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 
52 typedef mpi_limb_t *mpi_ptr_t;	/* pointer to a limb */
53 typedef int mpi_size_t;		/* (must be a signed type) */
54 
55 /* Copy N limbs from S to D.  */
56 #define MPN_COPY(d, s, n) \
57 	do {					\
58 		mpi_size_t _i;			\
59 		for (_i = 0; _i < (n); _i++)	\
60 			(d)[_i] = (s)[_i];	\
61 	} while (0)
62 
63 #define MPN_COPY_DECR(d, s, n) \
64 	do {					\
65 		mpi_size_t _i;			\
66 		for (_i = (n)-1; _i >= 0; _i--) \
67 			(d)[_i] = (s)[_i];	\
68 	} while (0)
69 
70 /* Zero N limbs at D */
71 #define MPN_ZERO(d, n) \
72 	do {					\
73 		int  _i;			\
74 		for (_i = 0; _i < (n); _i++)	\
75 			(d)[_i] = 0;		\
76 	} while (0)
77 
78 #define MPN_NORMALIZE(d, n)  \
79 	do {					\
80 		while ((n) > 0) {		\
81 			if ((d)[(n)-1])		\
82 				break;		\
83 			(n)--;			\
84 		}				\
85 	} while (0)
86 
87 #define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \
88 	do {							\
89 		if ((size) < KARATSUBA_THRESHOLD)		\
90 			mul_n_basecase(prodp, up, vp, size);	\
91 		else						\
92 			mul_n(prodp, up, vp, size, tspace);	\
93 	} while (0);
94 
95 /*-- mpiutil.c --*/
96 mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
97 void mpi_free_limb_space(mpi_ptr_t a);
98 void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs);
99 
100 static inline mpi_limb_t mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
101 			 mpi_size_t s1_size, mpi_limb_t s2_limb);
102 mpi_limb_t mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
103 			 mpi_ptr_t s2_ptr, mpi_size_t size);
104 static inline mpi_limb_t mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
105 		       mpi_ptr_t s2_ptr, mpi_size_t s2_size);
106 
107 static inline mpi_limb_t mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
108 			 mpi_size_t s1_size, mpi_limb_t s2_limb);
109 mpi_limb_t mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
110 			 mpi_ptr_t s2_ptr, mpi_size_t size);
111 static inline mpi_limb_t mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
112 		       mpi_ptr_t s2_ptr, mpi_size_t s2_size);
113 
114 /*-- mpih-cmp.c --*/
115 int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size);
116 
117 /*-- mpih-mul.c --*/
118 
119 struct karatsuba_ctx {
120 	struct karatsuba_ctx *next;
121 	mpi_ptr_t tspace;
122 	mpi_size_t tspace_size;
123 	mpi_ptr_t tp;
124 	mpi_size_t tp_size;
125 };
126 
127 void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx);
128 
129 mpi_limb_t mpihelp_addmul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
130 			    mpi_size_t s1_size, mpi_limb_t s2_limb);
131 mpi_limb_t mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
132 			    mpi_size_t s1_size, mpi_limb_t s2_limb);
133 int mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
134 		mpi_ptr_t vp, mpi_size_t vsize, mpi_limb_t *_result);
135 void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
136 void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
137 		mpi_ptr_t tspace);
138 
139 int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
140 			       mpi_ptr_t up, mpi_size_t usize,
141 			       mpi_ptr_t vp, mpi_size_t vsize,
142 			       struct karatsuba_ctx *ctx);
143 
144 /*-- generic_mpih-mul1.c --*/
145 mpi_limb_t mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
146 			 mpi_size_t s1_size, mpi_limb_t s2_limb);
147 
148 /*-- mpih-div.c --*/
149 mpi_limb_t mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs,
150 			  mpi_ptr_t np, mpi_size_t nsize,
151 			  mpi_ptr_t dp, mpi_size_t dsize);
152 
153 /*-- generic_mpih-[lr]shift.c --*/
154 mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
155 			  unsigned cnt);
156 mpi_limb_t mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
157 			  unsigned cnt);
158 
159 /* Define stuff for longlong.h.  */
160 #define W_TYPE_SIZE BITS_PER_MPI_LIMB
161 typedef mpi_limb_t UWtype;
162 typedef unsigned int UHWtype;
163 #if defined(__GNUC__)
164 typedef unsigned int UQItype __attribute__ ((mode(QI)));
165 typedef int SItype __attribute__ ((mode(SI)));
166 typedef unsigned int USItype __attribute__ ((mode(SI)));
167 typedef int DItype __attribute__ ((mode(DI)));
168 typedef unsigned int UDItype __attribute__ ((mode(DI)));
169 #else
170 typedef unsigned char UQItype;
171 typedef long SItype;
172 typedef unsigned long USItype;
173 #endif
174 
175 #ifdef __GNUC__
176 #include "mpi-inline.h"
177 #endif
178 
179 #endif /*G10_MPI_INTERNAL_H */
180