As a precursor of installing a web server such as Apache (http version 2.4.10) and to avail of certain features as in able to configure the certificate chain on a certificate basis, we need to update to this version.
An earlier post detailed the steps to compile the OpenSSL v1.0.1 series and this one would cover the next version. The steps remain the same however the earlier post is more detailed.
- Run “config”
- Run “make”
- Run “make test”
- Run “make install”
A little more granularity:
$ ./config shared --prefix=/installs/openssl-1.0.2
Here: I have specified the installation folder to be explicit. You could point it to any other location or go with the default “/usr/local/ssl”. Note that if you would like to compile in the ECC Optimizations (ECC accelerator) refer to my earlier post.
$ make test
$ make install
You might face build issues as in “gcc” not being available or an incorrect version. Try “yum update gcc”.
The final step is to set the environment as in:
To quickly setup either a DTLS server or client, the “s_client” and the “s_server” utilities can be utilized.
On the server, run “s_server”, provide it the certificate and the private key and specify the port:
$ openssl s_server -cert cert.pem -key pk.pem -dtls1 -accept 4444
Enter pass phrase for pk.pem:
Using default temp DH parameters
Using default temp ECDH parameters
On the client, run “s_client” and you would see something akin to the following:
$ openssl s_client -dtls1 -connect xx.xx.xx.xx:4444 -debug
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES256-SHA
Server public key is 2048 bit
Secure Renegotiation IS supported
Protocol : DTLSv1
Cipher : ECDHE-RSA-AES256-SHA
Key-Arg : None
PSK identity: None
PSK identity hint: None
SRP username: None
TLS session ticket:
If you would want to confirm if your version of OpenSSL that was compiled months ago (and the options specified at that time are forgotten) provides for SRTP support then one way to do that would be to utilize “objmap” on linux. If you see functions such as the following then it was not compiled with the “OPENSSL_NO_SRTP” option.
It seems that SRTP is compiled by default and is supported by default.
The command to use:
$ objdump -f libssl.so -x | grep -i SRTP
We have a new vulnerability well explained here. The easiest solution is to remove support for SSL 3.0 from the web server – that in itself is a trivial thing to do – be it Apache or Nginx. However there might be clients that support SSL 3.0 exclusively and none of the TLS versions.
As of now I see that Chrome, Firefox 33 and the Google Web Server (the server that powers its sites) supports this extension.
Once support for TLS Fallback Signaling Cipher Suite Value (SCSV) is available in OpenSSL then the web servers would support it as well.