diff options
author | Cyrille Bagard <nocbos@gmail.com> | 2025-03-12 23:53:26 (GMT) |
---|---|---|
committer | Cyrille Bagard <nocbos@gmail.com> | 2025-03-12 23:53:52 (GMT) |
commit | ccb49530f930701b1ca57e560564ae098dcef3c9 (patch) | |
tree | dc4abbca57f6838ac764b545181d01a66e6521f4 | |
parent | 04d5af777d42d02d0ec580373f7a50be1bfb3dac (diff) |
Update and improve the operations with LEB128 values.
-rw-r--r-- | plugins/pychrysalide/common/Makefile.am | 2 | ||||
-rw-r--r-- | plugins/pychrysalide/common/leb128.c | 139 | ||||
-rw-r--r-- | plugins/pychrysalide/common/module.c | 4 | ||||
-rw-r--r-- | src/common/bits.c | 1 | ||||
-rw-r--r-- | src/common/leb128.c | 171 | ||||
-rw-r--r-- | src/common/leb128.h | 11 | ||||
-rw-r--r-- | tests/common/leb128.py | 80 |
7 files changed, 247 insertions, 161 deletions
diff --git a/plugins/pychrysalide/common/Makefile.am b/plugins/pychrysalide/common/Makefile.am index 43e1fc4..ad58900 100644 --- a/plugins/pychrysalide/common/Makefile.am +++ b/plugins/pychrysalide/common/Makefile.am @@ -6,7 +6,6 @@ noinst_LTLIBRARIES = libpychrysacommon.la # fnv1a.h fnv1a.c \ # hex.h hex.c \ # itoa.h itoa.c \ -# leb128.h leb128.c \ # module.h module.c \ # packed.h packed.c \ # pathname.h pathname.c \ @@ -15,6 +14,7 @@ noinst_LTLIBRARIES = libpychrysacommon.la libpychrysacommon_la_SOURCES = \ bits.h bits.c \ entropy.h entropy.c \ + leb128.h leb128.c \ module.h module.c \ xdg.h xdg.c diff --git a/plugins/pychrysalide/common/leb128.c b/plugins/pychrysalide/common/leb128.c index 8b15303..2eeb191 100644 --- a/plugins/pychrysalide/common/leb128.c +++ b/plugins/pychrysalide/common/leb128.c @@ -2,7 +2,7 @@ /* Chrysalide - Outil d'analyse de fichiers binaires * leb128.c - équivalent Python du fichier "common/leb128.c" * - * Copyright (C) 2018-2020 Cyrille Bagard + * Copyright (C) 2018-2025 Cyrille Bagard * * This file is part of Chrysalide. * @@ -26,13 +26,13 @@ #include <assert.h> +#include <malloc.h> #include <pygobject.h> #include <common/leb128.h> -#include "packed.h" #include "../access.h" #include "../helpers.h" @@ -69,31 +69,29 @@ static PyObject *py_leb128_pack_uleb128(PyObject *self, PyObject *args) { PyObject *result; /* Valeur à retourner */ uleb128_t value; /* Valeur à manipuler */ - packed_buffer_t *pbuf; /* Tampon de données à employer*/ int ret; /* Bilan de lecture des args. */ - bool status; /* Bilan de l'opération */ - -#define LEB128_PACK_ULEB128_METHOD PYTHON_METHOD_DEF \ -( \ - pack_uleb128, "value, pbuf", \ - METH_VARARGS, py_leb128, \ - "Pack an unsigned LEB128 value into a data buffer.\n" \ - "\n" \ - "The *value* is an integer value. The *pbuf* argument has to" \ - " be a pychrysalide.common.PackedBuffer instance where data" \ - " will be appended.\n" \ - "\n" \ - "The returned value is the operation status: *True* for" \ - " success, *False* for failure." \ + size_t count; /* Nombre d'octets produits */ + void *bytes; /* Octets de représentation */ + +#define LEB128_PACK_ULEB128_METHOD PYTHON_METHOD_DEF \ +( \ + pack_uleb128, "value", \ + METH_VARARGS, py_leb128, \ + "Pack an unsigned LEB128 value into bytes.\n" \ + "\n" \ + "The *value* has to be an integer value.\n" \ + "\n" \ + "The returned value is byte data." \ ) - ret = PyArg_ParseTuple(args, "O&O&", convert_to_uleb128_value, &value, convert_to_packed_buffer, &pbuf); + ret = PyArg_ParseTuple(args, "O&", convert_to_uleb128_value, &value); if (!ret) return NULL; - status = pack_uleb128(&value, pbuf); + bytes = pack_uleb128(&value, &count); - result = status ? Py_True : Py_False; - Py_INCREF(result); + result = PyBytes_FromStringAndSize(bytes, count); + + free(bytes); return result; @@ -117,31 +115,29 @@ static PyObject *py_leb128_pack_leb128(PyObject *self, PyObject *args) { PyObject *result; /* Valeur à retourner */ leb128_t value; /* Valeur à manipuler */ - packed_buffer_t *pbuf; /* Tampon de données à employer*/ int ret; /* Bilan de lecture des args. */ - bool status; /* Bilan de l'opération */ - -#define LEB128_PACK_LEB128_METHOD PYTHON_METHOD_DEF \ -( \ - pack_leb128, "value, pbuf", \ - METH_VARARGS, py_leb128, \ - "Pack a signed LEB128 value into a data buffer.\n" \ - "\n" \ - "The *value* is an integer value. The *pbuf* argument has to" \ - " be a pychrysalide.common.PackedBuffer instance where data" \ - " will be appended.\n" \ - "\n" \ - "The returned value is the operation status: *True* for" \ - " success, *False* for failure." \ + size_t count; /* Nombre d'octets produits */ + void *bytes; /* Octets de représentation */ + +#define LEB128_PACK_LEB128_METHOD PYTHON_METHOD_DEF \ +( \ + pack_leb128, "value", \ + METH_VARARGS, py_leb128, \ + "Pack a signed LEB128 value into bytes.\n" \ + "\n" \ + "The *value* has to be an integer value.\n" \ + "\n" \ + "The returned value is byte data." \ ) - ret = PyArg_ParseTuple(args, "O&O&", convert_to_leb128_value, &value, convert_to_packed_buffer, &pbuf); + ret = PyArg_ParseTuple(args, "O&", convert_to_leb128_value, &value); if (!ret) return NULL; - status = pack_leb128(&value, pbuf); + bytes = pack_leb128(&value, &count); + + result = PyBytes_FromStringAndSize(bytes, count); - result = status ? Py_True : Py_False; - Py_INCREF(result); + free(bytes); return result; @@ -164,33 +160,42 @@ static PyObject *py_leb128_pack_leb128(PyObject *self, PyObject *args) static PyObject *py_leb128_unpack_uleb128(PyObject *self, PyObject *args) { PyObject *result; /* Valeur à retourner */ - packed_buffer_t *pbuf; /* Tampon de données à employer*/ + const char *bytes; /* Octets brutes transmis */ + Py_ssize_t count; /* Quantité de ces octets */ int ret; /* Bilan de lecture des args. */ + const void *pos; /* Tëte de lecture */ + const void *max; /* Position de lecture maximale*/ uleb128_t value; /* Valeur à manipuler */ bool status; /* Bilan de l'opération */ #define LEB128_UNPACK_ULEB128_METHOD PYTHON_METHOD_DEF \ ( \ - unpack_uleb128, "pbuf", \ + unpack_uleb128, "buf", \ METH_VARARGS, py_leb128, \ - "Unpack an unsigned LEB128 value into a data buffer.\n" \ + "Unpack an unsigned LEB128 value from bytes.\n" \ "\n" \ - "The *pbuf* argument has to be a" \ - " pychrysalide.common.PackedBuffer instance from where data" \ - " will be read.\n" \ + "The *buf* argument needs to be bytes with enough data aimed" \ + " to get translated into an unsigned LEB128 value.\n" \ "\n" \ "The returned value depends on the operation status: *None*" \ - " for failure or a integer value for success." \ + " for failure or a tuple with two items for success: the" \ + " decoded value and the remaining bytes." \ ) - ret = PyArg_ParseTuple(args, "O&", convert_to_packed_buffer, &pbuf); + ret = PyArg_ParseTuple(args, "y#", &bytes, &count); if (!ret) return NULL; - status = unpack_uleb128(&value, pbuf); + pos = bytes; + max = bytes + count; - if (status) - result = PyLong_FromUnsignedLongLong(value); + status = unpack_uleb128(&value, &pos, max); + if (status) + { + result = PyTuple_New(2); + PyTuple_SetItem(result, 0, PyLong_FromUnsignedLongLong(value)); + PyTuple_SetItem(result, 1, PyBytes_FromStringAndSize(pos, (char *)max - (char *)pos)); + } else { result = Py_None; @@ -218,33 +223,43 @@ static PyObject *py_leb128_unpack_uleb128(PyObject *self, PyObject *args) static PyObject *py_leb128_unpack_leb128(PyObject *self, PyObject *args) { PyObject *result; /* Valeur à retourner */ - packed_buffer_t *pbuf; /* Tampon de données à employer*/ + const char *bytes; /* Octets brutes transmis */ + Py_ssize_t count; /* Quantité de ces octets */ int ret; /* Bilan de lecture des args. */ + const void *pos; /* Tëte de lecture */ + const void *max; /* Position de lecture maximale*/ leb128_t value; /* Valeur à manipuler */ bool status; /* Bilan de l'opération */ #define LEB128_UNPACK_LEB128_METHOD PYTHON_METHOD_DEF \ ( \ - unpack_leb128, "pbuf", \ + unpack_leb128, "buf", \ METH_VARARGS, py_leb128, \ - "Unpack a signed LEB128 value into a data buffer.\n" \ + "Unpack a signed LEB128 value from bytes.\n" \ "\n" \ - "The *pbuf* argument has to be a" \ - " pychrysalide.common.PackedBuffer instance from where data" \ - " will be read.\n" \ + "\n" \ + "The *buf* argument needs to be bytes with enough data aimed" \ + " to get translated into a signed LEB128 value.\n" \ "\n" \ "The returned value depends on the operation status: *None*" \ - " for failure or a integer value for success." \ + " for failure or a tuple with two items for success: the" \ + " decoded value and the remaining bytes." \ ) - ret = PyArg_ParseTuple(args, "O&", convert_to_packed_buffer, &pbuf); + ret = PyArg_ParseTuple(args, "y#", &bytes, &count); if (!ret) return NULL; - status = unpack_leb128(&value, pbuf); + pos = bytes; + max = bytes + count; - if (status) - result = PyLong_FromLongLong(value); + status = unpack_leb128(&value, &pos, max); + if (status) + { + result = PyTuple_New(2); + PyTuple_SetItem(result, 0, PyLong_FromLongLong(value)); + PyTuple_SetItem(result, 1, PyBytes_FromStringAndSize(pos, (char *)max - (char *)pos)); + } else { result = Py_None; diff --git a/plugins/pychrysalide/common/module.c b/plugins/pychrysalide/common/module.c index fa2b4de..c82c7bc 100644 --- a/plugins/pychrysalide/common/module.c +++ b/plugins/pychrysalide/common/module.c @@ -30,7 +30,7 @@ //#include "fnv1a.h" //#include "hex.h" //#include "itoa.h" -//#include "leb128.h" +#include "leb128.h" //#include "packed.h" //#include "pathname.h" //#include "pearson.h" @@ -104,11 +104,11 @@ bool populate_common_module(void) if (result) result = populate_common_module_with_fnv1a(); if (result) result = populate_common_module_with_hex(); if (result) result = populate_common_module_with_itoa(); - 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 = populate_common_module_with_entropy(); + if (result) result = populate_common_module_with_leb128(); if (result) result = populate_common_module_with_xdg(); if (result) result = ensure_python_bitfield_is_registered(); diff --git a/src/common/bits.c b/src/common/bits.c index 26f570f..27296f2 100644 --- a/src/common/bits.c +++ b/src/common/bits.c @@ -31,6 +31,7 @@ #include "asm.h" +#include "io.h" #include "leb128.h" diff --git a/src/common/leb128.c b/src/common/leb128.c index 009aff6..7fae4d0 100644 --- a/src/common/leb128.c +++ b/src/common/leb128.c @@ -24,9 +24,20 @@ #include "leb128.h" +#include <malloc.h> + + #include "io.h" +/** + * Quantité maximale d'octets de représentation. + * + * sizeof([u]leb128_t) / 7 = 9.142857142857142 + * + */ +#define MAX_LEB128_BYTES 9 + /****************************************************************************** * * @@ -133,7 +144,7 @@ bool load_uleb128(uleb128_t *value, int fd) unsigned int shift; /* Décalage à appliquer */ uint8_t byte; /* Octet à transposer */ - result = true; + result = false; *value = 0; @@ -142,7 +153,7 @@ bool load_uleb128(uleb128_t *value, int fd) while (true) { /* Encodage sur trop d'octets ? */ - if (shift > (7 * sizeof(uleb128_t))) + if (shift > (7 * MAX_LEB128_BYTES)) { result = false; break; @@ -153,6 +164,8 @@ bool load_uleb128(uleb128_t *value, int fd) *value |= ((byte & 0x7f) << shift); + result = true; + if ((byte & 0x80) == 0x00) break; @@ -207,7 +220,7 @@ bool store_uleb128(const uleb128_t *value, int fd) /****************************************************************************** * * * Paramètres : value = valeur à consigner. * -* pbuf = tampon de données à constituer. [OUT] * +* len = taille du tampon de données à constitué. [OUT] * * * * Description : Encode un nombre non signé encodé au format LEB128. * * * @@ -217,26 +230,44 @@ bool store_uleb128(const uleb128_t *value, int fd) * * ******************************************************************************/ -bool pack_uleb128(const uleb128_t *value, packed_buffer_t *pbuf) +void *pack_uleb128(const uleb128_t *value, size_t *len) { - bool result; /* Bilan à retourner */ + uint8_t *result; /* Données à retourner */ uleb128_t tmp; /* Valeur modifiable */ - uint8_t byte; /* Octet à transposer */ + uint8_t *byte; /* Octet à transposer */ + + /* Calcul de la quantité d'octets nécessaires */ + + *len = 0; tmp = *value; do { - byte = (tmp & 0x7f); + tmp >>= 7; + (*len)++; + } + while (tmp != 0); + + /* Exportation */ + + result = malloc(*len * sizeof(uint8_t)); + byte = result; + + tmp = *value; + + do + { + *byte = (tmp & 0x7f); tmp >>= 7; if (tmp != 0) - byte |= 0x80; + *byte |= 0x80; - result = extend_packed_buffer(pbuf, &byte, sizeof(uint8_t), false); + byte++; } - while (result && tmp != 0); + while (tmp != 0); return result; @@ -246,7 +277,7 @@ bool pack_uleb128(const uleb128_t *value, packed_buffer_t *pbuf) /****************************************************************************** * * * Paramètres : value = valeur à consigner. * -* pbuf = tampon de données à constituer. [OUT] * +* len = taille du tampon de données à constitué. [OUT] * * * * Description : Encode un nombre signé encodé au format LEB128. * * * @@ -256,19 +287,24 @@ bool pack_uleb128(const uleb128_t *value, packed_buffer_t *pbuf) * * ******************************************************************************/ -bool pack_leb128(const leb128_t *value, packed_buffer_t *pbuf) +void *pack_leb128(const leb128_t *value, size_t *len) { - - bool result; /* Bilan à retourner */ + uint8_t *result; /* Données à retourner */ + bool negative; /* Nature de la valeur */ uleb128_t tmp; /* Valeur modifiable */ bool more; /* Poursuite des traitements */ - bool negative; /* Nature de la valeur */ uint8_t byte; /* Octet à transposer */ + uint8_t *iter; /* Boucle de parcours */ + + negative = (*value < 0); + + /* Calcul de la quantité d'octets nécessaires */ + + *len = 0; tmp = *value; more = true; - negative = (*value < 0); while (more) { @@ -291,10 +327,44 @@ bool pack_leb128(const leb128_t *value, packed_buffer_t *pbuf) if ((tmp == 0 && (byte & 0x40) == 0x00) || (tmp == -1 && (byte & 0x40) == 0x40)) more = false; + (*len)++; + + } + + /* Exportation */ + + result = malloc(*len * sizeof(uint8_t)); + iter = result; + + tmp = *value; + + more = true; + + while (more) + { + *iter = (tmp & 0x7f); + tmp >>= 7; + + /** + * Propagation forcée du bit de signe pour les implémentations de + * décalage basées sur une opération logique et non arithmétique. + */ + + if (negative) + tmp |= (~0llu << (LEB128_BITS_COUNT - 7)); + + /** + * Le bit de signe n'est pas le bit de poids fort ici : + * On travaille sur 7 bits, donc le masque est 0x40 ! + */ + + if ((tmp == 0 && (*iter & 0x40) == 0x00) || (tmp == -1 && (*iter & 0x40) == 0x40)) + more = false; + else - byte |= 0x80; + *iter |= 0x80; - result = extend_packed_buffer(pbuf, &byte, sizeof(uint8_t), false); + iter++; } @@ -306,7 +376,8 @@ bool pack_leb128(const leb128_t *value, packed_buffer_t *pbuf) /****************************************************************************** * * * Paramètres : value = valeur à constituer. [OUT] * -* pbuf = tampon de données à consulter. * +* pos = tête de lecture à faire évoluer. [OUT] * +* max = position maximale liée à la fin des données. * * * * Description : Décode un nombre non signé encodé au format LEB128. * * * @@ -316,38 +387,45 @@ bool pack_leb128(const leb128_t *value, packed_buffer_t *pbuf) * * ******************************************************************************/ -bool unpack_uleb128(uleb128_t *value, packed_buffer_t *pbuf) +bool unpack_uleb128(uleb128_t *value, const void **pos, const void *max) { bool result; /* Bilan à retourner */ unsigned int shift; /* Décalage à appliquer */ - uint8_t byte; /* Octet à transposer */ + uint8_t *byte; /* Octet à transposer */ - result = true; + result = false; *value = 0; shift = 0; + byte = *(uint8_t **)pos; - while (true) + do { /* Encodage sur trop d'octets ? */ - if (shift > (7 * sizeof(uleb128_t))) + if (shift > (7 * MAX_LEB128_BYTES)) { result = false; break; } - result = extract_packed_buffer(pbuf, &byte, sizeof(uint8_t), false); - if (!result) break; + /* Atteinte de la fin des données ? */ + if ((void *)byte >= max) + { + result = false; + break; + } - *value |= ((byte & 0x7f) << shift); + *value |= ((*byte & 0x7f) << shift); - if ((byte & 0x80) == 0x00) - break; + result = true; shift += 7; } + while ((*byte++ & 0x80) == 0x80); + + *pos = byte; return result; @@ -357,7 +435,8 @@ bool unpack_uleb128(uleb128_t *value, packed_buffer_t *pbuf) /****************************************************************************** * * * Paramètres : value = valeur à constituer. [OUT] * -* pbuf = tampon de données à consulter. * +* pos = tête de lecture à faire évoluer. [OUT] * +* max = position maximale liée à la fin des données. * * * * Description : Décode un nombre signé encodé au format LEB128. * * * @@ -367,44 +446,56 @@ bool unpack_uleb128(uleb128_t *value, packed_buffer_t *pbuf) * * ******************************************************************************/ -bool unpack_leb128(leb128_t *value, packed_buffer_t *pbuf) +bool unpack_leb128(leb128_t *value, const void **pos, const void *max) { bool result; /* Bilan à retourner */ unsigned int shift; /* Décalage à appliquer */ - uint8_t byte; /* Octet à transposer */ + uint8_t *byte; /* Octet à transposer */ - result = true; + result = false; *value = 0; shift = 0; + byte = *(uint8_t **)pos; do { /* Encodage sur trop d'octets ? */ - if (shift > (7 * sizeof(leb128_t))) + if (shift > (7 * MAX_LEB128_BYTES)) { result = false; break; } - result = extract_packed_buffer(pbuf, &byte, sizeof(uint8_t), false); - if (!result) break; + /* Atteinte de la fin des données ? */ + if ((void *)byte >= max) + { + result = false; + break; + } - *value |= ((byte & 0x7f) << shift); + *value |= ((*byte & 0x7f) << shift); + + result = true; shift += 7; } - while ((byte & 0x80) == 0x80); + while ((*byte++ & 0x80) == 0x80); /** * Le bit de signe n'est pas le bit de poids fort ici : * On travaille sur 7 bits, donc le masque est 0x40 ! */ - if (shift < LEB128_BITS_COUNT && (byte & 0x40) == 0x40) - *value |= (~0llu << shift); + if (result) + { + if (shift < LEB128_BITS_COUNT && (byte[-1] & 0x40) == 0x40) + *value |= (~0llu << shift); + } + + *pos = byte; return result; diff --git a/src/common/leb128.h b/src/common/leb128.h index 0313f5c..cb712a3 100644 --- a/src/common/leb128.h +++ b/src/common/leb128.h @@ -30,7 +30,6 @@ #include "datatypes.h" -#include "packed.h" @@ -65,16 +64,16 @@ bool load_uleb128(uleb128_t *, int); bool store_uleb128(const uleb128_t *, int); /* Encode un nombre non signé encodé au format LEB128. */ -bool pack_uleb128(const uleb128_t *, packed_buffer_t *); +void *pack_uleb128(const uleb128_t *, size_t *); /* Encode un nombre signé encodé au format LEB128. */ -bool pack_leb128(const leb128_t *, packed_buffer_t *); +void *pack_leb128(const leb128_t *, size_t *); -/* Décode un nombre non signé encodé au format LEB128. */ -bool unpack_uleb128(uleb128_t *, packed_buffer_t *); +/* Encode un nombre non signé encodé au format LEB128. */ +bool unpack_uleb128(uleb128_t *, const void **, const void *); /* Décode un nombre signé encodé au format LEB128. */ -bool unpack_leb128(leb128_t *, packed_buffer_t *); +bool unpack_leb128(leb128_t *, const void **, const void *); diff --git a/tests/common/leb128.py b/tests/common/leb128.py index db3013e..037af4d 100644 --- a/tests/common/leb128.py +++ b/tests/common/leb128.py @@ -1,7 +1,6 @@ from chrysacase import ChrysalideTestCase from pychrysalide.common import pack_uleb128, unpack_uleb128, pack_leb128, unpack_leb128 -from pychrysalide.common import PackedBuffer class TestLEB128Values(ChrysalideTestCase): @@ -16,34 +15,30 @@ class TestLEB128Values(ChrysalideTestCase): 128: b'\x80\x01', } - for value, encoding in cases.items(): - - pbuf = PackedBuffer() + # Lecture depuis des blocs individuels - status = pack_uleb128(value, pbuf) - self.assertTrue(status) + for value, encoding in cases.items(): - self.assertEqual(pbuf.payload_length, len(encoding)) + self.assertEqual(pack_uleb128(value), encoding) - pbuf.rewind() + v, r = unpack_uleb128(encoding) - got = pbuf.extract(len(encoding)) + self.assertEqual(value, v) + self.assertEqual(b'', r) - self.assertEqual(got, encoding) + # Lecture depuis un bloc commun - self.assertFalse(pbuf.more_data) + data = b''.join(cases.values()) - for value, encoding in cases.items(): + values = [] - pbuf = PackedBuffer() - pbuf.extend(encoding, False) + while len(data) > 0: - pbuf.rewind() + val, data = unpack_uleb128(data) - got = unpack_uleb128(pbuf) - self.assertIsNotNone(got) + values.append(val) - self.assertEqual(got, value) + self.assertEqual(values, [ k for k in cases.keys() ]) def testSignedLeb128Encoding(self): @@ -55,54 +50,39 @@ class TestLEB128Values(ChrysalideTestCase): -9001: b'\xd7\xb9\x7f', } - for value, encoding in cases.items(): + # Lecture depuis des blocs individuels - pbuf = PackedBuffer() + for value, encoding in cases.items(): - status = pack_leb128(value, pbuf) - self.assertTrue(status) + self.assertEqual(pack_leb128(value), encoding) - self.assertEqual(pbuf.payload_length, len(encoding)) + v, r = unpack_leb128(encoding) - pbuf.rewind() + self.assertEqual(value, v) + self.assertEqual(b'', r) - got = pbuf.extract(len(encoding)) + # Lecture depuis un bloc commun - self.assertEqual(got, encoding) + data = b''.join(cases.values()) - self.assertFalse(pbuf.more_data) + values = [] - for value, encoding in cases.items(): + while len(data) > 0: - pbuf = PackedBuffer() - pbuf.extend(encoding, False) + val, data = unpack_leb128(data) - pbuf.rewind() + values.append(val) - got = unpack_leb128(pbuf) - self.assertIsNotNone(got) - - self.assertEqual(got, value) + self.assertEqual(values, [ k for k in cases.keys() ]) def testTooBigLeb128Encodings(self): """Prevent overflow for LEB128 values.""" - pbuf = PackedBuffer() - pbuf.extend(b'\x80' * 10 + b'\x7f', False) - - pbuf.rewind() - - got = unpack_uleb128(pbuf) - - self.assertIsNone(got) - - pbuf = PackedBuffer() - pbuf.extend(b'\x80' * 10 + b'\x7f', False) - - pbuf.rewind() + v = unpack_uleb128(b'\x80' * 10 + b'\x7f') - got = unpack_leb128(pbuf) + self.assertIsNone(v) - self.assertIsNone(got) + v = unpack_leb128(b'\x80' * 10 + b'\x7f') + self.assertIsNone(v) |