sec_negotiate_openssl.h

/* FreeTDS - Library of routines accessing Sybase and Microsoft databases
 * Copyright (C) 2015  Frediano Ziglio
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
 
#include <openssl/rand.h>
#include <openssl/bio.h>
#include <openssl/pem.h>
#include <openssl/err.h>
 
#ifndef HAVE_OPENSSL
#error HAVE_OPENSSL not defines, this file should not be included
#endif
 
static inline const BIGNUM*
rsa_get_n(const RSA *rsa)
{
#if HAVE_RSA_GET0_KEY
    const BIGNUM *n, *e, *d;
    RSA_get0_key(rsa, &n, &e, &d);
    return n;
#else
    return rsa->n;
#endif
}
 
static void*
tds5_rsa_encrypt(const void *key, size_t key_len, const void *nonce, size_t nonce_len, const char *pwd, size_t *em_size)
{
    RSA *rsa = NULL;
    BIO *keybio;
 
    uint8_t *message = NULL;
    size_t message_len, pwd_len;
    uint8_t *em = NULL;
 
    int result;
 
    keybio = BIO_new_mem_buf((void*) key, key_len);
    if (keybio == NULL)
        goto error;
 
    rsa = PEM_read_bio_RSAPublicKey(keybio, &rsa, NULL, NULL);
    if (!rsa)
        goto error;
 
    pwd_len = strlen(pwd);
    message_len = nonce_len + pwd_len;
    message = tds_new(uint8_t, message_len);
    if (!message)
        goto error;
    memcpy(message, nonce, nonce_len);
    memcpy(message + nonce_len, pwd, pwd_len);
 
    em = tds_new(uint8_t, BN_num_bytes(rsa_get_n(rsa)));
    if (!em)
        goto error;
 
    result = RSA_public_encrypt(message_len, message, em, rsa, RSA_PKCS1_OAEP_PADDING);
    if (result < 0)
        goto error;
 
    free(message);
    RSA_free(rsa);
    BIO_free(keybio);
 
    *em_size = result;
    return em;
 
error:
    free(message);
    free(em);
    RSA_free(rsa);
    BIO_free(keybio);
    return NULL;
}