Adds description

このコミットが含まれているのは:
Krzysztof Kwiatkowski 2013-09-18 14:11:46 +02:00
コミット f6b77e1b27
2個のファイルの変更39行の追加3行の削除

ファイルの表示

@ -2,3 +2,37 @@ buggy_openssl_with_fullduplex
=============================
Toy code which shows problems with non-blocking, fullduplex I/O & renegotiation in OpenSSL
How it works:
Client & Server:
- it has two threads - sender & receiver
- writes and reads are mutexed
Client:
- I/O is blocking (but can be non-blocking)
Server:
- I/O is non-blocking
- each thread runs it's own select()
1. After client & server are connected (and SSL handshake done) client sender
thread starts sending first message (in a loop).
2. When server receives first query it starts sending string EXCHANGE_STRING for
SEND_ITERATIONS number of times. So now we have 4 threads that are sending
and receiving traffic at the same time ( 2 send/receive threads on each
server and client side )
3. When client receives RENEG_INIT_LEN number of characters it starts
renegotiation ( if other one is not pending ). Bug starts to occure here
BUG:
Client side: client starts to report SSL_ERROR_SYSCALL
Server side: server reports SSL_ERROR_WANT_READ when receive function is called
TCP:
In TCP exchange we can see that transfer between client & server is OK until
client sends "Client Hello" packet. This packet is sent when SSL_renegotiate
is called

ファイルの表示

@ -45,9 +45,11 @@ bool handle_error_code(int& len, SSL* SSLHandler, int code, const char* func)
break;
case SSL_ERROR_WANT_READ:
cout << func << " WANT READ" << endl;
return true;
break;
case SSL_ERROR_WANT_WRITE:
cout << func << " WANT WRITE" << endl;
return true;
break;
case SSL_ERROR_SYSCALL:
cout << func << " ESYSCALL" << endl;
@ -55,10 +57,12 @@ bool handle_error_code(int& len, SSL* SSLHandler, int code, const char* func)
break;
case SSL_ERROR_SSL:
cout << func << " ESSL" << endl;
return true;
exit(1);
break;
default:
cout << func << " SOMETHING ELSE" << endl;
return true;
exit(1);
}
@ -75,9 +79,7 @@ void Sender()
int len = 0;
do
{
bool flag = true;
while( flag )
while( 1 )
{
lock_guard<mutex> lock(WriteReadMutex);
cout << "SSL_write: start" << endl;