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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 | /* mpi-inline.h - Internal to the Multi Precision Integers * Copyright (C) 1994, 1996, 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 * * 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. */ #ifndef G10_MPI_INLINE_H #define G10_MPI_INLINE_H #ifndef G10_MPI_INLINE_DECL #define G10_MPI_INLINE_DECL extern inline #endif G10_MPI_INLINE_DECL mpi_limb_t mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size, mpi_limb_t s2_limb) { mpi_limb_t x; x = *s1_ptr++; s2_limb += x; *res_ptr++ = s2_limb; if (s2_limb < x) { /* sum is less than the left operand: handle carry */ while (--s1_size) { x = *s1_ptr++ + 1; /* add carry */ *res_ptr++ = x; /* and store */ if (x) /* not 0 (no overflow): we can stop */ goto leave; } return 1; /* return carry (size of s1 to small) */ } leave: if (res_ptr != s1_ptr) { /* not the same variable */ mpi_size_t i; /* copy the rest */ for (i = 0; i < s1_size - 1; i++) res_ptr[i] = s1_ptr[i]; } return 0; /* no carry */ } G10_MPI_INLINE_DECL mpi_limb_t mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size, mpi_ptr_t s2_ptr, mpi_size_t s2_size) { mpi_limb_t cy = 0; if (s2_size) cy = mpihelp_add_n(res_ptr, s1_ptr, s2_ptr, s2_size); if (s1_size - s2_size) cy = mpihelp_add_1(res_ptr + s2_size, s1_ptr + s2_size, s1_size - s2_size, cy); return cy; } G10_MPI_INLINE_DECL mpi_limb_t mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size, mpi_limb_t s2_limb) { mpi_limb_t x; x = *s1_ptr++; s2_limb = x - s2_limb; *res_ptr++ = s2_limb; if (s2_limb > x) { while (--s1_size) { x = *s1_ptr++; *res_ptr++ = x - 1; if (x) goto leave; } return 1; } leave: if (res_ptr != s1_ptr) { mpi_size_t i; for (i = 0; i < s1_size - 1; i++) res_ptr[i] = s1_ptr[i]; } return 0; } G10_MPI_INLINE_DECL mpi_limb_t mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size, mpi_ptr_t s2_ptr, mpi_size_t s2_size) { mpi_limb_t cy = 0; if (s2_size) cy = mpihelp_sub_n(res_ptr, s1_ptr, s2_ptr, s2_size); if (s1_size - s2_size) cy = mpihelp_sub_1(res_ptr + s2_size, s1_ptr + s2_size, s1_size - s2_size, cy); return cy; } #endif /*G10_MPI_INLINE_H */ |