OSX/libsecurity_apple_csp/open_ssl/bn/bn_mpi.c

   1 /*
   2  * Copyright (c) 2000-2001,2011,2014 Apple Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 /* crypto/bn/bn_mpi.c */
  20 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  21  * All rights reserved.
  22  *
  23  * This package is an SSL implementation written
  24  * by Eric Young (eay@cryptsoft.com).
  25  * The implementation was written so as to conform with Netscapes SSL.
  26  *
  27  * This library is free for commercial and non-commercial use as long as
  28  * the following conditions are aheared to.  The following conditions
  29  * apply to all code found in this distribution, be it the RC4, RSA,
  30  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  31  * included with this distribution is covered by the same copyright terms
  32  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  33  *
  34  * Copyright remains Eric Young's, and as such any Copyright notices in
  35  * the code are not to be removed.
  36  * If this package is used in a product, Eric Young should be given attribution
  37  * as the author of the parts of the library used.
  38  * This can be in the form of a textual message at program startup or
  39  * in documentation (online or textual) provided with the package.
  40  *
  41  * Redistribution and use in source and binary forms, with or without
  42  * modification, are permitted provided that the following conditions
  43  * are met:
  44  * 1. Redistributions of source code must retain the copyright
  45  *    notice, this list of conditions and the following disclaimer.
  46  * 2. Redistributions in binary form must reproduce the above copyright
  47  *    notice, this list of conditions and the following disclaimer in the
  48  *    documentation and/or other materials provided with the distribution.
  49  * 3. All advertising materials mentioning features or use of this software
  50  *    must display the following acknowledgement:
  51  *    "This product includes cryptographic software written by
  52  *     Eric Young (eay@cryptsoft.com)"
  53  *    The word 'cryptographic' can be left out if the rouines from the library
  54  *    being used are not cryptographic related :-).
  55  * 4. If you include any Windows specific code (or a derivative thereof) from
  56  *    the apps directory (application code) you must include an acknowledgement:
  57  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  58  *
  59  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  69  * SUCH DAMAGE.
  70  *
  71  * The licence and distribution terms for any publically available version or
  72  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  73  * copied and put under another distribution licence
  74  * [including the GNU Public Licence.]
  75  */
  76
  77 #include <stdio.h>
  78 #include "cryptlib.h"
  79 #include "bn_lcl.h"
  80
  81 int BN_bn2mpi(const BIGNUM *a, unsigned char *d)
  82         {
  83         int bits;
  84         int num=0;
  85         int ext=0;
  86         long l;
  87
  88         bits=BN_num_bits(a);
  89         num=(bits+7)/8;
  90         if (bits > 0)
  91                 {
  92                 ext=((bits & 0x07) == 0);
  93                 }
  94         if (d == NULL)
  95                 return(num+4+ext);
  96
  97         l=num+ext;
  98         d[0]=(unsigned char)(l>>24)&0xff;
  99         d[1]=(unsigned char)(l>>16)&0xff;
 100         d[2]=(unsigned char)(l>> 8)&0xff;
 101         d[3]=(unsigned char)(l    )&0xff;
 102         if (ext) d[4]=0;
 103         num=BN_bn2bin(a,&(d[4+ext]));
 104         if (a->neg)
 105                 d[4]|=0x80;
 106         return(num+4+ext);
 107         }
 108
 109 BIGNUM *BN_mpi2bn(unsigned char *d, int n, BIGNUM *a)
 110         {
 111         long len;
 112         int neg=0;
 113
 114         if (n < 4)
 115                 {
 116                 BNerr(BN_F_BN_MPI2BN,BN_R_INVALID_LENGTH);
 117                 return(NULL);
 118                 }
 119         len=((long)d[0]<<24)|((long)d[1]<<16)|((int)d[2]<<8)|(int)d[3];
 120         if ((len+4) != n)
 121                 {
 122                 BNerr(BN_F_BN_MPI2BN,BN_R_ENCODING_ERROR);
 123                 return(NULL);
 124                 }
 125
 126         if (a == NULL) a=BN_new();
 127         if (a == NULL) return(NULL);
 128
 129         if (len == 0)
 130                 {
 131                 a->neg=0;
 132                 a->top=0;
 133                 return(a);
 134                 }
 135         d+=4;
 136         if ((*d) & 0x80)
 137                 neg=1;
 138         if (BN_bin2bn(d,(int)len,a) == NULL)
 139                 return(NULL);
 140         a->neg=neg;
 141         if (neg)
 142                 {
 143                 BN_clear_bit(a,BN_num_bits(a)-1);
 144                 }
 145         return(a);
 146         }
 147