QUIC: support diversified keys with version 33.

net/quic/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 <openssl/err.h>
 #include <openssl/evp.h>
 
 #include <memory>
 
 #include "net/quic/crypto/aead_base_decrypter.h"
+#include "net/quic/quic_bug_tracker.h"
 #include "net/quic/quic_flags.h"
 #include "net/quic/quic_utils.h"
 
 using base::StringPiece;
+using std::string;
 
 namespace net {
 
 namespace {
 
 // Clear OpenSSL error stack.
 void ClearOpenSslErrors() {
   while (ERR_get_error()) {
   }
 }
@@ skipping 14 matching lines @@
 
 }  // namespace
 
 AeadBaseDecrypter::AeadBaseDecrypter(const EVP_AEAD* aead_alg,
                                      size_t key_size,
                                      size_t auth_tag_size,
                                      size_t nonce_prefix_size)
     : aead_alg_(aead_alg),
       key_size_(key_size),
       auth_tag_size_(auth_tag_size),
-      nonce_prefix_size_(nonce_prefix_size) {
+      nonce_prefix_size_(nonce_prefix_size),
+      have_preliminary_key_(false) {
+  DCHECK_GT(256u, key_size);
+  DCHECK_GT(256u, auth_tag_size);
+  DCHECK_GT(256u, nonce_prefix_size);
   DCHECK_LE(key_size_, sizeof(key_));
   DCHECK_LE(nonce_prefix_size_, sizeof(nonce_prefix_));
 }
 
 AeadBaseDecrypter::~AeadBaseDecrypter() {}
 
 bool AeadBaseDecrypter::SetKey(StringPiece key) {
   DCHECK_EQ(key.size(), key_size_);
   if (key.size() != key_size_) {
     return false;
@@ skipping 12 matching lines @@
 
 bool AeadBaseDecrypter::SetNoncePrefix(StringPiece nonce_prefix) {
   DCHECK_EQ(nonce_prefix.size(), nonce_prefix_size_);
   if (nonce_prefix.size() != nonce_prefix_size_) {
     return false;
   }
   memcpy(nonce_prefix_, nonce_prefix.data(), nonce_prefix.size());
   return true;
 }
 
+bool AeadBaseDecrypter::SetPreliminaryKey(StringPiece key) {
+  DCHECK(!have_preliminary_key_);
+  SetKey(key);
+  have_preliminary_key_ = true;
+
+  return true;
+}
+
+bool AeadBaseDecrypter::SetDiversificationNonce(DiversificationNonce nonce) {
+  if (!have_preliminary_key_) {
+    return true;
+  }
+
+  string key, nonce_prefix;
+  DiversifyPreliminaryKey(
+      StringPiece(reinterpret_cast<const char*>(key_), key_size_),
+      StringPiece(reinterpret_cast<const char*>(nonce_prefix_),
+                  nonce_prefix_size_),
+      nonce, key_size_, nonce_prefix_size_, &key, &nonce_prefix);
+
+  if (!SetKey(key) || !SetNoncePrefix(nonce_prefix)) {
+    DCHECK(false);
+    return false;
+  }
+
+  have_preliminary_key_ = false;
+  return true;
+}
+
 bool AeadBaseDecrypter::DecryptPacket(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));
   if (!EVP_AEAD_CTX_open(
           ctx_.get(), reinterpret_cast<uint8_t*>(output), output_length,
           max_output_length, reinterpret_cast<const uint8_t*>(nonce),
@@ skipping 15 matching lines @@
 
 StringPiece AeadBaseDecrypter::GetNoncePrefix() const {
   if (nonce_prefix_size_ == 0) {
     return StringPiece();
   }
   return StringPiece(reinterpret_cast<const char*>(nonce_prefix_),
                      nonce_prefix_size_);
 }
 
 }  // namespace net