From CACert website :
CAcert.org is a community-driven Certificate Authority that issues certificates to the public at large for free.
CAcert’s goal is to promote awareness and education on computer security through the use of encryption, specifically by providing cryptographic certificates. These certificates can be used to digitally sign and encrypt email, authenticate and authorize users connecting to websites and secure data transmission over the internet. Any application that supports the Secure Socket Layer Protocol (SSL or TLS) can make use of certificates signed by CAcert, as can any application that uses X.509 certificates, e.g. for encryption or code signing and document signatures.
If you want to have free certificates issued to you, join the CAcert Community .
If you want to use certificates issued by CAcert, read the CAcert Root Distribution License .This license applies to using the CAcert root keys .
So, what are you waiting for , head over to CACert.
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.