Updated: 2021/Apr/14


X509_check_ca(3)                    OpenSSL                   X509_check_ca(3)



NAME
       X509_check_ca - check if given certificate is CA certificate

LIBRARY
       libcrypto, -lcrypto

SYNOPSIS
        #include <openssl/x509v3.h>

        int X509_check_ca(X509 *cert);

DESCRIPTION
       This function checks if given certificate is CA certificate (can be
       used to sign other certificates).

RETURN VALUES
       Function return 0, if it is not CA certificate, 1 if it is proper
       X509v3 CA certificate with basicConstraints extension CA:TRUE, 3, if it
       is self-signed X509 v1 certificate, 4, if it is certificate with
       keyUsage extension with bit keyCertSign set, but without
       basicConstraints, and 5 if it has outdated Netscape Certificate Type
       extension telling that it is CA certificate.

       Actually, any nonzero value means that this certificate could have been
       used to sign other certificates.

SEE ALSO
       X509_verify_cert(3), X509_check_issued(3), X509_check_purpose(3)

COPYRIGHT
       Copyright 2015-2020 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>.



1.1.1i                            2020-12-10                  X509_check_ca(3)