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Diffstat (limited to 'plugins/pychrysalide/common/pearson.c')
-rw-r--r-- | plugins/pychrysalide/common/pearson.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/plugins/pychrysalide/common/pearson.c b/plugins/pychrysalide/common/pearson.c new file mode 100644 index 0000000..99c2d27 --- /dev/null +++ b/plugins/pychrysalide/common/pearson.c @@ -0,0 +1,179 @@ + +/* Chrysalide - Outil d'analyse de fichiers binaires + * pearson.c - équivalent Python du fichier "common/pearson.c" + * + * Copyright (C) 2018-2019 Cyrille Bagard + * + * This file is part of Chrysalide. + * + * Chrysalide 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. + * + * Chrysalide 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 + */ + + +#include "pearson.h" + + +#include <pygobject.h> + + +#include <i18n.h> +#include <common/pearson.h> + + +#include "../access.h" +#include "../helpers.h" + + + +/* Fournit les permutations par défaut par Pearson. */ +static PyObject *py_pearson_permutations(PyObject *, PyObject *); + +/* Détermine l'empreinte Pearson d'une chaîne de caractères. */ +static PyObject *py_pearson(PyObject *, PyObject *); + + + +/****************************************************************************** +* * +* Paramètres : self = NULL car méthode statique. * +* args = adresse non utilisée ici, en l'absence d'argument. * +* * +* Description : Fournit les permutations par défaut par Pearson. * +* * +* Retour : Table de valeurs utilisées par défaut. * +* * +* Remarques : - * +* * +******************************************************************************/ + +static PyObject *py_pearson_permutations(PyObject *self, PyObject *args) +{ + PyObject *result; /* Instance à retourner */ + const char *table; /* Eventuelle table à utiliser */ + +#define PEARSON_PERMUTATIONS_METHOD PYTHON_METHOD_DEF \ +( \ + pearson_permutations, "", \ + METH_NOARGS, py, \ + "Provide the default pseudorandom permutations" \ + " for the Pearson hash computation.\n" \ + "\n" \ + "The result is 256-byte value." \ +) + + table = get_pearson_permutations(); + + result = PyBytes_FromStringAndSize(table, 256); + + return result; + +} + + +/****************************************************************************** +* * +* Paramètres : self = NULL car méthode statique. * +* args = arguments fournis lors de l'appel à la fonction. * +* * +* Description : Détermine l'empreinte Pearson d'une chaîne de caractères. * +* * +* Retour : Numéro de révision. * +* * +* Remarques : - * +* * +******************************************************************************/ + +static PyObject *py_pearson(PyObject *self, PyObject *args) +{ + PyObject *result; /* Instance à retourner */ + const char *str; /* Chaîne à traiter. */ + PyObject *bytes; /* Tableau d'octets */ + int ret; /* Bilan de lecture des args. */ + const char *table; /* Eventuelle table à utiliser */ + uint8_t value; /* Empreinte calculée */ + +#define PEARSON_METHOD PYTHON_METHOD_DEF \ +( \ + pearson, "str, /, table", \ + METH_VARARGS, py, \ + "Compute the Pearson hash of a given string.\n" \ + "\n" \ + "The default pseudorandom permutations are used if" \ + " no *table* of 256 bytes is provided.\n" \ + "\n" \ + "A table of permutations can be created with this call:\n" \ + " bytes(sample(list(range(0, 256)), k=256))\n" \ + "\n" \ + "The result is 8-bit integer value." \ +) + + bytes = NULL; + + ret = PyArg_ParseTuple(args, "s|O!", &str, &PyBytes_Type, &bytes); + if (!ret) return NULL; + + if (bytes != NULL) + { + if (PyBytes_Size(bytes) != 256) + { + PyErr_SetString(PyExc_ValueError, _("256 bytes are required for the custom table.")); + return NULL; + } + + table = PyBytes_AsString(bytes); + + value = pearson_hash(str, table); + + } + else + value = pearson_hash(str, NULL); + + result = Py_BuildValue("B", (unsigned char)value); + + return result; + +} + + +/****************************************************************************** +* * +* Paramètres : - * +* * +* Description : Définit une extension du module 'common' à compléter. * +* * +* Retour : Bilan de l'opération. * +* * +* Remarques : - * +* * +******************************************************************************/ + +bool populate_common_module_with_pearson(void) +{ + bool result; /* Bilan à retourner */ + PyObject *module; /* Module à recompléter */ + + static PyMethodDef py_pearson_methods[] = { + PEARSON_PERMUTATIONS_METHOD, + PEARSON_METHOD, + { NULL } + }; + + module = get_access_to_python_module("pychrysalide.common"); + + result = register_python_module_methods(module, py_pearson_methods); + + return result; + +} |