x509 - X.509 certificate handling
An X.509 certificate is a structured grouping of information about an
individual, a device, or anything one can imagine. A X.509 CRL (certificate
revocation list) is a tool to help determine if a certificate is still valid.
The exact definition of those can be found in the X.509 document from ITU-T,
or in RFC3280 from PKIX. In OpenSSL, the type X509 is used to express such a
certificate, and the type X509_CRL is used to express a CRL.
A related structure is a certificate request, defined in PKCS#10 from RSA
Security, Inc, also reflected in RFC2896. In OpenSSL, the type X509_REQ is
used to express such a certificate request.
To handle some complex parts of a certificate, there are the types X509_NAME (to
express a certificate name), X509_ATTRIBUTE (to express a certificate
attributes), X509_EXTENSION (to express a certificate extension) and a few
Finally, there's the supertype X509_INFO, which can contain a CRL, a certificate
and a corresponding private key.
functions handle X.509 certificates, with some
exceptions, shown below.
functions handle X.509 CRLs.
functions handle PKCS#10 certificate requests.
functions handle certificate names.
functions handle certificate attributes.
functions handle certificate extensions.
Copyright 2003-2017 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy in the
file LICENSE in the source distribution or at