Problems with non-blocking sockets and SSL
Hello. I'm having a few delicate problems, and I think at least one of them adheres to non-blocking sockets, which is what I use. 1) Is it possible to get a WANT_WRITE error when I actually don't have anything to send (on my high-level layer)? In that case, how should I handle this? When I do SSL_write with an empty string, I get an error, but maybe I won't get an error when I do SSL_write with an empty string on a WANT_WRITE? Am I far out? Maybe I simply don't understand how WANT_READ/WRITE work. :( Exactly when will I get a WANT_WRITE? Is it only when the transporting BIO failed to send more? 2) Say I have a program that sends a tiny crucial piece of data to another program and can't do anything before it gets another tiny crucial piece of data back... Can this go wrong in the sense that the first (or second for that matter) piece of data isn't large enough to fill an SSL record, so that it won't get sent and everything locks down? Or can it be padded automatically in some way? Do I make sense? :) Regards, Martin -- Martin Sjögren [EMAIL PROTECTED] ICQ : 41245059 Phone: +46 (0)31 7710870 Cell: +46 (0)739 169191 GPG key: http://www.strakt.com/~martin/gpg.html __ OpenSSL Project http://www.openssl.org User Support Mailing List[EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]
Re: Problems with non-blocking sockets and SSL
On Fri, Jun 14, 2002 at 04:17:58PM +0200, Martin Sjögren wrote: I'm having a few delicate problems, and I think at least one of them adheres to non-blocking sockets, which is what I use. 1) Is it possible to get a WANT_WRITE error when I actually don't have anything to send (on my high-level layer)? [...] Yes. See the SSL_get_error() manpage, http://www.openssl.org/docs/ssl/SSL_get_error.html 2) Say I have a program that sends a tiny crucial piece of data to another program and can't do anything before it gets another tiny crucial piece of data back... Can this go wrong in the sense that the first (or second for that matter) piece of data isn't large enough to fill an SSL record, so that it won't get sent and everything locks down? [...] No. Records can be tiny, the application does not have to worry about this. -- Bodo Möller [EMAIL PROTECTED] PGP http://www.informatik.tu-darmstadt.de/TI/Mitarbeiter/moeller/0x36d2c658.html * TU Darmstadt, Theoretische Informatik, Alexanderstr. 10, D-64283 Darmstadt * Tel. +49-6151-16-6628, Fax +49-6151-16-6036 __ OpenSSL Project http://www.openssl.org User Support Mailing List[EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]
