def generate_signature(fp, updatefunc):
fp.seek(0)
# Magic
updatefunc(fp.read(4))
# index_offset
updatefunc(fp.read(4))
# file size
updatefunc(fp.read(8))
# number of signatures
num_sigs = fp.read(4)
updatefunc(num_sigs)
num_sigs = unpackint(num_sigs)
for i in range(num_sigs):
# signature algo
updatefunc(fp.read(4))
# signature size
sigsize = fp.read(4)
updatefunc(sigsize)
sigsize = unpackint(sigsize)
# Read this, but don't update the signature with it
fp.read(sigsize)
# Read the rest of the file
for block in read_file(fp):
updatefunc(block)
def from_fileobj(cls, fp):
_offset = fp.tell()
algo_id = unpackint(fp.read(4))
self = cls(algo_id)
self._offset = _offset
sigsize = unpackint(fp.read(4))
assert sigsize == self.sigsize
log.debug("signature data at %i to %i", fp.tell(), fp.tell() + sigsize)
self.signature = fp.read(self.sigsize)
log.debug("ver %i signature %i bytes at %i", algo_id, sigsize, _offset)
return self
def from_fileobj(cls, fp):
data = bytearray()
offset = fp.tell()
size = unpackint(fp.read(4))
data = bytearray(fp.read(size - 4))
return cls.from_bytes(data, offset, size)
def from_fileobj(cls, fp):
self = cls()
self._offset = fp.tell()
self.size = unpackint(fp.read(4))
self.block_id = unpackint(fp.read(4))
self.data = fp.read(self.size - 8)
self.info = {}
if self.block_id == 1:
self.name = "PRODUCT INFORMATION"
bits = self.data.split(b'\x00')
self.info['MARChannelName'] = bits[0].decode('ascii')
self.info['ProductVersion'] = bits[1].decode('ascii')
else:
raise ValueError("Unsupported additional info section: %s" %
self.block_id)
return self
def _read_signatures(self):
fp = self.fileobj
log.debug("reading signatures")
fp.seek(8)
file_size = unpacklongint(fp.read(8))
# Check that the file size matches
fp.seek(0, 2)
assert fp.tell() == file_size
fp.seek(16)
num_sigs = unpackint(fp.read(4))
log.debug("file_size: %i bytes", file_size)
log.debug("%i signatures present", num_sigs)
signatures = []
for i in range(num_sigs):
sig = MarSignature.from_fileobj(fp)
for algo_id, keyfile in self.signature_versions:
if algo_id == sig.algo_id:
sig.keyfile = keyfile
break
else:
log.info("no key specified to validate %i"
" signature", sig.algo_id)
signatures.append(sig)
# Read additional sections; this is also only present if we have a
# signature block
num_additional_sections = unpackint(fp.read(4))
log.debug("%i additional sections present",
num_additional_sections)
for i in range(num_additional_sections):
info = AdditionalInfo.from_fileobj(fp)
log.debug("%s", info)
self.additional_info.append(info)
return signatures
def _read_signatures(self):
fp = self.fileobj
log.debug("reading signatures")
fp.seek(8)
file_size = unpacklongint(fp.read(8))
# Check that the file size matches
fp.seek(0, 2)
assert fp.tell() == file_size
fp.seek(16)
num_sigs = unpackint(fp.read(4))
log.debug("file_size: %i bytes", file_size)
log.debug("%i signatures present", num_sigs)
signatures = []
for i in range(num_sigs):
sig = MarSignature.from_fileobj(fp)
for algo_id, keyfile in self.signature_versions:
if algo_id == sig.algo_id:
sig.keyfile = keyfile
break
else:
log.info("no key specified to validate %i"
" signature", sig.algo_id)
signatures.append(sig)
# Read additional sections; this is also only present if we have a
# signature block
num_additional_sections = unpackint(fp.read(4))
log.debug("%i additional sections present",
num_additional_sections)
for i in range(num_additional_sections):
info = AdditionalInfo.from_fileobj(fp)
log.debug("%s", info)
self.additional_info.append(info)
return signatures
def from_bytes(cls, data, offset, size):
"""Returns an AdditionalInfo object represended by the given bytearray.
Offset is where in the marfile this block is"""
assert isinstance(data, bytearray)
self = cls()
self._offset = offset
self.size = size
self.block_id = unpackint(data[:4])
self.data = data[4:]
self.info = {}
if self.block_id == 1:
self.name = "PRODUCT INFORMATION"
bits = self.data.split(b'\x00')
self.info['MARChannelName'] = bits[0].decode('ascii')
self.info['ProductVersion'] = bits[1].decode('ascii')
else:
raise ValueError("Unsupported additional info section: %s" %
self.block_id)
return self