.\"	$OpenBSD: X509_check_issued.3,v 1.4 2019/06/06 01:06:59 schwarze Exp $
.\"	OpenSSL 99d63d46 Oct 26 13:56:48 2016 -0400
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.Dd $Mdocdate: June 6 2019 $
.Dt X509_CHECK_ISSUED 3
.Os
.Sh NAME
.Nm X509_check_issued
.Nd check whether a certificate was issued using a given CA certificate
.Sh SYNOPSIS
.In openssl/x509v3.h
.Ft int
.Fo X509_check_issued
.Fa "X509 *issuer"
.Fa "X509 *subject"
.Fc
.Sh DESCRIPTION
This function checks whether the certificate
.Fa subject
was issued using the CA certificate
.Fa issuer .
It does the following checks:
.Bl -bullet
.It
match the issuer field of
.Fa subject
against the subject field of
.Fa issuer
.It
if
.Sy authorityKeyIdentifier
is present in the
.Fa subject
certificate,
compare it to the
.Sy subjectKeyIdentifier
of
.Fa issuer
.It
check the
.Sy keyUsage
field of
.Fa issuer .
.El
.Sh RETURN VALUES
This function returns
.Dv X509_V_OK
if the certificate
.Fa subject
is issued by
.Fa issuer ,
or some
.Dv X509_V_ERR*
constant to indicate an error.
.Sh SEE ALSO
.Xr X509_check_ca 3 ,
.Xr X509_new 3 ,
.Xr X509_verify_cert 3
.Sh HISTORY
.Fn X509_check_issued
first appeared in OpenSSL 0.9.6 and has been available since
.Ox 2.9 .