| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Normal-basis translation for binary fields |
| 4 | * |
| 5 | * (c) 2004 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of Catacomb. |
| 11 | * |
| 12 | * Catacomb is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU Library General Public License as |
| 14 | * published by the Free Software Foundation; either version 2 of the |
| 15 | * License, or (at your option) any later version. |
| 16 | * |
| 17 | * Catacomb is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU Library General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU Library General Public |
| 23 | * License along with Catacomb; if not, write to the Free |
| 24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 25 | * MA 02111-1307, USA. |
| 26 | */ |
| 27 | |
| 28 | #ifndef CATACOMB_GFN_H |
| 29 | #define CATACOMB_GFN_H |
| 30 | |
| 31 | #ifdef __cplusplus |
| 32 | extern "C" { |
| 33 | #endif |
| 34 | |
| 35 | /*----- Header files ------------------------------------------------------*/ |
| 36 | |
| 37 | #include "gf.h" |
| 38 | |
| 39 | /*----- Data structures ---------------------------------------------------*/ |
| 40 | |
| 41 | typedef struct gfn { |
| 42 | size_t n; /* Number of rows */ |
| 43 | mp **r; /* Array of the rows */ |
| 44 | } gfn; |
| 45 | |
| 46 | /*----- Functions provided ------------------------------------------------*/ |
| 47 | |
| 48 | /* --- @gfn_copy@ --- * |
| 49 | * |
| 50 | * Arguments: @gfn *d@ = where to put the copy |
| 51 | * @const gfn *s@ = where the source is |
| 52 | * |
| 53 | * Returns: --- |
| 54 | * |
| 55 | * Use: Makes a copy of a translation matrix. |
| 56 | */ |
| 57 | |
| 58 | extern void gfn_copy(gfn */*d*/, const gfn */*s*/); |
| 59 | |
| 60 | /* --- @gfn_destroy@ --- * |
| 61 | * |
| 62 | * Arguments: @gfn *m@ = a transformation matrix to free |
| 63 | * |
| 64 | * Returns: --- |
| 65 | * |
| 66 | * Use: Frees up a transformation matrix when it's no longer wanted. |
| 67 | */ |
| 68 | |
| 69 | extern void gfn_destroy(gfn */*m*/); |
| 70 | |
| 71 | /* --- @gfn_identity@ --- * |
| 72 | * |
| 73 | * Arguments: @gfn *m@ = where to put the matrix |
| 74 | * @size_t n@ = size of the matrix |
| 75 | * |
| 76 | * Returns: --- |
| 77 | * |
| 78 | * Use: Fills @m@ with an identity matrix. |
| 79 | */ |
| 80 | |
| 81 | extern void gfn_identity(gfn */*m*/, size_t /*n*/); |
| 82 | |
| 83 | /* --- @gfn_invert@ --- * |
| 84 | * |
| 85 | * Arguments: @gfn *m@ = a transformation matrix |
| 86 | * |
| 87 | * Returns: Zero if successful, nonzero if the matrix was singular. |
| 88 | * |
| 89 | * Use: Inverts a transformation matrix. |
| 90 | */ |
| 91 | |
| 92 | extern int gfn_invert(gfn */*m*/); |
| 93 | |
| 94 | /* --- @gfn_transform@ --- * |
| 95 | * |
| 96 | * Arguments: @gfn *m@ = conversion matrix to apply |
| 97 | * @mp *d@ = destination pointer |
| 98 | * @mp *x@ = input value |
| 99 | * |
| 100 | * Returns: The transformed element. |
| 101 | * |
| 102 | * Use: Transforms a field element according to the given matrix. |
| 103 | */ |
| 104 | |
| 105 | extern mp *gfn_transform(gfn */*m*/, mp */*d*/, mp */*x*/); |
| 106 | |
| 107 | /* --- @gfn_create@ --- * |
| 108 | * |
| 109 | * Arguments: @mp *p@ = modulus for polynomial basis |
| 110 | * @mp *beta@ = the generator of the normal basis, expressed |
| 111 | * relative to the polynomial basis |
| 112 | * @gfn *ntop@ = output normal-to-polynomail conversion matrix |
| 113 | * @gfn *pton@ = output polynomial-to-normal conversion matrix |
| 114 | * |
| 115 | * Returns: Zero if it worked, nonzero otherwise (e.g., if %$\beta$% |
| 116 | * doesn't generate a proper basis). |
| 117 | * |
| 118 | * Use: Constructs conversion matrices between polynomial and normal |
| 119 | * basis representations of binary field elements. |
| 120 | */ |
| 121 | |
| 122 | extern int gfn_create(mp */*p*/, mp */*beta*/, gfn */*ntop*/, gfn */*pton*/); |
| 123 | |
| 124 | /*----- That's all, folks -------------------------------------------------*/ |
| 125 | |
| 126 | #ifdef __cplusplus |
| 127 | } |
| 128 | #endif |
| 129 | |
| 130 | #endif |