Mercurial > dropbear
comparison libtommath/bn_mp_mul_d.c @ 1655:f52919ffd3b1
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
* make key-generation compliant to FIPS 186.4
* fix includes in tommath_class.h
* update fuzzcorpus instead of error-out
* fixup fuzzing make-targets
* update Makefile.in
* apply necessary patches to ltm sources
* clean-up not required ltm files
* update to vanilla ltm 1.1.0
this already only contains the required files
* remove set/get double
author | Steffen Jaeckel <s_jaeckel@gmx.de> |
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date | Mon, 16 Sep 2019 15:50:38 +0200 |
parents | 8bba51a55704 |
children | 1051e4eea25a |
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1654:cc0fc5131c5c | 1655:f52919ffd3b1 |
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1 #include <tommath_private.h> | 1 #include "tommath_private.h" |
2 #ifdef BN_MP_MUL_D_C | 2 #ifdef BN_MP_MUL_D_C |
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis | 3 /* LibTomMath, multiple-precision integer library -- Tom St Denis |
4 * | 4 * |
5 * LibTomMath is a library that provides multiple-precision | 5 * LibTomMath is a library that provides multiple-precision |
6 * integer arithmetic as well as number theoretic functionality. | 6 * integer arithmetic as well as number theoretic functionality. |
7 * | 7 * |
8 * The library was designed directly after the MPI library by | 8 * The library was designed directly after the MPI library by |
9 * Michael Fromberger but has been written from scratch with | 9 * Michael Fromberger but has been written from scratch with |
10 * additional optimizations in place. | 10 * additional optimizations in place. |
11 * | 11 * |
12 * The library is free for all purposes without any express | 12 * SPDX-License-Identifier: Unlicense |
13 * guarantee it works. | |
14 * | |
15 * Tom St Denis, [email protected], http://libtom.org | |
16 */ | 13 */ |
17 | 14 |
18 /* multiply by a digit */ | 15 /* multiply by a digit */ |
19 int | 16 int mp_mul_d(const mp_int *a, mp_digit b, mp_int *c) |
20 mp_mul_d (mp_int * a, mp_digit b, mp_int * c) | |
21 { | 17 { |
22 mp_digit u, *tmpa, *tmpc; | 18 mp_digit u, *tmpa, *tmpc; |
23 mp_word r; | 19 mp_word r; |
24 int ix, res, olduse; | 20 int ix, res, olduse; |
25 | 21 |
26 /* make sure c is big enough to hold a*b */ | 22 /* make sure c is big enough to hold a*b */ |
27 if (c->alloc < (a->used + 1)) { | 23 if (c->alloc < (a->used + 1)) { |
28 if ((res = mp_grow (c, a->used + 1)) != MP_OKAY) { | 24 if ((res = mp_grow(c, a->used + 1)) != MP_OKAY) { |
29 return res; | 25 return res; |
30 } | 26 } |
31 } | 27 } |
32 | 28 |
33 /* get the original destinations used count */ | 29 /* get the original destinations used count */ |
34 olduse = c->used; | 30 olduse = c->used; |
35 | 31 |
36 /* set the sign */ | 32 /* set the sign */ |
37 c->sign = a->sign; | 33 c->sign = a->sign; |
38 | 34 |
39 /* alias for a->dp [source] */ | 35 /* alias for a->dp [source] */ |
40 tmpa = a->dp; | 36 tmpa = a->dp; |
41 | 37 |
42 /* alias for c->dp [dest] */ | 38 /* alias for c->dp [dest] */ |
43 tmpc = c->dp; | 39 tmpc = c->dp; |
44 | 40 |
45 /* zero carry */ | 41 /* zero carry */ |
46 u = 0; | 42 u = 0; |
47 | 43 |
48 /* compute columns */ | 44 /* compute columns */ |
49 for (ix = 0; ix < a->used; ix++) { | 45 for (ix = 0; ix < a->used; ix++) { |
50 /* compute product and carry sum for this term */ | 46 /* compute product and carry sum for this term */ |
51 r = (mp_word)u + ((mp_word)*tmpa++ * (mp_word)b); | 47 r = (mp_word)u + ((mp_word)*tmpa++ * (mp_word)b); |
52 | 48 |
53 /* mask off higher bits to get a single digit */ | 49 /* mask off higher bits to get a single digit */ |
54 *tmpc++ = (mp_digit) (r & ((mp_word) MP_MASK)); | 50 *tmpc++ = (mp_digit)(r & (mp_word)MP_MASK); |
55 | 51 |
56 /* send carry into next iteration */ | 52 /* send carry into next iteration */ |
57 u = (mp_digit) (r >> ((mp_word) DIGIT_BIT)); | 53 u = (mp_digit)(r >> (mp_word)DIGIT_BIT); |
58 } | 54 } |
59 | 55 |
60 /* store final carry [if any] and increment ix offset */ | 56 /* store final carry [if any] and increment ix offset */ |
61 *tmpc++ = u; | 57 *tmpc++ = u; |
62 ++ix; | 58 ++ix; |
63 | 59 |
64 /* now zero digits above the top */ | 60 /* now zero digits above the top */ |
65 while (ix++ < olduse) { | 61 while (ix++ < olduse) { |
66 *tmpc++ = 0; | 62 *tmpc++ = 0; |
67 } | 63 } |
68 | 64 |
69 /* set used count */ | 65 /* set used count */ |
70 c->used = a->used + 1; | 66 c->used = a->used + 1; |
71 mp_clamp(c); | 67 mp_clamp(c); |
72 | 68 |
73 return MP_OKAY; | 69 return MP_OKAY; |
74 } | 70 } |
75 #endif | 71 #endif |
76 | 72 |
77 /* ref: $Format:%D$ */ | 73 /* ref: HEAD -> master, tag: v1.1.0 */ |
78 /* git commit: $Format:%H$ */ | 74 /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ |
79 /* commit time: $Format:%ai$ */ | 75 /* commit time: 2019-01-28 20:32:32 +0100 */ |