NAME

       X509_check_ca - check if given certificate is CA certificate

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       basicConstraints, and 5 if it has outdated Netscape Certificate Type extension telling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 non-zero 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 2015-2018 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>.