Hi Aravind:

On November 6, 2008 01:51:20 am Aravinda babu wrote:
> Hi all,
> Is there any OpenSSL API which will prepare the certificate chain from the
> peer certificate given as input ????????? I have only peer certificate.I
> have to build the cert chain from this ....

This was already answered yesterday - the answer is: If you want to use "raw"
OpenSSL, then it can be done in the _verify() callbacks. There are many
examples out there that may give you an idea of how to do this.

There are also other libraries and systems that already have this work done
for you, and you just have to call that library's callback in the appropriate
place in your code (usually in the set verify callback section).

Please take a look at the messages from yesterday. Is there a single API call
that will do this? - no. And depending on what you mean by "prepare a
certificate chain", you will have different requirements. If you want to do
full Path Discovery and Validation (build the certification chain back to a
pre-established trust anchor, using certificates that you may or may not
already have, and verify and validate each link in that chain using the
algorithms from PKIX) then something like the Pathfinder callback (I won't
link to it again, please check the previous post) is what you want. If you
only want to check the signatures and perform some cursory checks, then the
existing OpenSSL API's have this covered. If you want to know how to write
that code, then I would suggest picking up the O'Rilley OpenSSL book, or
looking at the code in the OpenSSL source tree - there are many examples in
there already that may do what you want.

Or, you could hire someone to do the integration for you.

Have fun.

Patrick Patterson
President and Chief PKI Architect,
Carillon Information Security Inc.
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