On 15/10/2019 10:32, Matt Caswell wrote: > > > On 15/10/2019 07:51, Naveen Shivanna wrote: >> Hi, >> >> After adding 'enable-sctp' compile option, OpenSSL (DTLS) can work with >> SCTP as transport. >> >> OpenSSL bss_dgram.c file includes the kernel /netinet/sctp.h. >> >> We have our own custom SCTP implementation (also implements custom BIO >> METHODS, do not use the default methods), so we need to remove the >> dependency of kernel sctp.h from bss_gram.c file. Our build environment >> do not have the sctp.h and we are not supposed to install lksctp-tools. >> >> Can we tailor the bss_gram.c with new compile macro or is there any >> other better solution ? > > Hmm. There isn't really a "good" way to do this. I can think of two options: > > 1) Modify the OpenSSL source (perhaps in the way that you suggest with a > compile time macro) > > or > > 2) Provide a "dummy" implementation of netinet/sctp.h. This would have > to provide "stub" implementations of any SCTP related functions/macros > used by bss_dgram.c. That would enable you to build unmodified OpenSSL > source. Thinking about this a little more, I think you may encounter other problems with replacing the standard SCTP BIO with your own one. The functions BIO_dgram_sctp_wait_for_dry() and BIO_dgram_sctp_msg_waiting() spring to mind. They get called by libssl in certain scenarios, are specific to the standard SCTP BIO, and are not replaceable via BIO_METHOD. I think you would have to implement your own versions of those functions, which implies that modifying the OpenSSL source is the only possibility. Matt
