Merge commit 'dfc115332c94a2f62058ac7f2bce7631fbd20b3d'
[unleashed/tickless.git] / lib / libcrypto / bn / bn_mpi.c
blob4801192b50d722773fa14bb3a0305465182aa6a0
1 /* $OpenBSD: bn_mpi.c,v 1.8 2017/01/29 17:49:22 beck Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
59 #include <stdio.h>
61 #include <openssl/err.h>
63 #include "bn_lcl.h"
65 int
66 BN_bn2mpi(const BIGNUM *a, unsigned char *d)
68 int bits;
69 int num = 0;
70 int ext = 0;
71 long l;
73 bits = BN_num_bits(a);
74 num = (bits + 7) / 8;
75 if (bits > 0) {
76 ext = ((bits & 0x07) == 0);
78 if (d == NULL)
79 return (num + 4 + ext);
81 l = num + ext;
82 d[0] = (unsigned char)(l >> 24) & 0xff;
83 d[1] = (unsigned char)(l >> 16) & 0xff;
84 d[2] = (unsigned char)(l >> 8) & 0xff;
85 d[3] = (unsigned char)(l) & 0xff;
86 if (ext)
87 d[4] = 0;
88 num = BN_bn2bin(a, &(d[4 + ext]));
89 if (a->neg)
90 d[4] |= 0x80;
91 return (num + 4 + ext);
94 BIGNUM *
95 BN_mpi2bn(const unsigned char *d, int n, BIGNUM *a)
97 long len;
98 int neg = 0;
100 if (n < 4) {
101 BNerror(BN_R_INVALID_LENGTH);
102 return (NULL);
104 len = ((long)d[0] << 24) | ((long)d[1] << 16) | ((int)d[2] << 8) |
105 (int)d[3];
106 if ((len + 4) != n) {
107 BNerror(BN_R_ENCODING_ERROR);
108 return (NULL);
111 if (a == NULL)
112 a = BN_new();
113 if (a == NULL)
114 return (NULL);
116 if (len == 0) {
117 a->neg = 0;
118 a->top = 0;
119 return (a);
121 d += 4;
122 if ((*d) & 0x80)
123 neg = 1;
124 if (BN_bin2bn(d, (int)len, a) == NULL)
125 return (NULL);
126 a->neg = neg;
127 if (neg) {
128 BN_clear_bit(a, BN_num_bits(a) - 1);
130 bn_check_top(a);
131 return (a);