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default:
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}
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for {
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select {
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case <-c.readDeadline.Done():
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return 0, errDeadlineExceeded
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case out, ok := <-c.decrypted:
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if !ok {
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return 0, io.EOF
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}
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switch val := out.(type) {
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case ([]byte):
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if len(p) < len(val) {
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return 0, errBufferTooSmall
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}
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copy(p, val)
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return len(val), nil
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case (error):
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return 0, val
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}
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}
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}
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}
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// Write writes len(p) bytes from p to the DTLS connection
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func (c *Conn) Write(p []byte) (int, error) {
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if c.isConnectionClosed() {
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return 0, ErrConnClosed
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}
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select {
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case <-c.writeDeadline.Done():
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return 0, errDeadlineExceeded
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default:
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}
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if !c.isHandshakeCompletedSuccessfully() {
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return 0, errHandshakeInProgress
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}
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return len(p), c.writePackets(c.writeDeadline, []*packet{
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{
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record: &recordlayer.RecordLayer{
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Header: recordlayer.Header{
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Epoch: c.getLocalEpoch(),
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Version: protocol.Version1_2,
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},
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Content: &protocol.ApplicationData{
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Data: p,
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},
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},
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shouldEncrypt: true,
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},
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})
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}
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// Close closes the connection.
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func (c *Conn) Close() error {
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err := c.close(true)
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c.handshakeLoopsFinished.Wait()
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return err
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}
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// ConnectionState returns basic DTLS details about the connection.
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// Note that this replaced the `Export` function of v1.
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func (c *Conn) ConnectionState() State {
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c.lock.RLock()
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defer c.lock.RUnlock()
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return *c.state.clone()
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}
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// SelectedSRTPProtectionProfile returns the selected SRTPProtectionProfile
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func (c *Conn) SelectedSRTPProtectionProfile() (SRTPProtectionProfile, bool) {
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c.lock.RLock()
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defer c.lock.RUnlock()
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if c.state.srtpProtectionProfile == 0 {
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return 0, false
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}
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return c.state.srtpProtectionProfile, true
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}
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func (c *Conn) writePackets(ctx context.Context, pkts []*packet) error {
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c.lock.Lock()
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defer c.lock.Unlock()
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var rawPackets [][]byte
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for _, p := range pkts {
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if h, ok := p.record.Content.(*handshake.Handshake); ok {
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handshakeRaw, err := p.record.Marshal()
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if err != nil {
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return err
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}
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c.log.Tracef("[handshake:%v] -> %s (epoch: %d, seq: %d)",
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srvCliStr(c.state.isClient), h.Header.Type.String(),
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p.record.Header.Epoch, h.Header.MessageSequence)
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c.handshakeCache.push(handshakeRaw[recordlayer.HeaderSize:], p.record.Header.Epoch, h.Header.MessageSequence, h.Header.Type, c.state.isClient)
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rawHandshakePackets, err := c.processHandshakePacket(p, h)
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if err != nil {
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return err
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}
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rawPackets = append(rawPackets, rawHandshakePackets...)
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} else {
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rawPacket, err := c.processPacket(p)
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if err != nil {
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return err
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}
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rawPackets = append(rawPackets, rawPacket)
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}
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}
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if len(rawPackets) == 0 {
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return nil
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}
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compactedRawPackets := c.compactRawPackets(rawPackets)
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for _, compactedRawPackets := range compactedRawPackets {
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if _, err := c.nextConn.WriteContext(ctx, compactedRawPackets); err != nil {
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return netError(err)
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}
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}
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return nil
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}
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func (c *Conn) compactRawPackets(rawPackets [][]byte) [][]byte {
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combinedRawPackets := make([][]byte, 0)
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currentCombinedRawPacket := make([]byte, 0)
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for _, rawPacket := range rawPackets {
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if len(currentCombinedRawPacket) > 0 && len(currentCombinedRawPacket)+len(rawPacket) >= c.maximumTransmissionUnit {
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combinedRawPackets = append(combinedRawPackets, currentCombinedRawPacket)
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currentCombinedRawPacket = []byte{}
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}
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currentCombinedRawPacket = append(currentCombinedRawPacket, rawPacket...)
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}
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combinedRawPackets = append(combinedRawPackets, currentCombinedRawPacket)
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return combinedRawPackets
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}
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func (c *Conn) processPacket(p *packet) ([]byte, error) {
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epoch := p.record.Header.Epoch
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for len(c.state.localSequenceNumber) <= int(epoch) {
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c.state.localSequenceNumber = append(c.state.localSequenceNumber, uint64(0))
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}
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seq := atomic.AddUint64(&c.state.localSequenceNumber[epoch], 1) - 1
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if seq > recordlayer.MaxSequenceNumber {
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// RFC 6347 Section 4.1.0
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// The implementation must either abandon an association or rehandshake
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// prior to allowing the sequence number to wrap.
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return nil, errSequenceNumberOverflow
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}
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p.record.Header.SequenceNumber = seq
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rawPacket, err := p.record.Marshal()
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if err != nil {
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return nil, err
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}
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if p.shouldEncrypt {
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var err error
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rawPacket, err = c.state.cipherSuite.Encrypt(p.record, rawPacket)
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if err != nil {
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return nil, err
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}
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}
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return rawPacket, nil
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}
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func (c *Conn) processHandshakePacket(p *packet, h *handshake.Handshake) ([][]byte, error) {
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rawPackets := make([][]byte, 0)
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handshakeFragments, err := c.fragmentHandshake(h)
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if err != nil {
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return nil, err
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}
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epoch := p.record.Header.Epoch
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for len(c.state.localSequenceNumber) <= int(epoch) {
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c.state.localSequenceNumber = append(c.state.localSequenceNumber, uint64(0))
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}
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for _, handshakeFragment := range handshakeFragments {
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seq := atomic.AddUint64(&c.state.localSequenceNumber[epoch], 1) - 1
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if seq > recordlayer.MaxSequenceNumber {
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return nil, errSequenceNumberOverflow
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}
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recordlayerHeader := &recordlayer.Header{
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Version: p.record.Header.Version,
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ContentType: p.record.Header.ContentType,
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ContentLen: uint16(len(handshakeFragment)),
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Epoch: p.record.Header.Epoch,
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SequenceNumber: seq,
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}
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recordlayerHeaderBytes, err := recordlayerHeader.Marshal()
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if err != nil {
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return nil, err
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}
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p.record.Header = *recordlayerHeader
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rawPacket := append(recordlayerHeaderBytes, handshakeFragment...)
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if p.shouldEncrypt {
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var err error
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rawPacket, err = c.state.cipherSuite.Encrypt(p.record, rawPacket)
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if err != nil {
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return nil, err
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}
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}
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rawPackets = append(rawPackets, rawPacket)
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}
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return rawPackets, nil
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}
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func (c *Conn) fragmentHandshake(h *handshake.Handshake) ([][]byte, error) {
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content, err := h.Message.Marshal()
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if err != nil {
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return nil, err
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}
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fragmentedHandshakes := make([][]byte, 0)
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contentFragments := splitBytes(content, c.maximumTransmissionUnit)
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if len(contentFragments) == 0 {
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contentFragments = [][]byte{
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{},
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}
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}
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offset := 0
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for _, contentFragment := range contentFragments {
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contentFragmentLen := len(contentFragment)
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headerFragment := &handshake.Header{
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Type: h.Header.Type,
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Length: h.Header.Length,
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MessageSequence: h.Header.MessageSequence,
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FragmentOffset: uint32(offset),
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FragmentLength: uint32(contentFragmentLen),
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}
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offset += contentFragmentLen
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headerFragmentRaw, err := headerFragment.Marshal()
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if err != nil {
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return nil, err
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}
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fragmentedHandshake := append(headerFragmentRaw, contentFragment...)
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fragmentedHandshakes = append(fragmentedHandshakes, fragmentedHandshake)
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}
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return fragmentedHandshakes, nil
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}
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var poolReadBuffer = sync.Pool{ //nolint:gochecknoglobals
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New: func() interface{} {
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b := make([]byte, inboundBufferSize)
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return &b
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},
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}
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func (c *Conn) readAndBuffer(ctx context.Context) error {
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bufptr := poolReadBuffer.Get().(*[]byte)
|
|
defer poolReadBuffer.Put(bufptr)
|
|
|
|
b := *bufptr
|
|
i, err := c.nextConn.ReadContext(ctx, b)
|
|
if err != nil {
|
|
return netError(err)
|
|
}
|
|
|
|
pkts, err := recordlayer.UnpackDatagram(b[:i])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
var hasHandshake bool
|
|
for _, p := range pkts {
|
|
hs, alert, err := c.handleIncomingPacket(p, true)
|
|
if alert != nil {
|
|
if alertErr := c.notify(ctx, alert.Level, alert.Description); alertErr != nil {
|
|
if err == nil {
|
|
err = alertErr
|
|
}
|
|
}
|
|
}
|
|
if hs {
|
|
hasHandshake = true
|
|
}
|
|
switch e := err.(type) {
|
|
case nil:
|
|
case *errAlert:
|
|
if e.IsFatalOrCloseNotify() {
|
|
return e
|
|
}
|
|
default:
|
|
return e
|
|
}
|
|
}
|
|
if hasHandshake {
|
|
done := make(chan struct{})
|
|
select {
|
|
case c.handshakeRecv <- done:
|
|
// If the other party may retransmit the flight,
|
|
// we should respond even if it not a new message.
|
|
<-done
|
|
case <-c.fsm.Done():
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (c *Conn) handleQueuedPackets(ctx context.Context) error {
|
|
pkts := c.encryptedPackets
|
|
c.encryptedPackets = nil
|
|
|
|
for _, p := range pkts {
|
|
_, alert, err := c.handleIncomingPacket(p, false) // don't re-enqueue
|
|
if alert != nil {
|
|
if alertErr := c.notify(ctx, alert.Level, alert.Description); alertErr != nil {
|
|
if err == nil {
|
|
err = alertErr
|
|
}
|
|
}
|
|
}
|
|
switch e := err.(type) {
|
|
case nil:
|
|
case *errAlert:
|
|
if e.IsFatalOrCloseNotify() {
|
|
return e
|
|
}
|
|
default:
|
|
return e
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (c *Conn) handleIncomingPacket(buf []byte, enqueue bool) (bool, *alert.Alert, error) { //nolint:gocognit
|
|
h := &recordlayer.Header{}
|
|
if err := h.Unmarshal(buf); err != nil {
|
|
// Decode error must be silently discarded
|
|
// [RFC6347 Section-4.1.2.7]
|
|
c.log.Debugf("discarded broken packet: %v", err)
|
|
return false, nil, nil
|
|
}
|
|
|
|
// Validate epoch
|
|
remoteEpoch := c.getRemoteEpoch()
|
|
if h.Epoch > remoteEpoch {
|
|
if h.Epoch > remoteEpoch+1 {
|
|
c.log.Debugf("discarded future packet (epoch: %d, seq: %d)",
|
|
h.Epoch, h.SequenceNumber,
|
|
)
|
|
return false, nil, nil
|
|
}
|
|
if enqueue {
|
|
c.log.Debug("received packet of next epoch, queuing packet")
|
|
c.encryptedPackets = append(c.encryptedPackets, buf)
|
|
}
|
|
return false, nil, nil
|
|
}
|
|
|
|
// Anti-replay protection
|
|
for len(c.state.replayDetector) <= int(h.Epoch) {
|
|
c.state.replayDetector = append(c.state.replayDetector,
|
|
replaydetector.New(c.replayProtectionWindow, recordlayer.MaxSequenceNumber),
|
|
)
|
|
}
|
|
markPacketAsValid, ok := c.state.replayDetector[int(h.Epoch)].Check(h.SequenceNumber)
|
|
if !ok {
|
|
c.log.Debugf("discarded duplicated packet (epoch: %d, seq: %d)",
|
|
h.Epoch, h.SequenceNumber,
|
|
)
|
|
return false, nil, nil
|
|
}
|
|
|
|
// Decrypt
|
|
if h.Epoch != 0 {
|
|
if c.state.cipherSuite == nil || !c.state.cipherSuite.IsInitialized() {
|
|
if enqueue {
|
|
c.encryptedPackets = append(c.encryptedPackets, buf)
|
|
c.log.Debug("handshake not finished, queuing packet")
|
|
}
|
|
return false, nil, nil
|
|
}
|
|
|
|
var err error
|
|
buf, err = c.state.cipherSuite.Decrypt(buf)
|
|
if err != nil {
|
|
c.log.Debugf("%s: decrypt failed: %s", srvCliStr(c.state.isClient), err)
|
|
return false, nil, nil
|
|
}
|
|
}
|
|
|
|
isHandshake, err := c.fragmentBuffer.push(append([]byte{}, buf...))
|
|
if err != nil {
|
|
// Decode error must be silently discarded
|
|
// [RFC6347 Section-4.1.2.7]
|
|
c.log.Debugf("defragment failed: %s", err)
|
|
return false, nil, nil
|
|
} else if isHandshake {
|
|
markPacketAsValid()
|
|
for out, epoch := c.fragmentBuffer.pop(); out != nil; out, epoch = c.fragmentBuffer.pop() {
|
|
rawHandshake := &handshake.Handshake{}
|
|
if err := rawHandshake.Unmarshal(out); err != nil {
|
|
c.log.Debugf("%s: handshake parse failed: %s", srvCliStr(c.state.isClient), err)
|
|
continue
|
|
}
|
|
|
|
_ = c.handshakeCache.push(out, epoch, rawHandshake.Header.MessageSequence, rawHandshake.Header.Type, !c.state.isClient)
|
|
}
|
|
|
|
return true, nil, nil
|
|
}
|
|
|
|
r := &recordlayer.RecordLayer{}
|
|
if err := r.Unmarshal(buf); err != nil {
|
|
return false, &alert.Alert{Level: alert.Fatal, Description: alert.DecodeError}, err
|
|
}
|
|
|
|
switch content := r.Content.(type) {
|
|
case *alert.Alert:
|
|
c.log.Tracef("%s: <- %s", srvCliStr(c.state.isClient), content.String())
|
|
var a *alert.Alert
|
|
if content.Description == alert.CloseNotify {
|
|
// Respond with a close_notify [RFC5246 Section 7.2.1]
|
|
a = &alert.Alert{Level: alert.Warning, Description: alert.CloseNotify}
|
|
}
|
|
markPacketAsValid()
|
|
return false, a, &errAlert{content}
|
|
case *protocol.ChangeCipherSpec:
|
|
if c.state.cipherSuite == nil || !c.state.cipherSuite.IsInitialized() {
|
|
if enqueue {
|
|
c.encryptedPackets = append(c.encryptedPackets, buf)
|
|
c.log.Debugf("CipherSuite not initialized, queuing packet")
|
|
}
|
|
return false, nil, nil
|
|
}
|
|
|
|
newRemoteEpoch := h.Epoch + 1
|
|
c.log.Tracef("%s: <- ChangeCipherSpec (epoch: %d)", srvCliStr(c.state.isClient), newRemoteEpoch)
|
|
|
|
if c.getRemoteEpoch()+1 == newRemoteEpoch {
|
|
c.setRemoteEpoch(newRemoteEpoch)
|
|
markPacketAsValid()
|
|
}
|
|
case *protocol.ApplicationData:
|
|
if h.Epoch == 0 {
|
|
return false, &alert.Alert{Level: alert.Fatal, Description: alert.UnexpectedMessage}, errApplicationDataEpochZero
|
|
}
|
|
|
|
markPacketAsValid()
|
|
|
|
select {
|
|
case c.decrypted <- content.Data:
|
|
case <-c.closed.Done():
|
|
}
|
|
|
|
default:
|
|
return false, &alert.Alert{Level: alert.Fatal, Description: alert.UnexpectedMessage}, fmt.Errorf("%w: %d", errUnhandledContextType, content.ContentType())
|
|
}
|
|
return false, nil, nil
|
|
}
|
|
|
|
func (c *Conn) recvHandshake() <-chan chan struct{} {
|
|
return c.handshakeRecv
|
|
}
|
|
|
|
func (c *Conn) notify(ctx context.Context, level alert.Level, desc alert.Description) error {
|
|
return c.writePackets(ctx, []*packet{
|
|
{
|
|
record: &recordlayer.RecordLayer{
|
|
Header: recordlayer.Header{
|
|
Epoch: c.getLocalEpoch(),
|
|
Version: protocol.Version1_2,
|
|
},
|
|
Content: &alert.Alert{
|
|
Level: level,
|
|
Description: desc,
|
|
},
|
|
},
|
|
shouldEncrypt: c.isHandshakeCompletedSuccessfully(),
|
|
},
|
|
})
|
|
}
|
|
|
|
func (c *Conn) setHandshakeCompletedSuccessfully() {
|
|
c.handshakeCompletedSuccessfully.Store(struct{ bool }{true})
|
|
}
|
|
|
|
func (c *Conn) isHandshakeCompletedSuccessfully() bool {
|
|
boolean, _ := c.handshakeCompletedSuccessfully.Load().(struct{ bool })
|
|
return boolean.bool
|
|
}
|
|
|
|
func (c *Conn) handshake(ctx context.Context, cfg *handshakeConfig, initialFlight flightVal, initialState handshakeState) error { //nolint:gocognit
|
|
c.fsm = newHandshakeFSM(&c.state, c.handshakeCache, cfg, initialFlight)
|
|
|
|
done := make(chan struct{})
|
|
ctxRead, cancelRead := context.WithCancel(context.Background())
|
|
c.cancelHandshakeReader = cancelRead
|
|
cfg.onFlightState = func(f flightVal, s handshakeState) {
|
|
if s == handshakeFinished && !c.isHandshakeCompletedSuccessfully() {
|
|
c.setHandshakeCompletedSuccessfully()
|
|
close(done)
|
|
}
|
|
}
|
|
|
|
ctxHs, cancel := context.WithCancel(context.Background())
|
|
c.cancelHandshaker = cancel
|
|
|
|
firstErr := make(chan error, 1)
|
|
|
|
c.handshakeLoopsFinished.Add(2)
|
|
|
|
// Handshake routine should be live until close.
|
|
// The other party may request retransmission of the last flight to cope with packet drop.
|
|
go func() {
|
|
defer c.handshakeLoopsFinished.Done()
|
|
err := c.fsm.Run(ctxHs, c, initialState)
|
|
if !errors.Is(err, context.Canceled) {
|
|
select {
|
|
case firstErr <- err:
|
|
default:
|
|
}
|
|
}
|
|
}()
|
|
go func() {
|
|
defer func() {
|
|
// Escaping read loop.
|
|
// It's safe to close decrypted channnel now.
|
|
close(c.decrypted)
|
|
|
|
// Force stop handshaker when the underlying connection is closed.
|
|
cancel()
|
|
}()
|
|
defer c.handshakeLoopsFinished.Done()
|
|
for {
|
|
if err := c.readAndBuffer(ctxRead); err != nil {
|
|
switch e := err.(type) {
|
|
case *errAlert:
|
|
if !e.IsFatalOrCloseNotify() {
|
|
if c.isHandshakeCompletedSuccessfully() {
|
|
// Pass the error to Read()
|
|
select {
|
|
case c.decrypted <- err:
|
|
case <-c.closed.Done():
|
|
}
|
|
}
|
|
continue // non-fatal alert must not stop read loop
|
|
}
|
|
case error:
|
|
switch err {
|
|
case context.DeadlineExceeded, context.Canceled, io.EOF:
|
|
default:
|
|
if c.isHandshakeCompletedSuccessfully() {
|
|
// Keep read loop and pass the read error to Read()
|
|
select {
|
|
case c.decrypted <- err:
|
|
case <-c.closed.Done():
|
|
}
|
|
continue // non-fatal alert must not stop read loop
|
|
}
|
|
}
|
|
}
|
|
select {
|
|
case firstErr <- err:
|
|
default:
|
|
}
|
|
|
|
if e, ok := err.(*errAlert); ok {
|
|
if e.IsFatalOrCloseNotify() {
|
|
_ = c.close(false)
|
|
}
|
|
}
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
|
|
select {
|
|
case err := <-firstErr:
|
|
cancelRead()
|
|
cancel()
|
|
return c.translateHandshakeCtxError(err)
|
|
case <-ctx.Done():
|
|
cancelRead()
|
|
cancel()
|
|
return c.translateHandshakeCtxError(ctx.Err())
|
|
case <-done:
|
|
return nil
|
|
}
|
|
}
|
|
|
|
func (c *Conn) translateHandshakeCtxError(err error) error {
|
|
if err == nil {
|
|
return nil
|
|
}
|
|
if errors.Is(err, context.Canceled) && c.isHandshakeCompletedSuccessfully() {
|
|
return nil
|
|
}
|
|
return &HandshakeError{Err: err}
|
|
}
|
|
|
|
func (c *Conn) close(byUser bool) error {
|
|
c.cancelHandshaker()
|
|
c.cancelHandshakeReader()
|
|
|
|
if c.isHandshakeCompletedSuccessfully() && byUser {
|
|
// Discard error from notify() to return non-error on the first user call of Close()
|
|
// even if the underlying connection is already closed.
|
|
_ = c.notify(context.Background(), alert.Warning, alert.CloseNotify)
|
|
}
|
|
|
|
c.closeLock.Lock()
|
|
// Don't return ErrConnClosed at the first time of the call from user.
|
|
closedByUser := c.connectionClosedByUser
|
|
if byUser {
|
|
c.connectionClosedByUser = true
|
|
}
|
|
c.closed.Close()
|
|
c.closeLock.Unlock()
|
|
|
|
if closedByUser {
|
|
return ErrConnClosed
|
|
}
|
|
|
|
return c.nextConn.Close()
|
|
}
|
|
|
|
func (c *Conn) isConnectionClosed() bool {
|
|
select {
|
|
case <-c.closed.Done():
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
func (c *Conn) setLocalEpoch(epoch uint16) {
|
|
c.state.localEpoch.Store(epoch)
|
|
}
|
|
|
|
func (c *Conn) getLocalEpoch() uint16 {
|
|
return c.state.localEpoch.Load().(uint16)
|
|
}
|
|
|
|
func (c *Conn) setRemoteEpoch(epoch uint16) {
|
|
c.state.remoteEpoch.Store(epoch)
|
|
}
|
|
|
|
func (c *Conn) getRemoteEpoch() uint16 {
|
|
return c.state.remoteEpoch.Load().(uint16)
|
|
}
|
|
|
|
// LocalAddr implements net.Conn.LocalAddr
|
|
func (c *Conn) LocalAddr() net.Addr {
|
|
return c.nextConn.LocalAddr()
|
|
}
|
|
|
|
// RemoteAddr implements net.Conn.RemoteAddr
|
|
func (c *Conn) RemoteAddr() net.Addr {
|
|
return c.nextConn.RemoteAddr()
|
|
}
|
|
|
|
// SetDeadline implements net.Conn.SetDeadline
|
|
func (c *Conn) SetDeadline(t time.Time) error {
|
|
c.readDeadline.Set(t)
|
|
return c.SetWriteDeadline(t)
|
|
}
|
|
|
|
// SetReadDeadline implements net.Conn.SetReadDeadline
|
|
func (c *Conn) SetReadDeadline(t time.Time) error {
|
|
c.readDeadline.Set(t)
|
|
// Read deadline is fully managed by this layer.
|
|
// Don't set read deadline to underlying connection.
|
|
return nil
|
|
}
|
|
|
|
// SetWriteDeadline implements net.Conn.SetWriteDeadline
|
|
func (c *Conn) SetWriteDeadline(t time.Time) error {
|
|
c.writeDeadline.Set(t)
|
|
// Write deadline is also fully managed by this layer.
|
|
return nil
|
|
}
|