| 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 | } |
| 143 | |
