- NAME
- SYNOPSIS
- DESCRIPTION
- NOTES
- RETURN VALUES
- SEE ALSO
- COPYRIGHT

# 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.