/*

 * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan

 * (Royal Institute of Technology, Stockholm, Sweden).

 * 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. Neither the name of the Institute nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE 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.

 */

#include "krb5_locl.h"

const int _krb5_AES_SHA2_string_to_default_iterator = 32768;

static krb5_error_code

AES_SHA2_string_to_key(krb5_context context,

           krb5_enctype enctype,

           krb5_data password,

           krb5_salt salt,

           krb5_data opaque,

           krb5_keyblock *key)

{

    krb5_error_code ret;

    uint32_t iter;

    struct _krb5_encryption_type *et = NULL;

    struct _krb5_key_data kd;

    krb5_data saltp;

    size_t enctypesz;

    const EVP_MD *md = NULL;

    krb5_data_zero(&saltp);

    kd.key = NULL;

    kd.schedule = NULL;

    if (opaque.length == 0) {

  iter = _krb5_AES_SHA2_string_to_default_iterator;

    } else if (opaque.length == 4) {

  unsigned long v;

  _krb5_get_int(opaque.data, &v, 4);

  iter = ((uint32_t)v);

    } else {

  ret = KRB5_PROG_KEYTYPE_NOSUPP; /* XXX */

  goto cleanup;

    }

    et = _krb5_find_enctype(enctype);

    if (et == NULL) {

  ret = KRB5_PROG_KEYTYPE_NOSUPP;

  goto cleanup;

    }

    kd.schedule = NULL;

    ALLOC(kd.key, 1);

    if (kd.key == NULL) {

  ret = krb5_enomem(context);

  goto cleanup;

    }

    kd.key->keytype = enctype;

    ret = krb5_data_alloc(&kd.key->keyvalue, et->keytype->size);

    if (ret) {

  ret = krb5_enomem(context);

  goto cleanup;

    }

    enctypesz = strlen(et->name) + 1;

    ret = krb5_data_alloc(&saltp, enctypesz + salt.saltvalue.length);

    if (ret) {

  ret = krb5_enomem(context);

  goto cleanup;

    }

    memcpy(saltp.data, et->name, enctypesz);

    if (salt.saltvalue.length)

        memcpy((unsigned char *)saltp.data + enctypesz,

               salt.saltvalue.data, salt.saltvalue.length);

    ret = _krb5_aes_sha2_md_for_enctype(context, enctype, &md);

    if (ret)

  goto cleanup;

    ret = PKCS5_PBKDF2_HMAC(password.data, password.length,

          saltp.data, saltp.length,

          iter, md,

          et->keytype->size, kd.key->keyvalue.data);

    if (ret != 1) {

  krb5_set_error_message(context, KRB5_PROG_KEYTYPE_NOSUPP,

             "Error calculating s2k");

  ret = KRB5_PROG_KEYTYPE_NOSUPP;

  goto cleanup;

    }

    ret = _krb5_derive_key(context, et, &kd, "kerberos", strlen("kerberos"));

    if (ret)

  goto cleanup;

    ret = krb5_copy_keyblock_contents(context, kd.key, key);

    if (ret)

  goto cleanup;

cleanup:

    krb5_data_free(&saltp);

    _krb5_free_key_data(context, &kd, et);

    return ret;

}

struct salt_type _krb5_AES_SHA2_salt[] = {

    {

  KRB5_PW_SALT,

  "pw-salt",

  AES_SHA2_string_to_key

    },

    { 0, NULL, NULL }

};