OPENSSL API Examples
Compile all examples with "make"

1) Client.c : A simple SSL Client that does a HTTP GET from a server, 
running using "openssl s_server -WWW command.
Code modifed from linux.die.net/man/3/bio_new_ssl_connect code example
for using OpenSSL API.
2) client_tcp.c: Use native TCP/IP socket as FD of SSL_NEW structure. This is
other way, we can bring up a SSL connection. 
3) mem.c: This program tries the Memory BIO.
4) read_mem.c: This program tries the Memory BIO.

Generation of Keys for openssl_s:
(ref: akadia.com/services/ssh_test_certificate.html)
Generate 1024 bit Private Key, which is encrypted using triple DES
$ openssl genrsa -des3 -out server.key 1024
Generate a CSR - enter various details like Org Name, etc.
$ openssl req -new -key server.key -out server.csr
Remove passphrase from Key - removed triple des encrption from key. This
ensures that if the server.cert/server.key pair is used in Apache, it 
will not ask for password whenever web server is started.
$ cp server.key server.key.org
$ openssl rsa -in server.key.org -out server.key
Generate a Sel-Signed Certificate
$ openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
At the End of the above excercise the pair server.crt and server.key are used
in any SSL Server like Apache Server.

Testing the SSL Client program:
To Test the SSL Client program, openssl_s test server was used as follows

Start Server
openssl0.9.8x is used in this example as a server.
$ openssl s_server -key server.key -cert server.crt -debug -state -msg -WWW
The -WWW starts a simple Web Server, and retrives files relative to where the 
openssl_s is started from.
The Keys are generated as explained above:
1) server.key	- private key
1) server.cert	-  Self Signed Certificate
1) Flags	- -debug -state -msg 
Note: create a file called index.html in the same directory, where "openssl s_server -WWW" is started. The client does a HTTP Get for this file in the example code.

Start Client
./client
Note; server.crt is the Public Cert that is needed at the client, for 
Certificate verification. Copy the file into the directory, from where the
client is being run.