package/ead/src/tinysrp/bn_ctx.c

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