Add support for the crc32 checksum.

9 files changed, 673 insertions, 3 deletions

diff --git a/plugins/apihashing/classics/Makefile.am b/plugins/apihashing/classics/Makefile.am
index b914d9a..9f97b47 100644
--- a/plugins/apihashing/classics/Makefile.am
+++ b/plugins/apihashing/classics/Makefile.am
@@ -2,6 +2,7 @@
 noinst_LTLIBRARIES = libapihashingclassics.la
 
 libapihashingclassics_la_SOURCES =			\
+	crc32.h crc32.c							\
 	djb2.h djb2.c							\
 	ror13.h ror13.c
 
diff --git a/plugins/apihashing/classics/crc32.c b/plugins/apihashing/classics/crc32.c
new file mode 100644
index 0000000..98f9a6b
--- /dev/null
+++ b/plugins/apihashing/classics/crc32.c
@@ -0,0 +1,332 @@
+
+/* Chrysalide - Outil d'analyse de fichiers binaires
+ * crc32.c - transormation en empreinte d'API crc32
+ *
+ * Copyright (C) 2023 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 Foobar.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "crc32.h"
+
+
+#include <malloc.h>
+#include <string.h>
+
+
+#include <analysis/scan/patterns/modifier-int.h>
+
+
+
+
+/* ----------------------- RECHERCHE D'UN MOTIF DE TEXTE BRUT ----------------------- */
+
+
+/* Initialise la classe des transmissions en empreintes crc32. */
+static void g_scan_crc32_modifier_class_init(GScanCrc32ModifierClass *klass);
+
+/* Initialise une instance de transmission en empreinte crc32. */
+static void g_scan_crc32_modifier_init(GScanCrc32Modifier *);
+
+/* Supprime toutes les références externes. */
+static void g_scan_crc32_modifier_dispose(GScanCrc32Modifier *);
+
+/* Procède à la libération totale de la mémoire. */
+static void g_scan_crc32_modifier_finalize(GScanCrc32Modifier *);
+
+
+
+/* --------------------- IMPLEMENTATION DES FONCTIONS DE CLASSE --------------------- */
+
+
+/* Fournit le nom d'appel d'un modificateur pour motif. */
+static char *g_scan_crc32_modifier_get_name(const GScanCrc32Modifier *);
+
+/* Calcule l'empreinte crc32 d'un motif de recherche. */
+static uint32_t compute_crc32(const sized_binary_t *);
+
+/* Transforme une séquence d'octets pour motif de recherche. */
+static bool g_scan_crc32_modifier_transform(const GScanCrc32Modifier *, const sized_binary_t *, size_t, sized_binary_t **, size_t *);
+
+/* Retrouve l'origine d'une correspondance à partir d'un indice. */
+static char *g_scan_crc32_modifier_get_path(const GScanCrc32Modifier *, size_t *);
+
+
+
+/* ---------------------------------------------------------------------------------- */
+/*                         RECHERCHE D'UN MOTIF DE TEXTE BRUT                         */
+/* ---------------------------------------------------------------------------------- */
+
+
+/* Indique le type défini pour une transormation en encodage Crc32. */
+G_DEFINE_TYPE(GScanCrc32Modifier, g_scan_crc32_modifier, G_TYPE_API_HASH_MODIFIER);
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : klass = classe à initialiser.                                *
+*                                                                             *
+*  Description : Initialise la classe des transmissions en empreintes crc32.  *
+*                                                                             *
+*  Retour      : -                                                            *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+static void g_scan_crc32_modifier_class_init(GScanCrc32ModifierClass *klass)
+{
+    GObjectClass *object;                   /* Autre version de la classe  */
+    GScanTokenModifierClass *modifier;      /* Version de classe parente   */
+
+    object = G_OBJECT_CLASS(klass);
+
+    object->dispose = (GObjectFinalizeFunc/* ! */)g_scan_crc32_modifier_dispose;
+    object->finalize = (GObjectFinalizeFunc)g_scan_crc32_modifier_finalize;
+
+    modifier = G_SCAN_TOKEN_MODIFIER_CLASS(klass);
+
+    modifier->get_name = (get_scan_modifier_name_fc)g_scan_crc32_modifier_get_name;
+
+    modifier->transform = (transform_scan_token_fc)g_scan_crc32_modifier_transform;
+    modifier->get_path = (get_modifier_path)g_scan_crc32_modifier_get_path;
+
+}
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : modifier = instance à initialiser.                           *
+*                                                                             *
+*  Description : Initialise une instance de transmission en empreinte crc32.  *
+*                                                                             *
+*  Retour      : -                                                            *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+static void g_scan_crc32_modifier_init(GScanCrc32Modifier *modifier)
+{
+
+}
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : modifier = instance d'objet GLib à traiter.                  *
+*                                                                             *
+*  Description : Supprime toutes les références externes.                     *
+*                                                                             *
+*  Retour      : -                                                            *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+static void g_scan_crc32_modifier_dispose(GScanCrc32Modifier *modifier)
+{
+    G_OBJECT_CLASS(g_scan_crc32_modifier_parent_class)->dispose(G_OBJECT(modifier));
+
+}
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : modifier = instance d'objet GLib à traiter.                  *
+*                                                                             *
+*  Description : Procède à la libération totale de la mémoire.                *
+*                                                                             *
+*  Retour      : -                                                            *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+static void g_scan_crc32_modifier_finalize(GScanCrc32Modifier *modifier)
+{
+    G_OBJECT_CLASS(g_scan_crc32_modifier_parent_class)->finalize(G_OBJECT(modifier));
+
+}
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : -                                                            *
+*                                                                             *
+*  Description : Construit un modificateur livrant des empreintes crc32.      *
+*                                                                             *
+*  Retour      : Mécanisme mis en place.                                      *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+GScanTokenModifier *g_scan_crc32_modifier_new(void)
+{
+    GScanTokenModifier *result;                    /* Structure à retourner       */
+
+    result = g_object_new(G_TYPE_SCAN_CRC32_MODIFIER, NULL);
+
+    return result;
+
+}
+
+
+
+/* ---------------------------------------------------------------------------------- */
+/*                       IMPLEMENTATION DES FONCTIONS DE CLASSE                       */
+/* ---------------------------------------------------------------------------------- */
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : modifier = modificateur à consulter.                         *
+*                                                                             *
+*  Description : Fournit le nom d'appel d'un modificateur pour motif.         *
+*                                                                             *
+*  Retour      : Désignation humaine.                                         *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+static char *g_scan_crc32_modifier_get_name(const GScanCrc32Modifier *modifier)
+{
+    char *result;                           /* Désignation à retourner     */
+
+    result = strdup("crc32");
+
+    return result;
+
+}
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : src = séquence d'octets à traiter.                           *
+*                                                                             *
+*  Description : Calcule l'empreinte crc32 d'un motif de recherche.           *
+*                                                                             *
+*  Retour      : Valeur entière de l'empreinte déterminée.                    *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+static uint32_t compute_crc32(const sized_binary_t *src)
+{
+    uint32_t result;                        /* Valeur à retourner          */
+    size_t i;                               /* Boucle de parcours #1       */
+    size_t k;                               /* Boucle de parcours #2       */
+
+    result = 0xffffffff;
+
+    for (i = 0; i < src->len; i++)
+    {
+        result ^= src->data[i];
+
+        for (k = 0; k < 8; k++)
+            result = result & 1 ? (result >> 1) ^ 0xedb88320 : result >> 1;
+
+    }
+
+    result = ~result;
+
+    return result;
+
+}
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : modifier = modificateur à solliciter.                        *
+*                src      = séquences d'octets à traiter.                     *
+*                scount   = quantité de ces séquences.                        *
+*                dest     = nouvelle(s) séquence(s) d'octets obtenue(s) [OUT] *
+*                dcount   = quantité de ces séquences.                        *
+*                                                                             *
+*  Description : Transforme une séquence d'octets pour motif de recherche.    *
+*                                                                             *
+*  Retour      : Bilan de l'opération : succès ou échec.                      *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+static bool g_scan_crc32_modifier_transform(const GScanCrc32Modifier *modifier, const sized_binary_t *src, size_t scount, sized_binary_t **dest, size_t *dcount)
+{
+    bool result;                            /* Bilan d'opération à renvoyer*/
+    sized_binary_t *binary;                 /* Raccourci vers le stockage  */
+    size_t i;                               /* Boucle de parcours #1       */
+    const sized_binary_t *_src;             /* Source courante             */
+    uint32_t hash;                          /* Valeur d'empreinte calculée */
+
+    result = true;
+
+    *dcount = scount;
+    *dest = calloc(*dcount, sizeof(sized_binary_t));
+
+    binary = &(*dest)[0];
+
+    for (i = 0; i < scount; i++, binary++)
+    {
+        _src = src + i;
+
+        hash = compute_crc32(_src);
+
+        binary->data = malloc(sizeof(hash) * sizeof(bin_t));
+        binary->len = sizeof(hash);
+
+        memcpy(binary->data, &hash, sizeof(hash));
+
+    }
+
+    return result;
+
+}
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : modifier = modificateur à consulter.                         *
+*                index    = indice de la combinaison ciblée. [OUT]            *
+*                                                                             *
+*  Description : Retrouve l'origine d'une correspondance à partir d'un indice.*
+*                                                                             *
+*  Retour      : Version humainement lisible de la combinaison.               *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+static char *g_scan_crc32_modifier_get_path(const GScanCrc32Modifier *modifier, size_t *index)
+{
+    char *result;                           /* Combinaison à retourner     */
+
+    if (*index > 0)
+    {
+        result = NULL;
+        (*index)--;
+    }
+
+    else
+        result = strdup("crc32");
+
+    return result;
+
+}
diff --git a/plugins/apihashing/classics/crc32.h b/plugins/apihashing/classics/crc32.h
new file mode 100644
index 0000000..0198c5d
--- /dev/null
+++ b/plugins/apihashing/classics/crc32.h
@@ -0,0 +1,58 @@
+
+/* Chrysalide - Outil d'analyse de fichiers binaires
+ * crc32.h - prototypes pour la transormation en empreinte d'API crc32
+ *
+ * Copyright (C) 2023 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 Foobar.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#ifndef _PLUGINS_APIHASHING_CLASSICS_CRC32_H
+#define _PLUGINS_APIHASHING_CLASSICS_CRC32_H
+
+
+#include <glib-object.h>
+
+
+#include "../apihash.h"
+
+
+
+#define G_TYPE_SCAN_CRC32_MODIFIER            g_scan_crc32_modifier_get_type()
+#define G_SCAN_CRC32_MODIFIER(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj), G_TYPE_SCAN_CRC32_MODIFIER, GScanCrc32Modifier))
+#define G_IS_SCAN_CRC32_MODIFIER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), G_TYPE_SCAN_CRC32_MODIFIER))
+#define G_SCAN_CRC32_MODIFIER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass), G_TYPE_SCAN_CRC32_MODIFIER, GScanCrc32ModifierClass))
+#define G_IS_SCAN_CRC32_MODIFIER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), G_TYPE_SCAN_CRC32_MODIFIER))
+#define G_SCAN_CRC32_MODIFIER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj), G_TYPE_SCAN_CRC32_MODIFIER, GScanCrc32ModifierClass))
+
+
+/* Transormation en empreinte d'API crc32 (instance) */
+typedef GApiHashModifier GScanCrc32Modifier;
+
+/* Transormation en empreinte d'API crc32 (classe) */
+typedef GApiHashModifierClass GScanCrc32ModifierClass;
+
+
+/* Indique le type défini pour une transormation en empreinte crc32. */
+GType g_scan_crc32_modifier_get_type(void);
+
+/* Construit un modificateur livrant des empreintes crc32. */
+GScanTokenModifier *g_scan_crc32_modifier_new(void);
+
+
+
+#endif  /* _PLUGINS_APIHASHING_CLASSICS_CRC32_H */
diff --git a/plugins/apihashing/core.c b/plugins/apihashing/core.c
index 9114afe..7e98f7c 100644
--- a/plugins/apihashing/core.c
+++ b/plugins/apihashing/core.c
@@ -32,6 +32,7 @@
 #   include "python/module.h"
 #   include "python/classics/module.h"
 #endif
+#include "classics/crc32.h"
 #include "classics/djb2.h"
 #include "classics/ror13.h"
 
@@ -78,6 +79,7 @@ G_MODULE_EXPORT bool chrysalide_plugin_init(GPluginModule *plugin)
         __status;                                       \
     })
 
+    if (result) result = REGISTER_SCAN_MODIFIER(g_scan_crc32_modifier_new());
     if (result) result = REGISTER_SCAN_MODIFIER(g_scan_djb2_modifier_new());
     if (result) result = REGISTER_SCAN_MODIFIER(g_scan_ror13_modifier_new());
 
diff --git a/plugins/apihashing/python/classics/Makefile.am b/plugins/apihashing/python/classics/Makefile.am
index e3dbc7e..316e13f 100644
--- a/plugins/apihashing/python/classics/Makefile.am
+++ b/plugins/apihashing/python/classics/Makefile.am
@@ -2,6 +2,7 @@
 noinst_LTLIBRARIES = libapihashingpythonclassics.la
 
 libapihashingpythonclassics_la_SOURCES = 	\
+	crc32.h crc32.c							\
 	djb2.h djb2.c							\
 	module.h module.c						\
 	ror13.h ror13.c
diff --git a/plugins/apihashing/python/classics/crc32.c b/plugins/apihashing/python/classics/crc32.c
new file mode 100644
index 0000000..d7c6f7c
--- /dev/null
+++ b/plugins/apihashing/python/classics/crc32.c
@@ -0,0 +1,211 @@
+
+/* Chrysalide - Outil d'analyse de fichiers binaires
+ * crc32.c - équivalent Python du fichier "plugins/apihashing/classics/crc32.c"
+ *
+ * Copyright (C) 2023 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 "crc32.h"
+
+
+#include <pygobject.h>
+
+
+#include <i18n.h>
+#include <plugins/pychrysalide/access.h>
+#include <plugins/pychrysalide/helpers.h>
+
+
+#include "../apihash.h"
+#include "../../classics/crc32.h"
+
+
+
+CREATE_DYN_CONSTRUCTOR(scan_crc32_modifier, G_TYPE_SCAN_CRC32_MODIFIER);
+
+/* Initialise une instance sur la base du dérivé de GObject. */
+static int py_scan_crc32_modifier_init(PyObject *, PyObject *, PyObject *);
+
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : self = objet à initialiser (théoriquement).                  *
+*                args = arguments fournis à l'appel.                          *
+*                kwds = arguments de type key=val fournis.                    *
+*                                                                             *
+*  Description : Initialise une instance sur la base du dérivé de GObject.    *
+*                                                                             *
+*  Retour      : 0.                                                           *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+static int py_scan_crc32_modifier_init(PyObject *self, PyObject *args, PyObject *kwds)
+{
+    int ret;                                /* Bilan de lecture des args.  */
+
+#define SCAN_CRC32_MODIFIER_DOC                                     \
+    "The *Crc32Modifier* class transforms a byte pattern into its"  \
+    " crc32 encoded form.\n"                                        \
+    "\n"                                                            \
+    "Instances can be created using the following constructor:\n"   \
+    "\n"                                                            \
+    "    Crc32Modifier()"
+
+    /* Initialisation d'un objet GLib */
+
+    ret = forward_pygobjet_init(self);
+    if (ret == -1) return -1;
+
+    return 0;
+
+}
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : -                                                            *
+*                                                                             *
+*  Description : Fournit un accès à une définition de type à diffuser.        *
+*                                                                             *
+*  Retour      : Définition d'objet pour Python.                              *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+PyTypeObject *get_python_scan_crc32_modifier_type(void)
+{
+    static PyMethodDef py_scan_crc32_modifier_methods[] = {
+        { NULL }
+    };
+
+    static PyGetSetDef py_scan_crc32_modifier_getseters[] = {
+        { NULL }
+    };
+
+    static PyTypeObject py_scan_crc32_modifier_type = {
+
+        PyVarObject_HEAD_INIT(NULL, 0)
+
+        .tp_name        = "pychrysalide.analysis.scan.patterns.modifiers.Crc32Modifier",
+        .tp_basicsize   = sizeof(PyGObject),
+
+        .tp_flags       = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
+
+        .tp_doc         = SCAN_CRC32_MODIFIER_DOC,
+
+        .tp_methods     = py_scan_crc32_modifier_methods,
+        .tp_getset      = py_scan_crc32_modifier_getseters,
+
+        .tp_init        = py_scan_crc32_modifier_init,
+        .tp_new         = py_scan_crc32_modifier_new,
+
+    };
+
+    return &py_scan_crc32_modifier_type;
+
+}
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : -                                                            *
+*                                                                             *
+*  Description : Prend en charge l'objet 'pychrysalide....Crc32Modifier'.     *
+*                                                                             *
+*  Retour      : Bilan de l'opération.                                        *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+bool ensure_python_scan_crc32_modifier_is_registered(void)
+{
+    PyTypeObject *type;                     /* Type Python Crc32Modifier   */
+    PyObject *module;                       /* Module à recompléter        */
+    PyObject *dict;                         /* Dictionnaire du module      */
+
+    type = get_python_scan_crc32_modifier_type();
+
+    if (!PyType_HasFeature(type, Py_TPFLAGS_READY))
+    {
+        module = get_access_to_python_module("pychrysalide.analysis.scan.patterns.modifiers");
+
+        dict = PyModule_GetDict(module);
+
+        if (!ensure_python_api_hash_modifier_is_registered())
+            return false;
+
+        if (!register_class_for_pygobject(dict, G_TYPE_SCAN_CRC32_MODIFIER, type))
+            return false;
+
+    }
+
+    return true;
+
+}
+
+
+/******************************************************************************
+*                                                                             *
+*  Paramètres  : arg = argument quelconque à tenter de convertir.             *
+*                dst = destination des valeurs récupérées en cas de succès.   *
+*                                                                             *
+*  Description : Tente de convertir en transformation en empreinte crc32.     *
+*                                                                             *
+*  Retour      : Bilan de l'opération, voire indications supplémentaires.     *
+*                                                                             *
+*  Remarques   : -                                                            *
+*                                                                             *
+******************************************************************************/
+
+int convert_to_scan_crc32_modifier(PyObject *arg, void *dst)
+{
+    int result;                             /* Bilan à retourner           */
+
+    result = PyObject_IsInstance(arg, (PyObject *)get_python_scan_crc32_modifier_type());
+
+    switch (result)
+    {
+        case -1:
+            /* L'exception est déjà fixée par Python */
+            result = 0;
+            break;
+
+        case 0:
+            PyErr_SetString(PyExc_TypeError, "unable to convert the provided argument to crc32 modifier");
+            break;
+
+        case 1:
+            *((GScanCrc32Modifier **)dst) = G_SCAN_CRC32_MODIFIER(pygobject_get(arg));
+            break;
+
+        default:
+            assert(false);
+            break;
+
+    }
+
+    return result;
+
+}
diff --git a/plugins/apihashing/python/classics/crc32.h b/plugins/apihashing/python/classics/crc32.h
new file mode 100644
index 0000000..118a916
--- /dev/null
+++ b/plugins/apihashing/python/classics/crc32.h
@@ -0,0 +1,45 @@
+
+/* Chrysalide - Outil d'analyse de fichiers binaires
+ * crc32.h - équivalent Python du fichier "plugins/apihashing/classics/crc32.h"
+ *
+ * Copyright (C) 2023 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_APIHASHING_PYTHON_CLASSICS_CRC32_H
+#define _PLUGINS_APIHASHING_PYTHON_CLASSICS_CRC32_H
+
+
+#include <Python.h>
+#include <stdbool.h>
+
+
+
+/* Fournit un accès à une définition de type à diffuser. */
+PyTypeObject *get_python_scan_crc32_modifier_type(void);
+
+/* Prend en charge l'objet 'pychrysalide.analysis.scan.patterns.modifiers.Crc32Modifier'. */
+bool ensure_python_scan_crc32_modifier_is_registered(void);
+
+/* Tente de convertir en transformation en empreinte crc32. */
+int convert_to_scan_crc32_modifier(PyObject *, void *);
+
+
+
+#endif  /* _PLUGINS_APIHASHING_PYTHON_CLASSICS_CRC32_H */
diff --git a/plugins/apihashing/python/classics/module.c b/plugins/apihashing/python/classics/module.c
index 7a2d3fa..b00757a 100644
--- a/plugins/apihashing/python/classics/module.c
+++ b/plugins/apihashing/python/classics/module.c
@@ -33,6 +33,7 @@
 #include <plugins/pychrysalide/helpers.h>
 
 
+#include "crc32.h"
 #include "djb2.h"
 #include "ror13.h"
 
@@ -56,6 +57,7 @@ bool register_apihashing_classics_modifiers(void)
 
     result = true;
 
+    if (result) result = ensure_python_scan_crc32_modifier_is_registered();
     if (result) result = ensure_python_scan_djb2_modifier_is_registered();
     if (result) result = ensure_python_scan_ror13_modifier_is_registered();
 
diff --git a/tests/analysis/scan/pyapi.py b/tests/analysis/scan/pyapi.py
index 0574d2c..e81e947 100644
--- a/tests/analysis/scan/pyapi.py
+++ b/tests/analysis/scan/pyapi.py
@@ -139,15 +139,21 @@ class TestRostPythonAPI(ChrysalideTestCase):
             return struct.unpack('<I', t)[0]
 
 
-        mod = find_token_modifiers_for_name('ror13')
+        # Example :
+        #  - PlugX (2020) - https://vms.drweb.fr/virus/?i=21512304
+
+        mod = find_token_modifiers_for_name('crc32')
         self.assertIsNotNone(mod)
 
-        source = b'GetProcAddress'
+        source = b'GetCurrentProcess\x00'
         transformed = mod.transform(source)
 
-        self.assertEqual(b2i(transformed[0]), 0x7c0dfcaa)
+        self.assertEqual(b2i(transformed[0]), 0x3690e66)
 
 
+        # Example :
+        #  - GuLoader (2020) - https://www.crowdstrike.com/blog/guloader-malware-analysis/
+
         mod = find_token_modifiers_for_name('djb2')
         self.assertIsNotNone(mod)
 
@@ -157,6 +163,18 @@ class TestRostPythonAPI(ChrysalideTestCase):
         self.assertEqual(b2i(transformed[0]), 0xcf31bb1f)
 
 
+        # Example :
+        #  - ?? (2021) - https://www.threatspike.com/blogs/reflective-dll-injection
+
+        mod = find_token_modifiers_for_name('ror13')
+        self.assertIsNotNone(mod)
+
+        source = b'GetProcAddress'
+        transformed = mod.transform(source)
+
+        self.assertEqual(b2i(transformed[0]), 0x7c0dfcaa)
+
+
     def testBytePatternModifiersAPI(self):
         """Validate the API for pattern modifiers."""