[openssl-users] Query regarding MSG_NOSIGNAL with SSL_Write

[Viktor Dukhovni]

On Thu, Apr 27, 2017 at 12:32:42PM +0000, Salz, Rich via openssl-users wrote:

> > Does openssl  provide any way to set MSG_NOSIGNAL on sendmsg (Underlying TCP/IP socket layer) ?
> 
> No.  You will have to modify the code yourself.

Actually, it is possible to do the I/O in application code, using
any "write some data down a socket" API of the application's choice.

    https://www.openssl.org/docs/man1.0.2/crypto/BIO_s_bio.html

In particular, the OP could use sendmsg() to move data between the
SSL layer and the network.

For a complete example, see network_biopair_interop() function in
Postfix 2.3 (recent Postfix releases no longer use this approach).

    https://github.com/vdukhovni/postfix/blob/postfix-2.3/postfix/src/tls/tls_bio_ops.c

-- 
	Viktor.