about openssl development files
 

Hello, I was configuring the IpSec-tools library, and i got the following error:
openSSl version is too old and must be 0.9... at least.
then i downloaded the version 1.0e of openssl source package then configure, ok make ok, and make install is ok too.
then configuring the ipsec-tools gives the same error of openssl version.
the command dpkg -d openssl gives the version 1.0e.
I've read somewhere that it could be that I haven't installed the development files of ssl, then installed the deb file for ssllib-dev then its ok but i got another warning error when configuring ipsec-tools:
error: #warning "Attempt to use kernel headers from user space
anybody can help me to understand what are these develeopment files and what are they for?
and if further help for the next error i would be thanxful.

openssl development packages allow you to compile applications that use openssl.

thank you :)