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 = 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)
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 = 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)
def commit(self, outpath=None, keep_parsed=False):
super(EpubContainer, self).commit(keep_parsed=keep_parsed)
for name in self.obfuscated_fonts:
if name not in self.name_path_map:
continue
alg, key = self.obfuscated_fonts[name]
# Decrypting and encrypting are the same operation (XOR with key)
decrypt_font(key, self.name_path_map[name], alg)
if outpath is None:
outpath = self.pathtoepub
from calibre.ebooks.tweak import zip_rebuilder
with open(join(self.root, 'mimetype'), 'wb') as f:
f.write(guess_type('a.epub'))
zip_rebuilder(self.root, outpath)
def commit(self, outpath=None, keep_parsed=False):
super(EpubContainer, self).commit(keep_parsed=keep_parsed)
for name in self.obfuscated_fonts:
if name not in self.name_path_map:
continue
alg, key = self.obfuscated_fonts[name]
# Decrypting and encrypting are the same operation (XOR with key)
decrypt_font(key, self.name_path_map[name], alg)
if outpath is None:
outpath = self.pathtoepub
from calibre.ebooks.tweak import zip_rebuilder
with open(join(self.root, 'mimetype'), 'wb') as f:
f.write(guess_type('a.epub'))
zip_rebuilder(self.root, outpath)
