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/* $OpenBSD: bn_mpi.c,v 1.8 2017/01/29 17:49:22 beck Exp $ */ |
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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
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* All rights reserved. |
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* |
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* This package is an SSL implementation written |
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* by Eric Young (eay@cryptsoft.com). |
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* The implementation was written so as to conform with Netscapes SSL. |
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* |
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* This library is free for commercial and non-commercial use as long as |
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* the following conditions are aheared to. The following conditions |
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* apply to all code found in this distribution, be it the RC4, RSA, |
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* lhash, DES, etc., code; not just the SSL code. The SSL documentation |
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* included with this distribution is covered by the same copyright terms |
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* except that the holder is Tim Hudson (tjh@cryptsoft.com). |
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* |
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* Copyright remains Eric Young's, and as such any Copyright notices in |
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* the code are not to be removed. |
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* If this package is used in a product, Eric Young should be given attribution |
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* as the author of the parts of the library used. |
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* This can be in the form of a textual message at program startup or |
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* in documentation (online or textual) provided with the package. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. All advertising materials mentioning features or use of this software |
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* must display the following acknowledgement: |
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* "This product includes cryptographic software written by |
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* Eric Young (eay@cryptsoft.com)" |
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* The word 'cryptographic' can be left out if the rouines from the library |
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* being used are not cryptographic related :-). |
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* 4. If you include any Windows specific code (or a derivative thereof) from |
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* the apps directory (application code) you must include an acknowledgement: |
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* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
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* |
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* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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* |
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* The licence and distribution terms for any publically available version or |
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* derivative of this code cannot be changed. i.e. this code cannot simply be |
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* copied and put under another distribution licence |
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* [including the GNU Public Licence.] |
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*/ |
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#include <stdio.h> |
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#include <openssl/err.h> |
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#include "bn_lcl.h" |
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int |
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BN_bn2mpi(const BIGNUM *a, unsigned char *d) |
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{ |
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int bits; |
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int num = 0; |
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int ext = 0; |
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long l; |
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bits = BN_num_bits(a); |
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num = (bits + 7) / 8; |
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if (bits > 0) { |
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ext = ((bits & 0x07) == 0); |
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} |
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if (d == NULL) |
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return (num + 4 + ext); |
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l = num + ext; |
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d[0] = (unsigned char)(l >> 24) & 0xff; |
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d[1] = (unsigned char)(l >> 16) & 0xff; |
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d[2] = (unsigned char)(l >> 8) & 0xff; |
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d[3] = (unsigned char)(l) & 0xff; |
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if (ext) |
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d[4] = 0; |
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num = BN_bn2bin(a, &(d[4 + ext])); |
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if (a->neg) |
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d[4] |= 0x80; |
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return (num + 4 + ext); |
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} |
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BIGNUM * |
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BN_mpi2bn(const unsigned char *d, int n, BIGNUM *a) |
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{ |
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long len; |
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int neg = 0; |
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if (n < 4) { |
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BNerror(BN_R_INVALID_LENGTH); |
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return (NULL); |
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} |
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len = ((long)d[0] << 24) | ((long)d[1] << 16) | ((int)d[2] << 8) | |
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(int)d[3]; |
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if ((len + 4) != n) { |
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BNerror(BN_R_ENCODING_ERROR); |
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return (NULL); |
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} |
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if (a == NULL) |
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a = BN_new(); |
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if (a == NULL) |
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return (NULL); |
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if (len == 0) { |
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a->neg = 0; |
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a->top = 0; |
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return (a); |
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} |
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d += 4; |
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if ((*d) & 0x80) |
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neg = 1; |
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if (BN_bin2bn(d, (int)len, a) == NULL) |
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return (NULL); |
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a->neg = neg; |
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if (neg) { |
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BN_clear_bit(a, BN_num_bits(a) - 1); |
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} |
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bn_check_top(a); |
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return (a); |
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} |