# HG changeset patch

# User Yann Leboulanger <asterix@lagaule.org>

# Date 1334652355 -7200

# Node ID f046e4aaf7d49b2934622db66da1667ddddb1703

# Parent  0a8585330ccaa26f97ead998c29427d31c5d395b

more secure tmp file creation for latex

diff --git a/src/common/latex.py b/src/common/latex.py

--- a/src/common/latex.py

+++ b/src/common/latex.py

@@ -29,7 +29,7 @@

 import os

 import random

-from tempfile import gettempdir

+from tempfile import mkstemp, mkdtemp

 from subprocess import Popen, PIPE

 import logging

@@ -57,24 +57,6 @@

             return True

     return False

-def get_tmpfile_name():

-    random.seed()

-    nb = 0

-    while(nb < 100):

-        int_ = random.randint(0, 10000)

-        filename = os.path.join(gettempdir(), 'gajimtex_' + int_.__str__())

-        # Check if a file to not overwrite it

-        ok = True

-        extensions = ['.tex', '.log', '.aux', '.dvi']

-        for ext in extensions:

-            if os.path.exists(filename + ext):

-                ok = False

-                break

-        if ok:

-            return filename

-        nb += 1

-    return filename

-

 def write_latex(filename, str_):

     texstr = '\\documentclass[12pt]{article}\\usepackage[dvips]{graphicx}'

     texstr += '\\usepackage{amsmath}\\usepackage{amssymb}'

@@ -91,12 +73,13 @@

 # a wrapper for Popen so that no window gets opened on Windows

 # (i think this is the reason we're using Popen rather than just system())

 # stdout goes to a pipe so that it can be read

-def popen_nt_friendly(command):

+def popen_nt_friendly(command, directory):

     if os.name == 'nt':

         # CREATE_NO_WINDOW

-        return Popen(command, creationflags=0x08000000, cwd=gettempdir(), stdout=PIPE)

+        return Popen(command, creationflags=0x08000000, cwd=directory,

+            stdout=PIPE)

     else:

-        return Popen(command, cwd=gettempdir(), stdout=PIPE)

+        return Popen(command, cwd=directory, stdout=PIPE)

 def check_for_latex_support():

     """

@@ -112,16 +95,16 @@

     except LatexError:

         return False

-def try_run(argv):

+def try_run(argv, directory):

     try:

-        p = popen_nt_friendly(argv)

+        p = popen_nt_friendly(argv, directory)

         out = p.communicate()[0]

         log.info(out)

         return p.wait()

     except Exception, e:

         return _('Error executing "%(command)s": %(error)s') % {

-                'command': " ".join(argv),

-                'error': helpers.decode_string(str(e))}

+            'command': " ".join(argv),

+            'error': helpers.decode_string(str(e))}

 def latex_to_image(str_):

@@ -137,32 +120,41 @@

             return []

         except AttributeError:

             # interface may not be available when we test latext at startup

-            return ['-fg', 'rgb 0.0 0.0 0.0']

+            return {'hex': ['+level-colors', '0x000000'],

+                'tex': ['-fg', 'rgb 0.0 0.0 0.0']}[fmt]

     # filter latex code with bad commands

     if check_blacklist(str_):

         # we triggered the blacklist, immediately return None

         return None

-    tmpfile = get_tmpfile_name()

+    try:

+        tmpdir = mkdtemp(prefix='gajimtex')

+        tmppng = mkstemp(prefix='gajim_tex', suffix='.png')[1]

+    except Exception:

+        raise LatexError('could not securely create one or more temporary files'

+            ' for LaTeX conversion')

+

+    tmpfile = os.path.join(tmpdir, 'gajim_tex')

     # build latex string

-    write_latex(os.path.join(tmpfile + '.tex'), str_)

+    write_latex(tmpfile + '.tex', str_)

     # convert TeX to dvi

-    exitcode = try_run(['latex', '--interaction=nonstopmode',

-                      tmpfile + '.tex'])

+    exitcode = try_run(['latex', '--interaction=nonstopmode', tmpfile + '.tex'],

+        tmpdir)

     if exitcode == 0:

         # convert dvi to png

         latex_png_dpi = gajim.config.get('latex_png_dpi')

         exitcode = try_run(['dvipng'] + fg_str('tex') + ['-T', 'tight', '-D',

-            latex_png_dpi, tmpfile + '.dvi', '-o', tmpfile + '.png'])

+            latex_png_dpi, tmpfile + '.dvi', '-o', tmpfile + '.png'], tmpdir)

         if exitcode:

             # dvipng failed, try convert

             exitcode = try_run(['convert'] + fg_str('hex') + ['-trim',

-                '-density', latex_png_dpi, tmpfile + '.dvi', tmpfile + '.png'])

+                '-density', latex_png_dpi, tmpfile + '.dvi', tmpfile + '.png'],

+                tmpdir)

     # remove temp files created by us and TeX

     extensions = ['.tex', '.log', '.aux', '.dvi']

@@ -172,10 +164,15 @@

         except Exception:

             pass

+    if exitcode == 0:

+        os.rename(tmpfile + '.png', tmppng)

+

+    os.rmdir(tmpdir)

+

     if isinstance(exitcode, (unicode, str)):

         raise LatexError(exitcode)

     if exitcode == 0:

-        result = tmpfile + '.png'

+        result = tmppng

     return result