]>
Commit | Line | Data |
---|---|---|
58964a49 | 1 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
d02b48c6 RE |
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. | |
0f113f3e | 7 | * |
d02b48c6 RE |
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). | |
0f113f3e | 14 | * |
d02b48c6 RE |
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. | |
0f113f3e | 21 | * |
d02b48c6 RE |
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 :-). | |
0f113f3e | 36 | * 4. If you include any Windows specific code (or a derivative thereof) from |
d02b48c6 RE |
37 | * the apps directory (application code) you must include an acknowledgement: |
38 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
0f113f3e | 39 | * |
d02b48c6 RE |
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. | |
0f113f3e | 51 | * |
d02b48c6 RE |
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 | ||
b39fc560 | 58 | #include "internal/cryptlib.h" |
d02b48c6 RE |
59 | #include "bn_lcl.h" |
60 | ||
020fc820 | 61 | int BN_lshift1(BIGNUM *r, const BIGNUM *a) |
0f113f3e MC |
62 | { |
63 | register BN_ULONG *ap, *rp, t, c; | |
64 | int i; | |
d02b48c6 | 65 | |
0f113f3e MC |
66 | bn_check_top(r); |
67 | bn_check_top(a); | |
18f62d4b | 68 | |
0f113f3e MC |
69 | if (r != a) { |
70 | r->neg = a->neg; | |
71 | if (bn_wexpand(r, a->top + 1) == NULL) | |
72 | return (0); | |
73 | r->top = a->top; | |
74 | } else { | |
75 | if (bn_wexpand(r, a->top + 1) == NULL) | |
76 | return (0); | |
77 | } | |
78 | ap = a->d; | |
79 | rp = r->d; | |
80 | c = 0; | |
81 | for (i = 0; i < a->top; i++) { | |
82 | t = *(ap++); | |
83 | *(rp++) = ((t << 1) | c) & BN_MASK2; | |
84 | c = (t & BN_TBIT) ? 1 : 0; | |
85 | } | |
86 | if (c) { | |
87 | *rp = 1; | |
88 | r->top++; | |
89 | } | |
90 | bn_check_top(r); | |
91 | return (1); | |
92 | } | |
d02b48c6 | 93 | |
020fc820 | 94 | int BN_rshift1(BIGNUM *r, const BIGNUM *a) |
0f113f3e MC |
95 | { |
96 | BN_ULONG *ap, *rp, t, c; | |
97 | int i, j; | |
d02b48c6 | 98 | |
0f113f3e MC |
99 | bn_check_top(r); |
100 | bn_check_top(a); | |
18f62d4b | 101 | |
0f113f3e MC |
102 | if (BN_is_zero(a)) { |
103 | BN_zero(r); | |
104 | return (1); | |
105 | } | |
106 | i = a->top; | |
107 | ap = a->d; | |
108 | j = i - (ap[i - 1] == 1); | |
109 | if (a != r) { | |
110 | if (bn_wexpand(r, j) == NULL) | |
111 | return (0); | |
112 | r->neg = a->neg; | |
113 | } | |
114 | rp = r->d; | |
115 | t = ap[--i]; | |
116 | c = (t & 1) ? BN_TBIT : 0; | |
117 | if (t >>= 1) | |
118 | rp[i] = t; | |
119 | while (i > 0) { | |
120 | t = ap[--i]; | |
121 | rp[i] = ((t >> 1) & BN_MASK2) | c; | |
122 | c = (t & 1) ? BN_TBIT : 0; | |
123 | } | |
124 | r->top = j; | |
125 | bn_check_top(r); | |
126 | return (1); | |
127 | } | |
d02b48c6 | 128 | |
84c15db5 | 129 | int BN_lshift(BIGNUM *r, const BIGNUM *a, int n) |
0f113f3e MC |
130 | { |
131 | int i, nw, lb, rb; | |
132 | BN_ULONG *t, *f; | |
133 | BN_ULONG l; | |
d02b48c6 | 134 | |
0f113f3e MC |
135 | bn_check_top(r); |
136 | bn_check_top(a); | |
18f62d4b | 137 | |
7cc18d81 MC |
138 | if (n < 0) { |
139 | BNerr(BN_F_BN_LSHIFT, BN_R_INVALID_SHIFT); | |
140 | return 0; | |
141 | } | |
142 | ||
0f113f3e MC |
143 | r->neg = a->neg; |
144 | nw = n / BN_BITS2; | |
145 | if (bn_wexpand(r, a->top + nw + 1) == NULL) | |
146 | return (0); | |
147 | lb = n % BN_BITS2; | |
148 | rb = BN_BITS2 - lb; | |
149 | f = a->d; | |
150 | t = r->d; | |
151 | t[a->top + nw] = 0; | |
152 | if (lb == 0) | |
153 | for (i = a->top - 1; i >= 0; i--) | |
154 | t[nw + i] = f[i]; | |
155 | else | |
156 | for (i = a->top - 1; i >= 0; i--) { | |
157 | l = f[i]; | |
158 | t[nw + i + 1] |= (l >> rb) & BN_MASK2; | |
159 | t[nw + i] = (l << lb) & BN_MASK2; | |
160 | } | |
16f8d4eb | 161 | memset(t, 0, sizeof(*t) * nw); |
0f113f3e MC |
162 | r->top = a->top + nw + 1; |
163 | bn_correct_top(r); | |
164 | bn_check_top(r); | |
165 | return (1); | |
166 | } | |
d02b48c6 | 167 | |
020fc820 | 168 | int BN_rshift(BIGNUM *r, const BIGNUM *a, int n) |
0f113f3e MC |
169 | { |
170 | int i, j, nw, lb, rb; | |
171 | BN_ULONG *t, *f; | |
172 | BN_ULONG l, tmp; | |
d02b48c6 | 173 | |
0f113f3e MC |
174 | bn_check_top(r); |
175 | bn_check_top(a); | |
18f62d4b | 176 | |
7cc18d81 MC |
177 | if (n < 0) { |
178 | BNerr(BN_F_BN_RSHIFT, BN_R_INVALID_SHIFT); | |
179 | return 0; | |
180 | } | |
181 | ||
0f113f3e MC |
182 | nw = n / BN_BITS2; |
183 | rb = n % BN_BITS2; | |
184 | lb = BN_BITS2 - rb; | |
185 | if (nw >= a->top || a->top == 0) { | |
186 | BN_zero(r); | |
187 | return (1); | |
188 | } | |
189 | i = (BN_num_bits(a) - n + (BN_BITS2 - 1)) / BN_BITS2; | |
190 | if (r != a) { | |
191 | r->neg = a->neg; | |
192 | if (bn_wexpand(r, i) == NULL) | |
193 | return (0); | |
194 | } else { | |
195 | if (n == 0) | |
196 | return 1; /* or the copying loop will go berserk */ | |
197 | } | |
d02b48c6 | 198 | |
0f113f3e MC |
199 | f = &(a->d[nw]); |
200 | t = r->d; | |
201 | j = a->top - nw; | |
202 | r->top = i; | |
d02b48c6 | 203 | |
0f113f3e MC |
204 | if (rb == 0) { |
205 | for (i = j; i != 0; i--) | |
206 | *(t++) = *(f++); | |
207 | } else { | |
208 | l = *(f++); | |
209 | for (i = j - 1; i != 0; i--) { | |
210 | tmp = (l >> rb) & BN_MASK2; | |
211 | l = *(f++); | |
212 | *(t++) = (tmp | (l << lb)) & BN_MASK2; | |
213 | } | |
214 | if ((l = (l >> rb) & BN_MASK2)) | |
215 | *(t) = l; | |
216 | } | |
217 | bn_check_top(r); | |
218 | return (1); | |
219 | } |