343 lines
9.8 KiB
Groff
343 lines
9.8 KiB
Groff
.\" $OpenBSD: EVP_PKEY_keygen.3,v 1.14 2024/07/21 08:02:17 tb Exp $
|
|
.\" full merge up to: OpenSSL 24a535ea Sep 22 13:14:20 2020 +0100
|
|
.\"
|
|
.\" This file is a derived work.
|
|
.\" The changes are covered by the following Copyright and license:
|
|
.\"
|
|
.\" Copyright (c) 2023 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) 2006, 2009, 2013, 2015, 2016, 2018 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: July 21 2024 $
|
|
.Dt EVP_PKEY_KEYGEN 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm EVP_PKEY_keygen_init ,
|
|
.Nm EVP_PKEY_keygen ,
|
|
.Nm EVP_PKEY_paramgen_init ,
|
|
.Nm EVP_PKEY_paramgen ,
|
|
.Nm EVP_PKEY_gen_cb ,
|
|
.Nm EVP_PKEY_CTX_set_cb ,
|
|
.Nm EVP_PKEY_CTX_get_cb ,
|
|
.Nm EVP_PKEY_CTX_set0_keygen_info ,
|
|
.Nm EVP_PKEY_CTX_get_keygen_info ,
|
|
.Nm EVP_PKEY_CTX_set_app_data ,
|
|
.Nm EVP_PKEY_CTX_get_app_data
|
|
.Nd key and parameter generation functions
|
|
.Sh SYNOPSIS
|
|
.In openssl/evp.h
|
|
.Ft int
|
|
.Fo EVP_PKEY_keygen_init
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fc
|
|
.Ft int
|
|
.Fo EVP_PKEY_keygen
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fa "EVP_PKEY **ppkey"
|
|
.Fc
|
|
.Ft int
|
|
.Fo EVP_PKEY_paramgen_init
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fc
|
|
.Ft int
|
|
.Fo EVP_PKEY_paramgen
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fa "EVP_PKEY **ppkey"
|
|
.Fc
|
|
.Ft typedef int
|
|
.Fo EVP_PKEY_gen_cb
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fc
|
|
.Ft void
|
|
.Fo EVP_PKEY_CTX_set_cb
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fa "EVP_PKEY_gen_cb *cb"
|
|
.Fc
|
|
.Ft EVP_PKEY_gen_cb *
|
|
.Fo EVP_PKEY_CTX_get_cb
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fc
|
|
.Ft void
|
|
.Fo EVP_PKEY_CTX_set0_keygen_info
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fa "int *dat"
|
|
.Fa "int datlen"
|
|
.Fc
|
|
.Ft int
|
|
.Fo EVP_PKEY_CTX_get_keygen_info
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fa "int idx"
|
|
.Fc
|
|
.Ft void
|
|
.Fo EVP_PKEY_CTX_set_app_data
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fa "void *data"
|
|
.Fc
|
|
.Ft void *
|
|
.Fo EVP_PKEY_CTX_get_app_data
|
|
.Fa "EVP_PKEY_CTX *ctx"
|
|
.Fc
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn EVP_PKEY_keygen_init
|
|
function initializes a public key algorithm context using key
|
|
.Fa ctx->pkey
|
|
for a key generation operation.
|
|
.Pp
|
|
The
|
|
.Fn EVP_PKEY_keygen
|
|
function performs a key generation operation.
|
|
The generated key is written to
|
|
.Fa ppkey .
|
|
.Pp
|
|
The functions
|
|
.Fn EVP_PKEY_paramgen_init
|
|
and
|
|
.Fn EVP_PKEY_paramgen
|
|
are similar except parameters are generated.
|
|
.Pp
|
|
The functions
|
|
.Fn EVP_PKEY_CTX_set_cb
|
|
and
|
|
.Fn EVP_PKEY_CTX_get_cb
|
|
set and retrieve the key or parameter generation callback, respectively.
|
|
.Pp
|
|
The function
|
|
.Fn EVP_PKEY_CTX_set0_keygen_info
|
|
sets the parameters associated with the generation operation to the array
|
|
.Fa dat
|
|
containing
|
|
.Ft datlen
|
|
integer parameters.
|
|
The caller retains ownership of the
|
|
.Fa dat
|
|
array; it will never be freed by the library.
|
|
.Pp
|
|
The function
|
|
.Fn EVP_PKEY_CTX_get_keygen_info
|
|
returns parameters associated with the generation operation.
|
|
If
|
|
.Fa idx
|
|
is -1, the total number of parameters available is returned.
|
|
Any non-negative value returns the value of that parameter.
|
|
.Fn EVP_PKEY_CTX_get_keygen_info
|
|
with a non-negative value for
|
|
.Fa idx
|
|
should only be called within the generation callback.
|
|
.Pp
|
|
If the callback returns 0, then the key generation operation is aborted
|
|
and an error occurs.
|
|
This might occur during a time consuming operation where a user clicks
|
|
on a "cancel" button.
|
|
.Pp
|
|
The functions
|
|
.Fn EVP_PKEY_CTX_set_app_data
|
|
and
|
|
.Fn EVP_PKEY_CTX_get_app_data
|
|
set and retrieve an opaque pointer.
|
|
This can be used to set some application defined value which can be
|
|
retrieved in the callback: for example a handle which is used to update
|
|
a "progress dialog".
|
|
.Pp
|
|
After the call to
|
|
.Fn EVP_PKEY_keygen_init
|
|
or
|
|
.Fn EVP_PKEY_paramgen_init ,
|
|
algorithm specific control operations can be performed to set any
|
|
appropriate parameters for the operation.
|
|
.Pp
|
|
The functions
|
|
.Fn EVP_PKEY_keygen
|
|
and
|
|
.Fn EVP_PKEY_paramgen
|
|
can be called more than once on the same context if several operations
|
|
are performed using the same parameters.
|
|
.Pp
|
|
The meaning of the parameters passed to the callback will depend on the
|
|
algorithm and the specific implementation of the algorithm.
|
|
Some might not give any useful information at all during key or
|
|
parameter generation.
|
|
Others might not even call the callback.
|
|
.Pp
|
|
The operation performed by key or parameter generation depends on the
|
|
algorithm used.
|
|
In some cases (e.g. EC with a supplied named curve) the "generation"
|
|
option merely sets the appropriate fields in an
|
|
.Vt EVP_PKEY
|
|
structure.
|
|
.Pp
|
|
In OpenSSL, an
|
|
.Vt EVP_PKEY
|
|
structure containing a private key also contains the public key
|
|
components and parameters (if any).
|
|
An OpenSSL private key is equivalent to what some libraries call a "key
|
|
pair".
|
|
A private key can be used in functions which require the use of a public
|
|
key or parameters.
|
|
.Sh RETURN VALUES
|
|
.Fn EVP_PKEY_keygen_init ,
|
|
.Fn EVP_PKEY_paramgen_init ,
|
|
.Fn EVP_PKEY_keygen ,
|
|
and
|
|
.Fn EVP_PKEY_paramgen
|
|
return 1 for success and 0 or a negative value for failure.
|
|
In particular, a return value of -2 indicates the operation is not
|
|
supported by the public key algorithm.
|
|
.Pp
|
|
Callback functions of the type
|
|
.Fn EVP_PKEY_gen_cb
|
|
are supposed to return 1 on success or 0 on error.
|
|
.Pp
|
|
.Fn EVP_PKEY_CTX_get_cb
|
|
returns a function pointer to the currently installed callback function or
|
|
.Dv NULL
|
|
if no callback function is installed.
|
|
.Pp
|
|
.Fn EVP_PKEY_CTX_get_keygen_info
|
|
returns the number of available parameters if
|
|
.Fa idx
|
|
is \-1, one of these parameters if
|
|
.Fa idx
|
|
is greater than or equal to zero but less than the number
|
|
of available parameters, or 0 otherwise.
|
|
.Sh EXAMPLES
|
|
Generate a 2048-bit RSA key:
|
|
.Bd -literal -offset indent
|
|
#include <openssl/evp.h>
|
|
#include <openssl/rsa.h>
|
|
|
|
EVP_PKEY_CTX *ctx;
|
|
EVP_PKEY *pkey = NULL;
|
|
|
|
ctx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA, NULL);
|
|
if (!ctx)
|
|
/* Error occurred */
|
|
if (EVP_PKEY_keygen_init(ctx) <= 0)
|
|
/* Error */
|
|
if (EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, 2048) <= 0)
|
|
/* Error */
|
|
|
|
/* Generate key */
|
|
if (EVP_PKEY_keygen(ctx, &pkey) <= 0)
|
|
/* Error */
|
|
.Ed
|
|
.Pp
|
|
Generate a key from a set of parameters:
|
|
.Bd -literal -offset indent
|
|
#include <openssl/evp.h>
|
|
#include <openssl/rsa.h>
|
|
|
|
EVP_PKEY_CTX *ctx;
|
|
EVP_PKEY *pkey = NULL, *param;
|
|
|
|
/* Assumes that param is already set up. */
|
|
ctx = EVP_PKEY_CTX_new(param, NULL);
|
|
if (!ctx)
|
|
/* Error occurred */
|
|
if (EVP_PKEY_keygen_init(ctx) <= 0)
|
|
/* Error */
|
|
|
|
/* Generate key */
|
|
if (EVP_PKEY_keygen(ctx, &pkey) <= 0)
|
|
/* Error */
|
|
.Ed
|
|
.Pp
|
|
Example of generation callback for OpenSSL public key implementations:
|
|
.Bd -literal -offset indent
|
|
/* Application data is a BIO to output status to */
|
|
|
|
EVP_PKEY_CTX_set_app_data(ctx, status_bio);
|
|
|
|
static int
|
|
genpkey_cb(EVP_PKEY_CTX *ctx)
|
|
{
|
|
char c = '*';
|
|
BIO *b = EVP_PKEY_CTX_get_app_data(ctx);
|
|
int p;
|
|
|
|
p = EVP_PKEY_CTX_get_keygen_info(ctx, 0);
|
|
if (p == 0)
|
|
c = '.';
|
|
if (p == 1)
|
|
c = '+';
|
|
if (p == 2)
|
|
c = '*';
|
|
if (p == 3)
|
|
c = '\en';
|
|
BIO_write(b, &c, 1);
|
|
(void)BIO_flush(b);
|
|
return 1;
|
|
}
|
|
.Ed
|
|
.Sh SEE ALSO
|
|
.Xr EVP_PKEY_CTX_new 3 ,
|
|
.Xr EVP_PKEY_decrypt 3 ,
|
|
.Xr EVP_PKEY_derive 3 ,
|
|
.Xr EVP_PKEY_encrypt 3 ,
|
|
.Xr EVP_PKEY_meth_set_keygen 3 ,
|
|
.Xr EVP_PKEY_sign 3 ,
|
|
.Xr EVP_PKEY_verify 3 ,
|
|
.Xr EVP_PKEY_verify_recover 3 ,
|
|
.Xr X25519 3
|
|
.Sh HISTORY
|
|
These functions first appeared in OpenSSL 1.0.0
|
|
and have been available since
|
|
.Ox 4.9 .
|