Improved cookie/mac computation code
This commit is contained in:
Mathias Hall-Andersen
parent
a4eff12d7f
commit
12e8db2066
@ -15,6 +15,7 @@ const (
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RejectAfterTime = time.Second * 180
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KeepaliveTimeout = time.Second * 10
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CookieRefreshTime = time.Second * 120
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HandshakeInitationRate = time.Second / 20
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PaddingMultiple = 16
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)
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256
src/cookie.go
Normal file
256
src/cookie.go
Normal file
@ -0,0 +1,256 @@
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package main
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import (
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"crypto/hmac"
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"crypto/rand"
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"golang.org/x/crypto/blake2s"
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"golang.org/x/crypto/chacha20poly1305"
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"net"
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"sync"
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"time"
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"unsafe"
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)
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type CookieChecker struct {
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mutex sync.RWMutex
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mac1 struct {
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key [blake2s.Size]byte
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}
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mac2 struct {
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secret [blake2s.Size]byte
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secretSet time.Time
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encryptionKey [chacha20poly1305.KeySize]byte
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}
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}
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type CookieGenerator struct {
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mutex sync.RWMutex
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mac1 struct {
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key [blake2s.Size]byte
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}
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mac2 struct {
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cookie [blake2s.Size128]byte
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cookieSet time.Time
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hasLastMAC1 bool
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lastMAC1 [blake2s.Size128]byte
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encryptionKey [chacha20poly1305.KeySize]byte
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}
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}
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func (st *CookieChecker) Init(pk NoisePublicKey) {
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st.mutex.Lock()
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defer st.mutex.Unlock()
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// mac1 state
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func() {
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hsh, _ := blake2s.New256(nil)
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hsh.Write([]byte(WGLabelMAC1))
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hsh.Write(pk[:])
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hsh.Sum(st.mac1.key[:0])
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}()
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// mac2 state
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func() {
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hsh, _ := blake2s.New256(nil)
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hsh.Write([]byte(WGLabelCookie))
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hsh.Write(pk[:])
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hsh.Sum(st.mac2.encryptionKey[:0])
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}()
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st.mac2.secretSet = time.Time{}
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}
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func (st *CookieChecker) CheckMAC1(msg []byte) bool {
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size := len(msg)
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smac2 := size - blake2s.Size128
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smac1 := smac2 - blake2s.Size128
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var mac1 [blake2s.Size128]byte
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mac, _ := blake2s.New128(st.mac1.key[:])
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mac.Write(msg[:smac1])
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mac.Sum(mac1[:0])
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return hmac.Equal(mac1[:], msg[smac1:smac2])
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}
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func (st *CookieChecker) CheckMAC2(msg []byte, src *net.UDPAddr) bool {
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st.mutex.RLock()
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defer st.mutex.RUnlock()
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if time.Now().Sub(st.mac2.secretSet) > CookieRefreshTime {
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return false
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}
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// derive cookie key
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var cookie [blake2s.Size128]byte
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func() {
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mac, _ := blake2s.New128(st.mac2.secret[:])
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mac.Write(src.IP)
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mac.Write((*[unsafe.Sizeof(src.Port)]byte)(unsafe.Pointer(&src.Port))[:])
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mac.Sum(cookie[:0])
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}()
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// calculate mac of packet (including mac1)
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smac2 := len(msg) - blake2s.Size128
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var mac2 [blake2s.Size128]byte
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func() {
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mac, _ := blake2s.New128(cookie[:])
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mac.Write(msg[:smac2])
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mac.Sum(mac2[:0])
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}()
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return hmac.Equal(mac2[:], msg[smac2:])
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}
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func (st *CookieChecker) CreateReply(
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msg []byte,
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recv uint32,
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src *net.UDPAddr,
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) (*MessageCookieReply, error) {
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st.mutex.RLock()
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// refresh cookie secret
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if time.Now().Sub(st.mac2.secretSet) > CookieRefreshTime {
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st.mutex.RUnlock()
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st.mutex.Lock()
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_, err := rand.Read(st.mac2.secret[:])
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if err != nil {
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st.mutex.Unlock()
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return nil, err
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}
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st.mac2.secretSet = time.Now()
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st.mutex.Unlock()
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st.mutex.RLock()
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}
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// derive cookie
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var cookie [blake2s.Size128]byte
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func() {
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mac, _ := blake2s.New128(st.mac2.secret[:])
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mac.Write(src.IP)
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mac.Write((*[unsafe.Sizeof(src.Port)]byte)(unsafe.Pointer(&src.Port))[:])
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mac.Sum(cookie[:0])
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}()
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// encrypt cookie
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size := len(msg)
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smac2 := size - blake2s.Size128
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smac1 := smac2 - blake2s.Size128
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reply := new(MessageCookieReply)
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reply.Type = MessageCookieReplyType
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reply.Receiver = recv
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_, err := rand.Read(reply.Nonce[:])
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if err != nil {
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st.mutex.RUnlock()
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return nil, err
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}
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XChaCha20Poly1305Encrypt(
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reply.Cookie[:0],
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&reply.Nonce,
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cookie[:],
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msg[smac1:smac2],
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&st.mac2.encryptionKey,
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)
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st.mutex.RUnlock()
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return reply, nil
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}
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func (st *CookieGenerator) Init(pk NoisePublicKey) {
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st.mutex.Lock()
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defer st.mutex.Unlock()
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func() {
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hsh, _ := blake2s.New256(nil)
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hsh.Write([]byte(WGLabelMAC1))
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hsh.Write(pk[:])
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hsh.Sum(st.mac1.key[:0])
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}()
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func() {
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hsh, _ := blake2s.New256(nil)
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hsh.Write([]byte(WGLabelCookie))
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hsh.Write(pk[:])
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hsh.Sum(st.mac2.encryptionKey[:0])
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}()
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st.mac2.cookieSet = time.Time{}
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}
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func (st *CookieGenerator) ConsumeReply(msg *MessageCookieReply) bool {
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st.mutex.Lock()
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defer st.mutex.Unlock()
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if !st.mac2.hasLastMAC1 {
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return false
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}
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var cookie [blake2s.Size128]byte
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_, err := XChaCha20Poly1305Decrypt(
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cookie[:0],
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&msg.Nonce,
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msg.Cookie[:],
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st.mac2.lastMAC1[:],
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&st.mac2.encryptionKey,
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)
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if err != nil {
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return false
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}
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st.mac2.cookieSet = time.Now()
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st.mac2.cookie = cookie
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return true
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}
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func (st *CookieGenerator) AddMacs(msg []byte) {
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size := len(msg)
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smac2 := size - blake2s.Size128
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smac1 := smac2 - blake2s.Size128
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mac1 := msg[smac1:smac2]
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mac2 := msg[smac2:]
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st.mutex.Lock()
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defer st.mutex.Unlock()
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// set mac1
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func() {
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mac, _ := blake2s.New128(st.mac1.key[:])
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mac.Write(msg[:smac1])
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mac.Sum(mac1[:0])
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}()
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copy(st.mac2.lastMAC1[:], mac1)
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st.mac2.hasLastMAC1 = true
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// set mac2
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if time.Now().Sub(st.mac2.cookieSet) > CookieRefreshTime {
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return
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}
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func() {
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mac, _ := blake2s.New128(st.mac2.cookie[:])
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mac.Write(msg[:smac2])
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mac.Sum(mac2[:0])
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}()
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}
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187
src/cookie_test.go
Normal file
187
src/cookie_test.go
Normal file
@ -0,0 +1,187 @@
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package main
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import (
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"net"
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"testing"
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)
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func TestCookieMAC1(t *testing.T) {
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// setup generator / checker
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var (
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generator CookieGenerator
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checker CookieChecker
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)
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sk, err := newPrivateKey()
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if err != nil {
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t.Fatal(err)
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}
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pk := sk.publicKey()
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generator.Init(pk)
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checker.Init(pk)
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// check mac1
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src, _ := net.ResolveUDPAddr("udp", "192.168.13.37:4000")
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checkMAC1 := func(msg []byte) {
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generator.AddMacs(msg)
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if !checker.CheckMAC1(msg) {
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t.Fatal("MAC1 generation/verification failed")
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}
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if checker.CheckMAC2(msg, src) {
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t.Fatal("MAC2 generation/verification failed")
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}
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}
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checkMAC1([]byte{
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0x99, 0xbb, 0xa5, 0xfc, 0x99, 0xaa, 0x83, 0xbd,
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0x7b, 0x00, 0xc5, 0x9a, 0x4c, 0xb9, 0xcf, 0x62,
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0x40, 0x23, 0xf3, 0x8e, 0xd8, 0xd0, 0x62, 0x64,
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0x5d, 0xb2, 0x80, 0x13, 0xda, 0xce, 0xc6, 0x91,
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0x61, 0xd6, 0x30, 0xf1, 0x32, 0xb3, 0xa2, 0xf4,
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0x7b, 0x43, 0xb5, 0xa7, 0xe2, 0xb1, 0xf5, 0x6c,
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0x74, 0x6b, 0xb0, 0xcd, 0x1f, 0x94, 0x86, 0x7b,
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0xc8, 0xfb, 0x92, 0xed, 0x54, 0x9b, 0x44, 0xf5,
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0xc8, 0x7d, 0xb7, 0x8e, 0xff, 0x49, 0xc4, 0xe8,
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0x39, 0x7c, 0x19, 0xe0, 0x60, 0x19, 0x51, 0xf8,
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0xe4, 0x8e, 0x02, 0xf1, 0x7f, 0x1d, 0xcc, 0x8e,
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0xb0, 0x07, 0xff, 0xf8, 0xaf, 0x7f, 0x66, 0x82,
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0x83, 0xcc, 0x7c, 0xfa, 0x80, 0xdb, 0x81, 0x53,
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0xad, 0xf7, 0xd8, 0x0c, 0x10, 0xe0, 0x20, 0xfd,
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0xe8, 0x0b, 0x3f, 0x90, 0x15, 0xcd, 0x93, 0xad,
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0x0b, 0xd5, 0x0c, 0xcc, 0x88, 0x56, 0xe4, 0x3f,
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})
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checkMAC1([]byte{
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0x33, 0xe7, 0x2a, 0x84, 0x9f, 0xff, 0x57, 0x6c,
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0x2d, 0xc3, 0x2d, 0xe1, 0xf5, 0x5c, 0x97, 0x56,
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0xb8, 0x93, 0xc2, 0x7d, 0xd4, 0x41, 0xdd, 0x7a,
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0x4a, 0x59, 0x3b, 0x50, 0xdd, 0x7a, 0x7a, 0x8c,
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0x9b, 0x96, 0xaf, 0x55, 0x3c, 0xeb, 0x6d, 0x0b,
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0x13, 0x0b, 0x97, 0x98, 0xb3, 0x40, 0xc3, 0xcc,
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0xb8, 0x57, 0x33, 0x45, 0x6e, 0x8b, 0x09, 0x2b,
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0x81, 0x2e, 0xd2, 0xb9, 0x66, 0x0b, 0x93, 0x05,
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})
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checkMAC1([]byte{
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0x9b, 0x96, 0xaf, 0x55, 0x3c, 0xeb, 0x6d, 0x0b,
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0x13, 0x0b, 0x97, 0x98, 0xb3, 0x40, 0xc3, 0xcc,
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0xb8, 0x57, 0x33, 0x45, 0x6e, 0x8b, 0x09, 0x2b,
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0x81, 0x2e, 0xd2, 0xb9, 0x66, 0x0b, 0x93, 0x05,
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})
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// exchange cookie reply
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func() {
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msg := []byte{
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0x6d, 0xd7, 0xc3, 0x2e, 0xb0, 0x76, 0xd8, 0xdf,
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0x30, 0x65, 0x7d, 0x62, 0x3e, 0xf8, 0x9a, 0xe8,
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0xe7, 0x3c, 0x64, 0xa3, 0x78, 0x48, 0xda, 0xf5,
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0x25, 0x61, 0x28, 0x53, 0x79, 0x32, 0x86, 0x9f,
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0xa0, 0x27, 0x95, 0x69, 0xb6, 0xba, 0xd0, 0xa2,
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0xf8, 0x68, 0xea, 0xa8, 0x62, 0xf2, 0xfd, 0x1b,
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0xe0, 0xb4, 0x80, 0xe5, 0x6b, 0x3a, 0x16, 0x9e,
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0x35, 0xf6, 0xa8, 0xf2, 0x4f, 0x9a, 0x7b, 0xe9,
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0x77, 0x0b, 0xc2, 0xb4, 0xed, 0xba, 0xf9, 0x22,
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0xc3, 0x03, 0x97, 0x42, 0x9f, 0x79, 0x74, 0x27,
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0xfe, 0xf9, 0x06, 0x6e, 0x97, 0x3a, 0xa6, 0x8f,
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0xc9, 0x57, 0x0a, 0x54, 0x4c, 0x64, 0x4a, 0xe2,
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0x4f, 0xa1, 0xce, 0x95, 0x9b, 0x23, 0xa9, 0x2b,
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0x85, 0x93, 0x42, 0xb0, 0xa5, 0x53, 0xed, 0xeb,
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0x63, 0x2a, 0xf1, 0x6d, 0x46, 0xcb, 0x2f, 0x61,
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0x8c, 0xe1, 0xe8, 0xfa, 0x67, 0x20, 0x80, 0x6d,
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}
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generator.AddMacs(msg)
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reply, err := checker.CreateReply(msg, 1377, src)
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if err != nil {
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t.Fatal("Failed to create cookie reply:", err)
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}
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if !generator.ConsumeReply(reply) {
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t.Fatal("Failed to consume cookie reply")
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}
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}()
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// check mac2
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checkMAC2 := func(msg []byte) {
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generator.AddMacs(msg)
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if !checker.CheckMAC1(msg) {
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t.Fatal("MAC1 generation/verification failed")
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}
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if !checker.CheckMAC2(msg, src) {
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t.Fatal("MAC2 generation/verification failed")
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}
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msg[5] ^= 0x20
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if checker.CheckMAC1(msg) {
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t.Fatal("MAC1 generation/verification failed")
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}
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if checker.CheckMAC2(msg, src) {
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t.Fatal("MAC2 generation/verification failed")
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}
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msg[5] ^= 0x20
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srcBad1, _ := net.ResolveUDPAddr("udp", "192.168.13.37:4001")
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if checker.CheckMAC2(msg, srcBad1) {
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t.Fatal("MAC2 generation/verification failed")
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}
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srcBad2, _ := net.ResolveUDPAddr("udp", "192.168.13.38:4000")
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if checker.CheckMAC2(msg, srcBad2) {
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t.Fatal("MAC2 generation/verification failed")
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}
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}
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checkMAC2([]byte{
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0x03, 0x31, 0xb9, 0x9e, 0xb0, 0x2a, 0x54, 0xa3,
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0xc1, 0x3f, 0xb4, 0x96, 0x16, 0xb9, 0x25, 0x15,
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0x3d, 0x3a, 0x82, 0xf9, 0x58, 0x36, 0x86, 0x3f,
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0x13, 0x2f, 0xfe, 0xb2, 0x53, 0x20, 0x8c, 0x3f,
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0xba, 0xeb, 0xfb, 0x4b, 0x1b, 0x22, 0x02, 0x69,
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0x2c, 0x90, 0xbc, 0xdc, 0xcf, 0xcf, 0x85, 0xeb,
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0x62, 0x66, 0x6f, 0xe8, 0xe1, 0xa6, 0xa8, 0x4c,
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0xa0, 0x04, 0x23, 0x15, 0x42, 0xac, 0xfa, 0x38,
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})
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checkMAC2([]byte{
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0x0e, 0x2f, 0x0e, 0xa9, 0x29, 0x03, 0xe1, 0xf3,
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0x24, 0x01, 0x75, 0xad, 0x16, 0xa5, 0x66, 0x85,
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0xca, 0x66, 0xe0, 0xbd, 0xc6, 0x34, 0xd8, 0x84,
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0x09, 0x9a, 0x58, 0x14, 0xfb, 0x05, 0xda, 0xf5,
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0x90, 0xf5, 0x0c, 0x4e, 0x22, 0x10, 0xc9, 0x85,
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0x0f, 0xe3, 0x77, 0x35, 0xe9, 0x6b, 0xc2, 0x55,
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0x32, 0x46, 0xae, 0x25, 0xe0, 0xe3, 0x37, 0x7a,
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0x4b, 0x71, 0xcc, 0xfc, 0x91, 0xdf, 0xd6, 0xca,
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0xfe, 0xee, 0xce, 0x3f, 0x77, 0xa2, 0xfd, 0x59,
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0x8e, 0x73, 0x0a, 0x8d, 0x5c, 0x24, 0x14, 0xca,
|
||||
0x38, 0x91, 0xb8, 0x2c, 0x8c, 0xa2, 0x65, 0x7b,
|
||||
0xbc, 0x49, 0xbc, 0xb5, 0x58, 0xfc, 0xe3, 0xd7,
|
||||
0x02, 0xcf, 0xf7, 0x4c, 0x60, 0x91, 0xed, 0x55,
|
||||
0xe9, 0xf9, 0xfe, 0xd1, 0x44, 0x2c, 0x75, 0xf2,
|
||||
0xb3, 0x5d, 0x7b, 0x27, 0x56, 0xc0, 0x48, 0x4f,
|
||||
0xb0, 0xba, 0xe4, 0x7d, 0xd0, 0xaa, 0xcd, 0x3d,
|
||||
0xe3, 0x50, 0xd2, 0xcf, 0xb9, 0xfa, 0x4b, 0x2d,
|
||||
0xc6, 0xdf, 0x3b, 0x32, 0x98, 0x45, 0xe6, 0x8f,
|
||||
0x1c, 0x5c, 0xa2, 0x20, 0x7d, 0x1c, 0x28, 0xc2,
|
||||
0xd4, 0xa1, 0xe0, 0x21, 0x52, 0x8f, 0x1c, 0xd0,
|
||||
0x62, 0x97, 0x48, 0xbb, 0xf4, 0xa9, 0xcb, 0x35,
|
||||
0xf2, 0x07, 0xd3, 0x50, 0xd8, 0xa9, 0xc5, 0x9a,
|
||||
0x0f, 0xbd, 0x37, 0xaf, 0xe1, 0x45, 0x19, 0xee,
|
||||
0x41, 0xf3, 0xf7, 0xe5, 0xe0, 0x30, 0x3f, 0xbe,
|
||||
0x3d, 0x39, 0x64, 0x00, 0x7a, 0x1a, 0x51, 0x5e,
|
||||
0xe1, 0x70, 0x0b, 0xb9, 0x77, 0x5a, 0xf0, 0xc4,
|
||||
0x8a, 0xa1, 0x3a, 0x77, 0x1a, 0xe0, 0xc2, 0x06,
|
||||
0x91, 0xd5, 0xe9, 0x1c, 0xd3, 0xfe, 0xab, 0x93,
|
||||
0x1a, 0x0a, 0x4c, 0xbb, 0xf0, 0xff, 0xdc, 0xaa,
|
||||
0x61, 0x73, 0xcb, 0x03, 0x4b, 0x71, 0x68, 0x64,
|
||||
0x3d, 0x82, 0x31, 0x41, 0xd7, 0x8b, 0x22, 0x7b,
|
||||
0x7d, 0xa1, 0xd5, 0x85, 0x6d, 0xf0, 0x1b, 0xaa,
|
||||
})
|
||||
}
|
||||
@ -42,7 +42,7 @@ type Device struct {
|
||||
underLoadUntil atomic.Value
|
||||
ratelimiter Ratelimiter
|
||||
peers map[NoisePublicKey]*Peer
|
||||
mac MACStateDevice
|
||||
mac CookieChecker
|
||||
}
|
||||
|
||||
/* Warning:
|
||||
|
||||
@ -29,3 +29,9 @@ func (kp *KeyPairs) Current() *KeyPair {
|
||||
defer kp.mutex.RUnlock()
|
||||
return kp.current
|
||||
}
|
||||
|
||||
func (device *Device) DeleteKeyPair(key *KeyPair) {
|
||||
key.send = nil
|
||||
key.receive = nil
|
||||
device.indices.Delete(key.localIndex)
|
||||
}
|
||||
|
||||
270
src/macs.go
270
src/macs.go
@ -1,270 +0,0 @@
|
||||
package main
|
||||
|
||||
import (
|
||||
"crypto/hmac"
|
||||
"crypto/rand"
|
||||
"golang.org/x/crypto/blake2s"
|
||||
"net"
|
||||
"sync"
|
||||
"time"
|
||||
)
|
||||
|
||||
type MACStateDevice struct {
|
||||
mutex sync.RWMutex
|
||||
refreshed time.Time
|
||||
secret [blake2s.Size]byte
|
||||
keyMAC1 [blake2s.Size]byte
|
||||
keyMAC2 [blake2s.Size]byte // TODO: Change to more descriptive size constant, rename to something.
|
||||
}
|
||||
|
||||
type MACStatePeer struct {
|
||||
mutex sync.RWMutex
|
||||
cookieSet time.Time
|
||||
cookie [blake2s.Size128]byte
|
||||
lastMAC1Set bool
|
||||
lastMAC1 [blake2s.Size128]byte
|
||||
keyMAC1 [blake2s.Size]byte
|
||||
keyMAC2 [blake2s.Size]byte
|
||||
}
|
||||
|
||||
/* Methods for verifing MAC fields
|
||||
* and creating/consuming cookies replies
|
||||
* (per device)
|
||||
*/
|
||||
|
||||
func (state *MACStateDevice) Init(pk NoisePublicKey) {
|
||||
state.mutex.Lock()
|
||||
defer state.mutex.Unlock()
|
||||
|
||||
func() {
|
||||
hsh, _ := blake2s.New256(nil)
|
||||
hsh.Write([]byte(WGLabelMAC1))
|
||||
hsh.Write(pk[:])
|
||||
hsh.Sum(state.keyMAC1[:0])
|
||||
}()
|
||||
|
||||
func() {
|
||||
hsh, _ := blake2s.New256(nil)
|
||||
hsh.Write([]byte(WGLabelCookie))
|
||||
hsh.Write(pk[:])
|
||||
hsh.Sum(state.keyMAC2[:0])
|
||||
}()
|
||||
|
||||
state.refreshed = time.Time{}
|
||||
}
|
||||
|
||||
func (state *MACStateDevice) CheckMAC1(msg []byte) bool {
|
||||
size := len(msg)
|
||||
startMac1 := size - (blake2s.Size128 * 2)
|
||||
startMac2 := size - blake2s.Size128
|
||||
|
||||
var mac1 [blake2s.Size128]byte
|
||||
func() {
|
||||
mac, _ := blake2s.New128(state.keyMAC1[:])
|
||||
mac.Write(msg[:startMac1])
|
||||
mac.Sum(mac1[:0])
|
||||
}()
|
||||
|
||||
return hmac.Equal(mac1[:], msg[startMac1:startMac2])
|
||||
}
|
||||
|
||||
func (state *MACStateDevice) CheckMAC2(msg []byte, addr *net.UDPAddr) bool {
|
||||
state.mutex.RLock()
|
||||
defer state.mutex.RUnlock()
|
||||
|
||||
if time.Now().Sub(state.refreshed) > CookieRefreshTime {
|
||||
return false
|
||||
}
|
||||
|
||||
// derive cookie key
|
||||
|
||||
var cookie [blake2s.Size128]byte
|
||||
func() {
|
||||
port := [2]byte{byte(addr.Port >> 8), byte(addr.Port)}
|
||||
mac, _ := blake2s.New128(state.secret[:])
|
||||
mac.Write(addr.IP)
|
||||
mac.Write(port[:]) // TODO: Be faster and more platform dependent?
|
||||
mac.Sum(cookie[:0])
|
||||
}()
|
||||
|
||||
// calculate mac of packet
|
||||
|
||||
start := len(msg) - blake2s.Size128
|
||||
|
||||
var mac2 [blake2s.Size128]byte
|
||||
func() {
|
||||
mac, _ := blake2s.New128(cookie[:])
|
||||
mac.Write(msg[:start])
|
||||
mac.Sum(mac2[:0])
|
||||
}()
|
||||
|
||||
return hmac.Equal(mac2[:], msg[start:])
|
||||
}
|
||||
|
||||
func (device *Device) CreateMessageCookieReply(
|
||||
msg []byte, receiver uint32, addr *net.UDPAddr,
|
||||
) (*MessageCookieReply, error) {
|
||||
|
||||
state := &device.mac
|
||||
state.mutex.RLock()
|
||||
|
||||
// refresh cookie secret
|
||||
|
||||
if time.Now().Sub(state.refreshed) > CookieRefreshTime {
|
||||
state.mutex.RUnlock()
|
||||
state.mutex.Lock()
|
||||
_, err := rand.Read(state.secret[:])
|
||||
if err != nil {
|
||||
state.mutex.Unlock()
|
||||
return nil, err
|
||||
}
|
||||
state.refreshed = time.Now()
|
||||
state.mutex.Unlock()
|
||||
state.mutex.RLock()
|
||||
}
|
||||
|
||||
// derive cookie key
|
||||
|
||||
var cookie [blake2s.Size128]byte
|
||||
func() {
|
||||
port := [2]byte{byte(addr.Port >> 8), byte(addr.Port)}
|
||||
mac, _ := blake2s.New128(state.secret[:])
|
||||
mac.Write(addr.IP)
|
||||
mac.Write(port[:]) // TODO: Do whatever we did above
|
||||
mac.Sum(cookie[:0])
|
||||
}()
|
||||
|
||||
// encrypt cookie
|
||||
|
||||
size := len(msg)
|
||||
|
||||
startMac1 := size - (blake2s.Size128 * 2)
|
||||
startMac2 := size - blake2s.Size128
|
||||
|
||||
mac1 := msg[startMac1:startMac2]
|
||||
|
||||
reply := new(MessageCookieReply)
|
||||
reply.Type = MessageCookieReplyType
|
||||
reply.Receiver = receiver
|
||||
_, err := rand.Read(reply.Nonce[:])
|
||||
if err != nil {
|
||||
state.mutex.RUnlock()
|
||||
return nil, err
|
||||
}
|
||||
|
||||
XChaCha20Poly1305Encrypt(
|
||||
reply.Cookie[:0],
|
||||
&reply.Nonce,
|
||||
cookie[:],
|
||||
mac1,
|
||||
&state.keyMAC2,
|
||||
)
|
||||
|
||||
state.mutex.RUnlock()
|
||||
return reply, nil
|
||||
}
|
||||
|
||||
func (device *Device) ConsumeMessageCookieReply(msg *MessageCookieReply) bool {
|
||||
|
||||
if msg.Type != MessageCookieReplyType {
|
||||
return false
|
||||
}
|
||||
|
||||
// lookup peer
|
||||
|
||||
lookup := device.indices.Lookup(msg.Receiver)
|
||||
if lookup.handshake == nil {
|
||||
return false
|
||||
}
|
||||
|
||||
// decrypt and store cookie
|
||||
|
||||
var cookie [blake2s.Size128]byte
|
||||
state := &lookup.peer.mac
|
||||
|
||||
state.mutex.Lock()
|
||||
defer state.mutex.Unlock()
|
||||
|
||||
if !state.lastMAC1Set {
|
||||
return false
|
||||
}
|
||||
|
||||
_, err := XChaCha20Poly1305Decrypt(
|
||||
cookie[:0],
|
||||
&msg.Nonce,
|
||||
msg.Cookie[:],
|
||||
state.lastMAC1[:],
|
||||
&state.keyMAC2,
|
||||
)
|
||||
|
||||
if err != nil {
|
||||
return false
|
||||
}
|
||||
|
||||
state.cookieSet = time.Now()
|
||||
state.cookie = cookie
|
||||
return true
|
||||
}
|
||||
|
||||
/* Methods for generating the MAC fields
|
||||
* (per peer)
|
||||
*/
|
||||
|
||||
func (state *MACStatePeer) Init(pk NoisePublicKey) {
|
||||
state.mutex.Lock()
|
||||
defer state.mutex.Unlock()
|
||||
|
||||
func() {
|
||||
hsh, _ := blake2s.New256(nil)
|
||||
hsh.Write([]byte(WGLabelMAC1))
|
||||
hsh.Write(pk[:])
|
||||
hsh.Sum(state.keyMAC1[:0])
|
||||
}()
|
||||
|
||||
func() {
|
||||
hsh, _ := blake2s.New256(nil)
|
||||
hsh.Write([]byte(WGLabelCookie))
|
||||
hsh.Write(pk[:])
|
||||
hsh.Sum(state.keyMAC2[:0])
|
||||
}()
|
||||
|
||||
state.cookieSet = time.Time{} // never
|
||||
}
|
||||
|
||||
func (state *MACStatePeer) AddMacs(msg []byte) {
|
||||
size := len(msg)
|
||||
|
||||
startMac1 := size - (blake2s.Size128 * 2)
|
||||
startMac2 := size - blake2s.Size128
|
||||
|
||||
mac1 := msg[startMac1 : startMac1+blake2s.Size128]
|
||||
mac2 := msg[startMac2 : startMac2+blake2s.Size128]
|
||||
|
||||
state.mutex.Lock()
|
||||
defer state.mutex.Unlock()
|
||||
|
||||
// set mac1
|
||||
|
||||
func() {
|
||||
mac, _ := blake2s.New128(state.keyMAC1[:])
|
||||
mac.Write(msg[:startMac1])
|
||||
mac.Sum(mac1[:0])
|
||||
}()
|
||||
copy(state.lastMAC1[:], mac1)
|
||||
state.lastMAC1Set = true
|
||||
|
||||
// set mac2
|
||||
|
||||
if state.cookieSet.IsZero() {
|
||||
return
|
||||
}
|
||||
if time.Now().Sub(state.cookieSet) > CookieRefreshTime {
|
||||
state.cookieSet = time.Time{}
|
||||
return
|
||||
}
|
||||
func() {
|
||||
mac, _ := blake2s.New128(state.cookie[:])
|
||||
mac.Write(msg[:startMac2])
|
||||
mac.Sum(mac2[:0])
|
||||
}()
|
||||
}
|
||||
116
src/macs_test.go
116
src/macs_test.go
@ -1,116 +0,0 @@
|
||||
package main
|
||||
|
||||
import (
|
||||
"net"
|
||||
"testing"
|
||||
"testing/quick"
|
||||
)
|
||||
|
||||
func TestMAC1(t *testing.T) {
|
||||
dev1 := randDevice(t)
|
||||
dev2 := randDevice(t)
|
||||
|
||||
defer dev1.Close()
|
||||
defer dev2.Close()
|
||||
|
||||
peer1, _ := dev2.NewPeer(dev1.privateKey.publicKey())
|
||||
peer2, _ := dev1.NewPeer(dev2.privateKey.publicKey())
|
||||
|
||||
assertEqual(t, peer1.mac.keyMAC1[:], dev1.mac.keyMAC1[:])
|
||||
assertEqual(t, peer2.mac.keyMAC1[:], dev2.mac.keyMAC1[:])
|
||||
|
||||
msg1 := make([]byte, 256)
|
||||
copy(msg1, []byte("some content"))
|
||||
peer1.mac.AddMacs(msg1)
|
||||
if dev1.mac.CheckMAC1(msg1) == false {
|
||||
t.Fatal("failed to verify mac1")
|
||||
}
|
||||
}
|
||||
|
||||
func TestMACs(t *testing.T) {
|
||||
assertion := func(
|
||||
addr net.UDPAddr,
|
||||
addrInvalid net.UDPAddr,
|
||||
sk1 NoisePrivateKey,
|
||||
sk2 NoisePrivateKey,
|
||||
msg []byte,
|
||||
receiver uint32,
|
||||
) bool {
|
||||
device1 := randDevice(t)
|
||||
device1.SetPrivateKey(sk1)
|
||||
|
||||
device2 := randDevice(t)
|
||||
device2.SetPrivateKey(sk2)
|
||||
|
||||
defer device1.Close()
|
||||
defer device2.Close()
|
||||
|
||||
peer1, _ := device2.NewPeer(device1.privateKey.publicKey())
|
||||
peer2, _ := device1.NewPeer(device2.privateKey.publicKey())
|
||||
|
||||
if addr.Port < 0 {
|
||||
return true
|
||||
}
|
||||
|
||||
addr.Port &= 0xffff
|
||||
|
||||
if len(msg) < 32 {
|
||||
return true
|
||||
}
|
||||
|
||||
assertEqual(t, peer1.mac.keyMAC1[:], device1.mac.keyMAC1[:])
|
||||
assertEqual(t, peer2.mac.keyMAC1[:], device2.mac.keyMAC1[:])
|
||||
|
||||
device2.indices.Insert(receiver, IndexTableEntry{
|
||||
peer: peer1,
|
||||
handshake: &peer1.handshake,
|
||||
})
|
||||
|
||||
// test just MAC1
|
||||
|
||||
peer1.mac.AddMacs(msg)
|
||||
if device1.mac.CheckMAC1(msg) == false {
|
||||
return false
|
||||
}
|
||||
|
||||
// exchange cookie reply
|
||||
|
||||
cr, err := device1.CreateMessageCookieReply(msg, receiver, &addr)
|
||||
if err != nil {
|
||||
return false
|
||||
}
|
||||
|
||||
if !device2.ConsumeMessageCookieReply(cr) {
|
||||
return false
|
||||
}
|
||||
|
||||
// test MAC1 + MAC2
|
||||
|
||||
peer1.mac.AddMacs(msg)
|
||||
if !device1.mac.CheckMAC1(msg) {
|
||||
return false
|
||||
}
|
||||
if !device1.mac.CheckMAC2(msg, &addr) {
|
||||
return false
|
||||
}
|
||||
|
||||
// test invalid
|
||||
|
||||
if device1.mac.CheckMAC2(msg, &addrInvalid) {
|
||||
return false
|
||||
}
|
||||
msg[5] ^= 1
|
||||
if device1.mac.CheckMAC1(msg) {
|
||||
return false
|
||||
}
|
||||
|
||||
t.Log("Passed")
|
||||
|
||||
return true
|
||||
}
|
||||
|
||||
err := quick.Check(assertion, nil)
|
||||
if err != nil {
|
||||
t.Error(err)
|
||||
}
|
||||
}
|
||||
@ -99,6 +99,7 @@ type Handshake struct {
|
||||
remoteEphemeral NoisePublicKey // ephemeral public key
|
||||
precomputedStaticStatic [NoisePublicKeySize]byte // precomputed shared secret
|
||||
lastTimestamp TAI64N
|
||||
lastInitiationConsumption time.Time
|
||||
}
|
||||
|
||||
var (
|
||||
@ -239,34 +240,27 @@ func (device *Device) ConsumeMessageInitiation(msg *MessageInitiation) *Peer {
|
||||
// verify identity
|
||||
|
||||
var timestamp TAI64N
|
||||
ok := func() bool {
|
||||
|
||||
// read lock handshake
|
||||
var key [chacha20poly1305.KeySize]byte
|
||||
|
||||
handshake.mutex.RLock()
|
||||
defer handshake.mutex.RUnlock()
|
||||
|
||||
// decrypt timestamp
|
||||
|
||||
func() {
|
||||
var key [chacha20poly1305.KeySize]byte
|
||||
chainKey, key = KDF2(
|
||||
chainKey[:],
|
||||
handshake.precomputedStaticStatic[:],
|
||||
)
|
||||
aead, _ := chacha20poly1305.New(key[:])
|
||||
_, err = aead.Open(timestamp[:0], ZeroNonce[:], msg.Timestamp[:], hash[:])
|
||||
}()
|
||||
if err != nil {
|
||||
return false
|
||||
handshake.mutex.RUnlock()
|
||||
return nil
|
||||
}
|
||||
hash = mixHash(hash, msg.Timestamp[:])
|
||||
|
||||
// check for replay attack
|
||||
|
||||
return timestamp.After(handshake.lastTimestamp)
|
||||
}()
|
||||
// protect against replay & flood
|
||||
|
||||
var ok bool
|
||||
ok = timestamp.After(handshake.lastTimestamp)
|
||||
ok = ok && time.Now().Sub(handshake.lastInitiationConsumption) > HandshakeInitationRate
|
||||
handshake.mutex.RUnlock()
|
||||
if !ok {
|
||||
return nil
|
||||
}
|
||||
@ -280,6 +274,7 @@ func (device *Device) ConsumeMessageInitiation(msg *MessageInitiation) *Peer {
|
||||
handshake.remoteIndex = msg.Sender
|
||||
handshake.remoteEphemeral = msg.Ephemeral
|
||||
handshake.lastTimestamp = timestamp
|
||||
handshake.lastInitiationConsumption = time.Now()
|
||||
handshake.state = HandshakeInitiationConsumed
|
||||
|
||||
handshake.mutex.Unlock()
|
||||
@ -483,15 +478,21 @@ func (peer *Peer) NewKeyPair() *KeyPair {
|
||||
// TODO: Adapt kernel behavior noise.c:161
|
||||
if isInitiator {
|
||||
if kp.previous != nil {
|
||||
kp.previous.send = nil
|
||||
kp.previous.receive = nil
|
||||
indices.Delete(kp.previous.localIndex)
|
||||
}
|
||||
|
||||
if kp.next != nil {
|
||||
kp.previous = kp.next
|
||||
kp.next = keyPair
|
||||
} else {
|
||||
kp.previous = kp.current
|
||||
kp.current = keyPair
|
||||
signalSend(peer.signal.newKeyPair)
|
||||
signalSend(peer.signal.newKeyPair) // TODO: This more places (after confirming the key)
|
||||
}
|
||||
|
||||
} else {
|
||||
kp.next = keyPair
|
||||
kp.previous = nil // TODO: Discuss why
|
||||
}
|
||||
}()
|
||||
|
||||
|
||||
@ -56,7 +56,7 @@ type Peer struct {
|
||||
outbound chan *QueueOutboundElement // sequential ordering of work
|
||||
inbound chan *QueueInboundElement // sequential ordering of work
|
||||
}
|
||||
mac MACStatePeer
|
||||
mac CookieGenerator
|
||||
}
|
||||
|
||||
func (device *Device) NewPeer(pk NoisePublicKey) (*Peer, error) {
|
||||
|
||||
@ -272,7 +272,9 @@ func (device *Device) RoutineHandshake() {
|
||||
|
||||
case MessageCookieReplyType:
|
||||
|
||||
// verify and update peer cookie state
|
||||
// unmarshal packet
|
||||
|
||||
logDebug.Println("Process cookie reply from:", elem.source.String())
|
||||
|
||||
var reply MessageCookieReply
|
||||
reader := bytes.NewReader(elem.packet)
|
||||
@ -281,7 +283,14 @@ func (device *Device) RoutineHandshake() {
|
||||
logDebug.Println("Failed to decode cookie reply")
|
||||
return
|
||||
}
|
||||
device.ConsumeMessageCookieReply(&reply)
|
||||
|
||||
// lookup peer and consume response
|
||||
|
||||
entry := device.indices.Lookup(reply.Receiver)
|
||||
if entry.peer == nil {
|
||||
return
|
||||
}
|
||||
entry.peer.mac.ConsumeReply(&reply)
|
||||
continue
|
||||
|
||||
case MessageInitiationType, MessageResponseType:
|
||||
@ -298,12 +307,17 @@ func (device *Device) RoutineHandshake() {
|
||||
|
||||
// construct cookie reply
|
||||
|
||||
logDebug.Println("Sending cookie reply to:", elem.source.String())
|
||||
|
||||
sender := binary.LittleEndian.Uint32(elem.packet[4:8]) // "sender" always follows "type"
|
||||
reply, err := device.CreateMessageCookieReply(elem.packet, sender, elem.source)
|
||||
reply, err := device.mac.CreateReply(elem.packet, sender, elem.source)
|
||||
if err != nil {
|
||||
logError.Println("Failed to create cookie reply:", err)
|
||||
return
|
||||
}
|
||||
|
||||
// marshal and send reply
|
||||
|
||||
writer := bytes.NewBuffer(temp[:0])
|
||||
binary.Write(writer, binary.LittleEndian, reply)
|
||||
_, err = device.net.conn.WriteToUDP(
|
||||
@ -392,6 +406,8 @@ func (device *Device) RoutineHandshake() {
|
||||
|
||||
case MessageResponseType:
|
||||
|
||||
logDebug.Println("Process response")
|
||||
|
||||
// unmarshal
|
||||
|
||||
var msg MessageResponse
|
||||
|
||||
Loading…
Reference in New Issue
Block a user