cda774223d
And update find-doc-nits to complain if "=head1 EXAMPLE" is found. Reviewed-by: Richard Levitte <levitte@openssl.org> Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com> (Merged from https://github.com/openssl/openssl/pull/9602)
115 lines
3.3 KiB
Text
115 lines
3.3 KiB
Text
=pod
|
|
|
|
=head1 NAME
|
|
|
|
EVP_PKEY_sign_init, EVP_PKEY_sign - sign using a public key algorithm
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/evp.h>
|
|
|
|
int EVP_PKEY_sign_init(EVP_PKEY_CTX *ctx);
|
|
int EVP_PKEY_sign(EVP_PKEY_CTX *ctx,
|
|
unsigned char *sig, size_t *siglen,
|
|
const unsigned char *tbs, size_t tbslen);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
The EVP_PKEY_sign_init() function initializes a public key algorithm
|
|
context using key B<pkey> for a signing operation.
|
|
|
|
The EVP_PKEY_sign() function performs a public key signing operation
|
|
using B<ctx>. The data to be signed is specified using the B<tbs> and
|
|
B<tbslen> parameters. If B<sig> is B<NULL> then the maximum size of the output
|
|
buffer is written to the B<siglen> parameter. If B<sig> is not B<NULL> then
|
|
before the call the B<siglen> parameter should contain the length of the
|
|
B<sig> buffer, if the call is successful the signature is written to
|
|
B<sig> and the amount of data written to B<siglen>.
|
|
|
|
=head1 NOTES
|
|
|
|
EVP_PKEY_sign() does not hash the data to be signed, and therefore is
|
|
normally used to sign digests. For signing arbitrary messages, see the
|
|
L<EVP_DigestSignInit(3)> and
|
|
L<EVP_SignInit(3)> signing interfaces instead.
|
|
|
|
After the call to EVP_PKEY_sign_init() algorithm specific control
|
|
operations can be performed to set any appropriate parameters for the
|
|
operation (see L<EVP_PKEY_CTX_ctrl(3)>).
|
|
|
|
The function EVP_PKEY_sign() can be called more than once on the same
|
|
context if several operations are performed using the same parameters.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
EVP_PKEY_sign_init() and EVP_PKEY_sign() 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.
|
|
|
|
=head1 EXAMPLES
|
|
|
|
Sign data using RSA with PKCS#1 padding and SHA256 digest:
|
|
|
|
#include <openssl/evp.h>
|
|
#include <openssl/rsa.h>
|
|
|
|
EVP_PKEY_CTX *ctx;
|
|
/* md is a SHA-256 digest in this example. */
|
|
unsigned char *md, *sig;
|
|
size_t mdlen = 32, siglen;
|
|
EVP_PKEY *signing_key;
|
|
|
|
/*
|
|
* NB: assumes signing_key and md are set up before the next
|
|
* step. signing_key must be an RSA private key and md must
|
|
* point to the SHA-256 digest to be signed.
|
|
*/
|
|
ctx = EVP_PKEY_CTX_new(signing_key, NULL /* no engine */);
|
|
if (!ctx)
|
|
/* Error occurred */
|
|
if (EVP_PKEY_sign_init(ctx) <= 0)
|
|
/* Error */
|
|
if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) <= 0)
|
|
/* Error */
|
|
if (EVP_PKEY_CTX_set_signature_md(ctx, EVP_sha256()) <= 0)
|
|
/* Error */
|
|
|
|
/* Determine buffer length */
|
|
if (EVP_PKEY_sign(ctx, NULL, &siglen, md, mdlen) <= 0)
|
|
/* Error */
|
|
|
|
sig = OPENSSL_malloc(siglen);
|
|
|
|
if (!sig)
|
|
/* malloc failure */
|
|
|
|
if (EVP_PKEY_sign(ctx, sig, &siglen, md, mdlen) <= 0)
|
|
/* Error */
|
|
|
|
/* Signature is siglen bytes written to buffer sig */
|
|
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<EVP_PKEY_CTX_new(3)>,
|
|
L<EVP_PKEY_CTX_ctrl(3)>,
|
|
L<EVP_PKEY_encrypt(3)>,
|
|
L<EVP_PKEY_decrypt(3)>,
|
|
L<EVP_PKEY_verify(3)>,
|
|
L<EVP_PKEY_verify_recover(3)>,
|
|
L<EVP_PKEY_derive(3)>
|
|
|
|
=head1 HISTORY
|
|
|
|
These functions were added in OpenSSL 1.0.0.
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
Licensed under the Apache License 2.0 (the "License"). You may not use
|
|
this file except in compliance with the License. You can obtain a copy
|
|
in the file LICENSE in the source distribution or at
|
|
L<https://www.openssl.org/source/license.html>.
|
|
|
|
=cut
|