Add hooks into more parts of the wg code

tunsafe_config.h

@@ -6,10 +6,17 @@
 #define TUNSAFE_VERSION_STRING_LONG "TunSafe 1.5-rc1"
 
 #define WITH_HANDSHAKE_EXT 0
+#define WITH_CIPHER_SUITES 0
+#define WITH_BOOLEAN_FEATURES 0
+#define WITH_PACKET_COMPRESSION 0
+ 
 #define WITH_SHORT_HEADERS 0
 #define WITH_HEADER_OBFUSCATION 0
 #define WITH_AVX512_OPTIMIZATIONS 0
 #define WITH_BENCHMARK 0
 
+
+
+
 // Use bytell hashmap instead. Only works in 64-bit builds
 #define WITH_BYTELL_HASHMAP 0

wireguard.cpp

@@ -436,7 +436,7 @@ void WireguardProcessor::WriteAndEncryptPacketToUdp_WillUnlock(WgPeer *peer, Pac
     peer->OnDataSent();
 
     // Attempt to compress the packet headers
-    if (WITH_HANDSHAKE_EXT && keypair->compress_handler_) {
+    if (WITH_PACKET_COMPRESSION && keypair->compress_handler_) {
       WgCompressHandler::CompressState st = keypair->compress_handler_->Compress(packet);
       if (st == WgCompressHandler::COMPRESS_FAIL)
         goto getout_discard;
@@ -626,10 +626,13 @@ void WireguardProcessor::SendHandshakeInitiation(WgPeer *peer) {
 
   if (!peer->CheckHandshakeRateLimit() || peer->endpoint_.sin.sin_family == 0)
     return;
-  stats_.handshakes_out++;
   Packet *packet = AllocPacket();
   if (packet) {
-    peer->CreateMessageHandshakeInitiation(packet);
+    if (!peer->CreateMessageHandshakeInitiation(packet)) {
+      FreePacket(packet);
+      return;
+    }
+    stats_.handshakes_out++;
     WG_ACQUIRE_LOCK(peer->mutex_);
     int attempts = ++peer->total_handshake_attempts_;
     if (procdel_)
@@ -888,7 +891,7 @@ void WireguardProcessor::HandleAuthenticatedDataPacket_WillUnlock(WgKeypair *key
   WG_RELEASE_LOCK(peer->mutex_);
 
   // Unpack the packet headers?
-  if (WITH_HANDSHAKE_EXT && keypair->compress_handler_) {
+  if (WITH_PACKET_COMPRESSION && keypair->compress_handler_) {
     WgCompressHandler::CompressState st = keypair->compress_handler_->Decompress(packet);
     if (st == WgCompressHandler::COMPRESS_FAIL)
       goto getout;

wireguard_config.cpp

@@ -185,7 +185,8 @@ bool WgFileParser::ParseFlag(const char *group, const char *key, char *value) {
         wg_->AddExcludedIp(addr);
       }
     } else {
-      goto err;
+      if (!wg_->dev().plugin() || !wg_->dev().plugin()->OnUnknownInterfaceSetting(key, value))
+        goto err;
     }
   } else if (strcmp(group, "[Peer]") == 0) {
     if (key == NULL) {
@@ -251,7 +252,8 @@ bool WgFileParser::ParseFlag(const char *group, const char *key, char *value) {
           return false;
       }
     } else {
-      goto err;
+      if (!wg_->dev().plugin() || !wg_->dev().plugin()->OnUnknownPeerSetting(peer_, key, value))
+        goto err;
     }
   } else {
   err:

wireguard_proto.cpp

@@ -54,7 +54,7 @@ bool ReplayDetector::CheckReplay(uint64 seq_nr) {
 WgDevice::WgDevice() {
   peers_ = NULL;
   last_peer_ptr_ = &peers_;
-  delegate_ = NULL;
+  plugin_ = NULL;
   header_obfuscation_ = false;
   is_private_key_initialized_ = false;
   next_rng_slot_ = 0;
@@ -349,6 +349,7 @@ WgPeer::WgPeer(WgDevice *dev) {
   endpoint_.sin.sin_family = 0;
   endpoint_protocol_ = 0;
   next_peer_ = NULL;
+  peer_extra_data_ = NULL;
   curr_keypair_ = next_keypair_ = prev_keypair_ = NULL;
   expect_cookie_reply_ = false;
   has_mac2_cookie_ = false;
@@ -391,6 +392,7 @@ WgPeer::~WgPeer() {
   assert(curr_keypair_ == NULL && next_keypair_ == NULL && prev_keypair_ == NULL);
   assert(local_key_id_during_hs_ == 0);
   assert(first_queued_packet_ == NULL);
+  delete peer_extra_data_;
 }
 
 void WgPeer::DelayedDelete(void *x) {
@@ -518,12 +520,23 @@ void WgPeer::SetPresharedKey(const uint8 preshared_key[WG_SYMMETRIC_KEY_LEN]) {
 }
 
 // run on the client
-void WgPeer::CreateMessageHandshakeInitiation(Packet *packet) {
+bool WgPeer::CreateMessageHandshakeInitiation(Packet *packet) {
   assert(dev_->IsMainThread());
 
   uint8 k[WG_SYMMETRIC_KEY_LEN];
   MessageHandshakeInitiation *dst = (MessageHandshakeInitiation *)packet->data;
 
+  int extfield_size = 0;
+  if (WITH_HANDSHAKE_EXT && supports_handshake_extensions_)
+    extfield_size = WriteHandshakeExtension(dst->timestamp_enc + WG_TIMESTAMP_LEN, NULL);
+
+  if (dev_->plugin_) {
+    uint32 rv = dev_->plugin_->OnHandshake0(this, dst->timestamp_enc + WG_TIMESTAMP_LEN + extfield_size, MAX_SIZE_OF_HANDSHAKE_EXTENSION - extfield_size);
+    if (rv & WgPlugin::kHandshakeResponseFail)
+      return false;
+    extfield_size += rv;
+  }
+
   // Ci := HASH(CONSTRUCTION)
   memcpy(hs_.ci, kWgInitChainingKey, sizeof(hs_.ci));
   // Hi := HASH(Ci || IDENTIFIER)
@@ -550,11 +563,6 @@ void WgPeer::CreateMessageHandshakeInitiation(Packet *packet) {
   // TAI64N
   OsGetTimestampTAI64N(dst->timestamp_enc);
 
-  size_t extfield_size = 0;
-#if WITH_HANDSHAKE_EXT
-  if (supports_handshake_extensions_)
-    extfield_size = WriteHandshakeExtension(dst->timestamp_enc + WG_TIMESTAMP_LEN, NULL);
-#endif  // WITH_HANDSHAKE_EXT
   // msg.timestamp := AEAD(K, 0, timestamp, hi)
   chacha20poly1305_encrypt(dst->timestamp_enc, dst->timestamp_enc, extfield_size + WG_TIMESTAMP_LEN, hs_.hi, sizeof(hs_.hi), 0, k);
   // Hi := HASH(Hi || msg.timestamp)
@@ -566,6 +574,7 @@ void WgPeer::CreateMessageHandshakeInitiation(Packet *packet) {
   dst->type = MESSAGE_HANDSHAKE_INITIATION;
   memzero_crypto(k, sizeof(k));
   WriteMacToPacket((uint8*)dst, (MessageMacs*)((uint8*)&dst->mac + extfield_size));
+  return true;
 }
 
 // Parsed by server
@@ -591,7 +600,7 @@ WgPeer *WgPeer::ParseMessageHandshakeInitiation(WgDevice *dev, Packet *packet) {
   uint8 extbuf[MAX_SIZE_OF_HANDSHAKE_EXTENSION + WG_TIMESTAMP_LEN];
   MessageHandshakeInitiation *src = (MessageHandshakeInitiation *)packet->data;
   MessageHandshakeResponse *dst;
-  size_t extfield_size;
+  int extfield_size;
 
   // Ci := HASH(CONSTRUCTION)
   memcpy(ci, kWgInitChainingKey, sizeof(ci));
@@ -612,7 +621,7 @@ WgPeer *WgPeer::ParseMessageHandshakeInitiation(WgDevice *dev, Packet *packet) {
   BlakeMix(hi, src->static_enc, sizeof(src->static_enc));
   // Lookup the peer with this ID
   while ((peer = dev->GetPeerFromPublicKey(spubi)) == NULL) {
-    if (dev->delegate_ == NULL || !dev->delegate_->HandleUnknownPeerId(spubi.bytes, packet))
+    if (dev->plugin_ == NULL || !dev->plugin_->HandleUnknownPeerId(spubi.bytes, packet))
       goto getout;
   }
   // (Ci, K) := KDF2(Ci, DH(sprivr, spubi))
@@ -620,7 +629,7 @@ WgPeer *WgPeer::ParseMessageHandshakeInitiation(WgDevice *dev, Packet *packet) {
   // Hi2 := Hi
   memcpy(hi2, hi, sizeof(hi2));
   extfield_size = packet->size - sizeof(MessageHandshakeInitiation);
-  if (extfield_size > MAX_SIZE_OF_HANDSHAKE_EXTENSION || (extfield_size && !peer->supports_handshake_extensions_))
+  if ((uint32)extfield_size > MAX_SIZE_OF_HANDSHAKE_EXTENSION || (extfield_size && !peer->supports_handshake_extensions_))
     goto getout;
   // Hi := HASH(Hi || msg.timestamp)
   BlakeMix(hi, src->timestamp_enc, extfield_size + WG_TIMESTAMP_LEN + WG_MAC_LEN);
@@ -643,7 +652,7 @@ WgPeer *WgPeer::ParseMessageHandshakeInitiation(WgDevice *dev, Packet *packet) {
   remote_key_id = src->sender_key_id;
 
   dst = (MessageHandshakeResponse *)src;
-  
+  dst->receiver_key_id = remote_key_id;
   // (Epriv_r, Epub_r) := DH-GENERATE()
   // msg.ephemeral = Epub_r
   OsGetRandomBytes(e_priv, sizeof(e_priv));
@@ -662,28 +671,40 @@ WgPeer *WgPeer::ParseMessageHandshakeInitiation(WgDevice *dev, Packet *packet) {
   // Hr := HASH(Hr || T)
   BlakeMix(hi, t, sizeof(t));
 
-  dst->receiver_key_id = remote_key_id;
+  keypair = WgPeer::CreateNewKeypair(false, ci, remote_key_id);
-  keypair = WgPeer::CreateNewKeypair(false, ci, remote_key_id, extbuf + WG_TIMESTAMP_LEN, extfield_size);
   if (keypair) {
+    if (WITH_HANDSHAKE_EXT && !peer->ParseExtendedHandshake(keypair, extbuf + WG_TIMESTAMP_LEN, extfield_size))
+      goto getout;
 
-    dst->sender_key_id = dev->InsertInKeyIdLookup(peer, keypair);
+    int extfield_out_size = 0;
-
+    if (WITH_HANDSHAKE_EXT && extfield_size)
-    size_t extfield_out_size = 0;
-#if WITH_HANDSHAKE_EXT
-    if (extfield_size)
       extfield_out_size = peer->WriteHandshakeExtension(dst->empty_enc, keypair);
-#endif  // WITH_HANDSHAKE_EXT
 
-    uint32 orig_packet_size = packet->size;
+    // Allow plugin to determine what to do with the packet,
-    packet->size = (unsigned)(sizeof(MessageHandshakeResponse) + extfield_out_size);
+    // it can append new headers to the response, and decide what to do.  
+    if (dev->plugin_) {
+      uint32 rv = dev->plugin_->OnHandshake1(peer, extbuf + WG_TIMESTAMP_LEN, extfield_size,
+                                                     dst->empty_enc + extfield_out_size, MAX_SIZE_OF_HANDSHAKE_EXTENSION - extfield_out_size);
+      if (rv == WgPlugin::kHandshakeResponseDrop)
+        goto getout;
+      if (rv & WgPlugin::kHandshakeResponseFail)
+        delete exch_null(keypair);
+      extfield_out_size += rv & ~WgPlugin::kHandshakeResponseFail;
+    }
+
+    dst->sender_key_id = keypair ? dev->InsertInKeyIdLookup(peer, keypair) : 0;
 
     WG_ACQUIRE_LOCK(peer->mutex_);
-    peer->rx_bytes_ += orig_packet_size;
+    peer->rx_bytes_ += packet->size;
+    if (keypair != NULL) {
+      peer->InsertKeypairInPeer_Locked(keypair);
+      peer->OnHandshakeAuthComplete();
+    }
+    packet->size = (unsigned)(sizeof(MessageHandshakeResponse) + extfield_out_size);
     peer->tx_bytes_ += packet->size;
-    peer->InsertKeypairInPeer_Locked(keypair);
-    peer->OnHandshakeAuthComplete();
     WG_RELEASE_LOCK(peer->mutex_);
 
+
     // msg.empty := AEAD(K, 0, "", Hr)
     chacha20poly1305_encrypt(dst->empty_enc, dst->empty_enc, extfield_out_size, hi, sizeof(hi), 0, k);
     // Hr := HASH(Hr || "")
@@ -693,6 +714,7 @@ WgPeer *WgPeer::ParseMessageHandshakeInitiation(WgDevice *dev, Packet *packet) {
     peer->WriteMacToPacket((uint8*)dst, (MessageMacs*)((uint8*)&dst->mac + extfield_out_size));
   } else {
 getout:
+    delete keypair;
     peer = NULL;
   }
   memzero_crypto(hi, sizeof(hi));
@@ -728,18 +750,33 @@ WgPeer *WgPeer::ParseMessageHandshakeResponse(WgDevice *dev, const Packet *packe
   // Hr := HASH(Hr || T)
   BlakeMix(hs.hi, t, sizeof(t));
 
-  size_t extfield_size = packet->size - sizeof(MessageHandshakeResponse);
+  int extfield_size = packet->size - sizeof(MessageHandshakeResponse);
-  if (extfield_size > MAX_SIZE_OF_HANDSHAKE_EXTENSION)
+  if ((uint32)extfield_size > MAX_SIZE_OF_HANDSHAKE_EXTENSION)
     goto getout;
 
   // "" := AEAD_DEC(K, 0, msg.empty, Hr)
   if (!chacha20poly1305_decrypt(src->empty_enc, src->empty_enc, extfield_size + sizeof(src->empty_enc), hs.hi, sizeof(hs.hi), 0, k))
     goto getout;
 
-  keypair = WgPeer::CreateNewKeypair(true, hs.ci, src->sender_key_id, src->empty_enc, extfield_size);
+  keypair = WgPeer::CreateNewKeypair(true, hs.ci, src->sender_key_id);
   if (!keypair)
     goto getout;
 
+  if (WITH_HANDSHAKE_EXT && !peer->ParseExtendedHandshake(keypair, src->empty_enc, extfield_size)) {
+    delete keypair;
+    goto getout;
+  }
+
+  // Allow plugin to determine what to do with the packet,
+  // it can append new headers to the response, and decide what to do.  
+  if (dev->plugin_) {
+    uint32 rv = dev->plugin_->OnHandshake2(peer, src->empty_enc, extfield_size);
+    if (rv & WgPlugin::kHandshakeResponseFail) {
+      delete keypair;
+      goto getout;
+    }
+  }
+
   // Re-map the entry in the id table so it points at this keypair instead.
   keypair->local_key_id = peer->local_key_id_during_hs_;
   peer->local_key_id_during_hs_ = 0;
@@ -787,42 +824,43 @@ void WgPeer::ParseMessageHandshakeCookie(WgDevice *dev, const MessageHandshakeCo
   memcpy(peer->mac2_cookie_, cookie, sizeof(peer->mac2_cookie_));
 }
 
-#if WITH_HANDSHAKE_EXT
+int WgPeer::WriteHandshakeExtension(uint8 *dst, WgKeypair *keypair) {
+  uint8 *dst_org = dst, *dst_end = dst + MAX_SIZE_OF_HANDSHAKE_EXTENSION;
 
-size_t WgPeer::WriteHandshakeExtension(uint8 *dst, WgKeypair *keypair) {
+  if (WITH_HANDSHAKE_EXT) {
-  uint8 *dst_end = dst + MAX_SIZE_OF_HANDSHAKE_EXTENSION;
+    if (WITH_BOOLEAN_FEATURES) {
-  uint8 *dst_org = dst, value = 0;
+      uint8 value = 0;
-  // Include the supported features extension
+      // Include the supported features extension
-  if (!IsOnlyZeros(features_, sizeof(features_))) {
+      if (!IsOnlyZeros(features_, sizeof(features_))) {
-    *dst++ = EXT_BOOLEAN_FEATURES;
+        *dst++ = EXT_BOOLEAN_FEATURES;
-    *dst++ = (WG_FEATURES_COUNT + 3) >> 2;
+        *dst++ = (WG_FEATURES_COUNT + 3) >> 2;
-    for (size_t i = 0; i != WG_FEATURES_COUNT; i++) {
+        for (size_t i = 0; i != WG_FEATURES_COUNT; i++) {
-      if ((i & 3) == 0)
+          if ((i & 3) == 0)
-        value = 0;
+            value = 0;
-      dst[i >> 2] = (value += (features_[i] << ((i * 2) & 7)));
+          dst[i >> 2] = (value += (features_[i] << ((i * 2) & 7)));
+        }
+        // swap WG_FEATURE_ID_SKIP_KEYID_IN and WG_FEATURE_ID_SKIP_KEYID_OUT
+        dst[1] = (dst[1] & 0xF0) + ((dst[1] >> 2) & 0x03) + ((dst[1] << 2) & 0x0C);
+        dst += (WG_FEATURES_COUNT + 3) >> 2;
+      }
     }
-    // swap WG_FEATURE_ID_SKIP_KEYID_IN and WG_FEATURE_ID_SKIP_KEYID_OUT
+    if (WITH_CIPHER_SUITES) {
-    dst[1] = (dst[1] & 0xF0) + ((dst[1] >> 2) & 0x03) + ((dst[1] << 2) & 0x0C);
+      // Ordered list of cipher suites
-    dst += (WG_FEATURES_COUNT + 3) >> 2;
+      size_t ciphers = num_ciphers_;
-  }
+      if (ciphers) {
-  // Ordered list of cipher suites
+        *dst++ = EXT_CIPHER_SUITES + cipher_prio_;
-  size_t ciphers = num_ciphers_;
+        if (keypair) {
-  if (ciphers) {
+          *dst++ = 1;
-    *dst++ = EXT_CIPHER_SUITES + cipher_prio_;
+          *dst++ = keypair->cipher_suite;
-    if (keypair) {
+        } else {
-      *dst++ = 1;
+          *dst++ = (uint8)ciphers;
-      *dst++ = keypair->cipher_suite;
+          memcpy(dst, ciphers_, ciphers);
-    } else {
+          dst += ciphers;
-      *dst++ = (uint8)ciphers;
+        }
-      memcpy(dst, ciphers_, ciphers);
+      }
-      dst += ciphers;
     }
   }
-  // Packet compression extension?
+  return (int)(dst - dst_org);
-  if (features_[WG_FEATURE_ID_IPZIP] && dev_->delegate_)
-    dst += dev_->delegate_->WritePacketCompressionExtension(dst, dst_end - dst);
-
-  return dst - dst_org;
 }
 
 static bool ResolveBooleanFeatureValue(uint8 other, uint8 self, bool *result) {
@@ -853,48 +891,6 @@ static uint32 ResolveCipherSuite(int tie, const uint8 *a, size_t a_size, const u
           (tie == 0 && cipher_strengths[found_a] > cipher_strengths[found_b])) ? found_a : found_b;
 }
 
-bool WgPeer::ParseExtendedHandshake(WgKeypair *keypair, const uint8 *data, size_t data_size) {
-  while (data_size >= 2) {
-    uint8 type = data[0], size = data[1];
-    data += 2, data_size -= 2;
-    if (size > data_size)
-      return false;
-    switch (type) {
-    case EXT_CIPHER_SUITES_PRIO:
-    case EXT_CIPHER_SUITES:
-      keypair->cipher_suite = ResolveCipherSuite(keypair->peer->cipher_prio_ - (type - EXT_CIPHER_SUITES),
-                                                 keypair->peer->ciphers_, keypair->peer->num_ciphers_,
-                                                 data, size);
-      break;
-    case EXT_BOOLEAN_FEATURES:
-      for (size_t i = 0, j = std::max<uint32>(WG_FEATURES_COUNT, size * 4); i != j; i++) {
-        uint8 value = (i < size * 4) ? (data[i >> 2] >> ((i * 2) & 7)) & 3 : 0;
-        if (i >= WG_FEATURES_COUNT ? (value == WG_BOOLEAN_FEATURE_ENFORCES) : 
-            !ResolveBooleanFeatureValue(value, keypair->peer->features_[i], &keypair->enabled_features[i]))
-          return false;
-      }
-      break;
-    case EXT_PACKET_COMPRESSION:
-      if (keypair->enabled_features[WG_FEATURE_ID_IPZIP] && !keypair->compress_handler_ && keypair->peer->dev_->delegate_)
-        keypair->compress_handler_ = keypair->peer->dev_->delegate_->ParsePacketCompressionExtension(keypair, data, size);
-      break;
-    }
-    data += size, data_size -= size;
-  }
-  if (data_size != 0)
-    return false;
-  
-  if (!keypair->compress_handler_)
-    keypair->enabled_features[WG_FEATURE_ID_IPZIP] = false;
-  keypair->auth_tag_length = (keypair->enabled_features[WG_FEATURE_ID_SHORT_MAC] ? 8 : CHACHA20POLY1305_AUTHTAGLEN);
-
-//  RINFO("Cipher Suite = %d", keypair->cipher_suite);
-
-  return true;
-}
-
-#endif  // WITH_HANDSHAKE_EXT
-
 static void WgKeypairDelayedDelete(void *x) {
   WgKeypair *t = (WgKeypair*)x;
   if (t->aes_gcm128_context_)
@@ -922,7 +918,60 @@ void WgPeer::DeleteKeypair(WgKeypair **kp) {
   }
 }
 
-WgKeypair *WgPeer::CreateNewKeypair(bool is_initiator, const uint8 chaining_key[WG_HASH_LEN], uint32 remote_key_id, const uint8 *extfield, size_t extfield_size) {
+bool WgPeer::ParseExtendedHandshake(WgKeypair *kp, const uint8 *data, size_t data_size) {
+  assert(WITH_HANDSHAKE_EXT);
+
+  while (data_size >= 2) {
+    uint8 type = data[0], size = data[1];
+    data += 2, data_size -= 2;
+    if (size > data_size)
+      return false;
+    switch (type) {
+    case EXT_CIPHER_SUITES_PRIO:
+    case EXT_CIPHER_SUITES:
+      if (WITH_CIPHER_SUITES) {
+        kp->cipher_suite = ResolveCipherSuite(cipher_prio_ - (type - EXT_CIPHER_SUITES),
+                                              ciphers_, num_ciphers_, data, size);
+      }
+      break;
+
+    case EXT_BOOLEAN_FEATURES:
+      if (WITH_BOOLEAN_FEATURES) {
+        for (size_t i = 0, j = std::max<uint32>(WG_FEATURES_COUNT, size * 4); i != j; i++) {
+          uint8 value = (i < size * 4) ? (data[i >> 2] >> ((i * 2) & 7)) & 3 : 0;
+          if (i >= WG_FEATURES_COUNT ? (value == WG_BOOLEAN_FEATURE_ENFORCES) :
+              !ResolveBooleanFeatureValue(value, features_[i], &kp->enabled_features[i]))
+            return false;
+        }
+      }
+      break;
+    }
+    data += size, data_size -= size;
+  }
+  if (data_size != 0)
+    return false;
+
+  if (WITH_BOOLEAN_FEATURES)
+    kp->auth_tag_length = (kp->enabled_features[WG_FEATURE_ID_SHORT_MAC] ? 8 : CHACHA20POLY1305_AUTHTAGLEN);
+  return true;
+
+
+  if (WITH_CIPHER_SUITES && kp->cipher_suite >= EXT_CIPHER_SUITE_AES128_GCM && kp->cipher_suite <= EXT_CIPHER_SUITE_AES256_GCM) {
+#if WITH_AESGCM
+    kp->aes_gcm128_context_ = (AesGcm128StaticContext *)malloc(sizeof(*kp->aes_gcm128_context_) * 2);
+    if (!kp->aes_gcm128_context_)
+      return false;
+    int key_size = (kp->cipher_suite == EXT_CIPHER_SUITE_AES128_GCM) ? 128 : 256;
+    CRYPTO_gcm128_init(&kp->aes_gcm128_context_[0], kp->send_key, key_size);
+    CRYPTO_gcm128_init(&kp->aes_gcm128_context_[1], kp->recv_key, key_size);
+#else  // WITH_AESGCM
+    return false;
+#endif  // WITH_AESGCM
+  }
+
+}
+
+WgKeypair *WgPeer::CreateNewKeypair(bool is_initiator, const uint8 chaining_key[WG_HASH_LEN], uint32 remote_key_id) {
   WgKeypair *kp = new WgKeypair;
   uint8 *first_key, *second_key;
   if (!kp)
@@ -932,14 +981,6 @@ WgKeypair *WgPeer::CreateNewKeypair(bool is_initiator, const uint8 chaining_key[
   kp->remote_key_id = remote_key_id;
   kp->auth_tag_length = CHACHA20POLY1305_AUTHTAGLEN;
   
-#if WITH_HANDSHAKE_EXT
-  if (!ParseExtendedHandshake(kp, extfield, extfield_size)) {
-fail:
-    delete kp;
-    return NULL;
-  }
-#endif  // WITH_HANDSHAKE_EXT
-
   first_key = kp->send_key, second_key = kp->recv_key;
   if (!is_initiator)
     std::swap(first_key, second_key);
@@ -952,21 +993,6 @@ fail:
     std::swap(kp->compress_mac_keys[0][1], kp->compress_mac_keys[1][1]);
   }
 
-#if WITH_HANDSHAKE_EXT
-  if (kp->cipher_suite >= EXT_CIPHER_SUITE_AES128_GCM && kp->cipher_suite <= EXT_CIPHER_SUITE_AES256_GCM) {
-#if WITH_AESGCM
-    kp->aes_gcm128_context_ = (AesGcm128StaticContext *)malloc(sizeof(*kp->aes_gcm128_context_) * 2);
-    if (!kp->aes_gcm128_context_)
-      goto fail;
-    int key_size = (kp->cipher_suite == EXT_CIPHER_SUITE_AES128_GCM) ? 128 : 256;
-    CRYPTO_gcm128_init(&kp->aes_gcm128_context_[0], kp->send_key, key_size);
-    CRYPTO_gcm128_init(&kp->aes_gcm128_context_[1], kp->recv_key, key_size);
-#else  // WITH_AESGCM
-    goto fail;
-#endif  // WITH_AESGCM
-  }
-#endif  // WITH_HANDSHAKE_EXT
-
   kp->send_key_state = kp->recv_key_state = WgKeypair::KEY_VALID;
   kp->key_timestamp = OsGetMilliseconds();
   return kp;

wireguard_proto.h

@@ -135,8 +135,6 @@ STATIC_ASSERT(sizeof(MessageHandshakeInitiation) == 148, MessageHandshakeInitiat
 // 1 byte length
 // <payload>
 
-
-
 struct MessageHandshakeResponse {
   uint32 type;
   uint32 sender_key_id;
@@ -163,9 +161,6 @@ struct MessageData {
 STATIC_ASSERT(sizeof(MessageData) == 16, MessageData_wrong_size);
 
 enum {
-  EXT_PACKET_COMPRESSION = 0x15,
-  EXT_PACKET_COMPRESSION_VER = 0x01,
-
   EXT_BOOLEAN_FEATURES = 0x16,
 
   EXT_CIPHER_SUITES = 0x18,
@@ -307,30 +302,43 @@ public:
   virtual CompressState Compress(Packet *packet);
 
   virtual CompressState Decompress(Packet *packet);
-
 };
 
+// Can be used to customize the behavior of the wireguard impl
+class WgPlugin {
+public:
+  virtual ~WgPlugin() {}
+
+  // This is called from the main thread whenever a public key was not found in the WgDevice,
+  // return true to try again or false to fail. The packet can be copied and saved
+  // to resume a handshake later on.
+  virtual bool HandleUnknownPeerId(uint8 public_key[WG_PUBLIC_KEY_LEN], Packet *packet) = 0;
+
+  // For handling unknown settings during config parsing
+  virtual bool OnUnknownInterfaceSetting(const char *key, const char *value) = 0;
+  virtual bool OnUnknownPeerSetting(WgPeer *peer, const char *key, const char *value) = 0;
+
+  enum {
+    kHandshakeResponseDrop = 0xffffffff,
+    kHandshakeResponseFail = 0x80000000
+  };
+
+  // Called right before handshake initiation is sent out. Can be dropped.
+  virtual uint32 OnHandshake0(WgPeer *peer, uint8 *extout, uint32 extout_size) = 0;
+  // Called after handshake initiation is parsed, but before handshake response is sent.
+  // Packet can be dropped or keypair failed.
+  virtual uint32 OnHandshake1(WgPeer *peer, const uint8 *ext, uint32 ext_size, uint8 *extout, uint32 extout_size) = 0;
+  // Called when handshake response is parsed
+  virtual uint32 OnHandshake2(WgPeer *peer, const uint8 *ext, uint32 ext_size) = 0;
+};
+
+
 class WgDevice {
   friend class WgPeer;
   friend class WireguardProcessor;
   friend class WgConfig;
 public:
 
-  // Can be used to customize the behavior of WgDevice
-  class Delegate {
-  public:
-    // This is called from the main thread whenever a public key was not found in the WgDevice,
-    // return true to try again or false to fail. The packet can be copied and saved
-    // to resume a handshake later on.
-    virtual bool HandleUnknownPeerId(uint8 public_key[WG_PUBLIC_KEY_LEN], Packet *packet) = 0;
-
-    // Write out the compression header
-    virtual size_t WritePacketCompressionExtension(uint8 *data, size_t data_size) = 0;
-
-    // Parse the packet compression extension
-    virtual WgCompressHandler *ParsePacketCompressionExtension(WgKeypair *keypair, const uint8 *data, size_t data_size) = 0;
-  };
-
   WgDevice();
   ~WgDevice();
 
@@ -364,7 +372,8 @@ public:
   bool IsMainThread() { return CurrentThreadIdEquals(main_thread_id_); }
   bool IsMainOrDataThread() { return CurrentThreadIdEquals(main_thread_id_) || WG_IF_LOCKS_ENABLED_ELSE(delayed_delete_.enabled(), false);  }
 
-  void SetDelegate(Delegate *del) { delegate_ = del; }
+  void SetPlugin(WgPlugin *del) { plugin_ = del; }
+  WgPlugin *plugin() { return plugin_; }
     
 private:
   std::pair<WgPeer*, WgKeypair*> *LookupPeerInKeyIdLookup(uint32 key_id);
@@ -393,7 +402,7 @@ private:
   WgPeer *peers_, **last_peer_ptr_;
 
   // For hooking
-  Delegate *delegate_;
+  WgPlugin *plugin_;
 
 
   // Keypair IDs are generated randomly by us so no point in wasting cycles on
@@ -452,6 +461,12 @@ private:
   MultithreadedDelayedDelete delayed_delete_;
 };
 
+// Allows associating extradata with peers that can be used by plugins etc.
+class WgPeerExtraData {
+public:
+  virtual ~WgPeerExtraData() {}
+};
+
 // State for peer
 class WgPeer {
   friend class WgDevice;
@@ -476,7 +491,7 @@ public:
   static WgPeer *ParseMessageHandshakeInitiation(WgDevice *dev, Packet *packet);
   static WgPeer *ParseMessageHandshakeResponse(WgDevice *dev, const Packet *packet);
   static void ParseMessageHandshakeCookie(WgDevice *dev, const MessageHandshakeCookie *src);
-  void CreateMessageHandshakeInitiation(Packet *packet);
+  bool CreateMessageHandshakeInitiation(Packet *packet);
   bool CheckSwitchToNextKey_Locked(WgKeypair *keypair);
   void RemovePeer();
   bool CheckHandshakeRateLimit();
@@ -503,20 +518,25 @@ public:
   uint8 endpoint_protocol() const { return endpoint_protocol_; }
   WgPeer *next_peer() { return next_peer_; }
 
+  WgPeerExtraData *extradata() { return peer_extra_data_; }
+  void SetExtradata(WgPeerExtraData *ex) { peer_extra_data_ = ex; }
+  WgDevice *dev() { return dev_; }
+
 private:
-  static bool ParseExtendedHandshake(WgKeypair *keypair, const uint8 *data, size_t data_size);
+  bool ParseExtendedHandshake(WgKeypair *keypair, const uint8 *data, size_t data_size);
-  static WgKeypair *CreateNewKeypair(bool is_initiator, const uint8 key[WG_HASH_LEN], uint32 send_key_id, const uint8 *extfield, size_t extfield_size);
+  static WgKeypair *CreateNewKeypair(bool is_initiator, const uint8 key[WG_HASH_LEN], uint32 send_key_id);
   void WriteMacToPacket(const uint8 *data, MessageMacs *mac);
   void CheckAndUpdateTimeOfNextKeyEvent(uint64 now);
   static void DeleteKeypair(WgKeypair **kp);
   static void DelayedDelete(void *x);
-  size_t WriteHandshakeExtension(uint8 *dst, WgKeypair *keypair);
+  int WriteHandshakeExtension(uint8 *dst, WgKeypair *keypair);
   void InsertKeypairInPeer_Locked(WgKeypair *keypair);
   void ClearKeys_Locked();
   void ClearHandshake_Locked();
   void ClearPacketQueue_Locked();
   void ScheduleNewHandshake();
 
+  
   WgDevice *dev_;
   WgPeer *next_peer_;
 
@@ -604,6 +624,8 @@ private:
   uint64 rx_bytes_;
   uint64 tx_bytes_;
 
+  WgPeerExtraData *peer_extra_data_;
+
   // Handshake state that gets setup in |CreateMessageHandshakeInitiation| and used in
   // the response.
   struct HandshakeState {