OSX/libsecurity_apple_csp/open_ssl/bn/bn_ctx.c

   1 /*
   2  * Copyright (c) 2000-2001,2011,2014 Apple Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 /* crypto/bn/bn_ctx.c */
  20 /* Written by Ulf Moeller for the OpenSSL project. */
  21 /* ====================================================================
  22  * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
  23  *
  24  * Redistribution and use in source and binary forms, with or without
  25  * modification, are permitted provided that the following conditions
  26  * are met:
  27  *
  28  * 1. Redistributions of source code must retain the above copyright
  29  *    notice, this list of conditions and the following disclaimer.
  30  *
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in
  33  *    the documentation and/or other materials provided with the
  34  *    distribution.
  35  *
  36  * 3. All advertising materials mentioning features or use of this
  37  *    software must display the following acknowledgment:
  38  *    "This product includes software developed by the OpenSSL Project
  39  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  40  *
  41  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  42  *    endorse or promote products derived from this software without
  43  *    prior written permission. For written permission, please contact
  44  *    openssl-core@openssl.org.
  45  *
  46  * 5. Products derived from this software may not be called "OpenSSL"
  47  *    nor may "OpenSSL" appear in their names without prior written
  48  *    permission of the OpenSSL Project.
  49  *
  50  * 6. Redistributions of any form whatsoever must retain the following
  51  *    acknowledgment:
  52  *    "This product includes software developed by the OpenSSL Project
  53  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  54  *
  55  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  56  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  58  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  59  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  60  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  61  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  62  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  64  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  65  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  66  * OF THE POSSIBILITY OF SUCH DAMAGE.
  67  * ====================================================================
  68  *
  69  * This product includes cryptographic software written by Eric Young
  70  * (eay@cryptsoft.com).  This product includes software written by Tim
  71  * Hudson (tjh@cryptsoft.com).
  72  *
  73  */
  74
  75 #ifndef BN_CTX_DEBUG
  76 # undef NDEBUG /* avoid conflicting definitions */
  77 # define NDEBUG
  78 #endif
  79
  80 #include <stdio.h>
  81 #include <assert.h>
  82 #include "cryptlib.h"
  83 #include <openssl/bn.h>
  84
  85
  86 BN_CTX *BN_CTX_new(void)
  87         {
  88         BN_CTX *ret;
  89
  90         ret=(BN_CTX *)Malloc(sizeof(BN_CTX));
  91         if (ret == NULL)
  92                 {
  93                 BNerr(BN_F_BN_CTX_NEW,ERR_R_MALLOC_FAILURE);
  94                 return(NULL);
  95                 }
  96
  97         BN_CTX_init(ret);
  98         ret->flags=BN_FLG_MALLOCED;
  99         return(ret);
 100         }
 101
 102 void BN_CTX_init(BN_CTX *ctx)
 103         {
 104         int i;
 105         ctx->tos = 0;
 106         ctx->flags = 0;
 107         ctx->depth = 0;
 108         ctx->too_many = 0;
 109         for (i = 0; i < BN_CTX_NUM; i++)
 110                 BN_init(&(ctx->bn[i]));
 111         }
 112
 113 void BN_CTX_free(BN_CTX *ctx)
 114         {
 115         int i;
 116
 117         if (ctx == NULL) return;
 118         assert(ctx->depth == 0);
 119
 120         for (i=0; i < BN_CTX_NUM; i++)
 121                 BN_clear_free(&(ctx->bn[i]));
 122         if (ctx->flags & BN_FLG_MALLOCED)
 123                 Free(ctx);
 124         }
 125
 126 void BN_CTX_start(BN_CTX *ctx)
 127         {
 128         if (ctx->depth < BN_CTX_NUM_POS)
 129                 ctx->pos[ctx->depth] = ctx->tos;
 130         ctx->depth++;
 131         }
 132
 133 BIGNUM *BN_CTX_get(BN_CTX *ctx)
 134         {
 135         if (ctx->depth > BN_CTX_NUM_POS || ctx->tos >= BN_CTX_NUM)
 136                 {
 137                 if (!ctx->too_many)
 138                         {
 139                         BNerr(BN_F_BN_CTX_GET,BN_R_TOO_MANY_TEMPORARY_VARIABLES);
 140                         /* disable error code until BN_CTX_end is called: */
 141                         ctx->too_many = 1;
 142                         }
 143                 return NULL;
 144                 }
 145         return (&(ctx->bn[ctx->tos++]));
 146         }
 147
 148 void BN_CTX_end(BN_CTX *ctx)
 149         {
 150         if (ctx == NULL) return;
 151         assert(ctx->depth > 0);
 152         if (ctx->depth == 0)
 153                 /* should never happen, but we can tolerate it if not in
 154                  * debug mode (could be a 'goto err' in the calling function
 155                  * before BN_CTX_start was reached) */
 156                 BN_CTX_start(ctx);
 157
 158         ctx->too_many = 0;
 159         ctx->depth--;
 160         if (ctx->depth < BN_CTX_NUM_POS)
 161                 ctx->tos = ctx->pos[ctx->depth];
 162         }