2 Setting Up TLS/SSL With OpenSSL

This chapter describes the OpenSSL tools that are available in Oracle Linux and how to use them to create Certificate Signing Requests (CSRs), self-signed certificates, and privately owned CA certificates. Also covered in this chapter are instructions on how to use the OpenSSL tools to validate and test certificates that are configured for a protocol to confirm that services are configured correctly.

Features of the Openssl Command

With the openssl command, which is included in the openssl package, you can perform a wide range of cryptography functions from the OpenSSL library, including the following:

  • Create and managing pairs of private and public keys.

  • Perform public key cryptographic operations.

  • Create self-signed certificates.

  • Create certificate signing requests (CSRs).

  • Create certificate revocation lists (CRLs).

  • Convert certificate files between various formats.

  • Calculate message digests.

  • Encrypt and decrypt files.

  • Test client-side and server-side TLS/SSL with HTTP and SMTP servers.

  • Verify, encrypt, and sign S/MIME email.

  • Generate and test prime numbers and generate pseudo random data.