lib/mpi/mpi-internal.h

   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
  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 */