When using OpenSSL to obtain a certificate signed by a Certification Authority (CA), you should submit the Certificate Signing Request (CSR) file, which is file1.pem, to the CA. The CSR contains the information about the entity requesting the certificate and the public key, but not the private key, which is in file2.pem. The CA uses the information in the CSR to create and sign the certificate.

1.CSR Submission: The CSR (file1.pem) includes the public key and the entity information required by the CA to issue a certificate.

2.Private Key Security: The private key (file2.pem) should never be sent to the CA or shared; it remains securely stored on the requestor’s server.

3.Certificate Issuance: After the CA signs the CSR, the resulting certificate can be used with the private key to establish secure communications.