NAME

       x509 - X.509 certificate handling

SYNOPSIS

        #include <openssl/x509.h>

DESCRIPTION

       A 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 more.

       Finally, there's the supertype X509_INFO, which can contain a CRL, a certificate and a
       corresponding private key.

       X509_..., d2i_X509_... and i2d_X509_... handle X.509 certificates, with some exceptions,
       shown below.

       X509_CRL_..., d2i_X509_CRL_... and i2d_X509_CRL_...  handle X.509 CRLs.

       X509_REQ_..., d2i_X509_REQ_... and i2d_X509_REQ_...  handle PKCS#10 certificate requests.

       X509_NAME_... handle certificate names.

       X509_ATTRIBUTE_... handle certificate attributes.

       X509_EXTENSION_... handle certificate extensions.

SEE ALSO

       X509_NAME_ENTRY_get_object(3), X509_NAME_add_entry_by_txt(3),
       X509_NAME_add_entry_by_NID(3), X509_NAME_print_ex(3), X509_NAME_new(3), d2i_X509(3),
       d2i_X509_ALGOR(3), d2i_X509_CRL(3), d2i_X509_NAME(3), d2i_X509_REQ(3), d2i_X509_SIG(3),
       crypto(3), x509v3(3)