Root/lib/mpi/mpi-internal.h

1/* mpi-internal.h - Internal to the Multi Precision Integers
2 * Copyright (C) 1994, 1996 Free Software Foundation, Inc.
3 * Copyright (C) 1998, 2000 Free Software Foundation, Inc.
4 *
5 * This file is part of GnuPG.
6 *
7 * GnuPG is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * GnuPG is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
20 *
21 * Note: This code is heavily based on the GNU MP Library.
22 * Actually it's the same code with only minor changes in the
23 * way the data is stored; this is to support the abstraction
24 * of an optional secure memory allocation which may be used
25 * to avoid revealing of sensitive data due to paging etc.
26 * The GNU MP Library itself is published under the LGPL;
27 * however I decided to publish this code under the plain GPL.
28 */
29
30#ifndef G10_MPI_INTERNAL_H
31#define G10_MPI_INTERNAL_H
32
33#include <linux/module.h>
34#include <linux/kernel.h>
35#include <linux/slab.h>
36#include <linux/string.h>
37#include <linux/mpi.h>
38#include <linux/errno.h>
39
40#define log_debug printk
41#define log_bug printk
42
43#define assert(x) \
44    do { \
45        if (!x) \
46            log_bug("failed assertion\n"); \
47    } while (0);
48
49/* If KARATSUBA_THRESHOLD is not already defined, define it to a
50 * value which is good on most machines. */
51
52/* tested 4, 16, 32 and 64, where 16 gave the best performance when
53 * checking a 768 and a 1024 bit ElGamal signature.
54 * (wk 22.12.97) */
55#ifndef KARATSUBA_THRESHOLD
56#define KARATSUBA_THRESHOLD 16
57#endif
58
59/* The code can't handle KARATSUBA_THRESHOLD smaller than 2. */
60#if KARATSUBA_THRESHOLD < 2
61#undef KARATSUBA_THRESHOLD
62#define KARATSUBA_THRESHOLD 2
63#endif
64
65typedef mpi_limb_t *mpi_ptr_t; /* pointer to a limb */
66typedef int mpi_size_t; /* (must be a signed type) */
67
68static inline int RESIZE_IF_NEEDED(MPI a, unsigned b)
69{
70    if (a->alloced < b)
71        return mpi_resize(a, b);
72    return 0;
73}
74
75/* Copy N limbs from S to D. */
76#define MPN_COPY(d, s, n) \
77    do { \
78        mpi_size_t _i; \
79        for (_i = 0; _i < (n); _i++) \
80            (d)[_i] = (s)[_i]; \
81    } while (0)
82
83#define MPN_COPY_INCR(d, s, n) \
84    do { \
85        mpi_size_t _i; \
86        for (_i = 0; _i < (n); _i++) \
87            (d)[_i] = (d)[_i]; \
88    } while (0)
89
90#define MPN_COPY_DECR(d, s, n) \
91    do { \
92        mpi_size_t _i; \
93        for (_i = (n)-1; _i >= 0; _i--) \
94            (d)[_i] = (s)[_i]; \
95    } while (0)
96
97/* Zero N limbs at D */
98#define MPN_ZERO(d, n) \
99    do { \
100        int _i; \
101        for (_i = 0; _i < (n); _i++) \
102            (d)[_i] = 0; \
103    } while (0)
104
105#define MPN_NORMALIZE(d, n) \
106    do { \
107        while ((n) > 0) { \
108            if ((d)[(n)-1]) \
109                break; \
110            (n)--; \
111        } \
112    } while (0)
113
114#define MPN_NORMALIZE_NOT_ZERO(d, n) \
115    do { \
116        for (;;) { \
117            if ((d)[(n)-1]) \
118                break; \
119            (n)--; \
120        } \
121    } while (0)
122
123#define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \
124    do { \
125        if ((size) < KARATSUBA_THRESHOLD) \
126            mul_n_basecase(prodp, up, vp, size); \
127        else \
128            mul_n(prodp, up, vp, size, tspace); \
129    } while (0);
130
131/* Divide the two-limb number in (NH,,NL) by D, with DI being the largest
132 * limb not larger than (2**(2*BITS_PER_MP_LIMB))/D - (2**BITS_PER_MP_LIMB).
133 * If this would yield overflow, DI should be the largest possible number
134 * (i.e., only ones). For correct operation, the most significant bit of D
135 * has to be set. Put the quotient in Q and the remainder in R.
136 */
137#define UDIV_QRNND_PREINV(q, r, nh, nl, d, di) \
138    do { \
139        mpi_limb_t _q, _ql, _r; \
140        mpi_limb_t _xh, _xl; \
141        umul_ppmm(_q, _ql, (nh), (di)); \
142        _q += (nh); /* DI is 2**BITS_PER_MPI_LIMB too small */ \
143        umul_ppmm(_xh, _xl, _q, (d)); \
144        sub_ddmmss(_xh, _r, (nh), (nl), _xh, _xl); \
145        if (_xh) { \
146            sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
147            _q++; \
148            if (_xh) { \
149                sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
150                _q++; \
151            } \
152        } \
153        if (_r >= (d)) { \
154            _r -= (d); \
155            _q++; \
156        } \
157        (r) = _r; \
158        (q) = _q; \
159    } while (0)
160
161/*-- mpiutil.c --*/
162mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
163void mpi_free_limb_space(mpi_ptr_t a);
164void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs);
165
166/*-- mpi-bit.c --*/
167void mpi_rshift_limbs(MPI a, unsigned int count);
168int mpi_lshift_limbs(MPI a, unsigned int count);
169
170/*-- mpihelp-add.c --*/
171mpi_limb_t mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
172             mpi_size_t s1_size, mpi_limb_t s2_limb);
173mpi_limb_t mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
174             mpi_ptr_t s2_ptr, mpi_size_t size);
175mpi_limb_t mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
176               mpi_ptr_t s2_ptr, mpi_size_t s2_size);
177
178/*-- mpihelp-sub.c --*/
179mpi_limb_t mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
180             mpi_size_t s1_size, mpi_limb_t s2_limb);
181mpi_limb_t mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
182             mpi_ptr_t s2_ptr, mpi_size_t size);
183mpi_limb_t mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
184               mpi_ptr_t s2_ptr, mpi_size_t s2_size);
185
186/*-- mpihelp-cmp.c --*/
187int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size);
188
189/*-- mpihelp-mul.c --*/
190
191struct karatsuba_ctx {
192    struct karatsuba_ctx *next;
193    mpi_ptr_t tspace;
194    mpi_size_t tspace_size;
195    mpi_ptr_t tp;
196    mpi_size_t tp_size;
197};
198
199void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx);
200
201mpi_limb_t mpihelp_addmul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
202                mpi_size_t s1_size, mpi_limb_t s2_limb);
203mpi_limb_t mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
204                mpi_size_t s1_size, mpi_limb_t s2_limb);
205int mpihelp_mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size);
206int mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
207        mpi_ptr_t vp, mpi_size_t vsize, mpi_limb_t *_result);
208void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
209void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
210        mpi_ptr_t tspace);
211
212int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
213                   mpi_ptr_t up, mpi_size_t usize,
214                   mpi_ptr_t vp, mpi_size_t vsize,
215                   struct karatsuba_ctx *ctx);
216
217/*-- mpihelp-mul_1.c (or xxx/cpu/ *.S) --*/
218mpi_limb_t mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
219             mpi_size_t s1_size, mpi_limb_t s2_limb);
220
221/*-- mpihelp-div.c --*/
222mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
223             mpi_limb_t divisor_limb);
224mpi_limb_t mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs,
225              mpi_ptr_t np, mpi_size_t nsize,
226              mpi_ptr_t dp, mpi_size_t dsize);
227mpi_limb_t mpihelp_divmod_1(mpi_ptr_t quot_ptr,
228                mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
229                mpi_limb_t divisor_limb);
230
231/*-- mpihelp-shift.c --*/
232mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
233              unsigned cnt);
234mpi_limb_t mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
235              unsigned cnt);
236
237/* Define stuff for longlong.h. */
238#define W_TYPE_SIZE BITS_PER_MPI_LIMB
239typedef mpi_limb_t UWtype;
240typedef unsigned int UHWtype;
241#if defined(__GNUC__)
242typedef unsigned int UQItype __attribute__ ((mode(QI)));
243typedef int SItype __attribute__ ((mode(SI)));
244typedef unsigned int USItype __attribute__ ((mode(SI)));
245typedef int DItype __attribute__ ((mode(DI)));
246typedef unsigned int UDItype __attribute__ ((mode(DI)));
247#else
248typedef unsigned char UQItype;
249typedef long SItype;
250typedef unsigned long USItype;
251#endif
252
253#ifdef __GNUC__
254#include "mpi-inline.h"
255#endif
256
257#endif /*G10_MPI_INTERNAL_H */
258

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