remove dns size limits, print error queue on fail

libs/visor_http_client/httpssession.cpp

@@ -73,16 +73,6 @@ void HTTPSSession::destroy_session()
 
 void HTTPSSession::process_receive(const uint8_t *data, size_t len)
 {
-    // dnsheader is 12, at least one byte for the minimum name,
-    // two bytes for the qtype and another two for the qclass
-    const size_t MIN_DNS_RESPONSE_SIZE = 17;
-    // 512 over UDP without EDNS, but 65535 over TCP
-    const size_t MAX_DNS_RESPONSE_SIZE = 65535;
-    if (len < MIN_DNS_RESPONSE_SIZE || len > MAX_DNS_RESPONSE_SIZE) {
-        std::cerr << "malformed data" << std::endl;
-        _malformed_data();
-        return;
-    }
     auto buf = std::make_unique<char[]>(len);
     memcpy(buf.get(), (const char *)data, len);
     _got_dns_msg(std::move(buf), len);
@@ -355,6 +345,7 @@ void HTTPSSession::do_handshake()
         int error = SSL_get_error(_ssl_session, err);
         if (error == SSL_ERROR_SSL || error == SSL_ERROR_SYSCALL) {
             std::cerr << "Handshake failed: SSL or syscall error" << std::endl;
+            ERR_print_errors_fp(stderr);
             _handshake_error();
         } else if (error == SSL_ERROR_WANT_READ || error == SSL_ERROR_WANT_WRITE) {
             // Non-fatal error. OpenSSL wants to either read or write.

libs/visor_http_client/tcpsession.cpp

@@ -58,10 +58,6 @@ void TCPSession::close()
 // accumulate data and try to extract DNS messages
 void TCPSession::receive_data(const char data[], size_t len)
 {
-    // dnsheader is 12, at least one byte for the minimum name,
-    // two bytes for the qtype and another two for the qclass
-    const size_t MIN_DNS_RESPONSE_SIZE = 17;
-
     _buffer.append(data, len);
 
     for (;;) {
@@ -73,14 +69,6 @@ void TCPSession::receive_data(const char data[], size_t len)
         // size is in network byte order.
         size = static_cast<unsigned char>(_buffer[1]) | static_cast<unsigned char>(_buffer[0]) << 8;
 
-        // no need to check the maximum size here since the maximum size
-        // that a std::uint16t_t can hold, std::numeric_limits<std::uint16_t>::max()
-        // (65535 bytes) is allowed over TCP
-        if (size < MIN_DNS_RESPONSE_SIZE) {
-            _malformed_data();
-            break;
-        }
-
         if (_buffer.size() >= sizeof(size) + size) {
             auto data = std::make_unique<char[]>(size);
             std::memcpy(data.get(), _buffer.data() + sizeof(size), size);

libs/visor_http_client/test_driver.cpp

@@ -119,7 +119,7 @@ TEST_CASE("HTTP Client", "[http]")
     auto tcp_handle = loop->resource<uvw::tcp_handle>(family);
 
     auto malformed_data = [tcp_handle]() {
-        std::cout << "malformed_data" << std::endl;
+        std::cout << "malformed_data or handshake error" << std::endl;
         tcp_handle->close();
     };
     auto got_dns_message = []([[maybe_unused]] std::unique_ptr<const char[]> data,