Jason Pettiss wrote: > I have a server which reads/writes a socket independently; that is to > say, at the same time (not a request-response model). I note in the > FAQ it says I must not allow multiple threads to use an SSL connection, > so clearly if my sockets are blocking I cannot support full-duplex > traffic (because I cannot call SSL_write while an SSL_read is blocking, > for instance).
> It's important that I be able to read a packet as soon as one is > available, and at the same time, send a packet as soon as I have one to > send... I would not want to delay the send until a pending read were > complete for example. > I'm uncertain whether placing the socket into non-blocking mode will > actually help here: if an SSL_read returns telling me I need to call it > again later, is it alright to go ahead and start a new SSL_write > operation? That's not what SSL_read will tell you. SSL_read will tell you that it cannot make further forward progress until something happens. You can call SSL_read at any later time you wish. The report that it cannot make forward progress is just a hint. The only quirks are with SSL_write. You must set SSL_ACCEPT_MOVING_WRITE_BUFFER (unless you are sure your write buffer will never move). And you must present a consistent data stream to SSL_write. (So you can't try to send 'FOO', get 1 back, and later try to send anything that doesn't start with 'OO'.) > Also I'm wondering if the limitation of not being able to write/read at > the same time in blocking mode is easily overcome, for example by > preventing re-negotiation (my application is on both ends of the pipe > here), or by replacing the read/write BIOs, or by supplying some > magical mutex callback function or something. Blocking mode is way more trouble than it's worth. I would just ditch it, and all the problems it causes, once and for all. Then never look back. DS ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager majord...@openssl.org
