Issue 4340 - Drop dependency on external xar tool

xarfile.py

 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 import re
 import struct
 import time
 import zlib
 
 from Crypto.Hash import SHA
@@ skipping 13 matching lines @@
         data = file.read()
 
     certificates = []
     key = None
     for match in re.finditer(r'-+BEGIN (.*?)-+(.*?)-+END \1-+', data, re.S):
         section = match.group(1)
         if section == 'CERTIFICATE':
             certificates.append(re.sub(r'\s+', '', match.group(2)))
         elif section == 'PRIVATE KEY':
             key = RSA.importKey(match.group(0))
-    if key is None:

[Sebastian Noack, 2016/08/17 18:41:33]

See
https://codereview.adblockplus.org/29349869/diff/29349942/packagerSafari.py#n...

[Wladimir Palant, 2016/08/17 19:22:28]

Done.

-        raise Exception('Cound not find private key in file')
+    if not key:
+        raise Exception('Could not find private key in file')
 
     return certificates, key
 
 
 def get_checksum(data):
     return SHA.new(data).digest()
 
 
 def get_hexchecksum(data):
     return SHA.new(data).hexdigest()
@@ skipping 73 matching lines @@
 
     offset = params['signature']['offset'] + params['signature']['size']
     compressed_data = compress_files(contents, params['files'], offset)
 
     template = getTemplate('xartoc.xml.tmpl', autoEscape=True)
     toc_uncompressed = template.render(params).encode('utf-8')
     toc_compressed = zlib.compress(toc_uncompressed, 9)
 
     with open(archivepath, 'wb') as file:
         # The file starts with a minimalistic header
-        header = XAR_HEADER.pack(XAR_HEADER_MAGIC, XAR_HEADER.size,

[Sebastian Noack, 2016/08/17 18:41:34]

Nit: I'd personally skip the variable:

  file.write(XAR_HEADER.pack(...))

[Wladimir Palant, 2016/08/17 19:22:28]

Done.

-                                 XAR_VERSION, len(toc_compressed),
-                                 len(toc_uncompressed), XAR_CKSUM_SHA1)
-        file.write(header)
+        file.write(XAR_HEADER.pack(XAR_HEADER_MAGIC, XAR_HEADER.size,
+                                   XAR_VERSION, len(toc_compressed),
+                                   len(toc_uncompressed), XAR_CKSUM_SHA1))
 
         # It's followed up with a compressed XML table of contents
         file.write(toc_compressed)
 
         # Now the actual data, all the offsets are in the table of contents
         file.write(get_checksum(toc_compressed))
         file.write(get_signature(key, toc_compressed))
         for blob in compressed_data:
             file.write(blob)