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
68 #define ABS(x) (x >= 0 ? x : -x)
69 #define MIN(l, o) ((l) < (o) ? (l) : (o))
70 #define MAX(h, i) ((h) > (i) ? (h) : (i))
71
RESIZE_IF_NEEDED(MPI a,unsigned b)72 static inline int RESIZE_IF_NEEDED(MPI a, unsigned b)
73 {
74 if (a->alloced < b)
75 return mpi_resize(a, b);
76 return 0;
77 }
78
79 /* Copy N limbs from S to D. */
80 #define MPN_COPY(d, s, n) \
81 do { \
82 mpi_size_t _i; \
83 for (_i = 0; _i < (n); _i++) \
84 (d)[_i] = (s)[_i]; \
85 } while (0)
86
87 #define MPN_COPY_INCR(d, s, n) \
88 do { \
89 mpi_size_t _i; \
90 for (_i = 0; _i < (n); _i++) \
91 (d)[_i] = (d)[_i]; \
92 } while (0)
93
94 #define MPN_COPY_DECR(d, s, n) \
95 do { \
96 mpi_size_t _i; \
97 for (_i = (n)-1; _i >= 0; _i--) \
98 (d)[_i] = (s)[_i]; \
99 } while (0)
100
101 /* Zero N limbs at D */
102 #define MPN_ZERO(d, n) \
103 do { \
104 int _i; \
105 for (_i = 0; _i < (n); _i++) \
106 (d)[_i] = 0; \
107 } while (0)
108
109 #define MPN_NORMALIZE(d, n) \
110 do { \
111 while ((n) > 0) { \
112 if ((d)[(n)-1]) \
113 break; \
114 (n)--; \
115 } \
116 } while (0)
117
118 #define MPN_NORMALIZE_NOT_ZERO(d, n) \
119 do { \
120 for (;;) { \
121 if ((d)[(n)-1]) \
122 break; \
123 (n)--; \
124 } \
125 } while (0)
126
127 #define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \
128 do { \
129 if ((size) < KARATSUBA_THRESHOLD) \
130 mul_n_basecase(prodp, up, vp, size); \
131 else \
132 mul_n(prodp, up, vp, size, tspace); \
133 } while (0);
134
135 /* Divide the two-limb number in (NH,,NL) by D, with DI being the largest
136 * limb not larger than (2**(2*BITS_PER_MP_LIMB))/D - (2**BITS_PER_MP_LIMB).
137 * If this would yield overflow, DI should be the largest possible number
138 * (i.e., only ones). For correct operation, the most significant bit of D
139 * has to be set. Put the quotient in Q and the remainder in R.
140 */
141 #define UDIV_QRNND_PREINV(q, r, nh, nl, d, di) \
142 do { \
143 mpi_limb_t _q, _ql, _r; \
144 mpi_limb_t _xh, _xl; \
145 umul_ppmm(_q, _ql, (nh), (di)); \
146 _q += (nh); /* DI is 2**BITS_PER_MPI_LIMB too small */ \
147 umul_ppmm(_xh, _xl, _q, (d)); \
148 sub_ddmmss(_xh, _r, (nh), (nl), _xh, _xl); \
149 if (_xh) { \
150 sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
151 _q++; \
152 if (_xh) { \
153 sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
154 _q++; \
155 } \
156 } \
157 if (_r >= (d)) { \
158 _r -= (d); \
159 _q++; \
160 } \
161 (r) = _r; \
162 (q) = _q; \
163 } while (0)
164
165 /*-- mpiutil.c --*/
166 mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
167 void mpi_free_limb_space(mpi_ptr_t a);
168 void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs);
169
170 /*-- mpi-bit.c --*/
171 void mpi_rshift_limbs(MPI a, unsigned int count);
172 int mpi_lshift_limbs(MPI a, unsigned int count);
173
174 /*-- mpihelp-add.c --*/
175 mpi_limb_t mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
176 mpi_size_t s1_size, mpi_limb_t s2_limb);
177 mpi_limb_t mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
178 mpi_ptr_t s2_ptr, mpi_size_t size);
179 mpi_limb_t mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
180 mpi_ptr_t s2_ptr, mpi_size_t s2_size);
181
182 /*-- mpihelp-sub.c --*/
183 mpi_limb_t mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
184 mpi_size_t s1_size, mpi_limb_t s2_limb);
185 mpi_limb_t mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
186 mpi_ptr_t s2_ptr, mpi_size_t size);
187 mpi_limb_t mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
188 mpi_ptr_t s2_ptr, mpi_size_t s2_size);
189
190 /*-- mpihelp-cmp.c --*/
191 int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size);
192
193 /*-- mpihelp-mul.c --*/
194
195 struct karatsuba_ctx {
196 struct karatsuba_ctx *next;
197 mpi_ptr_t tspace;
198 mpi_size_t tspace_size;
199 mpi_ptr_t tp;
200 mpi_size_t tp_size;
201 };
202
203 void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx);
204
205 mpi_limb_t mpihelp_addmul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
206 mpi_size_t s1_size, mpi_limb_t s2_limb);
207 mpi_limb_t mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
208 mpi_size_t s1_size, mpi_limb_t s2_limb);
209 int mpihelp_mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size);
210 int mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
211 mpi_ptr_t vp, mpi_size_t vsize, mpi_limb_t *_result);
212 void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
213 void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
214 mpi_ptr_t tspace);
215
216 int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
217 mpi_ptr_t up, mpi_size_t usize,
218 mpi_ptr_t vp, mpi_size_t vsize,
219 struct karatsuba_ctx *ctx);
220
221 /*-- mpihelp-mul_1.c (or xxx/cpu/ *.S) --*/
222 mpi_limb_t mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
223 mpi_size_t s1_size, mpi_limb_t s2_limb);
224
225 /*-- mpihelp-div.c --*/
226 mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
227 mpi_limb_t divisor_limb);
228 mpi_limb_t mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs,
229 mpi_ptr_t np, mpi_size_t nsize,
230 mpi_ptr_t dp, mpi_size_t dsize);
231 mpi_limb_t mpihelp_divmod_1(mpi_ptr_t quot_ptr,
232 mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
233 mpi_limb_t divisor_limb);
234
235 /*-- mpihelp-shift.c --*/
236 mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
237 unsigned cnt);
238 mpi_limb_t mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
239 unsigned cnt);
240
241 /* Define stuff for longlong.h. */
242 #define W_TYPE_SIZE BITS_PER_MPI_LIMB
243 typedef mpi_limb_t UWtype;
244 typedef unsigned int UHWtype;
245 #if defined(__GNUC__)
246 typedef unsigned int UQItype __attribute__ ((mode(QI)));
247 typedef int SItype __attribute__ ((mode(SI)));
248 typedef unsigned int USItype __attribute__ ((mode(SI)));
249 typedef int DItype __attribute__ ((mode(DI)));
250 typedef unsigned int UDItype __attribute__ ((mode(DI)));
251 #else
252 typedef unsigned char UQItype;
253 typedef long SItype;
254 typedef unsigned long USItype;
255 #endif
256
257 #ifdef __GNUC__
258 #include "mpi-inline.h"
259 #endif
260
261 #endif /*G10_MPI_INTERNAL_H */
262