Skip to content
Newer
Older
100644 56 lines (49 sloc) 1.26 KB
e549ccf added libtommath-0.32
Tom St Denis authored
1 #include <tommath.h>
2 #ifdef BN_MP_READ_UNSIGNED_BIN_C
57354e1 added libtommath-0.12
Tom St Denis authored
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
4 *
c1da6aa added libtommath-0.25
Tom St Denis authored
5 * LibTomMath is a library that provides multiple-precision
57354e1 added libtommath-0.12
Tom St Denis authored
6 * integer arithmetic as well as number theoretic functionality.
7 *
c1da6aa added libtommath-0.25
Tom St Denis authored
8 * The library was designed directly after the MPI library by
57354e1 added libtommath-0.12
Tom St Denis authored
9 * Michael Fromberger but has been written from scratch with
10 * additional optimizations in place.
11 *
12 * The library is free for all purposes without any express
13 * guarantee it works.
14 *
333aebc added libtommath-0.41
Tom St Denis authored
15 * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
57354e1 added libtommath-0.12
Tom St Denis authored
16 */
17
18 /* reads a unsigned char array, assumes the msb is stored first [big endian] */
9294e79 added libtommath-0.36
Tom St Denis authored
19 int mp_read_unsigned_bin (mp_int * a, const unsigned char *b, int c)
57354e1 added libtommath-0.12
Tom St Denis authored
20 {
b66471f added libtommath-0.13
Tom St Denis authored
21 int res;
6e73234 added libtommath-0.26
Tom St Denis authored
22
23 /* make sure there are at least two digits */
24 if (a->alloc < 2) {
25 if ((res = mp_grow(a, 2)) != MP_OKAY) {
26 return res;
27 }
28 }
29
30 /* zero the int */
57354e1 added libtommath-0.12
Tom St Denis authored
31 mp_zero (a);
6e73234 added libtommath-0.26
Tom St Denis authored
32
33 /* read the bytes in */
57354e1 added libtommath-0.12
Tom St Denis authored
34 while (c-- > 0) {
35 if ((res = mp_mul_2d (a, 8, a)) != MP_OKAY) {
36 return res;
37 }
38
eed6765 added libtommath-0.23
Tom St Denis authored
39 #ifndef MP_8BIT
57354e1 added libtommath-0.12
Tom St Denis authored
40 a->dp[0] |= *b++;
41 a->used += 1;
eed6765 added libtommath-0.23
Tom St Denis authored
42 #else
57354e1 added libtommath-0.12
Tom St Denis authored
43 a->dp[0] = (*b & MP_MASK);
44 a->dp[1] |= ((*b++ >> 7U) & 1);
45 a->used += 2;
eed6765 added libtommath-0.23
Tom St Denis authored
46 #endif
57354e1 added libtommath-0.12
Tom St Denis authored
47 }
48 mp_clamp (a);
49 return MP_OKAY;
50 }
e549ccf added libtommath-0.32
Tom St Denis authored
51 #endif
9294e79 added libtommath-0.36
Tom St Denis authored
52
53 /* $Source$ */
54 /* $Revision$ */
55 /* $Date$ */
Something went wrong with that request. Please try again.