If you are looking for some tool to manage X.509 certificates then probably xca is your best guess. This is a graphical tool and you can open any file and view the keys in it.
So, first install it:
sudo yum install xca
And some information on xca::
Description : X Certificate and Key management is a graphic interface for managing
: asymmetric keys like RSA or DSA, certificates and revocation lists. It is
: intended as a small CA for creation and signing certificates. It uses the
: OpenSSL library for the cryptographic operations.
: Certificate signing requests (PKCS#10), certificates (X509v3), the signing
: of requests, the creation of self-signed certificates, certificate revocation
: lists and SmartCards are supported. For an easy company-wide use, customizable
: templates can be used for certificate and request generation. The PKI structures
: can be imported and exported in several formats like PKCS#7, PKCS#12, PEM,
: DER, PKCS#8. All cryptographic data are stored in a byte order agnostic file
: format, portable across operating systems.
Related articles across the web