crypto: improve memory usage

ClientHelloParser used to contain an 18k buffer that was kept around
for the life of the connection, even though it was not needed in many
situations. I changed it to be deallocated when it's determined to
be no longer needed.

Signed-off-by: Fedor Indutny <fedor@indutny.com>

src/node_crypto.cc

@@ -784,12 +784,14 @@ Handle<Value> SecureContext::LoadPKCS12(const Arguments& args) {
 size_t ClientHelloParser::Write(const uint8_t* data, size_t len) {
   HandleScope scope;
 
+  assert(state_ != kEnded);
+  
   // Just accumulate data, everything will be pushed to BIO later
   if (state_ == kPaused) return 0;
 
   // Copy incoming data to the internal buffer
   // (which has a size of the biggest possible TLS frame)
-  size_t available = sizeof(data_) - offset_;
+  size_t available = kBufferSize - offset_;
   size_t copied = len < available ? len : available;
   memcpy(data_ + offset_, data, copied);
   offset_ += copied;
@@ -824,7 +826,7 @@ size_t ClientHelloParser::Write(const uint8_t* data, size_t len) {
     }
 
     // Sanity check (too big frame, or too small)
-    if (frame_len_ >= sizeof(data_)) {
+    if (frame_len_ >= kBufferSize) {
       // Let OpenSSL handle it
       Finish();
       return copied;
@@ -905,7 +907,6 @@ size_t ClientHelloParser::Write(const uint8_t* data, size_t len) {
     argv[0] = hello;
     MakeCallback(conn_->handle_, onclienthello_sym, 1, argv);
     break;
-   case kEnded:
    default:
     break;
   }
@@ -922,6 +923,9 @@ void ClientHelloParser::Finish() {
   int r = BIO_write(conn_->bio_read_, reinterpret_cast<char*>(data_), offset_);
   conn_->HandleBIOError(conn_->bio_read_, "BIO_write", r);
   conn_->SetShutdownFlags();
+
+  delete[] data_;
+  data_ = NULL;
 }
 
 

src/node_crypto.h

@@ -43,7 +43,6 @@
 
 #define EVP_F_EVP_DECRYPTFINAL 101
 
-
 namespace node {
 namespace crypto {
 
@@ -137,6 +136,16 @@ class ClientHelloParser {
                                      state_(kWaiting),
                                      offset_(0),
                                      body_offset_(0) {
+    data_ = new uint8_t[kBufferSize];
+    if (!data_)
+      abort();
+  }
+
+  ~ClientHelloParser() {
+    if (data_) {
+      delete[] data_;
+      data_ = NULL;
+    }
   }
 
   size_t Write(const uint8_t* data, size_t len);
@@ -145,11 +154,12 @@ class ClientHelloParser {
   inline bool ended() { return state_ == kEnded; }
 
  private:
+  static const int kBufferSize = 18432;
   Connection* conn_;
   ParseState state_;
   size_t frame_len_;
 
-  uint8_t data_[18432];
+  uint8_t* data_;
   size_t offset_;
   size_t body_offset_;
 };