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authorCyrille Bagard <nocbos@gmail.com>2021-03-09 21:54:43 (GMT)
committerCyrille Bagard <nocbos@gmail.com>2021-03-09 21:54:43 (GMT)
commiteb470f2e5e790ba107171a3ae8c5ed27a72ed8f8 (patch)
tree1d629fdb27b2e44062126d4c865f693b0adb305c /plugins/pychrysalide
parentc728479b9006dde8d377e9029936de9a625c806b (diff)
Implement the Pearson hash method.
Diffstat (limited to 'plugins/pychrysalide')
-rw-r--r--plugins/pychrysalide/common/Makefile.am3
-rw-r--r--plugins/pychrysalide/common/module.c2
-rw-r--r--plugins/pychrysalide/common/pearson.c179
-rw-r--r--plugins/pychrysalide/common/pearson.h39
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 */