M2Crypto: How to check server certificate?

[Hallvard B Furuseth (nospam nospam)]

Ng Pheng Siong wrote:
>According to Hallvard B Furuseth  <h.b.furuseth(nospam)@usit.uio(nospam).no>:
>> Does anyone know how I check the server certificate with M2Crypto?
>> Currently a program I have inherited does this:
> 
> Specify an SSL context:

Thank you.

>     from M2Crypto import SSL 
>     from M2Crypto.m2xmlrpclib import Server, SSL_Transport
> 
>     # Server is Zope-2.6.1 on ZServerSSL/0.12.
>     ctx = SSL.Context('sslv3')
>     ctx.load_cert_chain('client.pem')

I think I can drop that when I have ca.pem...

>     ctx.load_verify_locations('ca.pem')

Should be load_verify_location.

Heh.  That failed - correctly - because our test CA certificate is
expired.

>     ctx.set_verify(SSL.verify_peer, 10)

What does 10 mean?  I can see from the function declaration that it is
depth, but I don't know what depth is.

-- 
Hallvard