Key Certificates in GNUPG

[Rubis Paul]

Hi ,
  I am trying to generate some RSA keys and store them as
certificates. I am using libgcrypt library to generate RSA keys.

a. Is there any function in Libgrypt or Libksba to generate certificates ?

b. in the source directory of GNUPG, i can see certlist.c,
certreqgen.c etc under the 'sm' directory using structures defiened in
ksba.h file for creating certificate. Is there any format defined for
the certificate ? if yes, where i can see that ? also if i want to
store it  on my own format , what are the implications?

c. I am really new to this. Could some one tell me what exactly i have
to do in order to store RSA keys generated using libgcrypt as a
certificate.

  Thanks in advance,
    rubis