diff -r 6c33d4cc9b8f Modules/zipimport.c --- a/Modules/zipimport.c Fri Jan 22 12:33:12 2016 +0100 +++ b/Modules/zipimport.c Fri Jan 22 13:47:52 2016 +0200 @@ -827,23 +827,41 @@ static PyTypeObject ZipImporter_Type = { /* implementation */ -/* Given a buffer, return the long that is represented by the first +/* Given a buffer, return the unsigned int that is represented by the first 4 bytes, encoded as little endian. This partially reimplements marshal.c:r_long() */ -static long -get_long(const unsigned char *buf) { - long x; +static unsigned int +get_uint32(const unsigned char *buf) +{ + unsigned int x; x = buf[0]; - x |= (long)buf[1] << 8; - x |= (long)buf[2] << 16; - x |= (long)buf[3] << 24; -#if SIZEOF_LONG > 4 - /* Sign extension for 64-bit machines */ - x |= -(x & 0x80000000L); -#endif + x |= (unsigned int)buf[1] << 8; + x |= (unsigned int)buf[2] << 16; + x |= (unsigned int)buf[3] << 24; return x; } +/* Given a buffer, return the unsigned int that is represented by the first + 2 bytes, encoded as little endian. This partially reimplements + marshal.c:r_short() */ +static unsigned short +get_uint16(const unsigned char *buf) +{ + unsigned short x; + x = buf[0]; + x |= (unsigned short)buf[1] << 8; + return x; +} + +static void +set_file_error(PyObject *archive, int eof) +{ + if (eof) + PyErr_SetString(PyExc_EOFError, "EOF read where not expected"); + else + PyErr_SetFromErrnoWithFilenameObject(PyExc_OSError, archive); +} + /* read_directory(archive) -> files dict (new reference) @@ -871,20 +889,18 @@ read_directory(PyObject *archive) { PyObject *files = NULL; FILE *fp; - unsigned short flags; - short compress, time, date, name_size; - long crc, data_size, file_size, header_size; - Py_ssize_t file_offset, header_position, header_offset; - long l, count; - Py_ssize_t i; + unsigned short flags, compress, time, date, name_size; + unsigned int crc, data_size, file_size, header_size, header_offset; + unsigned long file_offset, header_position; + unsigned long arc_offset; /* Absolute offset to start of the zip-archive. */ + unsigned int count, i; + unsigned char buffer[46]; char name[MAXPATHLEN + 5]; - char dummy[8]; /* Buffer to read unused header values into */ PyObject *nameobj = NULL; - char *p, endof_central_dir[22]; - Py_ssize_t arc_offset; /* Absolute offset to start of the zip-archive. */ PyObject *path; const char *charset; int bootstrap; + const char *errmsg = NULL; fp = _Py_fopen_obj(archive, "rb"); if (fp == NULL) { @@ -897,28 +913,35 @@ read_directory(PyObject *archive) return NULL; } - if (fseek(fp, -22, SEEK_END) == -1) { - fclose(fp); - PyErr_Format(ZipImportError, "can't read Zip file: %R", archive); - return NULL; - } - header_position = ftell(fp); - if (fread(endof_central_dir, 1, 22, fp) != 22) { - fclose(fp); - PyErr_Format(ZipImportError, "can't read Zip file: %R", archive); - return NULL; - } - if (get_long((unsigned char *)endof_central_dir) != 0x06054B50) { + if (fseek(fp, -22, SEEK_END) == -1) + goto file_error; + header_position = (unsigned long)ftell(fp); + if (header_position == (unsigned long)-1) + goto file_error; + if (fread(buffer, 1, 22, fp) != 22) + goto file_error; + if (get_uint32(buffer) != 0x06054B50) { /* Bad: End of Central Dir signature */ - fclose(fp); - PyErr_Format(ZipImportError, "not a Zip file: %R", archive); - return NULL; + errmsg = "not a Zip file"; + goto invalid_header; } - header_size = get_long((unsigned char *)endof_central_dir + 12); - header_offset = get_long((unsigned char *)endof_central_dir + 16); - arc_offset = header_position - header_offset - header_size; - header_offset += arc_offset; + header_size = get_uint32(buffer + 12); + header_offset = get_uint32(buffer + 16); + if (header_position < header_size) { + errmsg = "bad central directory size"; + goto invalid_header; + } + if (header_position < header_offset) { + errmsg = "bad central directory offset"; + goto invalid_header; + } + if (header_position - header_size < header_offset) { + errmsg = "bad central directory size or offset"; + goto invalid_header; + } + header_position -= header_size; + arc_offset = header_position - header_offset; files = PyDict_New(); if (files == NULL) @@ -926,58 +949,60 @@ read_directory(PyObject *archive) /* Start of Central Directory */ count = 0; - if (fseek(fp, header_offset, 0) == -1) + if (fseek(fp, (long)header_position, 0) == -1) goto file_error; for (;;) { PyObject *t; + size_t n; int err; + n = fread(buffer, 1, 46, fp); + if (n < 4) + goto eof_error; + /* Start of file header */ - l = PyMarshal_ReadLongFromFile(fp); - if (l == -1 && PyErr_Occurred()) - goto error; - if (l != 0x02014B50) + if (get_uint32(buffer) != 0x02014B50) break; /* Bad: Central Dir File Header */ + if (n != 46) + goto eof_error; - /* On Windows, calling fseek to skip over the fields we don't use is - slower than reading the data into a dummy buffer because fseek flushes - stdio's internal buffers. See issue #8745. */ - if (fread(dummy, 1, 4, fp) != 4) /* Skip unused fields, avoid fseek */ - goto file_error; + flags = get_uint16(buffer + 8); + compress = get_uint16(buffer + 10); + time = get_uint16(buffer + 12); + date = get_uint16(buffer + 14); + crc = get_uint32(buffer + 16); + data_size = get_uint32(buffer + 20); + file_size = get_uint32(buffer + 24); + name_size = get_uint16(buffer + 28); + header_size = (unsigned int)name_size + + get_uint16(buffer + 30) /* extra field */ + + get_uint16(buffer + 32) /* comment */; - flags = (unsigned short)PyMarshal_ReadShortFromFile(fp); - compress = PyMarshal_ReadShortFromFile(fp); - time = PyMarshal_ReadShortFromFile(fp); - date = PyMarshal_ReadShortFromFile(fp); - crc = PyMarshal_ReadLongFromFile(fp); - data_size = PyMarshal_ReadLongFromFile(fp); - file_size = PyMarshal_ReadLongFromFile(fp); - name_size = PyMarshal_ReadShortFromFile(fp); - header_size = name_size + - PyMarshal_ReadShortFromFile(fp) + - PyMarshal_ReadShortFromFile(fp); - if (PyErr_Occurred()) - goto error; - - if (fread(dummy, 1, 8, fp) != 8) /* Skip unused fields, avoid fseek */ - goto file_error; - file_offset = PyMarshal_ReadLongFromFile(fp) + arc_offset; - if (PyErr_Occurred()) - goto error; + file_offset = get_uint32(buffer + 42); + if (file_offset > header_offset) { + errmsg = "bad local header offset"; + goto invalid_header; + } + file_offset += arc_offset; if (name_size > MAXPATHLEN) name_size = MAXPATHLEN; - p = name; - for (i = 0; i < (Py_ssize_t)name_size; i++) { - *p = (char)getc(fp); - if (*p == '/') - *p = SEP; - p++; + if (fread(name, 1, name_size, fp) != name_size) + goto file_error; + if (SEP != '/') { + for (i = 0; i < name_size; i++) + if (name[i] == '/') + name[i] = SEP; } - *p = 0; /* Add terminating null byte */ - for (; i < header_size; i++) /* Skip the rest of the header */ - if(getc(fp) == EOF) /* Avoid fseek */ + name[name_size] = '\0'; /* Add terminating null byte */ + /* Skip the rest of the header. + * On Windows, calling fseek to skip over the fields we don't use is + * slower than reading the data because fseek flushes stdio's + * internal buffers. See issue #8745. */ + assert(header_size <= 3*0xFFFF); + for (i = name_size; i < header_size; i++) + if (getc(fp) == EOF) goto file_error; bootstrap = 0; @@ -1009,7 +1034,7 @@ read_directory(PyObject *archive) path = PyUnicode_FromFormat("%U%c%U", archive, SEP, nameobj); if (path == NULL) goto error; - t = Py_BuildValue("Nhllnhhl", path, compress, data_size, + t = Py_BuildValue("NHIIkHHI", path, compress, data_size, file_size, file_offset, time, date, crc); if (t == NULL) goto error; @@ -1022,15 +1047,20 @@ read_directory(PyObject *archive) } fclose(fp); if (Py_VerboseFlag) - PySys_FormatStderr("# zipimport: found %ld names in %R\n", + PySys_FormatStderr("# zipimport: found %u names in %R\n", count, archive); return files; + +eof_error: + set_file_error(archive, !ferror(fp)); + goto error; file_error: - fclose(fp); - Py_XDECREF(files); - Py_XDECREF(nameobj); PyErr_Format(ZipImportError, "can't read Zip file: %R", archive); - return NULL; + goto error; +invalid_header: + assert(errmsg != NULL); + PyErr_Format(ZipImportError, "%s: %R", errmsg, archive); + goto error; error: fclose(fp); Py_XDECREF(files); @@ -1076,17 +1106,18 @@ get_decompress_func(void) static PyObject * get_data(PyObject *archive, PyObject *toc_entry) { - PyObject *raw_data, *data = NULL, *decompress; + PyObject *raw_data = NULL, *data, *decompress; char *buf; FILE *fp; - int err; - Py_ssize_t bytes_read = 0; - long l; PyObject *datapath; - long compress, data_size, file_size, file_offset, bytes_size; - long time, date, crc; + unsigned short compress, time, date; + unsigned int crc; + Py_ssize_t data_size, file_size, bytes_size; + long file_offset, header_size; + unsigned char buffer[30]; + const char *errmsg = NULL; - if (!PyArg_ParseTuple(toc_entry, "Olllllll", &datapath, &compress, + if (!PyArg_ParseTuple(toc_entry, "OHnnlHHI", &datapath, &compress, &data_size, &file_size, &file_offset, &time, &date, &crc)) { return NULL; @@ -1101,35 +1132,25 @@ get_data(PyObject *archive, PyObject *to return NULL; /* Check to make sure the local file header is correct */ - if (fseek(fp, file_offset, 0) == -1) { - fclose(fp); - PyErr_Format(ZipImportError, "can't read Zip file: %R", archive); - return NULL; + if (fseek(fp, file_offset, 0) == -1) + goto file_error; + if (fread(buffer, 1, 30, fp) != 30) + goto eof_error; + + if (get_uint32(buffer) != 0x04034B50) { + /* Bad: Local File Header */ + errmsg = "bad local file header"; + goto invalid_header; } - l = PyMarshal_ReadLongFromFile(fp); - if (l != 0x04034B50) { - /* Bad: Local File Header */ - if (!PyErr_Occurred()) - PyErr_Format(ZipImportError, - "bad local file header in %U", - archive); - fclose(fp); - return NULL; + header_size = 30 + + get_uint16(buffer + 26) /* file name */ + + get_uint16(buffer + 28) /* extra field */; + if (file_offset > LONG_MAX - header_size) { + errmsg = "bad local file header size"; + goto invalid_header; } - if (fseek(fp, file_offset + 26, 0) == -1) { - fclose(fp); - PyErr_Format(ZipImportError, "can't read Zip file: %R", archive); - return NULL; - } - - l = 30 + PyMarshal_ReadShortFromFile(fp) + - PyMarshal_ReadShortFromFile(fp); /* local header size */ - if (PyErr_Occurred()) { - fclose(fp); - return NULL; - } - file_offset += l; /* Start of file data */ + file_offset += header_size; /* Start of file data */ if (data_size > LONG_MAX - 1) { fclose(fp); @@ -1140,30 +1161,21 @@ get_data(PyObject *archive, PyObject *to if (bytes_size == 0) bytes_size++; raw_data = PyBytes_FromStringAndSize((char *)NULL, bytes_size); - - if (raw_data == NULL) { - fclose(fp); - return NULL; - } + if (raw_data == NULL) + goto error; buf = PyBytes_AsString(raw_data); - err = fseek(fp, file_offset, 0); - if (err == 0) { - bytes_read = fread(buf, 1, data_size, fp); - } else { - fclose(fp); - Py_DECREF(raw_data); - PyErr_Format(ZipImportError, "can't read Zip file: %R", archive); - return NULL; - } - fclose(fp); - if (err || bytes_read != data_size) { + if (fseek(fp, file_offset, 0) == -1) + goto file_error; + if (fread(buf, 1, data_size, fp) != (size_t)data_size) { PyErr_SetString(PyExc_IOError, "zipimport: can't read data"); - Py_DECREF(raw_data); - return NULL; + goto error; } + fclose(fp); + fp = NULL; + if (compress != 0) { buf[data_size] = 'Z'; /* saw this in zipfile.py */ data_size++; @@ -1186,9 +1198,24 @@ get_data(PyObject *archive, PyObject *to } data = PyObject_CallFunction(decompress, "Oi", raw_data, -15); Py_DECREF(decompress); -error: Py_DECREF(raw_data); return data; + +eof_error: + set_file_error(archive, !ferror(fp)); + goto error; +file_error: + PyErr_Format(ZipImportError, "can't read Zip file: %R", archive); + goto error; +invalid_header: + assert(errmsg != NULL); + PyErr_Format(ZipImportError, "%s: %R", errmsg, archive); + goto error; +error: + if (fp != NULL) + fclose(fp); + Py_XDECREF(raw_data); + return NULL; } /* Lenient date/time comparison function. The precision of the mtime @@ -1213,7 +1240,7 @@ static PyObject * unmarshal_code(PyObject *pathname, PyObject *data, time_t mtime) { PyObject *code; - char *buf = PyBytes_AsString(data); + unsigned char *buf = (unsigned char *)PyBytes_AsString(data); Py_ssize_t size = PyBytes_Size(data); if (size <= 9) { @@ -1222,7 +1249,7 @@ unmarshal_code(PyObject *pathname, PyObj return NULL; } - if (get_long((unsigned char *)buf) != PyImport_GetMagicNumber()) { + if (get_uint32(buf) != (unsigned int)PyImport_GetMagicNumber()) { if (Py_VerboseFlag) PySys_FormatStderr("# %R has bad magic\n", pathname); @@ -1230,8 +1257,7 @@ unmarshal_code(PyObject *pathname, PyObj return Py_None; /* signal caller to try alternative */ } - if (mtime != 0 && !eq_mtime(get_long((unsigned char *)buf + 4), - mtime)) { + if (mtime != 0 && !eq_mtime(get_uint32(buf + 4), mtime)) { if (Py_VerboseFlag) PySys_FormatStderr("# %R has bad mtime\n", pathname); @@ -1241,7 +1267,7 @@ unmarshal_code(PyObject *pathname, PyObj /* XXX the pyc's size field is ignored; timestamp collisions are probably unimportant with zip files. */ - code = PyMarshal_ReadObjectFromString(buf + 12, size - 12); + code = PyMarshal_ReadObjectFromString((char *)buf + 12, size - 12); if (code == NULL) return NULL; if (!PyCode_Check(code)) {