.\" $OpenBSD: EVP_PKEY_asn1_get_count.3,v 1.4 2019/06/06 01:06:58 schwarze Exp $
.\" full merge up to: OpenSSL 751148e2 Oct 27 00:11:11 2017 +0200
.\"
.\" This file was written by Richard Levitte <levitte@openssl.org>.
.\" Copyright (c) 2017 The OpenSSL Project.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\"
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\"
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in
.\"    the documentation and/or other materials provided with the
.\"    distribution.
.\"
.\" 3. All advertising materials mentioning features or use of this
.\"    software must display the following acknowledgment:
.\"    "This product includes software developed by the OpenSSL Project
.\"    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
.\"
.\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
.\"    endorse or promote products derived from this software without
.\"    prior written permission. For written permission, please contact
.\"    openssl-core@openssl.org.
.\"
.\" 5. Products derived from this software may not be called "OpenSSL"
.\"    nor may "OpenSSL" appear in their names without prior written
.\"    permission of the OpenSSL Project.
.\"
.\" 6. Redistributions of any form whatsoever must retain the following
.\"    acknowledgment:
.\"    "This product includes software developed by the OpenSSL Project
.\"    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
.\" OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd $Mdocdate: June 6 2019 $
.Dt EVP_PKEY_ASN1_GET_COUNT 3
.Os
.Sh NAME
.Nm EVP_PKEY_asn1_get_count ,
.Nm EVP_PKEY_asn1_get0 ,
.Nm EVP_PKEY_get0_asn1 ,
.Nm EVP_PKEY_asn1_find ,
.Nm EVP_PKEY_asn1_find_str ,
.Nm EVP_PKEY_asn1_get0_info
.Nd enumerate public key ASN.1 methods
.Sh SYNOPSIS
.In openssl/evp.h
.Ft int
.Fn EVP_PKEY_asn1_get_count void
.Ft const EVP_PKEY_ASN1_METHOD *
.Fo EVP_PKEY_asn1_get0
.Fa "int idx"
.Fc
.Ft const EVP_PKEY_ASN1_METHOD *
.Fo EVP_PKEY_get0_asn1
.Fa "const EVP_PKEY *pkey"
.Fc
.Ft const EVP_PKEY_ASN1_METHOD *
.Fo EVP_PKEY_asn1_find
.Fa "ENGINE **pe"
.Fa "int type"
.Fc
.Ft const EVP_PKEY_ASN1_METHOD *
.Fo EVP_PKEY_asn1_find_str
.Fa "ENGINE **pe"
.Fa "const char *str"
.Fa "int len"
.Fc
.Ft int
.Fo EVP_PKEY_asn1_get0_info
.Fa "int *ppkey_id"
.Fa "int *pkey_base_id"
.Fa "int *ppkey_flags"
.Fa "const char **pinfo"
.Fa "const char **ppem_str"
.Fa "const EVP_PKEY_ASN1_METHOD *ameth"
.Fc
.Sh DESCRIPTION
.Fn EVP_PKEY_asn1_get_count
returns a count of the number of public key ASN.1 methods available.
It includes standard methods and any methods added by the application.
.Pp
.Fn EVP_PKEY_asn1_get0
returns the public key ASN.1 method
.Fa idx .
The value of
.Fa idx
must be in the range from zero to
.Fn EVP_PKEY_asn1_get_count
\- 1.
.Pp
.Fn EVP_PKEY_asn1_find
looks up the method with NID
.Fa type .
If
.Fa pe
is not
.Dv NULL ,
it first looks for an engine implementing a method for the NID
.Fa type .
If one is found,
.Pf * Fa pe
is set to that engine and the method from that engine is returned instead.
.Pp
.Fn EVP_PKEY_asn1_find_str
looks up the method with PEM type string
.Fa str .
Just like
.Fn EVP_PKEY_asn1_find ,
if
.Fa pe
is not
.Dv NULL ,
methods from engines are preferred.
.Pp
.Fn EVP_PKEY_asn1_get0_info
retrieves the public key ID, the base public key ID (both NIDs), any flags,
the method description and the PEM type string associated with the public
key ASN.1 method
.Sy *ameth .
.Pp
.Fn EVP_PKEY_asn1_get_count ,
.Fn EVP_PKEY_asn1_get0 ,
.Fn EVP_PKEY_asn1_find
and
.Fn EVP_PKEY_asn1_find_str
are not thread safe, but as long as all
.Vt EVP_PKEY_ASN1_METHOD
objects are added before the application gets threaded, using them is
safe.
See
.Xr EVP_PKEY_asn1_add0 3 .
.Sh RETURN VALUES
.Fn EVP_PKEY_asn1_get_count
returns the number of available public key methods.
.Pp
.Fn EVP_PKEY_asn1_get0
returns a public key method or
.Dv NULL
if
.Fa idx
is out of range.
.Pp
.Fn EVP_PKEY_get0_asn1
returns the public key method used by
.Fa pkey .
.Pp
.Fn EVP_PKEY_asn1_get0_info
returns 1 on success or 0 on failure.
.Sh SEE ALSO
.Xr EVP_PKEY_asn1_new 3 ,
.Xr EVP_PKEY_base_id 3 ,
.Xr EVP_PKEY_new 3
.Sh HISTORY
These functions first appeared in OpenSSL 1.0.0
and have been available since
.Ox 4.9 .