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 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 --*/ 142mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs); 143void mpi_free_limb_space(mpi_ptr_t a); 144void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs); 145 146static 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); 148mpi_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); 150static 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 153static 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); 155mpi_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); 157static 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 --*/ 161int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size); 162 163/*-- mpih-mul.c --*/ 164 165struct 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 173void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx); 174 175mpi_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); 177mpi_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); 179int 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); 181void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size); 182void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size, 183 mpi_ptr_t tspace); 184void mpihelp_mul_n(mpi_ptr_t prodp, 185 mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size); 186 187int 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 --*/ 193mpi_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 --*/ 197mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size, 198 mpi_limb_t divisor_limb); 199mpi_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); 202mpi_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 --*/ 207mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, 208 unsigned cnt); 209mpi_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 214typedef mpi_limb_t UWtype; 215typedef unsigned int UHWtype; 216#if defined(__GNUC__) 217typedef unsigned int UQItype __attribute__ ((mode(QI))); 218typedef int SItype __attribute__ ((mode(SI))); 219typedef unsigned int USItype __attribute__ ((mode(SI))); 220typedef int DItype __attribute__ ((mode(DI))); 221typedef unsigned int UDItype __attribute__ ((mode(DI))); 222#else 223typedef unsigned char UQItype; 224typedef long SItype; 225typedef unsigned long USItype; 226#endif 227 228#ifdef __GNUC__ 229#include "mpi-inline.h" 230#endif 231 232#endif /*G10_MPI_INTERNAL_H */ 233