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
65 typedef mpi_limb_t *mpi_ptr_t; /* pointer to a limb */
66 typedef int mpi_size_t; /* (must be a signed type) */
67
RESIZE_IF_NEEDED(MPI a,unsigned b)68 static 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] = (s)[_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 --*/
162 mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
163 void mpi_free_limb_space(mpi_ptr_t a);
164 void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs);
165
166 /*-- mpi-bit.c --*/
167 void mpi_rshift_limbs(MPI a, unsigned int count);
168 int mpi_lshift_limbs(MPI a, unsigned int count);
169
170 /*-- mpihelp-add.c --*/
171 static inline mpi_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);
173 mpi_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);
175 static inline mpi_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 --*/
179 static inline mpi_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);
181 mpi_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);
183 static inline mpi_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 --*/
187 int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size);
188
189 /*-- mpihelp-mul.c --*/
190
191 struct 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
199 void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx);
200
201 mpi_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);
203 mpi_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);
205 int mpihelp_mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size);
206 int 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);
208 void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
209 void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
210 mpi_ptr_t tspace);
211
212 int 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) --*/
218 mpi_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 --*/
222 mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
223 mpi_limb_t divisor_limb);
224 mpi_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);
227 mpi_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 --*/
232 mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
233 unsigned cnt);
234 mpi_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
239 typedef mpi_limb_t UWtype;
240 typedef unsigned int UHWtype;
241 #if defined(__GNUC__)
242 typedef unsigned int UQItype __attribute__ ((mode(QI)));
243 typedef int SItype __attribute__ ((mode(SI)));
244 typedef unsigned int USItype __attribute__ ((mode(SI)));
245 typedef int DItype __attribute__ ((mode(DI)));
246 typedef unsigned int UDItype __attribute__ ((mode(DI)));
247 #else
248 typedef unsigned char UQItype;
249 typedef long SItype;
250 typedef unsigned long USItype;
251 #endif
252
253 #ifdef __GNUC__
254 #include "mpi-inline.h"
255 #endif
256
257 #endif /*G10_MPI_INTERNAL_H */
258