"Present but cannot be compiled" error message

[j-lowry]

Trying to attempting to build viewssld on Ubuntu 12.04.2 LTS and received the following above message. Here is a snippet from the ./confgure command:
"
checking dssl/sslcap.h usability... no
checking dssl/sslcap.h presence... yes
configure: WARNING: dssl/sslcap.h: present but cannot be compiled
configure: WARNING: dssl/sslcap.h: check for missing prerequisite headers?
configure: WARNING: dssl/sslcap.h: see the Autoconf documentation
configure: WARNING: dssl/sslcap.h: section "Present But Cannot Be Compiled"
configure: WARNING: dssl/sslcap.h: proceeding with the compiler's result
configure: WARNING: ## ------------------------------------- ##
configure: WARNING: ## Report this to [email protected] ##
configure: WARNING: ## ------------------------------------- ##
checking for dssl/sslcap.h... no
configure: error: libdssl header file not found. https:/downloads/plashchynski/viewssld/libdssl-2.1.1.tar.gz
"

https://www.gnu.org/software/autoconf/manual/autoconf-2.64/html_node/Present-But-Cannot-Be-Compiled.html

Will post a fix momentarily. It will still not be able to find the header, but the error message will be correct.

[sssindre]

Got it to configure & compile by adding two lines in /usr/local/include/dssl/packet.h (from libdssl):

#include <pcap/pcap.h>
#include <openssl/evp.h>

[alecrwaters]

Hi,

That’s interesting… just the two #include statements on their own? Not actually including anything?

The version of libdssl that we have is a bit out of touch with the current state of TLS – it doesn’t seem to work very well with modern browsers and servers. Visiting a given site in something elderly like IE6 will decrypt properly, but the same site in a current version of Chrome won’t.

libdssl needs looking at by someone who knows what they’re looking at ☺

alec

[sssindre]

Well, they include pcap and openssl header files... As libdssl compiles without them, they should probably be added in a viewssl header file instead, but this way solved my immediate problem. :/

Your issue with modern browsers probably comes from "Diffie–Hellman key exchange", and can't be solved by libdssl. Google that and "pfs ssl". Apache webservers can be told not to use that by adding "!kEDH" to the "SSLCipherSuite" line in ssl.conf.

[andreycpp]

Got it to configure & compile by adding two lines in /usr/local/include/dssl/packet.h (from libdssl):

#include <pcap/pcap.h>
#include <openssl/evp.h>

In case of Ubuntu 16.04 I managed to fix this by putting these includes into /usr/local/include/dssl/dssl_defs.h