def process_encryption(self):
fonts = {}
enc = self.parsed('META-INF/encryption.xml')
for em in enc.xpath(
'//*[local-name()="EncryptionMethod" and @Algorithm]'):
alg = em.get('Algorithm')
if alg not in {ADOBE_OBFUSCATION, IDPF_OBFUSCATION}:
raise DRMError()
try:
cr = em.getparent().xpath(
'descendant::*[local-name()="CipherReference" and @URI]'
)[0]
except (IndexError, ValueError, KeyError):
continue
name = self.href_to_name(cr.get('URI'))
path = self.name_path_map.get(name, None)
if path is not None:
fonts[name] = alg
if not fonts:
return
package_id = raw_unique_identifier = idpf_key = None
for attrib, val in self.opf.attrib.iteritems():
if attrib.endswith('unique-identifier'):
package_id = val
break
if package_id is not None:
for elem in self.opf_xpath('//*[@id=%r]' % package_id):
if elem.text:
raw_unique_identifier = elem.text
break
if raw_unique_identifier is not None:
idpf_key = raw_unique_identifier
idpf_key = re.sub(u'\u0020\u0009\u000d\u000a', u'', idpf_key)
idpf_key = hashlib.sha1(idpf_key.encode('utf-8')).digest()
key = None
for item in self.opf_xpath('//*[local-name()="metadata"]/*'
'[local-name()="identifier"]'):
scheme = None
for xkey in item.attrib.keys():
if xkey.endswith('scheme'):
scheme = item.get(xkey)
if (scheme and scheme.lower() == 'uuid') or \
(item.text and item.text.startswith('urn:uuid:')):
try:
key = bytes(item.text).rpartition(':')[-1]
key = uuid.UUID(key).bytes
except:
self.log.exception('Failed to parse obfuscation key')
key = None
for font, alg in fonts.iteritems():
tkey = key if alg == ADOBE_OBFUSCATION else idpf_key
if not tkey:
raise InvalidBook('Failed to find obfuscation key')
raw = self.raw_data(font, decode=False)
raw = decrypt_font_data(tkey, raw, alg)
with self.open(font, 'wb') as f:
f.write(raw)
self.obfuscated_fonts[font] = (alg, tkey)
def __init__(self, pathtoazw3, log, clone_data=None, tdir=None):
if clone_data is not None:
super(AZW3Container, self).__init__(None,
None,
log,
clone_data=clone_data)
for x in ('pathtoazw3', 'obfuscated_fonts'):
setattr(self, x, clone_data[x])
return
self.pathtoazw3 = pathtoazw3
if tdir is None:
tdir = PersistentTemporaryDirectory('_azw3_container')
tdir = os.path.abspath(os.path.realpath(tdir))
self.root = tdir
with open(pathtoazw3, 'rb') as stream:
raw = stream.read(3)
if raw == b'TPZ':
raise InvalidMobi(
_('This is not a MOBI file. It is a Topaz file.'))
try:
header = MetadataHeader(stream, default_log)
except MobiError:
raise InvalidMobi(_('This is not a MOBI file.'))
if header.encryption_type != 0:
raise DRMError()
kf8_type = header.kf8_type
if kf8_type is None:
raise InvalidMobi(
_('This MOBI file does not contain a KF8 format '
'book. KF8 is the new format from Amazon. calibre can '
'only edit MOBI files that contain KF8 books. Older '
'MOBI files without KF8 are not editable.'))
if kf8_type == 'joint':
raise InvalidMobi(
_('This MOBI file contains both KF8 and '
'older Mobi6 data. calibre can only edit MOBI files '
'that contain only KF8 data.'))
try:
opf_path, obfuscated_fonts = fork_job(
'calibre.ebooks.oeb.polish.container',
'do_explode',
args=(pathtoazw3, tdir),
no_output=True)['result']
except WorkerError as e:
log(e.orig_tb)
raise InvalidMobi('Failed to explode MOBI')
super(AZW3Container, self).__init__(tdir, opf_path, log)
self.obfuscated_fonts = {
x.replace(os.sep, '/')
for x in obfuscated_fonts
}
def process_encryption(self):
fonts = {}
enc = self.parsed('META-INF/encryption.xml')
for em in enc.xpath(
'//*[local-name()="EncryptionMethod" and @Algorithm]'):
alg = em.get('Algorithm')
if alg not in {ADOBE_OBFUSCATION, IDPF_OBFUSCATION}:
raise DRMError()
cr = em.getparent().xpath(
'descendant::*[local-name()="CipherReference" and @URI]')[0]
name = self.href_to_name(cr.get('URI'))
path = self.name_path_map.get(name, None)
if path is not None:
fonts[name] = alg
if not fonts:
return
package_id = unique_identifier = idpf_key = None
for attrib, val in self.opf.attrib.iteritems():
if attrib.endswith('unique-identifier'):
package_id = val
break
if package_id is not None:
for elem in self.opf_xpath('//*[@id=%r]' % package_id):
if elem.text:
unique_identifier = elem.text.rpartition(':')[-1]
break
if unique_identifier is not None:
idpf_key = hashlib.sha1(unique_identifier).digest()
key = None
for item in self.opf_xpath('//*[local-name()="metadata"]/*'
'[local-name()="identifier"]'):
scheme = None
for xkey in item.attrib.keys():
if xkey.endswith('scheme'):
scheme = item.get(xkey)
if (scheme and scheme.lower() == 'uuid') or \
(item.text and item.text.startswith('urn:uuid:')):
try:
key = bytes(item.text).rpartition(':')[-1]
key = uuid.UUID(key).bytes
except:
self.log.exception('Failed to parse obfuscation key')
key = None
for font, alg in fonts.iteritems():
path = self.name_path_map[font]
tkey = key if alg == ADOBE_OBFUSCATION else idpf_key
if not tkey:
raise InvalidBook('Failed to find obfuscation key')
decrypt_font(tkey, path, alg)
self.obfuscated_fonts[font] = (alg, tkey)