mirror of
https://github.com/v2fly/v2ray-core.git
synced 2024-06-07 00:20:42 +00:00
375 lines
11 KiB
Go
375 lines
11 KiB
Go
package encoding
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import (
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"context"
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"crypto/aes"
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"crypto/cipher"
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"crypto/md5"
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"hash/fnv"
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"io"
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"sync"
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"time"
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"golang.org/x/crypto/chacha20poly1305"
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"v2ray.com/core/common/buf"
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"v2ray.com/core/common/crypto"
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"v2ray.com/core/common/net"
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"v2ray.com/core/common/protocol"
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"v2ray.com/core/common/serial"
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"v2ray.com/core/common/signal"
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"v2ray.com/core/proxy/vmess"
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)
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type sessionId struct {
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user [16]byte
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key [16]byte
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nonce [16]byte
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}
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type SessionHistory struct {
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sync.RWMutex
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cache map[sessionId]time.Time
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token *signal.Semaphore
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ctx context.Context
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}
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func NewSessionHistory(ctx context.Context) *SessionHistory {
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h := &SessionHistory{
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cache: make(map[sessionId]time.Time, 128),
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token: signal.NewSemaphore(1),
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ctx: ctx,
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}
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return h
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}
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func (h *SessionHistory) add(session sessionId) {
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h.Lock()
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h.cache[session] = time.Now().Add(time.Minute * 3)
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select {
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case <-h.token.Wait():
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go h.run()
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default:
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}
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h.Unlock()
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}
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func (h *SessionHistory) has(session sessionId) bool {
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h.RLock()
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defer h.RUnlock()
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if expire, found := h.cache[session]; found {
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return expire.After(time.Now())
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}
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return false
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}
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func (h *SessionHistory) run() {
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defer h.token.Signal()
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for {
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select {
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case <-h.ctx.Done():
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return
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case <-time.After(time.Second * 30):
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}
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session2Remove := make([]sessionId, 0, 16)
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now := time.Now()
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h.Lock()
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if len(h.cache) == 0 {
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h.Unlock()
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return
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}
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for session, expire := range h.cache {
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if expire.Before(now) {
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session2Remove = append(session2Remove, session)
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}
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}
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for _, session := range session2Remove {
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delete(h.cache, session)
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}
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h.Unlock()
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}
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}
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func getSizeMask(b []byte) crypto.Uint16Generator {
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return crypto.NewShakeUint16Generator(b)
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}
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type ServerSession struct {
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userValidator protocol.UserValidator
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sessionHistory *SessionHistory
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requestBodyKey []byte
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requestBodyIV []byte
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responseBodyKey []byte
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responseBodyIV []byte
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responseHeader byte
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responseWriter io.Writer
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}
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// NewServerSession creates a new ServerSession, using the given UserValidator.
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// The ServerSession instance doesn't take ownership of the validator.
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func NewServerSession(validator protocol.UserValidator, sessionHistory *SessionHistory) *ServerSession {
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return &ServerSession{
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userValidator: validator,
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sessionHistory: sessionHistory,
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}
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}
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func (v *ServerSession) DecodeRequestHeader(reader io.Reader) (*protocol.RequestHeader, error) {
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buffer := make([]byte, 512)
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_, err := io.ReadFull(reader, buffer[:protocol.IDBytesLen])
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if err != nil {
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return nil, newError("failed to read request header").Base(err)
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}
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user, timestamp, valid := v.userValidator.Get(buffer[:protocol.IDBytesLen])
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if !valid {
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return nil, newError("invalid user")
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}
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timestampHash := md5.New()
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timestampHash.Write(hashTimestamp(timestamp))
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iv := timestampHash.Sum(nil)
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account, err := user.GetTypedAccount()
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if err != nil {
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return nil, newError("failed to get user account").Base(err)
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}
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vmessAccount := account.(*vmess.InternalAccount)
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aesStream := crypto.NewAesDecryptionStream(vmessAccount.ID.CmdKey(), iv)
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decryptor := crypto.NewCryptionReader(aesStream, reader)
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nBytes, err := io.ReadFull(decryptor, buffer[:41])
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if err != nil {
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return nil, newError("failed to read request header").Base(err)
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}
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bufferLen := nBytes
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request := &protocol.RequestHeader{
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User: user,
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Version: buffer[0],
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}
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if request.Version != Version {
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return nil, newError("invalid protocol version ", request.Version)
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}
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v.requestBodyIV = append([]byte(nil), buffer[1:17]...) // 16 bytes
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v.requestBodyKey = append([]byte(nil), buffer[17:33]...) // 16 bytes
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var sid sessionId
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copy(sid.user[:], vmessAccount.ID.Bytes())
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copy(sid.key[:], v.requestBodyKey)
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copy(sid.nonce[:], v.requestBodyIV)
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if v.sessionHistory.has(sid) {
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return nil, newError("duplicated session id, possibly under replay attack")
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}
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v.sessionHistory.add(sid)
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v.responseHeader = buffer[33] // 1 byte
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request.Option = protocol.RequestOption(buffer[34]) // 1 byte
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padingLen := int(buffer[35] >> 4)
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request.Security = protocol.NormSecurity(protocol.Security(buffer[35] & 0x0F))
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// 1 bytes reserved
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request.Command = protocol.RequestCommand(buffer[37])
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request.Port = net.PortFromBytes(buffer[38:40])
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switch buffer[40] {
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case AddrTypeIPv4:
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_, err = io.ReadFull(decryptor, buffer[41:45]) // 4 bytes
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bufferLen += 4
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if err != nil {
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return nil, newError("failed to read IPv4 address").Base(err)
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}
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request.Address = net.IPAddress(buffer[41:45])
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case AddrTypeIPv6:
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_, err = io.ReadFull(decryptor, buffer[41:57]) // 16 bytes
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bufferLen += 16
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if err != nil {
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return nil, newError("failed to read IPv6 address").Base(err)
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}
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request.Address = net.IPAddress(buffer[41:57])
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case AddrTypeDomain:
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_, err = io.ReadFull(decryptor, buffer[41:42])
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if err != nil {
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return nil, newError("failed to read domain address").Base(err)
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}
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domainLength := int(buffer[41])
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if domainLength == 0 {
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return nil, newError("zero length domain").Base(err)
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}
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_, err = io.ReadFull(decryptor, buffer[42:42+domainLength])
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if err != nil {
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return nil, newError("failed to read domain address").Base(err)
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}
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bufferLen += 1 + domainLength
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request.Address = net.DomainAddress(string(buffer[42 : 42+domainLength]))
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}
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if padingLen > 0 {
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_, err = io.ReadFull(decryptor, buffer[bufferLen:bufferLen+padingLen])
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if err != nil {
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return nil, newError("failed to read padding").Base(err)
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}
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bufferLen += padingLen
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}
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_, err = io.ReadFull(decryptor, buffer[bufferLen:bufferLen+4])
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if err != nil {
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return nil, newError("failed to read checksum").Base(err)
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}
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fnv1a := fnv.New32a()
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fnv1a.Write(buffer[:bufferLen])
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actualHash := fnv1a.Sum32()
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expectedHash := serial.BytesToUint32(buffer[bufferLen : bufferLen+4])
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if actualHash != expectedHash {
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return nil, newError("invalid auth")
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}
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if request.Address == nil {
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return nil, newError("invalid remote address")
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}
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return request, nil
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}
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func (v *ServerSession) DecodeRequestBody(request *protocol.RequestHeader, reader io.Reader) buf.Reader {
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var authReader io.Reader
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var sizeMask crypto.Uint16Generator = crypto.StaticUint16Generator(0)
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if request.Option.Has(protocol.RequestOptionChunkMasking) {
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sizeMask = getSizeMask(v.requestBodyIV)
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}
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if request.Security.Is(protocol.SecurityType_NONE) {
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if request.Option.Has(protocol.RequestOptionChunkStream) {
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auth := &crypto.AEADAuthenticator{
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AEAD: NoOpAuthenticator{},
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NonceGenerator: crypto.NoOpBytesGenerator{},
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AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
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}
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authReader = crypto.NewAuthenticationReader(auth, reader, sizeMask)
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} else {
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authReader = reader
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}
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} else if request.Security.Is(protocol.SecurityType_LEGACY) {
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aesStream := crypto.NewAesDecryptionStream(v.requestBodyKey, v.requestBodyIV)
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cryptionReader := crypto.NewCryptionReader(aesStream, reader)
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if request.Option.Has(protocol.RequestOptionChunkStream) {
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auth := &crypto.AEADAuthenticator{
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AEAD: new(FnvAuthenticator),
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NonceGenerator: crypto.NoOpBytesGenerator{},
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AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
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}
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authReader = crypto.NewAuthenticationReader(auth, cryptionReader, sizeMask)
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} else {
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authReader = cryptionReader
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}
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} else if request.Security.Is(protocol.SecurityType_AES128_GCM) {
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block, _ := aes.NewCipher(v.requestBodyKey)
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aead, _ := cipher.NewGCM(block)
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auth := &crypto.AEADAuthenticator{
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AEAD: aead,
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NonceGenerator: &ChunkNonceGenerator{
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Nonce: append([]byte(nil), v.requestBodyIV...),
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Size: aead.NonceSize(),
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},
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AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
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}
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authReader = crypto.NewAuthenticationReader(auth, reader, sizeMask)
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} else if request.Security.Is(protocol.SecurityType_CHACHA20_POLY1305) {
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aead, _ := chacha20poly1305.New(GenerateChacha20Poly1305Key(v.requestBodyKey))
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auth := &crypto.AEADAuthenticator{
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AEAD: aead,
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NonceGenerator: &ChunkNonceGenerator{
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Nonce: append([]byte(nil), v.requestBodyIV...),
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Size: aead.NonceSize(),
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},
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AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
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}
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authReader = crypto.NewAuthenticationReader(auth, reader, sizeMask)
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}
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return buf.NewReader(authReader)
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}
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func (v *ServerSession) EncodeResponseHeader(header *protocol.ResponseHeader, writer io.Writer) {
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responseBodyKey := md5.Sum(v.requestBodyKey)
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responseBodyIV := md5.Sum(v.requestBodyIV)
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v.responseBodyKey = responseBodyKey[:]
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v.responseBodyIV = responseBodyIV[:]
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aesStream := crypto.NewAesEncryptionStream(v.responseBodyKey, v.responseBodyIV)
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encryptionWriter := crypto.NewCryptionWriter(aesStream, writer)
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v.responseWriter = encryptionWriter
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encryptionWriter.Write([]byte{v.responseHeader, byte(header.Option)})
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err := MarshalCommand(header.Command, encryptionWriter)
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if err != nil {
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encryptionWriter.Write([]byte{0x00, 0x00})
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}
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}
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func (v *ServerSession) EncodeResponseBody(request *protocol.RequestHeader, writer io.Writer) buf.Writer {
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var authWriter io.Writer
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var sizeMask crypto.Uint16Generator = crypto.StaticUint16Generator(0)
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if request.Option.Has(protocol.RequestOptionChunkMasking) {
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sizeMask = getSizeMask(v.responseBodyIV)
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}
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if request.Security.Is(protocol.SecurityType_NONE) {
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if request.Option.Has(protocol.RequestOptionChunkStream) {
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auth := &crypto.AEADAuthenticator{
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AEAD: NoOpAuthenticator{},
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NonceGenerator: crypto.NoOpBytesGenerator{},
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AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
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}
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authWriter = crypto.NewAuthenticationWriter(auth, writer, sizeMask)
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} else {
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authWriter = writer
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}
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} else if request.Security.Is(protocol.SecurityType_LEGACY) {
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if request.Option.Has(protocol.RequestOptionChunkStream) {
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auth := &crypto.AEADAuthenticator{
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AEAD: new(FnvAuthenticator),
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NonceGenerator: crypto.NoOpBytesGenerator{},
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AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
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}
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authWriter = crypto.NewAuthenticationWriter(auth, v.responseWriter, sizeMask)
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} else {
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authWriter = v.responseWriter
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}
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} else if request.Security.Is(protocol.SecurityType_AES128_GCM) {
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block, _ := aes.NewCipher(v.responseBodyKey)
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aead, _ := cipher.NewGCM(block)
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auth := &crypto.AEADAuthenticator{
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AEAD: aead,
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NonceGenerator: &ChunkNonceGenerator{
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Nonce: append([]byte(nil), v.responseBodyIV...),
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Size: aead.NonceSize(),
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},
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AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
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}
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authWriter = crypto.NewAuthenticationWriter(auth, writer, sizeMask)
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} else if request.Security.Is(protocol.SecurityType_CHACHA20_POLY1305) {
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aead, _ := chacha20poly1305.New(GenerateChacha20Poly1305Key(v.responseBodyKey))
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auth := &crypto.AEADAuthenticator{
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AEAD: aead,
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NonceGenerator: &ChunkNonceGenerator{
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Nonce: append([]byte(nil), v.responseBodyIV...),
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Size: aead.NonceSize(),
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},
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AdditionalDataGenerator: crypto.NoOpBytesGenerator{},
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}
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authWriter = crypto.NewAuthenticationWriter(auth, writer, sizeMask)
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}
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return buf.NewWriter(authWriter)
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}
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