path: root/lib/libcrypto/man/X509_get_pubkey.3

.\" $OpenBSD: X509_get_pubkey.3,v 1.13 2022/03/31 17:27:17 naddy Exp $
.\" selective merge up to: OpenSSL 99d63d46 Oct 26 13:56:48 2016 -0400
.\"
.\" This file is a derived work.
.\" The changes are covered by the following Copyright and license:
.\"
.\" Copyright (c) 2020, 2021 Ingo Schwarze <schwarze@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.\" The original file was written by Dr. Stephen Henson <steve@openssl.org>.
.\" Copyright (c) 2015 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: March 31 2022 $
.Dt X509_GET_PUBKEY 3
.Os
.Sh NAME
.Nm X509_get_pubkey ,
.Nm X509_get0_pubkey ,
.Nm X509_set_pubkey ,
.Nm X509_get_X509_PUBKEY ,
.Nm X509_get0_pubkey_bitstr ,
.Nm X509_REQ_get_pubkey ,
.Nm X509_REQ_get0_pubkey ,
.Nm X509_REQ_set_pubkey ,
.Nm X509_extract_key ,
.Nm X509_REQ_extract_key
.Nd get or set certificate or certificate request public key
.Sh SYNOPSIS
.In openssl/x509.h
.Ft EVP_PKEY *
.Fo X509_get_pubkey
.Fa "X509 *x"
.Fc
.Ft EVP_PKEY *
.Fo X509_get0_pubkey
.Fa "const X509 *x"
.Fc
.Ft int
.Fo X509_set_pubkey
.Fa "X509 *x"
.Fa "EVP_PKEY *pkey"
.Fc
.Ft X509_PUBKEY *
.Fo X509_get_X509_PUBKEY
.Fa "const X509 *x"
.Fc
.Ft ASN1_BIT_STRING *
.Fo X509_get0_pubkey_bitstr
.Fa "const X509 *x"
.Fc
.Ft EVP_PKEY *
.Fo X509_REQ_get_pubkey
.Fa "X509_REQ *req"
.Fc
.Ft EVP_PKEY *
.Fo X509_REQ_get0_pubkey
.Fa "X509_REQ *req"
.Fc
.Ft int
.Fo X509_REQ_set_pubkey
.Fa "X509_REQ *x"
.Fa "EVP_PKEY *pkey"
.Fc
.Ft EVP_PKEY *
.Fo X509_extract_key
.Fa "X509 *x"
.Fc
.Ft EVP_PKEY *
.Fo X509_REQ_extract_key
.Fa "X509_REQ *req"
.Fc
.Sh DESCRIPTION
.Fn X509_get_pubkey
attempts to decode the public key for certificate
.Fa x .
If successful, it returns the public key as an
.Vt EVP_PKEY
pointer with its reference count incremented: this means the returned
key must be freed up after use.
.Fn X509_get0_pubkey
is similar except that it does not increment the reference count
of the returned
.Vt EVP_PKEY ,
so it must not be freed up after use.
.Pp
.Fn X509_get_X509_PUBKEY
returns an internal pointer to the
.Vt SubjectPublicKeyInfo
structure contained in
.Fa x .
The returned value must not be freed up after use.
.Pp
.Fn X509_get0_pubkey_bitstr
returns an internal pointer to just the public key contained in this
.Vt SubjectPublicKeyInfo
structure, without the information about the algorithm used.
.Pp
.Fn X509_set_pubkey
attempts to set the public key for certificate
.Fa x
to
.Fa pkey .
The key
.Fa pkey
should be freed up after use.
.Pp
.Fn X509_REQ_get_pubkey ,
.Fn X509_REQ_get0_pubkey ,
and
.Fn X509_REQ_set_pubkey
are similar but operate on certificate request
.Fa req .
.Pp
The first time a public key is decoded, the
.Vt EVP_PKEY
structure is cached in the certificate or certificate request itself.
Subsequent calls return the cached structure with its reference count
incremented to improve performance.
.Pp
.Fn X509_extract_key
and
.Fn X509_REQ_extract_key
are deprecated aliases for
.Fn X509_get_pubkey
and
.Fn X509_REQ_get_pubkey ,
respectively, implemented as macros.
.Sh RETURN VALUES
.Fn X509_get_pubkey ,
.Fn X509_get0_pubkey ,
.Fn X509_get_X509_PUBKEY ,
.Fn X509_get0_pubkey_bitstr ,
.Fn X509_REQ_get_pubkey ,
.Fn X509_REQ_get0_pubkey ,
.Fn X509_extract_key ,
and
.Fn X509_REQ_extract_key
return a public key or
.Dv NULL
if an error occurred.
.Pp
.Fn X509_set_pubkey
and
.Fn X509_REQ_set_pubkey
return 1 for success or 0 for failure.
.Pp
In some cases of failure of
.Fn X509_get0_pubkey ,
.Fn X509_set_pubkey ,
.Fn X509_REQ_get_pubkey ,
.Fn X509_REQ_get0_pubkey ,
and
.Fn X509_REQ_set_pubkey ,
the reason can be determined with
.Xr ERR_get_error 3 .
.Sh ERRORS
.Fn X509_get_pubkey ,
.Fn X509_get0_pubkey ,
.Fn X509_REQ_get_pubkey ,
.Fn X509_extract_key ,
and
.Fn X509_REQ_extract_key
provide diagnostics as documented for
.Xr X509_PUBKEY_get 3 .
If
.Fa x
or
.Fa req
is
.Dv NULL
or contains no certificate information,
they fail without pushing an error onto the stack.
.Pp
.Fn X509_get_X509_PUBKEY
provides no diagnostics and crashes by accessing a
.Dv NULL
pointer if
.Fa x
is
.Dv NULL
or contains no certificate information,
.Pp
.Fn X509_get0_pubkey_bitstr
provides no diagnostics
and fails without pushing an error onto the stack if
.Fa x
is
.Dv NULL ,
but it crashes by accessing a
.Dv NULL
pointer if
.Fa x
contains no certificate information.
.Sh SEE ALSO
.Xr d2i_X509 3 ,
.Xr X509_CRL_get0_by_serial 3 ,
.Xr X509_NAME_add_entry_by_txt 3 ,
.Xr X509_NAME_ENTRY_get_object 3 ,
.Xr X509_NAME_get_index_by_NID 3 ,
.Xr X509_NAME_print_ex 3 ,
.Xr X509_new 3 ,
.Xr X509_PUBKEY_new 3 ,
.Xr X509_REQ_new 3 ,
.Xr X509_sign 3 ,
.Xr X509_verify_cert 3 ,
.Xr X509V3_get_d2i 3
.Sh STANDARDS
RFC 5280, Internet X.509 Public Key Infrastructure Certificate
and Certificate Revocation List (CRL) Profile,
section 4.1 Basic Certificate Fields
.Pp
RFC 2986: PKCS #10: Certification Request Syntax Specification,
section 4.1 CertificationRequestInfo
.Sh HISTORY
.Fn X509_extract_key
and
.Fn X509_REQ_extract_key
first appeared in SSLeay 0.5.1 but returned a pointer to an
.Vt RSA
object before SSLeay 0.6.0.
.Fn X509_get_pubkey ,
.Fn X509_set_pubkey ,
.Fn X509_REQ_get_pubkey ,
and
.Fn X509_REQ_set_pubkey
first appeared in SSLeay 0.6.5.
.Fn X509_get_X509_PUBKEY
first appeared in SSLeay 0.8.0.
These functions have been available since
.Ox 2.4 .
.Pp
.Fn X509_get0_pubkey_bitstr
first appeared in OpenSSL 0.9.7 and has been available since
.Ox 3.4 .
.Pp
.Fn X509_get0_pubkey
first appeared in OpenSSL 1.1.0 and has been available since
.Ox 6.3 .
.Fn X509_REQ_get0_pubkey
first appeared in OpenSSL 1.1.0 and has been available since
.Ox 7.1 .