source: trunk/cscrypt/bn_ctx.c@ 8

Last change on this file since 8 was 8, checked in by smurzch2, 12 years ago

Start repository for OSCam (Open Source Cam)

The start is from the MpCS source code. Thanks a lot to the authors for this
great sources.

File size: 4.2 KB
Line 
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 <assert.h>
64#include "bn.h"
65#include "openssl_mods.h"
66
67BN_CTX *BN_CTX_new(void)
68 {
69 BN_CTX *ret;
70
71 ret=(BN_CTX *)OPENSSL_malloc(sizeof(BN_CTX));
72 if (ret == NULL)
73 {
74 return(NULL);
75 }
76
77 BN_CTX_init(ret);
78 ret->flags=BN_FLG_MALLOCED;
79 return(ret);
80 }
81
82void BN_CTX_init(BN_CTX *ctx)
83 {
84 int i;
85 ctx->tos = 0;
86 ctx->flags = 0;
87 ctx->depth = 0;
88 ctx->too_many = 0;
89 for (i = 0; i < BN_CTX_NUM; i++)
90 BN_init(&(ctx->bn[i]));
91 }
92
93void BN_CTX_free(BN_CTX *ctx)
94 {
95 int i;
96
97 if (ctx == NULL) return;
98 assert(ctx->depth == 0);
99
100 for (i=0; i < BN_CTX_NUM; i++)
101 BN_clear_free(&(ctx->bn[i]));
102 if (ctx->flags & BN_FLG_MALLOCED)
103 OPENSSL_free(ctx);
104 }
105
106void BN_CTX_start(BN_CTX *ctx)
107 {
108 if (ctx->depth < BN_CTX_NUM_POS)
109 ctx->pos[ctx->depth] = ctx->tos;
110 ctx->depth++;
111 }
112
113BIGNUM *BN_CTX_get(BN_CTX *ctx)
114 {
115 if (ctx->depth > BN_CTX_NUM_POS || ctx->tos >= BN_CTX_NUM)
116 {
117 if (!ctx->too_many)
118 {
119 /* disable error code until BN_CTX_end is called: */
120 ctx->too_many = 1;
121 }
122 return NULL;
123 }
124 return (&(ctx->bn[ctx->tos++]));
125 }
126
127void BN_CTX_end(BN_CTX *ctx)
128 {
129 if (ctx == NULL) return;
130 assert(ctx->depth > 0);
131 if (ctx->depth == 0)
132 /* should never happen, but we can tolerate it if not in
133 * debug mode (could be a 'goto err' in the calling function
134 * before BN_CTX_start was reached) */
135 BN_CTX_start(ctx);
136
137 ctx->too_many = 0;
138 ctx->depth--;
139 if (ctx->depth < BN_CTX_NUM_POS)
140 ctx->tos = ctx->pos[ctx->depth];
141 }
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