Remove path id from IV in QUIC encrytion algorithms.

net/quic/core/crypto/aead_base_decrypter.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/core/crypto/aead_base_decrypter.h"
 
 #include <cstdint>
 
 #include "net/quic/core/quic_utils.h"
 #include "net/quic/platform/api/quic_bug_tracker.h"
@@ skipping 98 matching lines @@
   if (!SetKey(key) || !SetNoncePrefix(nonce_prefix)) {
     DCHECK(false);
     return false;
   }
 
   have_preliminary_key_ = false;
   return true;
 }
 
 bool AeadBaseDecrypter::DecryptPacket(QuicVersion /*version*/,
-                                      QuicPathId path_id,
                                       QuicPacketNumber packet_number,
                                       StringPiece associated_data,
                                       StringPiece ciphertext,
                                       char* output,
                                       size_t* output_length,
                                       size_t max_output_length) {
   if (ciphertext.length() < auth_tag_size_) {
     return false;
   }
 
   if (have_preliminary_key_) {
     QUIC_BUG << "Unable to decrypt while key diversification is pending";
     return false;
   }
 
   uint8_t nonce[sizeof(nonce_prefix_) + sizeof(packet_number)];
   const size_t nonce_size = nonce_prefix_size_ + sizeof(packet_number);
   memcpy(nonce, nonce_prefix_, nonce_prefix_size_);
-  uint64_t path_id_packet_number =
-      QuicUtils::PackPathIdAndPacketNumber(path_id, packet_number);
-  memcpy(nonce + nonce_prefix_size_, &path_id_packet_number,
-         sizeof(path_id_packet_number));
+  memcpy(nonce + nonce_prefix_size_, &packet_number, sizeof(packet_number));
   if (!EVP_AEAD_CTX_open(
           ctx_.get(), reinterpret_cast<uint8_t*>(output), output_length,
           max_output_length, reinterpret_cast<const uint8_t*>(nonce),
           nonce_size, reinterpret_cast<const uint8_t*>(ciphertext.data()),
           ciphertext.size(),
           reinterpret_cast<const uint8_t*>(associated_data.data()),
           associated_data.size())) {
     // Because QuicFramer does trial decryption, decryption errors are expected
     // when encryption level changes. So we don't log decryption errors.
     ClearOpenSslErrors();
     return false;
   }
   return true;
 }
 
 StringPiece AeadBaseDecrypter::GetKey() const {
   return StringPiece(reinterpret_cast<const char*>(key_), key_size_);
 }
 
 StringPiece AeadBaseDecrypter::GetNoncePrefix() const {
   if (nonce_prefix_size_ == 0) {
     return StringPiece();
   }
   return StringPiece(reinterpret_cast<const char*>(nonce_prefix_),
                      nonce_prefix_size_);
 }
 
 }  // namespace net