summaryrefslogtreecommitdiff
path: root/lib/mpi/mpiutil.c
blob: eefc55d6b7f5b8a732992c070d5bca4bac65c374 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
/* mpiutil.ac  -  Utility functions for MPI
 * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * GnuPG is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * GnuPG is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include "mpi-internal.h"

/****************
 * Note:  It was a bad idea to use the number of limbs to allocate
 *	  because on a alpha the limbs are large but we normally need
 *	  integers of n bits - So we should chnage this to bits (or bytes).
 *
 *	  But mpi_alloc is used in a lot of places :-)
 */
MPI mpi_alloc(unsigned nlimbs)
{
	MPI a;

	a = kmalloc(sizeof *a, GFP_KERNEL);
	if (!a)
		return a;

	if (nlimbs) {
		a->d = mpi_alloc_limb_space(nlimbs);
		if (!a->d) {
			kfree(a);
			return NULL;
		}
	} else {
		a->d = NULL;
	}

	a->alloced = nlimbs;
	a->nlimbs = 0;
	a->sign = 0;
	a->flags = 0;
	a->nbits = 0;
	return a;
}
EXPORT_SYMBOL_GPL(mpi_alloc);

mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs)
{
	size_t len = nlimbs * sizeof(mpi_limb_t);

	return kmalloc(len, GFP_KERNEL);
}

void mpi_free_limb_space(mpi_ptr_t a)
{
	if (!a)
		return;

	kfree(a);
}

void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
{
	mpi_free_limb_space(a->d);
	a->d = ap;
	a->alloced = nlimbs;
}

/****************
 * Resize the array of A to NLIMBS. the additional space is cleared
 * (set to 0) [done by m_realloc()]
 */
int mpi_resize(MPI a, unsigned nlimbs)
{
	void *p;

	if (nlimbs <= a->alloced)
		return 0;	/* no need to do it */

	if (a->d) {
		p = kmalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
		if (!p)
			return -ENOMEM;
		memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
		kfree(a->d);
		a->d = p;
	} else {
		a->d = kzalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
		if (!a->d)
			return -ENOMEM;
	}
	a->alloced = nlimbs;
	return 0;
}

void mpi_clear(MPI a)
{
	a->nlimbs = 0;
	a->nbits = 0;
	a->flags = 0;
}

void mpi_free(MPI a)
{
	if (!a)
		return;

	if (a->flags & 4)
		kfree(a->d);
	else
		mpi_free_limb_space(a->d);

	if (a->flags & ~7)
		pr_info("invalid flag value in mpi\n");
	kfree(a);
}
EXPORT_SYMBOL_GPL(mpi_free);

/****************
 * Note: This copy function should not interpret the MPI
 *	 but copy it transparently.
 */
int mpi_copy(MPI *copied, const MPI a)
{
	size_t i;
	MPI b;

	*copied = MPI_NULL;

	if (a) {
		b = mpi_alloc(a->nlimbs);
		if (!b)
			return -ENOMEM;

		b->nlimbs = a->nlimbs;
		b->sign = a->sign;
		b->flags = a->flags;
		b->nbits = a->nbits;

		for (i = 0; i < b->nlimbs; i++)
			b->d[i] = a->d[i];

		*copied = b;
	}

	return 0;
}

int mpi_set(MPI w, const MPI u)
{
	mpi_ptr_t wp, up;
	mpi_size_t usize = u->nlimbs;
	int usign = u->sign;

	if (RESIZE_IF_NEEDED(w, (size_t) usize) < 0)
		return -ENOMEM;

	wp = w->d;
	up = u->d;
	MPN_COPY(wp, up, usize);
	w->nlimbs = usize;
	w->nbits = u->nbits;
	w->flags = u->flags;
	w->sign = usign;
	return 0;
}

int mpi_set_ui(MPI w, unsigned long u)
{
	if (RESIZE_IF_NEEDED(w, 1) < 0)
		return -ENOMEM;
	w->d[0] = u;
	w->nlimbs = u ? 1 : 0;
	w->sign = 0;
	w->nbits = 0;
	w->flags = 0;
	return 0;
}

MPI mpi_alloc_set_ui(unsigned long u)
{
	MPI w = mpi_alloc(1);
	if (!w)
		return w;
	w->d[0] = u;
	w->nlimbs = u ? 1 : 0;
	w->sign = 0;
	return w;
}

void mpi_swap(MPI a, MPI b)
{
	struct gcry_mpi tmp;

	tmp = *a;
	*a = *b;
	*b = tmp;
}