1.\" $OpenBSD: BASIC_CONSTRAINTS_new.3,v 1.2 2016/12/25 22:15:10 schwarze Exp $ 2.\" 3.\" Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: December 25 2016 $ 18.Dt BASIC_CONSTRAINTS_NEW 3 19.Os 20.Sh NAME 21.Nm BASIC_CONSTRAINTS_new , 22.Nm BASIC_CONSTRAINTS_free 23.Nd X.509 extension to mark CA certificates 24.Sh SYNOPSIS 25.In openssl/x509v3.h 26.Ft BASIC_CONSTRAINTS * 27.Fn BASIC_CONSTRAINTS_new void 28.Ft void 29.Fn BASIC_CONSTRAINTS_free "BASIC_CONSTRAINTS *bc" 30.Sh DESCRIPTION 31.Fn BASIC_CONSTRAINTS_new 32allocates and initializes an empty 33.Vt BASIC_CONSTRAINTS 34object, representing an ASN.1 35.Vt BasicConstraints 36structure defined in RFC 5280 section 4.2.1.9. 37.Pp 38This object contains two fields. 39The field 40.Fa "int ca" 41is non-zero if the certificate is a CA certificate. 42The field 43.Fa "ASN1_INTEGER *pathlen" 44specifies the maximum number of non-self-issued intermediate 45certificates that may follow this certificate in a valid 46certification path. 47.Pp 48If an X.509 version 3 certificate does not contain this extension 49or if the 50.Fa ca 51field of the 52.Vt BASIC_CONSTRAINTS 53object is 0, or if the certificate contains a key usage extension 54having the 55.Dv KU_KEY_CERT_SIGN 56bit unset, then it is not a CA certificate but an end entity 57certificate. 58.Pp 59.Fn BASIC_CONSTRAINTS_free 60frees 61.Fa bc . 62.Sh RETURN VALUES 63.Fn BASIC_CONSTRAINTS_new 64returns the new 65.Vt BASIC_CONSTRAINTS 66object or 67.Dv NULL 68if an error occurs. 69.Sh SEE ALSO 70.Xr X509_EXTENSION_new 3 , 71.Xr X509_new 3 72.Sh STANDARDS 73RFC 5280: Internet X.509 Public Key Infrastructure Certificate and 74Certificate Revocation List (CRL) Profile: 75.Bl -dash -compact 76.It 77section 4.2.1.9: Basic Constraints 78.It 79section 6.1: Basic Path Validation 80.El 81