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Diffstat (limited to 'lib/mpi/mpi-add.c')
| -rw-r--r-- | lib/mpi/mpi-add.c | 234 |
1 files changed, 0 insertions, 234 deletions
diff --git a/lib/mpi/mpi-add.c b/lib/mpi/mpi-add.c deleted file mode 100644 index f56b9ba..0000000 --- a/lib/mpi/mpi-add.c +++ /dev/null @@ -1,234 +0,0 @@ -/* 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; -} |
