LXR linux/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
  65typedef mpi_limb_t *mpi_ptr_t;  /* pointer to a limb */
  66typedef int mpi_size_t;         /* (must be a signed type) */
  67
  68static 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 --*/
 162mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
 163void mpi_free_limb_space(mpi_ptr_t a);
 164void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs);
 165
 166/*-- mpi-bit.c --*/
 167void mpi_rshift_limbs(MPI a, unsigned int count);
 168int mpi_lshift_limbs(MPI a, unsigned int count);
 169
 170/*-- mpihelp-add.c --*/
 171static 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);
 173mpi_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);
 175static 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 --*/
 179static 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);
 181mpi_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);
 183static 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 --*/
 187int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size);
 188
 189/*-- mpihelp-mul.c --*/
 190
 191struct 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
 199void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx);
 200
 201mpi_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);
 203mpi_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);
 205int mpihelp_mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size);
 206int 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);
 208void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
 209void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
 210                mpi_ptr_t tspace);
 211
 212int 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) --*/
 218mpi_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 --*/
 222mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
 223                         mpi_limb_t divisor_limb);
 224mpi_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);
 227mpi_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 --*/
 232mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
 233                          unsigned cnt);
 234mpi_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
 239typedef mpi_limb_t UWtype;
 240typedef unsigned int UHWtype;
 241#if defined(__GNUC__)
 242typedef unsigned int UQItype __attribute__ ((mode(QI)));
 243typedef int SItype __attribute__ ((mode(SI)));
 244typedef unsigned int USItype __attribute__ ((mode(SI)));
 245typedef int DItype __attribute__ ((mode(DI)));
 246typedef unsigned int UDItype __attribute__ ((mode(DI)));
 247#else
 248typedef unsigned char UQItype;
 249typedef long SItype;
 250typedef unsigned long USItype;
 251#endif
 252
 253#ifdef __GNUC__
 254#include "mpi-inline.h"
 255#endif
 256
 257#endif /*G10_MPI_INTERNAL_H */
 258