diff options
author | Cyrille Bagard <nocbos@gmail.com> | 2021-03-09 21:54:43 (GMT) |
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committer | Cyrille Bagard <nocbos@gmail.com> | 2021-03-09 21:54:43 (GMT) |
commit | eb470f2e5e790ba107171a3ae8c5ed27a72ed8f8 (patch) | |
tree | 1d629fdb27b2e44062126d4c865f693b0adb305c /plugins/pychrysalide/common | |
parent | c728479b9006dde8d377e9029936de9a625c806b (diff) |
Implement the Pearson hash method.
Diffstat (limited to 'plugins/pychrysalide/common')
-rw-r--r-- | plugins/pychrysalide/common/Makefile.am | 3 | ||||
-rw-r--r-- | plugins/pychrysalide/common/module.c | 2 | ||||
-rw-r--r-- | plugins/pychrysalide/common/pearson.c | 179 | ||||
-rw-r--r-- | plugins/pychrysalide/common/pearson.h | 39 |
4 files changed, 222 insertions, 1 deletions
diff --git a/plugins/pychrysalide/common/Makefile.am b/plugins/pychrysalide/common/Makefile.am index 66e7622..5f54fe8 100644 --- a/plugins/pychrysalide/common/Makefile.am +++ b/plugins/pychrysalide/common/Makefile.am @@ -7,7 +7,8 @@ libpychrysacommon_la_SOURCES = \ leb128.h leb128.c \ module.h module.c \ packed.h packed.c \ - pathname.h pathname.c + pathname.h pathname.c \ + pearson.h pearson.c libpychrysacommon_la_LDFLAGS = diff --git a/plugins/pychrysalide/common/module.c b/plugins/pychrysalide/common/module.c index 865b7e2..cc50c43 100644 --- a/plugins/pychrysalide/common/module.c +++ b/plugins/pychrysalide/common/module.c @@ -30,6 +30,7 @@ #include "leb128.h" #include "packed.h" #include "pathname.h" +#include "pearson.h" #include "../helpers.h" @@ -98,6 +99,7 @@ bool populate_common_module(void) if (result) result = populate_common_module_with_fnv1a(); if (result) result = populate_common_module_with_leb128(); if (result) result = populate_common_module_with_pathname(); + if (result) result = populate_common_module_with_pearson(); if (result) result = ensure_python_bitfield_is_registered(); if (result) result = ensure_python_packed_buffer_is_registered(); 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; + +} diff --git a/plugins/pychrysalide/common/pearson.h b/plugins/pychrysalide/common/pearson.h new file mode 100644 index 0000000..caff72a --- /dev/null +++ b/plugins/pychrysalide/common/pearson.h @@ -0,0 +1,39 @@ + +/* Chrysalide - Outil d'analyse de fichiers binaires + * pearson.h - prototypes pour l'équivalent Python du fichier "common/pearson.c" + * + * Copyright (C) 2021 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 + */ + + +#ifndef _PLUGINS_PYCHRYSALIDE_COMMON_PEARSON_H +#define _PLUGINS_PYCHRYSALIDE_COMMON_PEARSON_H + + +#include <Python.h> +#include <stdbool.h> + + + +/* Définit une extension du module 'common' à compléter. */ +bool populate_common_module_with_pearson(void); + + + +#endif /* _PLUGINS_PYCHRYSALIDE_COMMON_PEARSON_H */ |