This commit overhauls much of the meterpreter timeouts and staging processes. This fixes a bug with concurrent session handling, reduces CPU load by caching a single SSL certificate for all sessions, increases all of the critical timeouts, and generally makes mass ownage work better. We still need to limit the maximum number of concurrent on_session() threads to something sane to prevent sesssion spikes from dragging out the process even longer. The C-side meterpreter change is minimal and will only help with future compatibility if we move to non-blocking fd's for the SSL socket.

git-svn-id: file:///home/svn/framework3/trunk@10595 4d416f70-5f16-0410-b530-b9f4589650da

external/source/meterpreter/source/common/common.h

@@ -68,7 +68,7 @@ void real_dprintf(char *filename, int line, const char *function, char *format,
 
 #ifdef _WIN32
 
-//#define DEBUGTRACE
+// #define DEBUGTRACE 1
 
 #ifdef DEBUGTRACE
 #define dprintf(...) real_dprintf(__VA_ARGS__)

external/source/meterpreter/source/server/server_setup.c

@@ -251,7 +251,8 @@ static BOOL server_negotiate_ssl(Remote *remote)
 {
 	BOOL success = TRUE;
 	SOCKET fd    = 0;
-    DWORD ret    = 0;
+	DWORD ret    = 0;
+	DWORD res    = 0;
 
 	lock_acquire( remote->lock );
 
@@ -274,12 +275,23 @@ static BOOL server_negotiate_ssl(Remote *remote)
 			break;
 		}
 		
-		if( (ret = SSL_connect(remote->ssl)) != 1 )
-		{
-			dprintf("[SERVER] connect failed %d\n", SSL_get_error(remote->ssl, ret));
-			success = FALSE;
-			break;
-		}
+		do {
+			if( (ret = SSL_connect(remote->ssl)) != 1 )
+			{
+				res = SSL_get_error(remote->ssl, ret);
+				dprintf("[SERVER] connect failed %d\n", res);
+
+				if (res == SSL_ERROR_WANT_READ || res == SSL_ERROR_WANT_WRITE) {
+					// Catch non-blocking socket errors and retry
+					continue;
+				}
+
+				success = FALSE;
+				break;
+			}
+		} while(ret != 1);
+		
+		if (success == FALSE) break;
 
 		dprintf("[SERVER] Sending a HTTP GET request to the remote side...");
 

lib/msf/base/sessions/meterpreter.rb

@@ -187,7 +187,6 @@ class Meterpreter < Rex::Post::Meterpreter::Client
 	#
 	def load_stdapi()
 		original = console.disable_output
-
 		console.disable_output = true
 		console.run_single('use stdapi')
 		console.disable_output = original
@@ -209,7 +208,7 @@ class Meterpreter < Rex::Post::Meterpreter::Client
 	#
 	def load_session_info()
 		begin
-			::Timeout.timeout(20) do
+			::Timeout.timeout(60) do
 				username  = self.sys.config.getuid
 				sysinfo   = self.sys.config.sysinfo
 				self.info = "#{username} @ #{sysinfo['Computer']}"

lib/msf/base/sessions/meterpreter_options.rb

@@ -44,7 +44,7 @@ module MeterpreterOptions
 			end
 			
 			begin
-				::Timeout.timeout(10) do 
+				::Timeout.timeout(30) do 
 					if session.railgun and session.railgun.shell32.IsUserAnAdmin()["return"] == true
 						session.load_priv
 						session.info += " (ADMIN)"

lib/msf/core/handler/reverse_tcp.rb

@@ -161,10 +161,10 @@ module ReverseTcp
 				# Start a new thread and pass the client connection
 				# as the input and output pipe.  Client's are expected
 				# to implement the Stream interface.
-				conn_threads << Thread.new {
+				conn_threads << Thread.new(client) { |client_copy|
 					begin
-						handle_connection(client)
-					rescue
+						handle_connection(client_copy)
+					rescue ::Exception
 						elog("Exception raised from handle_connection: #{$!}\n\n#{$@.join("\n")}")
 					end
 				}

lib/rex/post/meterpreter/client.rb

@@ -41,6 +41,16 @@ class Client
 	#
 	@@ext_hash = {}
 
+	#
+	# Cached SSL certificate (required to scale)
+	#
+	@@ssl_ctx = nil
+	
+	#
+	# Mutex to synchronize class-wide operations
+	#
+	@@ssl_mutex = ::Mutex.new
+
 	#
 	# Checks the extension hash to see if a class has already been associated
 	# with the supplied extension name.
@@ -133,6 +143,11 @@ class Client
 	end
 
 	def generate_ssl_context
+		@@ssl_mutex.synchronize do 
+		if not @@ssl_ctx
+		
+		wlog("Generating SSL certificate for Meterpreter sessions")
+	
 		key  = OpenSSL::PKey::RSA.new(1024){ }
 		cert = OpenSSL::X509::Certificate.new
 		cert.version = 2
@@ -175,7 +190,14 @@ class Client
 
 		ctx.session_id_context = Rex::Text.rand_text(16)
 
-		return ctx
+		wlog("Generated SSL certificate for Meterpreter sessions")
+		
+		@@ssl_ctx = ctx
+		
+		end # End of if not @ssl_ctx
+		end # End of mutex.synchronize
+		
+		@@ssl_ctx
 	end
 
 	#
@@ -197,7 +219,7 @@ class Client
 	# waiting for a response.
 	#
 	def Client.default_timeout
-		return 30
+		return 300
 	end
 
 	##