lib/krb5/salt-aes-sha2.c

   1 /*
   2  * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "krb5_locl.h"
  35
  36 const int _krb5_AES_SHA2_string_to_default_iterator = 32768;
  37
  38 static krb5_error_code
  39 AES_SHA2_string_to_key(krb5_context context,
  40                        krb5_enctype enctype,
  41                        krb5_data password,
  42                        krb5_salt salt,
  43                        krb5_data opaque,
  44                        krb5_keyblock *key)
  45 {
  46     krb5_error_code ret;
  47     uint32_t iter;
  48     struct _krb5_encryption_type *et = NULL;
  49     struct _krb5_key_data kd;
  50     krb5_data saltp;
  51     size_t enctypesz;
  52     const EVP_MD *md = NULL;
  53
  54     krb5_data_zero(&saltp);
  55     kd.key = NULL;
  56     kd.schedule = NULL;
  57
  58     if (opaque.length == 0) {
  59         iter = _krb5_AES_SHA2_string_to_default_iterator;
  60     } else if (opaque.length == 4) {
  61         unsigned long v;
  62         _krb5_get_int(opaque.data, &v, 4);
  63         iter = ((uint32_t)v);
  64     } else {
  65         ret = KRB5_PROG_KEYTYPE_NOSUPP; /* XXX */
  66         goto cleanup;
  67     }
  68
  69     et = _krb5_find_enctype(enctype);
  70     if (et == NULL) {
  71         ret = KRB5_PROG_KEYTYPE_NOSUPP;
  72         goto cleanup;
  73     }
  74
  75     kd.schedule = NULL;
  76     ALLOC(kd.key, 1);
  77     if (kd.key == NULL) {
  78         ret = krb5_enomem(context);
  79         goto cleanup;
  80     }
  81     kd.key->keytype = enctype;
  82     ret = krb5_data_alloc(&kd.key->keyvalue, et->keytype->size);
  83     if (ret) {
  84         ret = krb5_enomem(context);
  85         goto cleanup;
  86     }
  87
  88     enctypesz = strlen(et->name) + 1;
  89     ret = krb5_data_alloc(&saltp, enctypesz + salt.saltvalue.length);
  90     if (ret) {
  91         ret = krb5_enomem(context);
  92         goto cleanup;
  93     }
  94     memcpy(saltp.data, et->name, enctypesz);
  95     if (salt.saltvalue.length)
  96         memcpy((unsigned char *)saltp.data + enctypesz,
  97                salt.saltvalue.data, salt.saltvalue.length);
  98
  99     ret = _krb5_aes_sha2_md_for_enctype(context, enctype, &md);
 100     if (ret)
 101         goto cleanup;
 102
 103     ret = PKCS5_PBKDF2_HMAC(password.data, password.length,
 104                             saltp.data, saltp.length,
 105                             iter, md,
 106                             et->keytype->size, kd.key->keyvalue.data);
 107     if (ret != 1) {
 108         krb5_set_error_message(context, KRB5_PROG_KEYTYPE_NOSUPP,
 109                                "Error calculating s2k");
 110         ret = KRB5_PROG_KEYTYPE_NOSUPP;
 111         goto cleanup;
 112     }
 113
 114     ret = _krb5_derive_key(context, et, &kd, "kerberos", strlen("kerberos"));
 115     if (ret)
 116         goto cleanup;
 117
 118     ret = krb5_copy_keyblock_contents(context, kd.key, key);
 119     if (ret)
 120         goto cleanup;
 121
 122 cleanup:
 123     krb5_data_free(&saltp);
 124     _krb5_free_key_data(context, &kd, et);
 125
 126     return ret;
 127 }
 128
 129 struct salt_type _krb5_AES_SHA2_salt[] = {
 130     {
 131         KRB5_PW_SALT,
 132         "pw-salt",
 133         AES_SHA2_string_to_key
 134     },
 135     { 0, NULL, NULL }
 136 };