X509_CHECK_ISSUED(3)       Library Functions Manual       X509_CHECK_ISSUED(3)

NAME
     X509_check_issued - check whether a certificate was issued using a given
     CA certificate

SYNOPSIS
     #include <openssl/x509v3.h>

     int
     X509_check_issued(X509 *issuer, X509 *subject);

DESCRIPTION
     This function checks whether the certificate subject was issued using the
     CA certificate issuer.  It does the following checks:

     o   match the issuer field of subject against the subject field of issuer

     o   if authorityKeyIdentifier is present in the subject certificate,
         compare it to the subjectKeyIdentifier of issuer

     o   check the keyUsage field of issuer.

RETURN VALUES
     This function returns X509_V_OK if the certificate subject is issued by
     issuer, or some X509_V_ERR* constant to indicate an error.

SEE ALSO
     X509_check_ca(3), X509_new(3), X509_verify_cert(3)

HISTORY
     X509_check_issued() first appeared in OpenSSL 0.9.6 and has been
     available since OpenBSD 2.9.

Linux 6.8.2-arch2-1              June 6, 2019              Linux 6.8.2-arch2-1