1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* mpi-internal.h - Internal to the Multi Precision Integers
3 * Copyright (C) 1994, 1996 Free Software Foundation, Inc.
4 * Copyright (C) 1998, 2000 Free Software Foundation, Inc.
5 *
6 * This file is part of GnuPG.
7 *
8 * Note: This code is heavily based on the GNU MP Library.
9 * Actually it's the same code with only minor changes in the
10 * way the data is stored; this is to support the abstraction
11 * of an optional secure memory allocation which may be used
12 * to avoid revealing of sensitive data due to paging etc.
13 * The GNU MP Library itself is published under the LGPL;
14 * however I decided to publish this code under the plain GPL.
15 */
16
17#ifndef G10_MPI_INTERNAL_H
18#define G10_MPI_INTERNAL_H
19
20#include <linux/module.h>
21#include <linux/kernel.h>
22#include <linux/slab.h>
23#include <linux/string.h>
24#include <linux/mpi.h>
25#include <linux/errno.h>
26
27#define log_debug printk
28#define log_bug printk
29
30#define assert(x) \
31 do { \
32 if (!x) \
33 log_bug("failed assertion\n"); \
34 } while (0);
35
36/* If KARATSUBA_THRESHOLD is not already defined, define it to a
37 * value which is good on most machines. */
38
39/* tested 4, 16, 32 and 64, where 16 gave the best performance when
40 * checking a 768 and a 1024 bit ElGamal signature.
41 * (wk 22.12.97) */
42#ifndef KARATSUBA_THRESHOLD
43#define KARATSUBA_THRESHOLD 16
44#endif
45
46/* The code can't handle KARATSUBA_THRESHOLD smaller than 2. */
47#if KARATSUBA_THRESHOLD < 2
48#undef KARATSUBA_THRESHOLD
49#define KARATSUBA_THRESHOLD 2
50#endif
51
52typedef mpi_limb_t *mpi_ptr_t; /* pointer to a limb */
53typedef int mpi_size_t; /* (must be a signed type) */
54
55static inline int RESIZE_IF_NEEDED(MPI a, unsigned b)
56{
57 if (a->alloced < b)
58 return mpi_resize(a, nlimbs: b);
59 return 0;
60}
61
62/* Copy N limbs from S to D. */
63#define MPN_COPY(d, s, n) \
64 do { \
65 mpi_size_t _i; \
66 for (_i = 0; _i < (n); _i++) \
67 (d)[_i] = (s)[_i]; \
68 } while (0)
69
70#define MPN_COPY_DECR(d, s, n) \
71 do { \
72 mpi_size_t _i; \
73 for (_i = (n)-1; _i >= 0; _i--) \
74 (d)[_i] = (s)[_i]; \
75 } while (0)
76
77/* Zero N limbs at D */
78#define MPN_ZERO(d, n) \
79 do { \
80 int _i; \
81 for (_i = 0; _i < (n); _i++) \
82 (d)[_i] = 0; \
83 } while (0)
84
85#define MPN_NORMALIZE(d, n) \
86 do { \
87 while ((n) > 0) { \
88 if ((d)[(n)-1]) \
89 break; \
90 (n)--; \
91 } \
92 } while (0)
93
94#define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \
95 do { \
96 if ((size) < KARATSUBA_THRESHOLD) \
97 mul_n_basecase(prodp, up, vp, size); \
98 else \
99 mul_n(prodp, up, vp, size, tspace); \
100 } while (0);
101
102/* Divide the two-limb number in (NH,,NL) by D, with DI being the largest
103 * limb not larger than (2**(2*BITS_PER_MP_LIMB))/D - (2**BITS_PER_MP_LIMB).
104 * If this would yield overflow, DI should be the largest possible number
105 * (i.e., only ones). For correct operation, the most significant bit of D
106 * has to be set. Put the quotient in Q and the remainder in R.
107 */
108#define UDIV_QRNND_PREINV(q, r, nh, nl, d, di) \
109 do { \
110 mpi_limb_t _ql __maybe_unused; \
111 mpi_limb_t _q, _r; \
112 mpi_limb_t _xh, _xl; \
113 umul_ppmm(_q, _ql, (nh), (di)); \
114 _q += (nh); /* DI is 2**BITS_PER_MPI_LIMB too small */ \
115 umul_ppmm(_xh, _xl, _q, (d)); \
116 sub_ddmmss(_xh, _r, (nh), (nl), _xh, _xl); \
117 if (_xh) { \
118 sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
119 _q++; \
120 if (_xh) { \
121 sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
122 _q++; \
123 } \
124 } \
125 if (_r >= (d)) { \
126 _r -= (d); \
127 _q++; \
128 } \
129 (r) = _r; \
130 (q) = _q; \
131 } while (0)
132
133
134/*-- mpiutil.c --*/
135mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
136void mpi_free_limb_space(mpi_ptr_t a);
137void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs);
138
139static inline mpi_limb_t mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
140 mpi_size_t s1_size, mpi_limb_t s2_limb);
141mpi_limb_t mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
142 mpi_ptr_t s2_ptr, mpi_size_t size);
143static inline mpi_limb_t mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
144 mpi_ptr_t s2_ptr, mpi_size_t s2_size);
145
146static inline mpi_limb_t mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
147 mpi_size_t s1_size, mpi_limb_t s2_limb);
148mpi_limb_t mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
149 mpi_ptr_t s2_ptr, mpi_size_t size);
150static inline mpi_limb_t mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
151 mpi_ptr_t s2_ptr, mpi_size_t s2_size);
152
153/*-- mpih-cmp.c --*/
154int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size);
155
156/*-- mpih-mul.c --*/
157
158struct karatsuba_ctx {
159 struct karatsuba_ctx *next;
160 mpi_ptr_t tspace;
161 mpi_size_t tspace_size;
162 mpi_ptr_t tp;
163 mpi_size_t tp_size;
164};
165
166void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx);
167
168mpi_limb_t mpihelp_addmul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
169 mpi_size_t s1_size, mpi_limb_t s2_limb);
170mpi_limb_t mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
171 mpi_size_t s1_size, mpi_limb_t s2_limb);
172int mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
173 mpi_ptr_t vp, mpi_size_t vsize, mpi_limb_t *_result);
174void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
175void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
176 mpi_ptr_t tspace);
177
178int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
179 mpi_ptr_t up, mpi_size_t usize,
180 mpi_ptr_t vp, mpi_size_t vsize,
181 struct karatsuba_ctx *ctx);
182
183/*-- generic_mpih-mul1.c --*/
184mpi_limb_t mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
185 mpi_size_t s1_size, mpi_limb_t s2_limb);
186
187/*-- mpih-div.c --*/
188mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
189 mpi_limb_t divisor_limb);
190mpi_limb_t mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs,
191 mpi_ptr_t np, mpi_size_t nsize,
192 mpi_ptr_t dp, mpi_size_t dsize);
193mpi_limb_t mpihelp_divmod_1(mpi_ptr_t quot_ptr,
194 mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
195 mpi_limb_t divisor_limb);
196
197/*-- generic_mpih-[lr]shift.c --*/
198mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
199 unsigned cnt);
200mpi_limb_t mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
201 unsigned cnt);
202
203/* Define stuff for longlong.h. */
204#define W_TYPE_SIZE BITS_PER_MPI_LIMB
205typedef mpi_limb_t UWtype;
206typedef unsigned int UHWtype;
207#if defined(__GNUC__)
208typedef unsigned int UQItype __attribute__ ((mode(QI)));
209typedef int SItype __attribute__ ((mode(SI)));
210typedef unsigned int USItype __attribute__ ((mode(SI)));
211typedef int DItype __attribute__ ((mode(DI)));
212typedef unsigned int UDItype __attribute__ ((mode(DI)));
213#else
214typedef unsigned char UQItype;
215typedef long SItype;
216typedef unsigned long USItype;
217#endif
218
219#ifdef __GNUC__
220#include "mpi-inline.h"
221#endif
222
223#endif /*G10_MPI_INTERNAL_H */
224