openssl/crypto/evp/p_sign.c

/* crypto/evp/p_sign.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * 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 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 acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS 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 AUTHOR OR 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.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/evp.h>
#include <openssl/objects.h>
#include <openssl/x509.h>
#include "internal/evp_int.h"

int EVP_SignFinal(EVP_MD_CTX *ctx, unsigned char *sigret,
                  unsigned int *siglen, EVP_PKEY *pkey)
{
    unsigned char m[EVP_MAX_MD_SIZE];
    unsigned int m_len = 0;
    int i = 0;
    size_t sltmp;
    EVP_PKEY_CTX *pkctx = NULL;

    *siglen = 0;
    if (EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_FINALISE)) {
        if (!EVP_DigestFinal_ex(ctx, m, &m_len))
            goto err;
    } else {
        int rv = 0;
        EVP_MD_CTX *tmp_ctx = EVP_MD_CTX_create();
        if (tmp_ctx == NULL) {
            EVPerr(EVP_F_EVP_SIGNFINAL, ERR_R_MALLOC_FAILURE);
            return 0;
        }
        rv = EVP_MD_CTX_copy_ex(tmp_ctx, ctx);
        if (rv)
            rv = EVP_DigestFinal_ex(tmp_ctx, m, &m_len);
        EVP_MD_CTX_destroy(tmp_ctx);
        if (!rv)
            return 0;
    }

    sltmp = (size_t)EVP_PKEY_size(pkey);
    i = 0;
    pkctx = EVP_PKEY_CTX_new(pkey, NULL);
    if (pkctx == NULL)
        goto err;
    if (EVP_PKEY_sign_init(pkctx) <= 0)
        goto err;
    if (EVP_PKEY_CTX_set_signature_md(pkctx, EVP_MD_CTX_md(ctx)) <= 0)
        goto err;
    if (EVP_PKEY_sign(pkctx, sigret, &sltmp, m, m_len) <= 0)
        goto err;
    *siglen = sltmp;
    i = 1;
 err:
    EVP_PKEY_CTX_free(pkctx);
    return i;
}