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
62int 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
84int 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
133int 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
153int 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
175int 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
186int BN_is_zero(const BIGNUM *bn) {
187  return bn->top == 0;
188}
189
190int BN_is_one(const BIGNUM *bn) {
191  return bn->neg == 0 && BN_abs_is_word(bn, 1);
192}
193
194int BN_is_word(const BIGNUM *bn, BN_ULONG w) {
195  return BN_abs_is_word(bn, w) && (w == 0 || bn->neg == 0);
196}
197
198int BN_is_odd(const BIGNUM *bn) {
199  return bn->top > 0 && (bn->d[0] & 1) == 1;
200}
201