1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
7 *
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.] */
56
57 #include <openssl/bn.h>
58
59 #include "internal.h"
60
61
BN_ucmp(const BIGNUM * a,const BIGNUM * b)62 int BN_ucmp(const BIGNUM *a, const BIGNUM *b) {
63 int i;
64 BN_ULONG t1, t2, *ap, *bp;
65
66 i = a->top - b->top;
67 if (i != 0) {
68 return i;
69 }
70
71 ap = a->d;
72 bp = b->d;
73 for (i = a->top - 1; i >= 0; i--) {
74 t1 = ap[i];
75 t2 = bp[i];
76 if (t1 != t2) {
77 return (t1 > t2) ? 1 : -1;
78 }
79 }
80
81 return 0;
82 }
83
BN_cmp(const BIGNUM * a,const BIGNUM * b)84 int BN_cmp(const BIGNUM *a, const BIGNUM *b) {
85 int i;
86 int gt, lt;
87 BN_ULONG t1, t2;
88
89 if ((a == NULL) || (b == NULL)) {
90 if (a != NULL) {
91 return -1;
92 } else if (b != NULL) {
93 return 1;
94 } else {
95 return 0;
96 }
97 }
98
99 if (a->neg != b->neg) {
100 if (a->neg) {
101 return -1;
102 }
103 return 1;
104 }
105 if (a->neg == 0) {
106 gt = 1;
107 lt = -1;
108 } else {
109 gt = -1;
110 lt = 1;
111 }
112
113 if (a->top > b->top) {
114 return gt;
115 }
116 if (a->top < b->top) {
117 return lt;
118 }
119
120 for (i = a->top - 1; i >= 0; i--) {
121 t1 = a->d[i];
122 t2 = b->d[i];
123 if (t1 > t2) {
124 return gt;
125 } if (t1 < t2) {
126 return lt;
127 }
128 }
129
130 return 0;
131 }
132
bn_cmp_words(const BN_ULONG * a,const BN_ULONG * b,int n)133 int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n) {
134 int i;
135 BN_ULONG aa, bb;
136
137 aa = a[n - 1];
138 bb = b[n - 1];
139 if (aa != bb) {
140 return (aa > bb) ? 1 : -1;
141 }
142
143 for (i = n - 2; i >= 0; i--) {
144 aa = a[i];
145 bb = b[i];
146 if (aa != bb) {
147 return (aa > bb) ? 1 : -1;
148 }
149 }
150 return 0;
151 }
152
bn_cmp_part_words(const BN_ULONG * a,const BN_ULONG * b,int cl,int dl)153 int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl) {
154 int n, i;
155 n = cl - 1;
156
157 if (dl < 0) {
158 for (i = dl; i < 0; i++) {
159 if (b[n - i] != 0) {
160 return -1; /* a < b */
161 }
162 }
163 }
164 if (dl > 0) {
165 for (i = dl; i > 0; i--) {
166 if (a[n + i] != 0) {
167 return 1; /* a > b */
168 }
169 }
170 }
171
172 return bn_cmp_words(a, b, cl);
173 }
174
BN_abs_is_word(const BIGNUM * bn,BN_ULONG w)175 int BN_abs_is_word(const BIGNUM *bn, BN_ULONG w) {
176 switch (bn->top) {
177 case 1:
178 return bn->d[0] == w;
179 case 0:
180 return w == 0;
181 default:
182 return 0;
183 }
184 }
185
BN_is_zero(const BIGNUM * bn)186 int BN_is_zero(const BIGNUM *bn) {
187 return bn->top == 0;
188 }
189
BN_is_one(const BIGNUM * bn)190 int BN_is_one(const BIGNUM *bn) {
191 return bn->neg == 0 && BN_abs_is_word(bn, 1);
192 }
193
BN_is_word(const BIGNUM * bn,BN_ULONG w)194 int BN_is_word(const BIGNUM *bn, BN_ULONG w) {
195 return BN_abs_is_word(bn, w) && (w == 0 || bn->neg == 0);
196 }
197
BN_is_odd(const BIGNUM * bn)198 int BN_is_odd(const BIGNUM *bn) {
199 return bn->top > 0 && (bn->d[0] & 1) == 1;
200 }
201