LXR linux/lib/mpi/mpi-internal.h

   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