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 #define RESIZE_IF_NEEDED(a, b) \ 56 do { \ 57 if ((a)->alloced < (b)) \ 58 mpi_resize((a), (b)); \ 59 } while (0) 60 61 /* Copy N limbs from S to D. */ 62 #define MPN_COPY(d, s, n) \ 63 do { \ 64 mpi_size_t _i; \ 65 for (_i = 0; _i < (n); _i++) \ 66 (d)[_i] = (s)[_i]; \ 67 } while (0) 68 69 #define MPN_COPY_INCR(d, s, n) \ 70 do { \ 71 mpi_size_t _i; \ 72 for (_i = 0; _i < (n); _i++) \ 73 (d)[_i] = (s)[_i]; \ 74 } while (0) 75 76 77 #define MPN_COPY_DECR(d, s, n) \ 78 do { \ 79 mpi_size_t _i; \ 80 for (_i = (n)-1; _i >= 0; _i--) \ 81 (d)[_i] = (s)[_i]; \ 82 } while (0) 83 84 /* Zero N limbs at D */ 85 #define MPN_ZERO(d, n) \ 86 do { \ 87 int _i; \ 88 for (_i = 0; _i < (n); _i++) \ 89 (d)[_i] = 0; \ 90 } while (0) 91 92 #define MPN_NORMALIZE(d, n) \ 93 do { \ 94 while ((n) > 0) { \ 95 if ((d)[(n)-1]) \ 96 break; \ 97 (n)--; \ 98 } \ 99 } while (0) 100 101 #define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \ 102 do { \ 103 if ((size) < KARATSUBA_THRESHOLD) \ 104 mul_n_basecase(prodp, up, vp, size); \ 105 else \ 106 mul_n(prodp, up, vp, size, tspace); \ 107 } while (0); 108 109 /* Divide the two-limb number in (NH,,NL) by D, with DI being the largest 110 * limb not larger than (2**(2*BITS_PER_MP_LIMB))/D - (2**BITS_PER_MP_LIMB). 111 * If this would yield overflow, DI should be the largest possible number 112 * (i.e., only ones). For correct operation, the most significant bit of D 113 * has to be set. Put the quotient in Q and the remainder in R. 114 */ 115 #define UDIV_QRNND_PREINV(q, r, nh, nl, d, di) \ 116 do { \ 117 mpi_limb_t _ql __maybe_unused; \ 118 mpi_limb_t _q, _r; \ 119 mpi_limb_t _xh, _xl; \ 120 umul_ppmm(_q, _ql, (nh), (di)); \ 121 _q += (nh); /* DI is 2**BITS_PER_MPI_LIMB too small */ \ 122 umul_ppmm(_xh, _xl, _q, (d)); \ 123 sub_ddmmss(_xh, _r, (nh), (nl), _xh, _xl); \ 124 if (_xh) { \ 125 sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \ 126 _q++; \ 127 if (_xh) { \ 128 sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \ 129 _q++; \ 130 } \ 131 } \ 132 if (_r >= (d)) { \ 133 _r -= (d); \ 134 _q++; \ 135 } \ 136 (r) = _r; \ 137 (q) = _q; \ 138 } while (0) 139 140 141 /*-- mpiutil.c --*/ 142 mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs); 143 void mpi_free_limb_space(mpi_ptr_t a); 144 void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs); 145 146 static inline mpi_limb_t mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, 147 mpi_size_t s1_size, mpi_limb_t s2_limb); 148 mpi_limb_t mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, 149 mpi_ptr_t s2_ptr, mpi_size_t size); 150 static inline mpi_limb_t mpihelp_add(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 static inline mpi_limb_t mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, 154 mpi_size_t s1_size, mpi_limb_t s2_limb); 155 mpi_limb_t mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, 156 mpi_ptr_t s2_ptr, mpi_size_t size); 157 static inline mpi_limb_t mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size, 158 mpi_ptr_t s2_ptr, mpi_size_t s2_size); 159 160 /*-- mpih-cmp.c --*/ 161 int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size); 162 163 /*-- mpih-mul.c --*/ 164 165 struct karatsuba_ctx { 166 struct karatsuba_ctx *next; 167 mpi_ptr_t tspace; 168 mpi_size_t tspace_size; 169 mpi_ptr_t tp; 170 mpi_size_t tp_size; 171 }; 172 173 void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx); 174 175 mpi_limb_t mpihelp_addmul_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_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, 178 mpi_size_t s1_size, mpi_limb_t s2_limb); 179 int mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize, 180 mpi_ptr_t vp, mpi_size_t vsize, mpi_limb_t *_result); 181 void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size); 182 void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size, 183 mpi_ptr_t tspace); 184 void mpihelp_mul_n(mpi_ptr_t prodp, 185 mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size); 186 187 int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp, 188 mpi_ptr_t up, mpi_size_t usize, 189 mpi_ptr_t vp, mpi_size_t vsize, 190 struct karatsuba_ctx *ctx); 191 192 /*-- generic_mpih-mul1.c --*/ 193 mpi_limb_t mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, 194 mpi_size_t s1_size, mpi_limb_t s2_limb); 195 196 /*-- mpih-div.c --*/ 197 mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size, 198 mpi_limb_t divisor_limb); 199 mpi_limb_t mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs, 200 mpi_ptr_t np, mpi_size_t nsize, 201 mpi_ptr_t dp, mpi_size_t dsize); 202 mpi_limb_t mpihelp_divmod_1(mpi_ptr_t quot_ptr, 203 mpi_ptr_t dividend_ptr, mpi_size_t dividend_size, 204 mpi_limb_t divisor_limb); 205 206 /*-- generic_mpih-[lr]shift.c --*/ 207 mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, 208 unsigned cnt); 209 mpi_limb_t mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, 210 unsigned cnt); 211 212 /* Define stuff for longlong.h. */ 213 #define W_TYPE_SIZE BITS_PER_MPI_LIMB 214 typedef mpi_limb_t UWtype; 215 typedef unsigned int UHWtype; 216 #if defined(__GNUC__) 217 typedef unsigned int UQItype __attribute__ ((mode(QI))); 218 typedef int SItype __attribute__ ((mode(SI))); 219 typedef unsigned int USItype __attribute__ ((mode(SI))); 220 typedef int DItype __attribute__ ((mode(DI))); 221 typedef unsigned int UDItype __attribute__ ((mode(DI))); 222 #else 223 typedef unsigned char UQItype; 224 typedef long SItype; 225 typedef unsigned long USItype; 226 #endif 227 228 #ifdef __GNUC__ 229 #include "mpi-inline.h" 230 #endif 231 232 #endif /*G10_MPI_INTERNAL_H */ 233