def _encrypt(self):
"""
Rebuild the master key from header settings and key-hash list. Encrypt
the stream start bytes and the out-buffer formatted as hashed block
stream with padding added as needed.
"""
# rebuild master key from (possibly) updated header
self._make_master_key()
# make hashed block stream
block_buffer = HashedBlockIO()
block_buffer.write(self.out_buffer.read())
# data is buffered in hashed block io, start a new one
self.out_buffer = io.BytesIO()
# write start bytes (for successful decrypt check)
self.out_buffer.write(self.header.StreamStartBytes)
# append blocked data to out-buffer
block_buffer.write_block_stream(self.out_buffer)
block_buffer.close()
self.out_buffer.seek(0)
# encrypt the whole thing with header settings and master key
data = pad(self.out_buffer.read())
self.out_buffer = aes_cbc_encrypt(data, self.master_key,
self.header.EncryptionIV)
def _encrypt(self):
"""
Rebuild the master key from header settings and key-hash list. Encrypt
the stream start bytes and the out-buffer formatted as hashed block
stream with padding added as needed.
"""
# rebuild master key from (possibly) updated header
self._make_master_key()
# make hashed block stream
block_buffer = HashedBlockIO()
block_buffer.write(self.out_buffer.read())
# data is buffered in hashed block io, start a new one
self.out_buffer = io.BytesIO()
# write start bytes (for successful decrypt check)
self.out_buffer.write(self.header.StreamStartBytes)
# append blocked data to out-buffer
block_buffer.write_block_stream(self.out_buffer)
block_buffer.close()
self.out_buffer.seek(0)
# encrypt the whole thing with header settings and master key
data = pad(self.out_buffer.read())
self.out_buffer = aes_cbc_encrypt(data, self.master_key,
self.header.EncryptionIV)
def _decrypt(self, stream):
"""
Build the master key from header settings and key-hash list.
Start reading from `stream` after the header and decrypt all the data.
Remove padding as needed and feed into hashed block reader, set as
in-buffer.
"""
super(KDB4File, self)._decrypt(stream)
data = aes_cbc_decrypt(stream.read(), self.master_key,
self.header.EncryptionIV)
data = unpad(data)
length = len(self.header.StreamStartBytes)
if self.header.StreamStartBytes == data[:length]:
# skip startbytes and wrap data in a hashed block io
self.in_buffer = HashedBlockIO(bytes=data[length:])
# set successful decryption flag
self.opened = True
else:
raise IOError('Master key invalid.')
def _decrypt(self, stream):
"""
Build the master key from header settings and key-hash list.
Start reading from `stream` after the header and decrypt all the data.
Remove padding as needed and feed into hashed block reader, set as
in-buffer.
"""
super(KDB4File, self)._decrypt(stream)
data = aes_cbc_decrypt(stream.read(), self.master_key,
self.header.EncryptionIV)
data = unpad(data)
length = len(self.header.StreamStartBytes)
if self.header.StreamStartBytes == data[:length]:
# skip startbytes and wrap data in a hashed block io
self.in_buffer = HashedBlockIO(bytes=data[length:])
# set successful decryption flag
self.opened = True
else:
raise IOError('Master key invalid.')
class KDB4File(KDBFile):
def __init__(self, stream=None, **credentials):
self.header = KDB4Header()
KDBFile.__init__(self, stream, **credentials)
def set_compression(self, flag=1):
"""Dis- (0) or enable (default: 1) compression"""
if flag not in [0, 1]:
raise ValueError('Compression flag can be 0 or 1.')
self.header.CompressionFlags = flag
#def set_comment(self, comment):
# self.header.Comment = comment
def read_from(self, stream):
"""
Read, parse, decrypt, decompress a KeePass file from a stream.
:arg stream: A file-like object (opened in 'rb' mode) or IO buffer
containing a KeePass file.
"""
super(KDB4File, self).read_from(stream)
if self.header.CompressionFlags == 1:
self._unzip()
def write_to(self, stream):
"""
Write the KeePass database back to a KeePass2 compatible file.
:arg stream: A writeable file-like object or IO buffer.
"""
if not (isinstance(stream, io.IOBase) or isinstance(stream, file)):
raise TypeError('Stream does not have the buffer interface.')
self._write_header(stream)
def _read_header(self, stream):
"""
Parse the header and write the values into self.header. Also sets
self.header_length.
"""
# KeePass 2.07 has version 1.01,
# 2.08 has 1.02,
# 2.09 has 2.00, 2.10 has 2.02, 2.11 has 2.04,
# 2.15 has 3.00.
# The first 2 bytes are critical (i.e. loading will fail, if the
# file version is too high), the last 2 bytes are informational.
#TODO implement version check
# the first header field starts at byte 12 after the signature
stream.seek(12)
while True:
# field_id is a single byte
field_id = stream_unpack(stream, None, 1, 'b')
# field_id >10 is undefined
if not field_id in self.header.fields.values():
raise IOError('Unknown header field found.')
# two byte (short) length of field data
length = stream_unpack(stream, None, 2, 'h')
if length > 0:
data = stream_unpack(stream, None, length,
'{}s'.format(length))
self.header.b[field_id] = data
# set position in data stream of end of header
if field_id == 0:
self.header_length = stream.tell()
break
# def _write_header(self, stream):
# """Serialize the header fields from self.header into a byte stream, prefix
# with file signature and version before writing header and out-buffer
# to `stream`.
# Note, that `stream` is flushed, but not closed!"""
# # serialize header to stream
# header = bytearray()
# # write file signature
# header.extend(struct.pack('<II', *KDB4_SIGNATURE))
# # and version
# header.extend(struct.pack('<hh', 0, 3))
# field_ids = self.header.keys()
# field_ids.sort()
# field_ids.reverse() # field_id 0 must be last
# for field_id in field_ids:
# value = self.header.b[field_id]
# length = len(value)
# header.extend(struct.pack('<b', field_id))
# header.extend(struct.pack('<h', length))
# header.extend(struct.pack('{}s'.format(length), value))
# # write header to stream
# stream.write(header)
# headerHash = base64.b64encode(sha256(header))
# self.obj_root.Meta.HeaderHash = headerHash
# # create HeaderHash if it does not exist
# if len(self.obj_root.Meta.xpath("HeaderHash")) < 1:
# etree.SubElement(self.obj_root.Meta, "HeaderHash")
# # reload out_buffer because we just changed the HeaderHash
# self.protect()
# self.out_buffer = io.BytesIO(self.pretty_print())
# # zip or not according to header setting
# if self.header.CompressionFlags == 1:
# self._zip()
# self._encrypt();
# # write encrypted block to stream
# stream.write(self.out_buffer)
# stream.flush()
def _decrypt(self, stream):
"""
Build the master key from header settings and key-hash list.
Start reading from `stream` after the header and decrypt all the data.
Remove padding as needed and feed into hashed block reader, set as
in-buffer.
"""
super(KDB4File, self)._decrypt(stream)
data = aes_cbc_decrypt(stream.read(), self.master_key,
self.header.EncryptionIV)
data = unpad(data)
length = len(self.header.StreamStartBytes)
if self.header.StreamStartBytes == data[:length]:
# skip startbytes and wrap data in a hashed block io
self.in_buffer = HashedBlockIO(bytes=data[length:])
# set successful decryption flag
self.opened = True
else:
raise IOError('Master key invalid.')
def _encrypt(self):
"""
Rebuild the master key from header settings and key-hash list. Encrypt
the stream start bytes and the out-buffer formatted as hashed block
stream with padding added as needed.
"""
# rebuild master key from (possibly) updated header
self._make_master_key()
# make hashed block stream
block_buffer = HashedBlockIO()
block_buffer.write(self.out_buffer.read())
# data is buffered in hashed block io, start a new one
self.out_buffer = io.BytesIO()
# write start bytes (for successful decrypt check)
self.out_buffer.write(self.header.StreamStartBytes)
# append blocked data to out-buffer
block_buffer.write_block_stream(self.out_buffer)
block_buffer.close()
self.out_buffer.seek(0)
# encrypt the whole thing with header settings and master key
data = pad(self.out_buffer.read())
self.out_buffer = aes_cbc_encrypt(data, self.master_key,
self.header.EncryptionIV)
def _unzip(self):
"""
Inplace decompress in-buffer. Read/write position is moved to 0.
"""
self.in_buffer.seek(0)
d = zlib.decompressobj(16 + zlib.MAX_WBITS)
self.in_buffer = io.BytesIO(d.decompress(self.in_buffer.read()))
self.in_buffer.seek(0)
def _zip(self):
"""
Inplace compress out-buffer. Read/write position is moved to 0.
"""
data = self.out_buffer.read()
self.out_buffer = io.BytesIO()
# note: compresslevel=6 seems to be important for kdb4!
gz = gzip.GzipFile(fileobj=self.out_buffer, mode='wb', compresslevel=6)
gz.write(data)
gz.close()
self.out_buffer.seek(0)
def _make_master_key(self):
"""
Make the master key by (1) combining the credentials to create
a composite hash, (2) transforming the hash using the transform seed
for a specific number of rounds and (3) finally hashing the result in
combination with the master seed.
"""
super(KDB4File, self)._make_master_key()
composite = sha256(''.join(self.keys))
tkey = transform_key(composite, self.header.TransformSeed,
self.header.TransformRounds)
self.master_key = sha256(self.header.MasterSeed + tkey)
class KDB4File(KDBFile):
def __init__(self, stream=None, **credentials):
self.header = KDB4Header()
KDBFile.__init__(self, stream, **credentials)
def set_compression(self, flag=1):
"""Dis- (0) or enable (default: 1) compression"""
if flag not in [0, 1]:
raise ValueError('Compression flag can be 0 or 1.')
self.header.CompressionFlags = flag
#def set_comment(self, comment):
# self.header.Comment = comment
def read_from(self, stream):
"""
Read, parse, decrypt, decompress a KeePass file from a stream.
:arg stream: A file-like object (opened in 'rb' mode) or IO buffer
containing a KeePass file.
"""
super(KDB4File, self).read_from(stream)
if self.header.CompressionFlags == 1:
self._unzip()
def write_to(self, stream):
"""
Write the KeePass database back to a KeePass2 compatible file.
:arg stream: A writeable file-like object or IO buffer.
"""
if not (isinstance(stream, io.IOBase) or isinstance(stream, file)):
raise TypeError('Stream does not have the buffer interface.')
self._write_header(stream)
def _read_header(self, stream):
"""
Parse the header and write the values into self.header. Also sets
self.header_length.
"""
# KeePass 2.07 has version 1.01,
# 2.08 has 1.02,
# 2.09 has 2.00, 2.10 has 2.02, 2.11 has 2.04,
# 2.15 has 3.00.
# The first 2 bytes are critical (i.e. loading will fail, if the
# file version is too high), the last 2 bytes are informational.
#TODO implement version check
# the first header field starts at byte 12 after the signature
stream.seek(12)
while True:
# field_id is a single byte
field_id = stream_unpack(stream, None, 1, 'b')
# field_id >10 is undefined
if not field_id in self.header.fields.values():
raise IOError('Unknown header field found.')
# two byte (short) length of field data
length = stream_unpack(stream, None, 2, 'h')
if length > 0:
data = stream_unpack(stream, None, length, '{}s'.format(length))
self.header.b[field_id] = data
# set position in data stream of end of header
if field_id == 0:
self.header_length = stream.tell()
break
def _write_header(self, stream):
"""Serialize the header fields from self.header into a byte stream, prefix
with file signature and version before writing header and out-buffer
to `stream`.
Note, that `stream` is flushed, but not closed!"""
# serialize header to stream
header = bytearray()
# write file signature
header.extend(struct.pack('<II', *KDB4_SIGNATURE))
# and version
header.extend(struct.pack('<hh', 0, 3))
field_ids = self.header.keys()
field_ids.sort()
field_ids.reverse() # field_id 0 must be last
for field_id in field_ids:
value = self.header.b[field_id]
length = len(value)
header.extend(struct.pack('<b', field_id))
header.extend(struct.pack('<h', length))
header.extend(struct.pack('{}s'.format(length), value))
# write header to stream
stream.write(header)
headerHash = base64.b64encode(sha256(header))
self.obj_root.Meta.HeaderHash = headerHash
# create HeaderHash if it does not exist
if len(self.obj_root.Meta.xpath("HeaderHash")) < 1:
etree.SubElement(self.obj_root.Meta, "HeaderHash")
# reload out_buffer because we just changed the HeaderHash
self.protect()
self.out_buffer = io.BytesIO(self.pretty_print())
# zip or not according to header setting
if self.header.CompressionFlags == 1:
self._zip()
self._encrypt();
# write encrypted block to stream
stream.write(self.out_buffer)
stream.flush()
def _decrypt(self, stream):
"""
Build the master key from header settings and key-hash list.
Start reading from `stream` after the header and decrypt all the data.
Remove padding as needed and feed into hashed block reader, set as
in-buffer.
"""
super(KDB4File, self)._decrypt(stream)
data = aes_cbc_decrypt(stream.read(), self.master_key,
self.header.EncryptionIV)
data = unpad(data)
length = len(self.header.StreamStartBytes)
if self.header.StreamStartBytes == data[:length]:
# skip startbytes and wrap data in a hashed block io
self.in_buffer = HashedBlockIO(bytes=data[length:])
# set successful decryption flag
self.opened = True
else:
raise IOError('Master key invalid.')
def _encrypt(self):
"""
Rebuild the master key from header settings and key-hash list. Encrypt
the stream start bytes and the out-buffer formatted as hashed block
stream with padding added as needed.
"""
# rebuild master key from (possibly) updated header
self._make_master_key()
# make hashed block stream
block_buffer = HashedBlockIO()
block_buffer.write(self.out_buffer.read())
# data is buffered in hashed block io, start a new one
self.out_buffer = io.BytesIO()
# write start bytes (for successful decrypt check)
self.out_buffer.write(self.header.StreamStartBytes)
# append blocked data to out-buffer
block_buffer.write_block_stream(self.out_buffer)
block_buffer.close()
self.out_buffer.seek(0)
# encrypt the whole thing with header settings and master key
data = pad(self.out_buffer.read())
self.out_buffer = aes_cbc_encrypt(data, self.master_key,
self.header.EncryptionIV)
def _unzip(self):
"""
Inplace decompress in-buffer. Read/write position is moved to 0.
"""
self.in_buffer.seek(0)
d = zlib.decompressobj(16+zlib.MAX_WBITS)
self.in_buffer = io.BytesIO(d.decompress(self.in_buffer.read()))
self.in_buffer.seek(0)
def _zip(self):
"""
Inplace compress out-buffer. Read/write position is moved to 0.
"""
data = self.out_buffer.read()
self.out_buffer = io.BytesIO()
# note: compresslevel=6 seems to be important for kdb4!
gz = gzip.GzipFile(fileobj=self.out_buffer, mode='wb', compresslevel=6)
gz.write(data)
gz.close()
self.out_buffer.seek(0)
def _make_master_key(self):
"""
Make the master key by (1) combining the credentials to create
a composite hash, (2) transforming the hash using the transform seed
for a specific number of rounds and (3) finally hashing the result in
combination with the master seed.
"""
super(KDB4File, self)._make_master_key()
composite = sha256(''.join(self.keys))
tkey = transform_key(composite,
self.header.TransformSeed,
self.header.TransformRounds)
self.master_key = sha256(self.header.MasterSeed + tkey)