cscrypt/bn_ctx.c

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