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
|
#include <tommath_private.h>
#ifdef BN_MP_IMPORT_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
* LibTomMath is a library that provides multiple-precision
* integer arithmetic as well as number theoretic functionality.
*
* The library was designed directly after the MPI library by
* Michael Fromberger but has been written from scratch with
* additional optimizations in place.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tstdenis82@gmail.com, http://libtom.org
*/
/* based on gmp's mpz_import.
* see http://gmplib.org/manual/Integer-Import-and-Export.html
*/
int mp_import(mp_int* rop, size_t count, int order, size_t size,
int endian, size_t nails, const void* op) {
int result;
size_t odd_nails, nail_bytes, i, j;
unsigned char odd_nail_mask;
mp_zero(rop);
if (endian == 0) {
union {
unsigned int i;
char c[4];
} lint;
lint.i = 0x01020304;
endian = (lint.c[0] == 4) ? -1 : 1;
}
odd_nails = (nails % 8);
odd_nail_mask = 0xff;
for (i = 0; i < odd_nails; ++i) {
odd_nail_mask ^= (1 << (7 - i));
}
nail_bytes = nails / 8;
for (i = 0; i < count; ++i) {
for (j = 0; j < (size - nail_bytes); ++j) {
unsigned char byte = *(
(unsigned char*)op +
(((order == 1) ? i : ((count - 1) - i)) * size) +
((endian == 1) ? (j + nail_bytes) : (((size - 1) - j) - nail_bytes))
);
if (
(result = mp_mul_2d(rop, ((j == 0) ? (8 - odd_nails) : 8), rop)) != MP_OKAY) {
return result;
}
rop->dp[0] |= (j == 0) ? (byte & odd_nail_mask) : byte;
rop->used += 1;
}
}
mp_clamp(rop);
return MP_OKAY;
}
#endif
/* $Source$ */
/* $Revision$ */
/* $Date$ */
|
