I have created my own CA in CentOS 7.

I need to sign digital certificates. I have signed SSL certs which working fine in CentOS webservers apache and nginx.

Now I need to sign a CSR which is in pkcs10 format generated from Oracle Wallet Manager for at Oracle 11 g Server. When export OWM csr to my CentOS CA, it is not being signed using openssl tool. it gives error private key not matched.

I don't get which arguments and options to use with openssl to sign pkcs10 csr. Need your help to get it done.

Please post the commands that you are using, and the verbatim text of the error-messages you are receiving.

Also, check the first few lines of each certificate file ... the first line is usually English descriptive text ... and show us a copy of, say, the first two lines of the file and tell us its total file-size in bytes.

Of course, do not post complete certificates, actual pass-phrases (if any), nor anything else that could be considered compromising. Just enough to let us see for ourselves, in detail, what you are actually trying to do.

This is the command and outpu of it.
openssl ca -config openssl.cnf -extensions usr_cert -days 375 -notext -md md5 -in owm.csr -out ca/intermediate/certs/owm.cert
Using configuration from ca/intermediate/openssl.cnf
Enter pass phrase for intermediate.key.pem:
Check that the request matches the signature
Signature verification problems....