mirror of https://github.com/borgbackup/borg.git
83 lines
2.2 KiB
Python
83 lines
2.2 KiB
Python
import hashlib
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import hmac
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import msgpack
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import os
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import zlib
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from Crypto.Cipher import AES
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class CryptoManager(object):
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KEY_CREATE = 1
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KEY_READ = 2
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KEY_ID = 3
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KEY_ARCHIVE = 4
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KEY_CINDEX = 5
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def __init__(self, store):
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self.key_cache = {}
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self.store = store
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self.tid = store.tid
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self.id_key = '0' * 32
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self.read_key = os.urandom(32)
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self.create_key = os.urandom(32)
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def get_key(self, tid):
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try:
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return self.key_cache[tid]
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except KeyError:
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keys = self.load_key(tid)
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self.key_cache[tid] = keys
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return keys
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def load_key(self, tid):
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data = self.store.get('K', str(tid))
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id = data[:32]
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if self.id_hash(data[32:]) != id:
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raise Exception('Invalid key object found')
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key = msgpack.unpackb(data[32:])
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return key['create'], key['read']
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def store_key(self):
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key = {
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'version': 1,
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'read': self.read_key,
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'create': self.create_key,
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}
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data = msgpack.packb(key)
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id = self.id_hash(data)
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self.store.put('K', str(self.tid), id + data)
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def id_hash(self, data):
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return hmac.new(self.id_key, data, hashlib.sha256).digest()
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def pack(self, data, key):
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data = zlib.compress(msgpack.packb(data))
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id = hmac.new(key, data, hashlib.sha256).digest()
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data = AES.new(key, AES.MODE_CFB, id[:16]).encrypt(data)
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return id + msgpack.packb((1, self.tid, data))
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def pack_read(self, data):
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return self.pack(data, self.read_key)
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def pack_create(self, data):
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return self.pack(data, self.create_key)
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def unpack(self, data, key_idx):
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id = data[:32]
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version, tid, data = msgpack.unpackb(data[32:])
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assert version == 1
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key = self.get_key(tid)[key_idx]
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data = AES.new(key, AES.MODE_CFB, id[:16]).decrypt(data)
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if hmac.new(key, data, hashlib.sha256).digest() != id:
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raise ValueError
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return msgpack.unpackb(zlib.decompress(data))
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def unpack_read(self, data):
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return self.unpack(data, 1)
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def unpack_create(self, data):
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return self.unpack(data, 0)
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