Certificate Authority:
 Cert file:ca.pem in the current directory.
 Key  file:ca.pem in the current directory.

 Note:Uses same file to store both cert and key of CA.

Server/Client:
 Cert files:  in cert subdirectory.
               commonName           subjectAltName
             ......................................
          0     <blank>                 <blank>
          1     *.a.com                 <blank>
          2     w*.a.com                <blank>
          3     *w.a.com                <blank>
          4     **.a.com                <blank>
          5     www.*.com               <blank>
          6     *.com                   <blank>
          7     *                       <blank>
          8     *.com.                  <blank>
          9     <blank>                 *.a.com
          10    <blank>                 w*.a.com
          11    <blank>                 *w.a.com 
          12    <blank>                 **.a.com
          13    <blank>                 www.*.com
          14    <blank>                 *.com
          15    <blank>                 *
          16    <blank>                 *.com. 

 Key files: in key subdirectory.

Note:All the above certificates can be generated easily with the help of gen-cert.sh script and openssl.cnf file
     present in this directory.
     Keep both of them in same directory and run the script.Then just type in yes(y) when prompted.Thats it :)

     To check whether the created certs are Ok,use the following command from the current directory:
     openssl verify -CAfile ca.pem cert/*.pem