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 #define ABS(x) (x >= 0 ? x : -x)
  69 #define MIN(l, o) ((l) < (o) ? (l) : (o))
  70 #define MAX(h, i) ((h) > (i) ? (h) : (i))
  71
  72 static inline int RESIZE_IF_NEEDED(MPI a, unsigned b)
  73 {
  74         if (a->alloced < b)
  75                 return mpi_resize(a, b);
  76         return 0;
  77 }
  78
  79 /* Copy N limbs from S to D.  */
  80 #define MPN_COPY(d, s, n) \
  81         do {                                    \
  82                 mpi_size_t _i;                  \
  83                 for (_i = 0; _i < (n); _i++)    \
  84                         (d)[_i] = (s)[_i];      \
  85         } while (0)
  86
  87 #define MPN_COPY_INCR(d, s, n) \
  88         do {                                    \
  89                 mpi_size_t _i;                  \
  90                 for (_i = 0; _i < (n); _i++)    \
  91                         (d)[_i] = (d)[_i];      \
  92         } while (0)
  93
  94 #define MPN_COPY_DECR(d, s, n) \
  95         do {                                    \
  96                 mpi_size_t _i;                  \
  97                 for (_i = (n)-1; _i >= 0; _i--) \
  98                         (d)[_i] = (s)[_i];      \
  99         } while (0)
 100
 101 /* Zero N limbs at D */
 102 #define MPN_ZERO(d, n) \
 103         do {                                    \
 104                 int  _i;                        \
 105                 for (_i = 0; _i < (n); _i++)    \
 106                         (d)[_i] = 0;            \
 107         } while (0)
 108
 109 #define MPN_NORMALIZE(d, n)  \
 110         do {                                    \
 111                 while ((n) > 0) {               \
 112                         if ((d)[(n)-1])         \
 113                                 break;          \
 114                         (n)--;                  \
 115                 }                               \
 116         } while (0)
 117
 118 #define MPN_NORMALIZE_NOT_ZERO(d, n) \
 119         do {                            \
 120                 for (;;) {              \
 121                         if ((d)[(n)-1]) \
 122                                 break;  \
 123                         (n)--;          \
 124                 }                       \
 125         } while (0)
 126
 127 #define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \
 128         do {                                                    \
 129                 if ((size) < KARATSUBA_THRESHOLD)               \
 130                         mul_n_basecase(prodp, up, vp, size);    \
 131                 else                                            \
 132                         mul_n(prodp, up, vp, size, tspace);     \
 133         } while (0);
 134
 135 /* Divide the two-limb number in (NH,,NL) by D, with DI being the largest
 136  * limb not larger than (2**(2*BITS_PER_MP_LIMB))/D - (2**BITS_PER_MP_LIMB).
 137  * If this would yield overflow, DI should be the largest possible number
 138  * (i.e., only ones).  For correct operation, the most significant bit of D
 139  * has to be set.  Put the quotient in Q and the remainder in R.
 140  */
 141 #define UDIV_QRNND_PREINV(q, r, nh, nl, d, di) \
 142         do {                                                            \
 143                 mpi_limb_t _q, _ql, _r;                                 \
 144                 mpi_limb_t _xh, _xl;                                    \
 145                 umul_ppmm(_q, _ql, (nh), (di));                         \
 146                 _q += (nh);     /* DI is 2**BITS_PER_MPI_LIMB too small */ \
 147                 umul_ppmm(_xh, _xl, _q, (d));                           \
 148                 sub_ddmmss(_xh, _r, (nh), (nl), _xh, _xl);              \
 149                 if (_xh) {                                              \
 150                         sub_ddmmss(_xh, _r, _xh, _r, 0, (d));           \
 151                         _q++;                                           \
 152                         if (_xh) {                                      \
 153                                 sub_ddmmss(_xh, _r, _xh, _r, 0, (d));   \
 154                                 _q++;                                   \
 155                         }                                               \
 156                 }                                                       \
 157                 if (_r >= (d)) {                                        \
 158                         _r -= (d);                                      \
 159                         _q++;                                           \
 160                 }                                                       \
 161                 (r) = _r;                                               \
 162                 (q) = _q;                                               \
 163         } while (0)
 164
 165 /*-- mpiutil.c --*/
 166 mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
 167 void mpi_free_limb_space(mpi_ptr_t a);
 168 void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs);
 169
 170 /*-- mpi-bit.c --*/
 171 void mpi_rshift_limbs(MPI a, unsigned int count);
 172 int mpi_lshift_limbs(MPI a, unsigned int count);
 173
 174 /*-- mpihelp-add.c --*/
 175 mpi_limb_t mpihelp_add_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_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
 178                          mpi_ptr_t s2_ptr, mpi_size_t size);
 179 mpi_limb_t mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
 180                        mpi_ptr_t s2_ptr, mpi_size_t s2_size);
 181
 182 /*-- mpihelp-sub.c --*/
 183 mpi_limb_t mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
 184                          mpi_size_t s1_size, mpi_limb_t s2_limb);
 185 mpi_limb_t mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
 186                          mpi_ptr_t s2_ptr, mpi_size_t size);
 187 mpi_limb_t mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
 188                        mpi_ptr_t s2_ptr, mpi_size_t s2_size);
 189
 190 /*-- mpihelp-cmp.c --*/
 191 int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size);
 192
 193 /*-- mpihelp-mul.c --*/
 194
 195 struct karatsuba_ctx {
 196         struct karatsuba_ctx *next;
 197         mpi_ptr_t tspace;
 198         mpi_size_t tspace_size;
 199         mpi_ptr_t tp;
 200         mpi_size_t tp_size;
 201 };
 202
 203 void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx);
 204
 205 mpi_limb_t mpihelp_addmul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
 206                             mpi_size_t s1_size, mpi_limb_t s2_limb);
 207 mpi_limb_t mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
 208                             mpi_size_t s1_size, mpi_limb_t s2_limb);
 209 int mpihelp_mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size);
 210 int mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
 211                 mpi_ptr_t vp, mpi_size_t vsize, mpi_limb_t *_result);
 212 void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
 213 void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
 214                 mpi_ptr_t tspace);
 215
 216 int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
 217                                mpi_ptr_t up, mpi_size_t usize,
 218                                mpi_ptr_t vp, mpi_size_t vsize,
 219                                struct karatsuba_ctx *ctx);
 220
 221 /*-- mpihelp-mul_1.c (or xxx/cpu/ *.S) --*/
 222 mpi_limb_t mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
 223                          mpi_size_t s1_size, mpi_limb_t s2_limb);
 224
 225 /*-- mpihelp-div.c --*/
 226 mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
 227                          mpi_limb_t divisor_limb);
 228 mpi_limb_t mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs,
 229                           mpi_ptr_t np, mpi_size_t nsize,
 230                           mpi_ptr_t dp, mpi_size_t dsize);
 231 mpi_limb_t mpihelp_divmod_1(mpi_ptr_t quot_ptr,
 232                             mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
 233                             mpi_limb_t divisor_limb);
 234
 235 /*-- mpihelp-shift.c --*/
 236 mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
 237                           unsigned cnt);
 238 mpi_limb_t mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
 239                           unsigned cnt);
 240
 241 /* Define stuff for longlong.h.  */
 242 #define W_TYPE_SIZE BITS_PER_MPI_LIMB
 243 typedef mpi_limb_t UWtype;
 244 typedef unsigned int UHWtype;
 245 #if defined(__GNUC__)
 246 typedef unsigned int UQItype __attribute__ ((mode(QI)));
 247 typedef int SItype __attribute__ ((mode(SI)));
 248 typedef unsigned int USItype __attribute__ ((mode(SI)));
 249 typedef int DItype __attribute__ ((mode(DI)));
 250 typedef unsigned int UDItype __attribute__ ((mode(DI)));
 251 #else
 252 typedef unsigned char UQItype;
 253 typedef long SItype;
 254 typedef unsigned long USItype;
 255 #endif
 256
 257 #ifdef __GNUC__
 258 #include "mpi-inline.h"
 259 #endif
 260
 261 #endif /*G10_MPI_INTERNAL_H */