NAME

       X509_verify_cert - discover and verify X509 certificate chain

SYNOPSIS

        #include <openssl/x509.h>

        int X509_verify_cert(X509_STORE_CTX *ctx);

DESCRIPTION

       The X509_verify_cert() function attempts to discover and validate a certificate chain
       based on parameters in ctx. A complete description of the process is contained in the
       verify(1) manual page.

RETURN VALUES

       If a complete chain can be built and validated this function returns 1, otherwise it
       return zero, in exceptional circumstances it can also return a negative code.

       If the function fails additional error information can be obtained by examining ctx using,
       for example X509_STORE_CTX_get_error().

NOTES

       Applications rarely call this function directly but it is used by OpenSSL internally for
       certificate validation, in both the S/MIME and SSL/TLS code.

       A negative return value from X509_verify_cert() can occur if it is invoked incorrectly,
       such as with no certificate set in ctx, or when it is called twice in succession without
       reinitialising ctx for the second call.  A negative return value can also happen due to
       internal resource problems or if a retry operation is requested during internal lookups
       (which never happens with standard lookup methods).  Applications must check for <= 0
       return value on error.

BUGS

       This function uses the header x509.h as opposed to most chain verification functions which
       use x509_vfy.h.

SEE ALSO

       X509_STORE_CTX_get_error(3)

COPYRIGHT

       Copyright 2009-2016 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>.