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-rw-r--r--lib/mpi/mpi-div.c338
1 files changed, 0 insertions, 338 deletions
diff --git a/lib/mpi/mpi-div.c b/lib/mpi/mpi-div.c
deleted file mode 100644
index f68cbbb4d4a4..000000000000
--- a/lib/mpi/mpi-div.c
+++ /dev/null
@@ -1,338 +0,0 @@
-/* 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);
-}