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
|
/**
* @file gmp_helper.c
*
* @brief Class with helper functions for gmp operations
*
*/
/*
* Copyright (C) 2005 Jan Hutter, Martin Willi
* Hochschule fuer Technik Rapperswil
*
* This program 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. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* This program 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.
*/
#include "gmp_helper.h"
#include "allocator.h"
#include "randomizer.h"
/**
* Private data of an gmp_helper_t object.
*
*/
typedef struct private_gmp_helper_s private_gmp_helper_t;
struct private_gmp_helper_s {
/**
* public gmp_helper_t interface
*/
gmp_helper_t public;
};
/**
* Implements private_gmp_helper_t's chunk_to_mpz function.
* See #private_gmp_helper_t.chunk_to_mpz for description.
*/
static void chunk_to_mpz(private_gmp_helper_t *this, mpz_t *mpz_value, chunk_t data)
{
size_t i;
mpz_init_set_ui(*(mpz_value), 0);
for (i = 0; i < data.len; i++)
{
mpz_mul_ui(*(mpz_value),*(mpz_value), 1 << 8);
mpz_add_ui(*(mpz_value),*(mpz_value), data.ptr[i]);
}
}
/**
* Implements private_gmp_helper_t's mpz_to_chunk function.
* See #private_gmp_helper_t.mpz_to_chunk for description.
*/
static status_t mpz_to_chunk (private_gmp_helper_t *this,mpz_t *mpz_value, chunk_t *data,size_t bytes)
{
mpz_t temp1, temp2;
status_t status = SUCCESS;
int i;
data->len = bytes;
data->ptr = allocator_alloc(data->len);
if (data->ptr == NULL)
{
return OUT_OF_RES;
}
/* free memory */
memset(data->ptr,0,data->len);
mpz_init(temp1);
mpz_init(temp2);
mpz_set(temp1, *mpz_value);
for (i = data->len-1; i >= 0; i--)
{
data->ptr[i] = mpz_mdivmod_ui(temp2, NULL, temp1, 1 << 8);
mpz_set(temp1, temp2);
}
if (mpz_sgn(temp1) != 0)
{
status = FAILED;
}
mpz_clear(temp1);
mpz_clear(temp2);
return status;
}
/**
* Implements gmp_helper_t's init_prime function.
* See #gmp_helper_t.init_prime for description.
*/
static status_t init_prime (private_gmp_helper_t *this, mpz_t *prime, int bytes)
{
randomizer_t *randomizer;
chunk_t random_bytes;
status_t status;
randomizer = randomizer_create();
if (randomizer == NULL)
{
return OUT_OF_RES;
}
status = randomizer->allocate_random_bytes(randomizer,bytes, &random_bytes);
/* not needed anymore */
randomizer->destroy(randomizer);
if (status != SUCCESS)
{
return status;
}
/* convert chunk to mpz value */
this->public.chunk_to_mpz(&(this->public),prime, random_bytes);
/* chunk is not used anymore */
allocator_free(random_bytes.ptr);
random_bytes.ptr = NULL;
mpz_nextprime (*(prime),*(prime));
return SUCCESS;
}
/**
* Implements gmp_helper_t's destroy function.
* See #gmp_helper_t.destroy for description.
*/
static status_t destroy(private_gmp_helper_t *this)
{
allocator_free(this);
return SUCCESS;
}
/*
* Described in header
*/
gmp_helper_t *gmp_helper_create()
{
private_gmp_helper_t *this = allocator_alloc_thing(private_gmp_helper_t);
if ((this == NULL))
{
return NULL;
}
/* public functions */
this->public.destroy = (status_t (*)(gmp_helper_t *)) destroy;
this->public.init_prime = (status_t (*) (gmp_helper_t *, mpz_t *, int)) init_prime;
/* private functions */
this->public.chunk_to_mpz = (void (*) (gmp_helper_t *,mpz_t *, chunk_t )) chunk_to_mpz;
this->public.mpz_to_chunk = (status_t (*) (gmp_helper_t *,mpz_t *, chunk_t *,size_t )) mpz_to_chunk;
return &(this->public);
}
|
