=pod=head1 NAMEX509_check_issued - checks if certificate is issued by anothercertificate=head1 SYNOPSIS #include <openssl/x509v3.h> int X509_check_issued(X509 *issuer, X509 *subject);=head1 DESCRIPTIONThis function checks if certificate I<subject> was issued using CAcertificate I<issuer>. This function takes into account not only matching of issuer field of I<subject> with subject field of I<issuer>,but also compares B<authorityKeyIdentifier> extension of I<subject> withB<subjectKeyIdentifier> of I<issuer> if B<authorityKeyIdentifier>present in the I<subject> certificate and checks B<keyUsage> field ofI<issuer>.=head1 RETURN VALUEFunction return B<X509_V_OK> if certificate I<subject> is issued byI<issuer> or some B<X509_V_ERR*> constant to indicate an error.=head1 SEE ALSOL<X509_verify_cert(3)>,L<X509_check_ca(3)>,L<verify(1)>=cut