OpenSSL source code

Hi.... I've created a few x.509 certificates using openSSL.... I want to extract all the fields from an x.509 certificate and I want to know in detail what each field in the x.509 certificate does.... Hence i need to know how exactly openSSL created the x.509 certificate... Hence can anyone help me in obtaining the source code (implementation) of openSSL for x.509 certificates? Or is there any other way to know "in detail" what are the fields in the x.509 certificate? I'll be really thankful to the person who will help me... I'm stuck up with this since 2 - 3 weeks and without this I cannot go further in my project... So i request you to kindly help me in this matter.... Thank You.