NAME

       X509_chain_up_ref, X509_new, X509_free, X509_up_ref - X509 certificate ASN1 allocation
       functions

SYNOPSIS

        #include <openssl/x509.h>

        X509 *X509_new(void);
        void X509_free(X509 *a);
        int X509_up_ref(X509 *a);
        STACK_OF(X509) *X509_chain_up_ref(STACK_OF(X509) *x);

DESCRIPTION

       The X509 ASN1 allocation routines, allocate and free an X509 structure, which represents
       an X509 certificate.

       X509_new() allocates and initializes a X509 structure with reference count 1.

       X509_free() decrements the reference count of X509 structure a and frees it up if the
       reference count is zero. If a is NULL nothing is done.

       X509_up_ref() increments the reference count of a.

       X509_chain_up_ref() increases the reference count of all certificates in chain x and
       returns a copy of the stack.

NOTES

       The function X509_up_ref() if useful if a certificate structure is being used by several
       different operations each of which will free it up after use: this avoids the need to
       duplicate the entire certificate structure.

       The function X509_chain_up_ref() doesn't just up the reference count of each certificate
       it also returns a copy of the stack, using sk_X509_dup(), but it serves a similar purpose:
       the returned chain persists after the original has been freed.

RETURN VALUES

       If the allocation fails, X509_new() returns NULL and sets an error code that can be
       obtained by ERR_get_error(3).  Otherwise it returns a pointer to the newly allocated
       structure.

       X509_up_ref() returns 1 for success and 0 for failure.

       X509_chain_up_ref() returns a copy of the stack or NULL if an error occurred.

SEE ALSO

       d2i_X509(3), ERR_get_error(3), X509_CRL_get0_by_serial(3), X509_get0_signature(3),
       X509_get_ext_d2i(3), X509_get_extension_flags(3), X509_get_pubkey(3),
       X509_get_subject_name(3), X509_get_version(3), X509_NAME_add_entry_by_txt(3),
       X509_NAME_ENTRY_get_object(3), X509_NAME_get_index_by_NID(3), X509_NAME_print_ex(3),
       X509_sign(3), X509V3_get_d2i(3), X509_verify_cert(3)

COPYRIGHT

       Copyright 2002-2016 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 <https://www.openssl.org/source/license.html>.