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