how to create SSL connection using PKCS12 file?

Dear Sir,   I put a key file and a certificate file into a PKCS12 file with a certfile. But when i put the PKCS12 file to create SSL connection an error message displayed as: can't load the certificate file. Can you help me?   Thanks very much.   chgu

how to sign a subordinate root CA certificate?

Dear Sir,   I have created a root CA using openssl. And it can sign server/user certificate(s) normally. Now i want to sign a subordinate root CA certificate. But  i don't know how to do it and what configuration files need. Can you help me?   Regards,   chgu

what does certificate chain means and functions?

much,   Regards,   chgu