This won't work for a variety of reasons. One is that an SSL_write may fail
because of a negotiation in progress and being able to *read* data from the
socket may allow the write to progress.
Even in my dreams I didn't imagined that you have try to compile it.
Of course it won't work!!!
Windows sends FD_WRITE event if writing is possible and previous
invokation of 'send' has failed with WSAEWOULDBLOCK code (only
this code, if it has failed from other reason, FD_WRITE will not
be send and waiting for it will cause deadlock)...
Let me try one more time:
1) The code
If OpenSSL is unable to perform an operation, that means it tried it and
couldn't do it. If that operation was a write, then when it becomes possible,
you will get a write event. If that operation wasn't a write, then who cares
when a write becomes possible?
Maybe I show it using
--- PSEUDO CODE
bool WaitOnWrite = false;
int res;
// it associates FD_WRITE event with SockEvent object
WSAEventSelect(sock,SockEvent,FD_WRITE);
for (;;)
{
if (WaitOnWrite)
WaitForMultipleObjects(SockEvent)
else
Don't get me wrong, but:
I have really appreciated you for time you have devoted to answer me,
but unfortunately it seems like it's rather your desire to be
guru for others (i don't want to say ignorance) then real desire
to help me, is why you are doing this. (I really don't want be
I'm not checking socket's possibility to write, i'm just issuing
SSL_write command till SSL_write will return
SSL_ERROR_WANT_WRITE. Now, what?
Retry the write when anything changes. That would include receiving an FD_WRITE
event.
On unix i can use 'select' with socket handle as input in
Don't get me wrong, but:
I have really appreciated you for time you have devoted to answer me,
but unfortunately it seems like it's rather your desire to be guru for others
(i don't want to say ignorance) then real desire to help me, is why you are
doing this. (I really don't want be malicious,
No. I don't like blocking sockets because it's very hard to get them
right
Experience, how EASY it could be done in nonblocking mode is what i'm currently
correlating with your words.
... let's cut this this thread. I've droped idea of using third party
components and now i'm writing
It works good (for unencrypted sockets of course) but
unfortunately in another way then someone may think. 'select'
statement returns immediately when desired condition is met - for
example you are waiting for some data to arrive and this data
arrives 'select' returns, if you will not
, October 20, 2006 9:57
To: openssl-users@openssl.org
Subject: Re: RE: Multithreading problem
I am very, very new to openssl. There is a good example (Example 5-16,
Network Security with Openssl book)) for using nonblocking openssl. It
is easy to understand. It uses one thread to handle 2
I am somewhat confused. Network Security with OpenSSL states quite clearly that OpenSSL handles multithreading and blocking sockets fine as long as you give it proper callbacks to acquire locks as needed. If you go to the book's site and download the code examples (
http://www.opensslbook.com/) it
Actually, it's extremely complicated. For example, what do you
do if you call 'write' and it doesn't return in a reasonable
amount of time?
You cannot use 'select' with blocking sockets. If you do, and
your 'write' blocks (say because only a few bytes could be
written at that
I am somewhat confused. Network Security with OpenSSL states quite
clearly that OpenSSL handles multithreading and blocking sockets
fine as long as you give it proper callbacks to acquire locks as
needed. If you go to the book's site and download the code examples
(
To: openssl-users@openssl.org
Subject: RE: Multithreading problem
This problem was raised on this mailing list many times, but the clear
solution (in my opinion) was not given. From OpenSSL FAQ:
...an SSL connection may not concurrently be used by multiple
threads... This means that I can't have 2
First... sorry for trash in my post's subjects. I'm using www
interface on my email provider site for sending emails and there is
no option to change this. (I don't known if this is my mailbox or this
mailing list server problem).
Actually, it's extremely complicated. For example, what do
I am very, very new to openssl. There is a good example (Example 5-16,
Network Security with Openssl book)) for using nonblocking openssl. It
is easy to understand. It uses one thread to handle 2 nonblocking
socket. You may have to modify it to handle multithread. At least, you
have example
This problem was raised on this mailing list many times, but the
clear solution (in my opinion) was not given. From OpenSSL FAQ:
...an SSL connection may not concurrently be used by multiple
threads... This means that I can't have 2 threads, one reading
and one writing at the same time
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