diff options
Diffstat (limited to 'src/common')
| -rwxr-xr-x | src/common/Makefile.am | 1 | ||||
| -rw-r--r-- | src/common/fnv1a.c | 83 | ||||
| -rw-r--r-- | src/common/fnv1a.h | 51 |
3 files changed, 135 insertions, 0 deletions
diff --git a/src/common/Makefile.am b/src/common/Makefile.am index 391f35a..9232fc4 100755 --- a/src/common/Makefile.am +++ b/src/common/Makefile.am @@ -7,6 +7,7 @@ libcommon_la_SOURCES = \ endianness.h endianness.c \ environment.h environment.c \ extstr.h extstr.c \ + fnv1a.h fnv1a.c \ leb128.h leb128.c \ macros.h \ net.h net.c \ diff --git a/src/common/fnv1a.c b/src/common/fnv1a.c new file mode 100644 index 0000000..57fddf7 --- /dev/null +++ b/src/common/fnv1a.c @@ -0,0 +1,83 @@ + +/* OpenIDA - Outil d'analyse de fichiers binaires + * fnv1a.c - implémentaton du calcul rapide d'empreintes de chaînes + * + * Copyright (C) 2012 Cyrille Bagard + * + * This file is part of OpenIDA. + * + * OpenIDA 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 3 of the License, or + * (at your option) any later version. + * + * OpenIDA 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 Foobar. If not, see <http://www.gnu.org/licenses/>. + */ + + +#include "fnv1a.h" + + + +/* Constante d'initialisation */ +#define FNV1A_64_INIT 0xcbf29ce484222325ull + +/* Coefficient magique ! */ +#define FNV_64_PRIME 0x100000001b3ull + + + +/****************************************************************************** +* * +* Paramètres : a = première empreinte à manipuler. * +* b = seconde empreinte à manipuler. * +* * +* Description : Détermine si deux empreintes FNV1a sont indentiques ou non. * +* * +* Retour : Bilan de la comparaison. * +* * +* Remarques : - * +* * +******************************************************************************/ + +bool cmp_fnv_64a(fnv64_t a, fnv64_t b) +{ + return (a == b); + +} + + +/****************************************************************************** +* * +* Paramètres : str = chaîne de caractères à traiter. * +* * +* Description : Détermine l'empreinte FNV1a d'une chaîne de caractères. * +* * +* Retour : Valeur calculée. * +* * +* Remarques : - * +* * +******************************************************************************/ + +fnv64_t fnv_64a_hash(const char *str) +{ + fnv64_t result; /* Valeur à retourner */ + unsigned char *iter; /* Boucle de parcours */ + + result = FNV1A_64_INIT; + + for (iter = (unsigned char *)str; *iter; iter++) + { + result ^= (fnv64_t)*iter; + result *= FNV_64_PRIME; + } + + return result; + +} diff --git a/src/common/fnv1a.h b/src/common/fnv1a.h new file mode 100644 index 0000000..f379ec8 --- /dev/null +++ b/src/common/fnv1a.h @@ -0,0 +1,51 @@ + +/* OpenIDA - Outil d'analyse de fichiers binaires + * fnv1a.h - prototypes pour l'implémentaton du calcul rapide d'empreintes de chaînes + * + * Copyright (C) 2012 Cyrille Bagard + * + * This file is part of OpenIDA. + * + * OpenIDA 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 3 of the License, or + * (at your option) any later version. + * + * OpenIDA 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 Foobar. If not, see <http://www.gnu.org/licenses/>. + */ + + +#ifndef _COMMON_FNV1A_H +#define _COMMON_FNV1A_H + + +#include <stdbool.h> +#include <stdint.h> + + +/** + * Plus d'informations avec les liens suivants : + * - http://en.wikipedia.org/wiki/Fowler-Noll-Vo_hash_function + * - http://isthe.com/chongo/tech/comp/fnv/ + */ + + +/* Détermination d'un type à part */ +typedef uint64_t fnv64_t; + + +/* Détermine si deux empreintes FNV1a sont indentiques ou non. */ +bool cmp_fnv_64a(fnv64_t, fnv64_t); + +/* Détermine l'empreinte FNV1a d'une chaîne de caractères. */ +fnv64_t fnv_64a_hash(const char *); + + + +#endif /* _COMMON_FNV1A_H */ |