1 /* mpiutil.ac - Utility functions for MPI 2 * Copyright (C) 1998, 1999 Free Software Foundation, Inc. 3 * 4 * This file is part of GnuPG. 5 * 6 * GnuPG is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * GnuPG is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 19 */ 20 21 #include <linux/export.h> 22 23 #include "mpi-internal.h" 24 25 /**************** 26 * Note: It was a bad idea to use the number of limbs to allocate 27 * because on a alpha the limbs are large but we normally need 28 * integers of n bits - So we should change this to bits (or bytes). 29 * 30 * But mpi_alloc is used in a lot of places :-) 31 */ 32 MPI mpi_alloc(unsigned nlimbs) 33 { 34 MPI a; 35 36 a = kmalloc(sizeof *a, GFP_KERNEL); 37 if (!a) 38 return a; 39 40 if (nlimbs) { 41 a->d = mpi_alloc_limb_space(nlimbs); 42 if (!a->d) { 43 kfree(a); 44 return NULL; 45 } 46 } else { 47 a->d = NULL; 48 } 49 50 a->alloced = nlimbs; 51 a->nlimbs = 0; 52 a->sign = 0; 53 a->flags = 0; 54 a->nbits = 0; 55 return a; 56 } 57 EXPORT_SYMBOL_GPL(mpi_alloc); 58 59 mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs) 60 { 61 size_t len = nlimbs * sizeof(mpi_limb_t); 62 63 if (!len) 64 return NULL; 65 66 return kmalloc(len, GFP_KERNEL); 67 } 68 69 void mpi_free_limb_space(mpi_ptr_t a) 70 { 71 if (!a) 72 return; 73 74 kfree_sensitive(a); 75 } 76 77 void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs) 78 { 79 mpi_free_limb_space(a->d); 80 a->d = ap; 81 a->alloced = nlimbs; 82 } 83 84 /**************** 85 * Resize the array of A to NLIMBS. the additional space is cleared 86 * (set to 0) [done by m_realloc()] 87 */ 88 int mpi_resize(MPI a, unsigned nlimbs) 89 { 90 void *p; 91 92 if (nlimbs <= a->alloced) 93 return 0; /* no need to do it */ 94 95 if (a->d) { 96 p = kcalloc(nlimbs, sizeof(mpi_limb_t), GFP_KERNEL); 97 if (!p) 98 return -ENOMEM; 99 memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t)); 100 kfree_sensitive(a->d); 101 a->d = p; 102 } else { 103 a->d = kcalloc(nlimbs, sizeof(mpi_limb_t), GFP_KERNEL); 104 if (!a->d) 105 return -ENOMEM; 106 } 107 a->alloced = nlimbs; 108 return 0; 109 } 110 111 void mpi_free(MPI a) 112 { 113 if (!a) 114 return; 115 116 if (a->flags & 4) 117 kfree_sensitive(a->d); 118 else 119 mpi_free_limb_space(a->d); 120 121 if (a->flags & ~7) 122 pr_info("invalid flag value in mpi\n"); 123 kfree(a); 124 } 125 EXPORT_SYMBOL_GPL(mpi_free); 126 127 /**************** 128 * Note: This copy function should not interpret the MPI 129 * but copy it transparently. 130 */ 131 MPI mpi_copy(MPI a) 132 { 133 int i; 134 MPI b; 135 136 if (a) { 137 b = mpi_alloc(a->nlimbs); 138 if (!b) 139 return NULL; 140 b->nlimbs = a->nlimbs; 141 b->sign = a->sign; 142 b->flags = a->flags; 143 b->flags &= ~(16|32); /* Reset the immutable and constant flags. */ 144 for (i = 0; i < b->nlimbs; i++) 145 b->d[i] = a->d[i]; 146 } else 147 b = NULL; 148 return b; 149 } 150 151 MODULE_DESCRIPTION("Multiprecision maths library"); 152 MODULE_LICENSE("GPL"); 153