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
81int 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
109BIGNUM *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
148