It is used to implement RSA digital signature verification,
which is used by IMA/EVM digital signature extension.
-config MPILIB_EXTRA
- bool
- depends on MPILIB
- help
- Additional sources of multiprecision maths library from GnuPG.
- This code is unnecessary for RSA digital signature verification,
- but can be compiled if needed.
-
config SIGNATURE
tristate
depends on KEYS && CRYPTO
mpih-mul.o \
mpi-pow.o \
mpiutil.o
-
-mpi-$(CONFIG_MPILIB_EXTRA) += \
- mpi-add.o \
- mpi-div.o \
- mpi-cmp.o \
- mpi-gcd.o \
- mpi-inline.o \
- mpi-inv.o \
- mpi-mpow.o \
- mpi-mul.o \
- mpi-scan.o
+++ /dev/null
-/* This file defines some basic constants for the MPI machinery. We
- * need to define the types on a per-CPU basis, so it is done with
- * this file here. */
-#define BYTES_PER_MPI_LIMB (SIZEOF_UNSIGNED_LONG)
+++ /dev/null
-/* mpi-add.c - MPI functions
- * Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
- * Copyright (C) 1994, 1996 Free Software Foundation, Inc.
- *
- * This file is part of GnuPG.
- *
- * GnuPG is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GnuPG is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- *
- * Note: This code is heavily based on the GNU MP Library.
- * Actually it's the same code with only minor changes in the
- * way the data is stored; this is to support the abstraction
- * of an optional secure memory allocation which may be used
- * to avoid revealing of sensitive data due to paging etc.
- * The GNU MP Library itself is published under the LGPL;
- * however I decided to publish this code under the plain GPL.
- */
-
-#include "mpi-internal.h"
-
-/****************
- * Add the unsigned integer V to the mpi-integer U and store the
- * result in W. U and V may be the same.
- */
-int mpi_add_ui(MPI w, const MPI u, unsigned long v)
-{
- mpi_ptr_t wp, up;
- mpi_size_t usize, wsize;
- int usign, wsign;
-
- usize = u->nlimbs;
- usign = u->sign;
- wsign = 0;
-
- /* If not space for W (and possible carry), increase space. */
- wsize = usize + 1;
- if (w->alloced < wsize)
- if (mpi_resize(w, wsize) < 0)
- return -ENOMEM;
-
- /* These must be after realloc (U may be the same as W). */
- up = u->d;
- wp = w->d;
-
- if (!usize) { /* simple */
- wp[0] = v;
- wsize = v ? 1 : 0;
- } else if (!usign) { /* mpi is not negative */
- mpi_limb_t cy;
- cy = mpihelp_add_1(wp, up, usize, v);
- wp[usize] = cy;
- wsize = usize + cy;
- } else { /* The signs are different. Need exact comparison to determine
- * which operand to subtract from which. */
- if (usize == 1 && up[0] < v) {
- wp[0] = v - up[0];
- wsize = 1;
- } else {
- mpihelp_sub_1(wp, up, usize, v);
- /* Size can decrease with at most one limb. */
- wsize = usize - (wp[usize - 1] == 0);
- wsign = 1;
- }
- }
-
- w->nlimbs = wsize;
- w->sign = wsign;
- return 0;
-}
-
-int mpi_add(MPI w, MPI u, MPI v)
-{
- mpi_ptr_t wp, up, vp;
- mpi_size_t usize, vsize, wsize;
- int usign, vsign, wsign;
-
- if (u->nlimbs < v->nlimbs) { /* Swap U and V. */
- usize = v->nlimbs;
- usign = v->sign;
- vsize = u->nlimbs;
- vsign = u->sign;
- wsize = usize + 1;
- if (RESIZE_IF_NEEDED(w, wsize) < 0)
- return -ENOMEM;
- /* These must be after realloc (u or v may be the same as w). */
- up = v->d;
- vp = u->d;
- } else {
- usize = u->nlimbs;
- usign = u->sign;
- vsize = v->nlimbs;
- vsign = v->sign;
- wsize = usize + 1;
- if (RESIZE_IF_NEEDED(w, wsize) < 0)
- return -ENOMEM;
- /* These must be after realloc (u or v may be the same as w). */
- up = u->d;
- vp = v->d;
- }
- wp = w->d;
- wsign = 0;
-
- if (!vsize) { /* simple */
- MPN_COPY(wp, up, usize);
- wsize = usize;
- wsign = usign;
- } else if (usign != vsign) { /* different sign */
- /* This test is right since USIZE >= VSIZE */
- if (usize != vsize) {
- mpihelp_sub(wp, up, usize, vp, vsize);
- wsize = usize;
- MPN_NORMALIZE(wp, wsize);
- wsign = usign;
- } else if (mpihelp_cmp(up, vp, usize) < 0) {
- mpihelp_sub_n(wp, vp, up, usize);
- wsize = usize;
- MPN_NORMALIZE(wp, wsize);
- if (!usign)
- wsign = 1;
- } else {
- mpihelp_sub_n(wp, up, vp, usize);
- wsize = usize;
- MPN_NORMALIZE(wp, wsize);
- if (usign)
- wsign = 1;
- }
- } else { /* U and V have same sign. Add them. */
- mpi_limb_t cy = mpihelp_add(wp, up, usize, vp, vsize);
- wp[usize] = cy;
- wsize = usize + cy;
- if (usign)
- wsign = 1;
- }
-
- w->nlimbs = wsize;
- w->sign = wsign;
- return 0;
-}
-
-/****************
- * Subtract the unsigned integer V from the mpi-integer U and store the
- * result in W.
- */
-int mpi_sub_ui(MPI w, MPI u, unsigned long v)
-{
- mpi_ptr_t wp, up;
- mpi_size_t usize, wsize;
- int usign, wsign;
-
- usize = u->nlimbs;
- usign = u->sign;
- wsign = 0;
-
- /* If not space for W (and possible carry), increase space. */
- wsize = usize + 1;
- if (w->alloced < wsize)
- if (mpi_resize(w, wsize) < 0)
- return -ENOMEM;
-
- /* These must be after realloc (U may be the same as W). */
- up = u->d;
- wp = w->d;
-
- if (!usize) { /* simple */
- wp[0] = v;
- wsize = v ? 1 : 0;
- wsign = 1;
- } else if (usign) { /* mpi and v are negative */
- mpi_limb_t cy;
- cy = mpihelp_add_1(wp, up, usize, v);
- wp[usize] = cy;
- wsize = usize + cy;
- } else { /* The signs are different. Need exact comparison to determine
- * which operand to subtract from which. */
- if (usize == 1 && up[0] < v) {
- wp[0] = v - up[0];
- wsize = 1;
- wsign = 1;
- } else {
- mpihelp_sub_1(wp, up, usize, v);
- /* Size can decrease with at most one limb. */
- wsize = usize - (wp[usize - 1] == 0);
- }
- }
-
- w->nlimbs = wsize;
- w->sign = wsign;
- return 0;
-}
-
-int mpi_sub(MPI w, MPI u, MPI v)
-{
- int rc;
-
- if (w == v) {
- MPI vv;
- if (mpi_copy(&vv, v) < 0)
- return -ENOMEM;
- vv->sign = !vv->sign;
- rc = mpi_add(w, u, vv);
- mpi_free(vv);
- } else {
- /* fixme: this is not thread-save (we temp. modify v) */
- v->sign = !v->sign;
- rc = mpi_add(w, u, v);
- v->sign = !v->sign;
- }
- return rc;
-}
-
-int mpi_addm(MPI w, MPI u, MPI v, MPI m)
-{
- if (mpi_add(w, u, v) < 0 || mpi_fdiv_r(w, w, m) < 0)
- return -ENOMEM;
- return 0;
-}
-
-int mpi_subm(MPI w, MPI u, MPI v, MPI m)
-{
- if (mpi_sub(w, u, v) < 0 || mpi_fdiv_r(w, w, m) < 0)
- return -ENOMEM;
- return 0;
-}
+++ /dev/null
-/* mpi-cmp.c - MPI functions
- * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
- *
- * This file is part of GnuPG.
- *
- * GnuPG is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GnuPG is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
-
-#include "mpi-internal.h"
-
-int mpi_cmp_ui(MPI u, unsigned long v)
-{
- mpi_limb_t limb = v;
-
- mpi_normalize(u);
- if (!u->nlimbs && !limb)
- return 0;
- if (u->sign)
- return -1;
- if (u->nlimbs > 1)
- return 1;
-
- if (u->d[0] == limb)
- return 0;
- else if (u->d[0] > limb)
- return 1;
- else
- return -1;
-}
-
-int mpi_cmp(MPI u, MPI v)
-{
- mpi_size_t usize, vsize;
- int cmp;
-
- mpi_normalize(u);
- mpi_normalize(v);
- usize = u->nlimbs;
- vsize = v->nlimbs;
- if (!u->sign && v->sign)
- return 1;
- if (u->sign && !v->sign)
- return -1;
- if (usize != vsize && !u->sign && !v->sign)
- return usize - vsize;
- if (usize != vsize && u->sign && v->sign)
- return vsize + usize;
- if (!usize)
- return 0;
- cmp = mpihelp_cmp(u->d, v->d, usize);
- if (!cmp)
- return 0;
- if ((cmp < 0 ? 1 : 0) == (u->sign ? 1 : 0))
- return 1;
- return -1;
-}
+++ /dev/null
-/* mpi-div.c - MPI functions
- * Copyright (C) 1994, 1996 Free Software Foundation, Inc.
- * Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
- *
- * This file is part of GnuPG.
- *
- * GnuPG is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GnuPG is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- *
- * Note: This code is heavily based on the GNU MP Library.
- * Actually it's the same code with only minor changes in the
- * way the data is stored; this is to support the abstraction
- * of an optional secure memory allocation which may be used
- * to avoid revealing of sensitive data due to paging etc.
- * The GNU MP Library itself is published under the LGPL;
- * however I decided to publish this code under the plain GPL.
- */
-
-#include <linux/string.h>
-#include "mpi-internal.h"
-#include "longlong.h"
-
-int mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor)
-{
- int rc = -ENOMEM;
- int divisor_sign = divisor->sign;
- MPI temp_divisor = NULL;
-
- /* We need the original value of the divisor after the remainder has been
- * preliminary calculated. We have to copy it to temporary space if it's
- * the same variable as REM. */
- if (rem == divisor) {
- if (mpi_copy(&temp_divisor, divisor) < 0)
- goto nomem;
- divisor = temp_divisor;
- }
-
- if (mpi_tdiv_qr(NULL, rem, dividend, divisor) < 0)
- goto nomem;
- if (((divisor_sign ? 1 : 0) ^ (dividend->sign ? 1 : 0)) && rem->nlimbs)
- if (mpi_add(rem, rem, divisor) < 0)
- goto nomem;
-
- rc = 0;
-
-nomem:
- if (temp_divisor)
- mpi_free(temp_divisor);
- return rc;
-}
-
-/****************
- * Division rounding the quotient towards -infinity.
- * The remainder gets the same sign as the denominator.
- * rem is optional
- */
-
-ulong mpi_fdiv_r_ui(MPI rem, MPI dividend, ulong divisor)
-{
- mpi_limb_t rlimb;
-
- rlimb = mpihelp_mod_1(dividend->d, dividend->nlimbs, divisor);
- if (rlimb && dividend->sign)
- rlimb = divisor - rlimb;
-
- if (rem) {
- rem->d[0] = rlimb;
- rem->nlimbs = rlimb ? 1 : 0;
- }
- return rlimb;
-}
-
-int mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor)
-{
- MPI tmp = mpi_alloc(mpi_get_nlimbs(quot));
- if (!tmp)
- return -ENOMEM;
- mpi_fdiv_qr(quot, tmp, dividend, divisor);
- mpi_free(tmp);
- return 0;
-}
-
-int mpi_fdiv_qr(MPI quot, MPI rem, MPI dividend, MPI divisor)
-{
- int divisor_sign = divisor->sign;
- MPI temp_divisor = NULL;
-
- if (quot == divisor || rem == divisor) {
- if (mpi_copy(&temp_divisor, divisor) < 0)
- return -ENOMEM;
- divisor = temp_divisor;
- }
-
- if (mpi_tdiv_qr(quot, rem, dividend, divisor) < 0)
- goto nomem;
-
- if ((divisor_sign ^ dividend->sign) && rem->nlimbs) {
- if (mpi_sub_ui(quot, quot, 1) < 0)
- goto nomem;
- if (mpi_add(rem, rem, divisor) < 0)
- goto nomem;
- }
-
- if (temp_divisor)
- mpi_free(temp_divisor);
-
- return 0;
-
-nomem:
- mpi_free(temp_divisor);
- return -ENOMEM;
-}
-
-/* If den == quot, den needs temporary storage.
- * If den == rem, den needs temporary storage.
- * If num == quot, num needs temporary storage.
- * If den has temporary storage, it can be normalized while being copied,
- * i.e no extra storage should be allocated.
- */
-
-int mpi_tdiv_r(MPI rem, MPI num, MPI den)
-{
- return mpi_tdiv_qr(NULL, rem, num, den);
-}
-
-int mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den)
-{
- int rc = -ENOMEM;
- mpi_ptr_t np, dp;
- mpi_ptr_t qp, rp;
- mpi_size_t nsize = num->nlimbs;
- mpi_size_t dsize = den->nlimbs;
- mpi_size_t qsize, rsize;
- mpi_size_t sign_remainder = num->sign;
- mpi_size_t sign_quotient = num->sign ^ den->sign;
- unsigned normalization_steps;
- mpi_limb_t q_limb;
- mpi_ptr_t marker[5];
- int markidx = 0;
-
- if (!dsize)
- return -EINVAL;
-
- memset(marker, 0, sizeof(marker));
-
- /* Ensure space is enough for quotient and remainder.
- * We need space for an extra limb in the remainder, because it's
- * up-shifted (normalized) below. */
- rsize = nsize + 1;
- if (mpi_resize(rem, rsize) < 0)
- goto nomem;
-
- qsize = rsize - dsize; /* qsize cannot be bigger than this. */
- if (qsize <= 0) {
- if (num != rem) {
- rem->nlimbs = num->nlimbs;
- rem->sign = num->sign;
- MPN_COPY(rem->d, num->d, nsize);
- }
- if (quot) {
- /* This needs to follow the assignment to rem, in case the
- * numerator and quotient are the same. */
- quot->nlimbs = 0;
- quot->sign = 0;
- }
- return 0;
- }
-
- if (quot)
- if (mpi_resize(quot, qsize) < 0)
- goto nomem;
-
- /* Read pointers here, when reallocation is finished. */
- np = num->d;
- dp = den->d;
- rp = rem->d;
-
- /* Optimize division by a single-limb divisor. */
- if (dsize == 1) {
- mpi_limb_t rlimb;
- if (quot) {
- qp = quot->d;
- rlimb = mpihelp_divmod_1(qp, np, nsize, dp[0]);
- qsize -= qp[qsize - 1] == 0;
- quot->nlimbs = qsize;
- quot->sign = sign_quotient;
- } else
- rlimb = mpihelp_mod_1(np, nsize, dp[0]);
- rp[0] = rlimb;
- rsize = rlimb != 0 ? 1 : 0;
- rem->nlimbs = rsize;
- rem->sign = sign_remainder;
- return 0;
- }
-
- if (quot) {
- qp = quot->d;
- /* Make sure QP and NP point to different objects. Otherwise the
- * numerator would be gradually overwritten by the quotient limbs. */
- if (qp == np) { /* Copy NP object to temporary space. */
- np = marker[markidx++] = mpi_alloc_limb_space(nsize);
- if (!np)
- goto nomem;
- MPN_COPY(np, qp, nsize);
- }
- } else /* Put quotient at top of remainder. */
- qp = rp + dsize;
-
- count_leading_zeros(normalization_steps, dp[dsize - 1]);
-
- /* Normalize the denominator, i.e. make its most significant bit set by
- * shifting it NORMALIZATION_STEPS bits to the left. Also shift the
- * numerator the same number of steps (to keep the quotient the same!).
- */
- if (normalization_steps) {
- mpi_ptr_t tp;
- mpi_limb_t nlimb;
-
- /* Shift up the denominator setting the most significant bit of
- * the most significant word. Use temporary storage not to clobber
- * the original contents of the denominator. */
- tp = marker[markidx++] = mpi_alloc_limb_space(dsize);
- if (!tp)
- goto nomem;
- mpihelp_lshift(tp, dp, dsize, normalization_steps);
- dp = tp;
-
- /* Shift up the numerator, possibly introducing a new most
- * significant word. Move the shifted numerator in the remainder
- * meanwhile. */
- nlimb = mpihelp_lshift(rp, np, nsize, normalization_steps);
- if (nlimb) {
- rp[nsize] = nlimb;
- rsize = nsize + 1;
- } else
- rsize = nsize;
- } else {
- /* The denominator is already normalized, as required. Copy it to
- * temporary space if it overlaps with the quotient or remainder. */
- if (dp == rp || (quot && (dp == qp))) {
- mpi_ptr_t tp;
-
- tp = marker[markidx++] = mpi_alloc_limb_space(dsize);
- if (!tp)
- goto nomem;
- MPN_COPY(tp, dp, dsize);
- dp = tp;
- }
-
- /* Move the numerator to the remainder. */
- if (rp != np)
- MPN_COPY(rp, np, nsize);
-
- rsize = nsize;
- }
-
- q_limb = mpihelp_divrem(qp, 0, rp, rsize, dp, dsize);
-
- if (quot) {
- qsize = rsize - dsize;
- if (q_limb) {
- qp[qsize] = q_limb;
- qsize += 1;
- }
-
- quot->nlimbs = qsize;
- quot->sign = sign_quotient;
- }
-
- rsize = dsize;
- MPN_NORMALIZE(rp, rsize);
-
- if (normalization_steps && rsize) {
- mpihelp_rshift(rp, rp, rsize, normalization_steps);
- rsize -= rp[rsize - 1] == 0 ? 1 : 0;
- }
-
- rem->nlimbs = rsize;
- rem->sign = sign_remainder;
-
- rc = 0;
-nomem:
- while (markidx)
- mpi_free_limb_space(marker[--markidx]);
- return rc;
-}
-
-int mpi_tdiv_q_2exp(MPI w, MPI u, unsigned count)
-{
- mpi_size_t usize, wsize;
- mpi_size_t limb_cnt;
-
- usize = u->nlimbs;
- limb_cnt = count / BITS_PER_MPI_LIMB;
- wsize = usize - limb_cnt;
- if (limb_cnt >= usize)
- w->nlimbs = 0;
- else {
- mpi_ptr_t wp;
- mpi_ptr_t up;
-
- if (RESIZE_IF_NEEDED(w, wsize) < 0)
- return -ENOMEM;
- wp = w->d;
- up = u->d;
-
- count %= BITS_PER_MPI_LIMB;
- if (count) {
- mpihelp_rshift(wp, up + limb_cnt, wsize, count);
- wsize -= !wp[wsize - 1];
- } else {
- MPN_COPY_INCR(wp, up + limb_cnt, wsize);
- }
-
- w->nlimbs = wsize;
- }
- return 0;
-}
-
-/****************
- * Check whether dividend is divisible by divisor
- * (note: divisor must fit into a limb)
- */
-int mpi_divisible_ui(MPI dividend, ulong divisor)
-{
- return !mpihelp_mod_1(dividend->d, dividend->nlimbs, divisor);
-}
+++ /dev/null
-/* mpi-gcd.c - MPI functions
- * Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
- *
- * This file is part of GnuPG.
- *
- * GnuPG is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GnuPG is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
-
-#include "mpi-internal.h"
-
-/****************
- * Find the greatest common divisor G of A and B.
- * Return: true if this 1, false in all other cases
- */
-int mpi_gcd(MPI g, const MPI xa, const MPI xb)
-{
- MPI a = NULL, b = NULL;
-
- if (mpi_copy(&a, xa) < 0)
- goto nomem;
-
- if (mpi_copy(&b, xb) < 0)
- goto nomem;
-
- /* TAOCP Vol II, 4.5.2, Algorithm A */
- a->sign = 0;
- b->sign = 0;
- while (mpi_cmp_ui(b, 0)) {
- if (mpi_fdiv_r(g, a, b) < 0) /* g used as temorary variable */
- goto nomem;
- if (mpi_set(a, b) < 0)
- goto nomem;
- if (mpi_set(b, g) < 0)
- goto nomem;
- }
- if (mpi_set(g, a) < 0)
- goto nomem;
-
- mpi_free(a);
- mpi_free(b);
- return !mpi_cmp_ui(g, 1);
-
-nomem:
- mpi_free(a);
- mpi_free(b);
- return -ENOMEM;
-}
+++ /dev/null
-/* mpi-inline.c
- * Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
- *
- * This file is part of GnuPG.
- *
- * GnuPG is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GnuPG is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
-
-/* put the inline functions as real functions into the lib */
-#define G10_MPI_INLINE_DECL
-
-#include "mpi-internal.h"
-
-/* always include the header becuase it is only
- * included by mpi-internal if __GCC__ is defined but we
- * need it here in all cases and the above definition of
- * of the macro allows us to do so
- */
-#include "mpi-inline.h"
+++ /dev/null
-/* mpi-inv.c - MPI functions
- * Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
- *
- * This file is part of GnuPG.
- *
- * GnuPG is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GnuPG is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
-
-#include "mpi-internal.h"
-
-/****************
- * Calculate the multiplicative inverse X of A mod N
- * That is: Find the solution x for
- * 1 = (a*x) mod n
- */
-int mpi_invm(MPI x, const MPI a, const MPI n)
-{
- /* Extended Euclid's algorithm (See TAOPC Vol II, 4.5.2, Alg X)
- * modified according to Michael Penk's solution for Exercice 35
- * with further enhancement */
- MPI u = NULL, v = NULL;
- MPI u1 = NULL, u2 = NULL, u3 = NULL;
- MPI v1 = NULL, v2 = NULL, v3 = NULL;
- MPI t1 = NULL, t2 = NULL, t3 = NULL;
- unsigned k;
- int sign;
- int odd = 0;
- int rc = -ENOMEM;
-
- if (mpi_copy(&u, a) < 0)
- goto cleanup;
- if (mpi_copy(&v, n) < 0)
- goto cleanup;
-
- for (k = 0; !mpi_test_bit(u, 0) && !mpi_test_bit(v, 0); k++) {
- if (mpi_rshift(u, u, 1) < 0)
- goto cleanup;
- if (mpi_rshift(v, v, 1) < 0)
- goto cleanup;
- }
- odd = mpi_test_bit(v, 0);
-
- u1 = mpi_alloc_set_ui(1);
- if (!u1)
- goto cleanup;
- if (!odd) {
- u2 = mpi_alloc_set_ui(0);
- if (!u2)
- goto cleanup;
- }
- if (mpi_copy(&u3, u) < 0)
- goto cleanup;
- if (mpi_copy(&v1, v) < 0)
- goto cleanup;
- if (!odd) {
- v2 = mpi_alloc(mpi_get_nlimbs(u));
- if (!v2)
- goto cleanup;
- if (mpi_sub(v2, u1, u) < 0)
- goto cleanup; /* U is used as const 1 */
- }
- if (mpi_copy(&v3, v) < 0)
- goto cleanup;
- if (mpi_test_bit(u, 0)) { /* u is odd */
- t1 = mpi_alloc_set_ui(0);
- if (!t1)
- goto cleanup;
- if (!odd) {
- t2 = mpi_alloc_set_ui(1);
- if (!t2)
- goto cleanup;
- t2->sign = 1;
- }
- if (mpi_copy(&t3, v) < 0)
- goto cleanup;
- t3->sign = !t3->sign;
- goto Y4;
- } else {
- t1 = mpi_alloc_set_ui(1);
- if (!t1)
- goto cleanup;
- if (!odd) {
- t2 = mpi_alloc_set_ui(0);
- if (!t2)
- goto cleanup;
- }
- if (mpi_copy(&t3, u) < 0)
- goto cleanup;
- }
- do {
- do {
- if (!odd) {
- if (mpi_test_bit(t1, 0) || mpi_test_bit(t2, 0)) { /* one is odd */
- if (mpi_add(t1, t1, v) < 0)
- goto cleanup;
- if (mpi_sub(t2, t2, u) < 0)
- goto cleanup;
- }
- if (mpi_rshift(t1, t1, 1) < 0)
- goto cleanup;
- if (mpi_rshift(t2, t2, 1) < 0)
- goto cleanup;
- if (mpi_rshift(t3, t3, 1) < 0)
- goto cleanup;
- } else {
- if (mpi_test_bit(t1, 0))
- if (mpi_add(t1, t1, v) < 0)
- goto cleanup;
- if (mpi_rshift(t1, t1, 1) < 0)
- goto cleanup;
- if (mpi_rshift(t3, t3, 1) < 0)
- goto cleanup;
- }
-Y4:
- ;
- } while (!mpi_test_bit(t3, 0)); /* while t3 is even */
-
- if (!t3->sign) {
- if (mpi_set(u1, t1) < 0)
- goto cleanup;
- if (!odd)
- if (mpi_set(u2, t2) < 0)
- goto cleanup;
- if (mpi_set(u3, t3) < 0)
- goto cleanup;
- } else {
- if (mpi_sub(v1, v, t1) < 0)
- goto cleanup;
- sign = u->sign;
- u->sign = !u->sign;
- if (!odd)
- if (mpi_sub(v2, u, t2) < 0)
- goto cleanup;
- u->sign = sign;
- sign = t3->sign;
- t3->sign = !t3->sign;
- if (mpi_set(v3, t3) < 0)
- goto cleanup;
- t3->sign = sign;
- }
- if (mpi_sub(t1, u1, v1) < 0)
- goto cleanup;
- if (!odd)
- if (mpi_sub(t2, u2, v2) < 0)
- goto cleanup;
- if (mpi_sub(t3, u3, v3) < 0)
- goto cleanup;
- if (t1->sign) {
- if (mpi_add(t1, t1, v) < 0)
- goto cleanup;
- if (!odd)
- if (mpi_sub(t2, t2, u) < 0)
- goto cleanup;
- }
- } while (mpi_cmp_ui(t3, 0)); /* while t3 != 0 */
- /* mpi_lshift( u3, k ); */
- rc = mpi_set(x, u1);
-
-cleanup:
- mpi_free(u1);
- mpi_free(v1);
- mpi_free(t1);
- if (!odd) {
- mpi_free(u2);
- mpi_free(v2);
- mpi_free(t2);
- }
- mpi_free(u3);
- mpi_free(v3);
- mpi_free(t3);
-
- mpi_free(u);
- mpi_free(v);
- return rc;
-}
+++ /dev/null
-/* mpi-mpow.c - MPI functions
- * Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
- *
- * This file is part of GnuPG.
- *
- * GnuPG is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GnuPG is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
-
-#include "mpi-internal.h"
-#include "longlong.h"
-
-static int build_index(const MPI *exparray, int k, int i, int t)
-{
- int j, bitno;
- int index = 0;
-
- bitno = t - i;
- for (j = k - 1; j >= 0; j--) {
- index <<= 1;
- if (mpi_test_bit(exparray[j], bitno))
- index |= 1;
- }
- return index;
-}
-
-/****************
- * RES = (BASE[0] ^ EXP[0]) * (BASE[1] ^ EXP[1]) * ... * mod M
- */
-int mpi_mulpowm(MPI res, MPI *basearray, MPI *exparray, MPI m)
-{
- int rc = -ENOMEM;
- int k; /* number of elements */
- int t; /* bit size of largest exponent */
- int i, j, idx;
- MPI *G = NULL; /* table with precomputed values of size 2^k */
- MPI tmp = NULL;
-
- for (k = 0; basearray[k]; k++)
- ;
- if (!k) {
- pr_emerg("mpi_mulpowm: assert(k) failed\n");
- BUG();
- }
- for (t = 0, i = 0; (tmp = exparray[i]); i++) {
- j = mpi_get_nbits(tmp);
- if (j > t)
- t = j;
- }
- if (i != k) {
- pr_emerg("mpi_mulpowm: assert(i==k) failed\n");
- BUG();
- }
- if (!t) {
- pr_emerg("mpi_mulpowm: assert(t) failed\n");
- BUG();
- }
- if (k >= 10) {
- pr_emerg("mpi_mulpowm: assert(k<10) failed\n");
- BUG();
- }
-
- G = kzalloc((1 << k) * sizeof *G, GFP_KERNEL);
- if (!G)
- goto err_out;
-
- /* and calculate */
- tmp = mpi_alloc(mpi_get_nlimbs(m) + 1);
- if (!tmp)
- goto nomem;
- if (mpi_set_ui(res, 1) < 0)
- goto nomem;
- for (i = 1; i <= t; i++) {
- if (mpi_mulm(tmp, res, res, m) < 0)
- goto nomem;
- idx = build_index(exparray, k, i, t);
- if (!(idx >= 0 && idx < (1 << k))) {
- pr_emerg("mpi_mulpowm: assert(idx >= 0 && idx < (1<<k)) failed\n");
- BUG();
- }
- if (!G[idx]) {
- if (!idx) {
- G[0] = mpi_alloc_set_ui(1);
- if (!G[0])
- goto nomem;
- } else {
- for (j = 0; j < k; j++) {
- if ((idx & (1 << j))) {
- if (!G[idx]) {
- if (mpi_copy
- (&G[idx],
- basearray[j]) < 0)
- goto nomem;
- } else {
- if (mpi_mulm
- (G[idx], G[idx],
- basearray[j],
- m) < 0)
- goto nomem;
- }
- }
- }
- if (!G[idx]) {
- G[idx] = mpi_alloc(0);
- if (!G[idx])
- goto nomem;
- }
- }
- }
- if (mpi_mulm(res, tmp, G[idx], m) < 0)
- goto nomem;
- }
-
- rc = 0;
-nomem:
- /* cleanup */
- mpi_free(tmp);
- for (i = 0; i < (1 << k); i++)
- mpi_free(G[i]);
- kfree(G);
-err_out:
- return rc;
-}
+++ /dev/null
-/* mpi-mul.c - MPI functions
- * Copyright (C) 1994, 1996 Free Software Foundation, Inc.
- * Copyright (C) 1998, 2001 Free Software Foundation, Inc.
- *
- * This file is part of GnuPG.
- *
- * GnuPG is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GnuPG is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- *
- * Note: This code is heavily based on the GNU MP Library.
- * Actually it's the same code with only minor changes in the
- * way the data is stored; this is to support the abstraction
- * of an optional secure memory allocation which may be used
- * to avoid revealing of sensitive data due to paging etc.
- * The GNU MP Library itself is published under the LGPL;
- * however I decided to publish this code under the plain GPL.
- */
-
-#include "mpi-internal.h"
-
-int mpi_mul_ui(MPI prod, MPI mult, unsigned long small_mult)
-{
- mpi_size_t size, prod_size;
- mpi_ptr_t prod_ptr;
- mpi_limb_t cy;
- int sign;
-
- size = mult->nlimbs;
- sign = mult->sign;
-
- if (!size || !small_mult) {
- prod->nlimbs = 0;
- prod->sign = 0;
- return 0;
- }
-
- prod_size = size + 1;
- if (prod->alloced < prod_size)
- if (mpi_resize(prod, prod_size) < 0)
- return -ENOMEM;
- prod_ptr = prod->d;
-
- cy = mpihelp_mul_1(prod_ptr, mult->d, size, (mpi_limb_t) small_mult);
- if (cy)
- prod_ptr[size++] = cy;
- prod->nlimbs = size;
- prod->sign = sign;
- return 0;
-}
-
-int mpi_mul_2exp(MPI w, MPI u, unsigned long cnt)
-{
- mpi_size_t usize, wsize, limb_cnt;
- mpi_ptr_t wp;
- mpi_limb_t wlimb;
- int usign, wsign;
-
- usize = u->nlimbs;
- usign = u->sign;
-
- if (!usize) {
- w->nlimbs = 0;
- w->sign = 0;
- return 0;
- }
-
- limb_cnt = cnt / BITS_PER_MPI_LIMB;
- wsize = usize + limb_cnt + 1;
- if (w->alloced < wsize)
- if (mpi_resize(w, wsize) < 0)
- return -ENOMEM;
- wp = w->d;
- wsize = usize + limb_cnt;
- wsign = usign;
-
- cnt %= BITS_PER_MPI_LIMB;
- if (cnt) {
- wlimb = mpihelp_lshift(wp + limb_cnt, u->d, usize, cnt);
- if (wlimb) {
- wp[wsize] = wlimb;
- wsize++;
- }
- } else {
- MPN_COPY_DECR(wp + limb_cnt, u->d, usize);
- }
-
- /* Zero all whole limbs at low end. Do it here and not before calling
- * mpn_lshift, not to lose for U == W. */
- MPN_ZERO(wp, limb_cnt);
-
- w->nlimbs = wsize;
- w->sign = wsign;
- return 0;
-}
-
-int mpi_mul(MPI w, MPI u, MPI v)
-{
- int rc = -ENOMEM;
- mpi_size_t usize, vsize, wsize;
- mpi_ptr_t up, vp, wp;
- mpi_limb_t cy;
- int usign, vsign, sign_product;
- int assign_wp = 0;
- mpi_ptr_t tmp_limb = NULL;
-
- if (u->nlimbs < v->nlimbs) { /* Swap U and V. */
- usize = v->nlimbs;
- usign = v->sign;
- up = v->d;
- vsize = u->nlimbs;
- vsign = u->sign;
- vp = u->d;
- } else {
- usize = u->nlimbs;
- usign = u->sign;
- up = u->d;
- vsize = v->nlimbs;
- vsign = v->sign;
- vp = v->d;
- }
- sign_product = usign ^ vsign;
- wp = w->d;
-
- /* Ensure W has space enough to store the result. */
- wsize = usize + vsize;
- if (w->alloced < (size_t) wsize) {
- if (wp == up || wp == vp) {
- wp = mpi_alloc_limb_space(wsize);
- if (!wp)
- goto nomem;
- assign_wp = 1;
- } else {
- if (mpi_resize(w, wsize) < 0)
- goto nomem;
- wp = w->d;
- }
- } else { /* Make U and V not overlap with W. */
- if (wp == up) {
- /* W and U are identical. Allocate temporary space for U. */
- up = tmp_limb = mpi_alloc_limb_space(usize);
- if (!up)
- goto nomem;
- /* Is V identical too? Keep it identical with U. */
- if (wp == vp)
- vp = up;
- /* Copy to the temporary space. */
- MPN_COPY(up, wp, usize);
- } else if (wp == vp) {
- /* W and V are identical. Allocate temporary space for V. */
- vp = tmp_limb = mpi_alloc_limb_space(vsize);
- if (!vp)
- goto nomem;
- /* Copy to the temporary space. */
- MPN_COPY(vp, wp, vsize);
- }
- }
-
- if (!vsize)
- wsize = 0;
- else {
- if (mpihelp_mul(wp, up, usize, vp, vsize, &cy) < 0)
- goto nomem;
- wsize -= cy ? 0 : 1;
- }
-
- if (assign_wp)
- mpi_assign_limb_space(w, wp, wsize);
-
- w->nlimbs = wsize;
- w->sign = sign_product;
- rc = 0;
-nomem:
- if (tmp_limb)
- mpi_free_limb_space(tmp_limb);
- return rc;
-}
-
-int mpi_mulm(MPI w, MPI u, MPI v, MPI m)
-{
- if (mpi_mul(w, u, v) < 0)
- return -ENOMEM;
- return mpi_fdiv_r(w, w, m);
-}
+++ /dev/null
-/* mpi-scan.c - MPI functions
- * Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
- *
- * This file is part of GnuPG.
- *
- * GnuPG is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GnuPG is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
-
-#include "mpi-internal.h"
-#include "longlong.h"
-
-/****************
- * Scan through an mpi and return byte for byte. a -1 is returned to indicate
- * the end of the mpi. Scanning is done from the lsb to the msb, returned
- * values are in the range of 0 .. 255.
- *
- * FIXME: This code is VERY ugly!
- */
-int mpi_getbyte(const MPI a, unsigned idx)
-{
- int i, j;
- unsigned n;
- mpi_ptr_t ap;
- mpi_limb_t limb;
-
- ap = a->d;
- for (n = 0, i = 0; i < a->nlimbs; i++) {
- limb = ap[i];
- for (j = 0; j < BYTES_PER_MPI_LIMB; j++, n++)
- if (n == idx)
- return (limb >> j * 8) & 0xff;
- }
- return -1;
-}
-
-/****************
- * Put a value at position IDX into A. idx counts from lsb to msb
- */
-void mpi_putbyte(MPI a, unsigned idx, int xc)
-{
- int i, j;
- unsigned n;
- mpi_ptr_t ap;
- mpi_limb_t limb, c;
-
- c = xc & 0xff;
- ap = a->d;
- for (n = 0, i = 0; i < a->alloced; i++) {
- limb = ap[i];
- for (j = 0; j < BYTES_PER_MPI_LIMB; j++, n++)
- if (n == idx) {
-#if BYTES_PER_MPI_LIMB == 4
- if (j == 0)
- limb = (limb & 0xffffff00) | c;
- else if (j == 1)
- limb = (limb & 0xffff00ff) | (c << 8);
- else if (j == 2)
- limb = (limb & 0xff00ffff) | (c << 16);
- else
- limb = (limb & 0x00ffffff) | (c << 24);
-#elif BYTES_PER_MPI_LIMB == 8
- if (j == 0)
- limb = (limb & 0xffffffffffffff00) | c;
- else if (j == 1)
- limb =
- (limb & 0xffffffffffff00ff) | (c <<
- 8);
- else if (j == 2)
- limb =
- (limb & 0xffffffffff00ffff) | (c <<
- 16);
- else if (j == 3)
- limb =
- (limb & 0xffffffff00ffffff) | (c <<
- 24);
- else if (j == 4)
- limb =
- (limb & 0xffffff00ffffffff) | (c <<
- 32);
- else if (j == 5)
- limb =
- (limb & 0xffff00ffffffffff) | (c <<
- 40);
- else if (j == 6)
- limb =
- (limb & 0xff00ffffffffffff) | (c <<
- 48);
- else
- limb =
- (limb & 0x00ffffffffffffff) | (c <<
- 56);
-#else
-#error please enhance this function, its ugly - i know.
-#endif
- if (a->nlimbs <= i)
- a->nlimbs = i + 1;
- ap[i] = limb;
- return;
- }
- }
- log_bug("index out of range\n");
-}
-
-/****************
- * Count the number of zerobits at the low end of A
- */
-unsigned mpi_trailing_zeros(const MPI a)
-{
- unsigned n, count = 0;
-
- for (n = 0; n < a->nlimbs; n++) {
- if (a->d[n]) {
- unsigned nn;
- mpi_limb_t alimb = a->d[n];
-
- count_trailing_zeros(nn, alimb);
- count += nn;
- break;
- }
- count += BITS_PER_MPI_LIMB;
- }
- return count;
-
-}
projects / mirror_ubuntu-eoan-kernel.git / commitdiff