sendMessage(
encodeMessage("policy_end_datetime: {}".format(policy_end_datetime)))
######################################
# Alice, the Authority of the Policy #
######################################
ALICE = Alice(network_middleware=RestMiddleware(),
known_nodes=[ursula],
learn_on_same_thread=True,
federated_only=True)
# Alice can get the public key even before creating the policy.
# From this moment on, any Data Source that knows the public key
# can encrypt data originally intended for Alice, but that can be shared with
# any Bob that Alice grants access.
policy_pubkey = ALICE.get_policy_pubkey_from_label(label)
BOB = Bob(known_nodes=[ursula],
network_middleware=RestMiddleware(),
federated_only=True,
start_learning_now=True,
learn_on_same_thread=True)
ALICE.start_learning_loop(now=True)
policy = ALICE.grant(BOB, label, m=m, n=n, expiration=policy_end_datetime)
assert policy.public_key == policy_pubkey
# Alice puts her public key somewhere for Bob to find later...
alices_pubkey_bytes_saved_for_posterity = bytes(ALICE.stamp)
class Client(object):
URSULA_SEEDNODE_URI = ""
def __init__(self, ursula_url):
self.URSULA_SEEDNODE_URI = ursula_url
# todo : customise ipfs host
self.ipfs = ipfsapi.connect("https://ipfs.infura.io", 5001)
random_name = fake.name()
self.label = random_name.encode()
self.m = 2
self.n = 3
def node_info(self):
return self.ipfs.id()
def generate_recipient_keys(self):
enc_privkey = UmbralPrivateKey.gen_key()
sig_privkey = UmbralPrivateKey.gen_key()
recipient_privkeys = {
'enc': enc_privkey.to_bytes().hex(),
'sig': sig_privkey.to_bytes().hex(),
}
enc_pubkey = enc_privkey.get_pubkey()
sig_pubkey = sig_privkey.get_pubkey()
recipient_pubkeys = {
'enc': enc_pubkey.to_bytes().hex(),
'sig': sig_pubkey.to_bytes().hex()
}
return recipient_privkeys, recipient_pubkeys
def generate_owner_policy_public_key(self, max_days):
self.ursula = Ursula.from_seed_and_stake_info(
seed_uri=self.URSULA_SEEDNODE_URI,
federated_only=True,
minimum_stake=0)
policy_end_datetime = maya.now() + datetime.timedelta(days=max_days)
self.ALICE = Alice(network_middleware=RestMiddleware(),
known_nodes=[self.ursula],
learn_on_same_thread=True,
federated_only=True)
policy_pubkey = self.ALICE.get_policy_pubkey_from_label(self.label)
return policy_pubkey
def uploadFile(self, filename, policy_pubkey):
data_source = Enrico(policy_encrypting_key=policy_pubkey)
data_source_public_key = bytes(data_source.stamp)
file = open(filename, "r").read()
encoded = base64.b64encode(file.encode())
encrypt_message, _signature = data_source.encrypt_message(encoded)
kit_bytes = encrypt_message.to_bytes()
try:
os.mkdir("./tmp")
except Exception as e:
logging.info("temp folder exist")
temp = open('./tmp/' + filename, 'wb')
temp.write(kit_bytes)
temp.close()
res = self.ipfs.add('./tmp/' + filename)
receipt_info = {
"data_source_public_key": data_source_public_key.hex(),
"hash_key": res['Hash']
}
return receipt_info
def authorize(self, recipient_pubkeys, max_days=5):
powers_and_material = {
DecryptingPower:
UmbralPublicKey.from_bytes(bytes.fromhex(
recipient_pubkeys["enc"])),
SigningPower:
UmbralPublicKey.from_bytes(bytes.fromhex(recipient_pubkeys["sig"]))
}
recipient = Bob.from_public_keys(
powers_and_material=powers_and_material, federated_only=True)
policy_end_datetime = maya.now() + datetime.timedelta(days=max_days)
m, n = self.m, self.n
self.ALICE.start_learning_loop(now=True)
policy = self.ALICE.grant(recipient,
self.label,
m=m,
n=n,
expiration=policy_end_datetime)
alices_pubkey = bytes(self.ALICE.stamp)
policy_info = {
"policy_pubkey": policy.public_key.to_bytes().hex(),
"alice_sig_pubkey": alices_pubkey,
"label": self.label.decode("utf-8")
}
return policy_info
def downloadFile(self, downloadFilename, recipient_privkeys, receipt,
policy_info):
hash = receipt['hash_key']
input = self.ipfs.cat(hash)
ursula = Ursula.from_seed_and_stake_info(
seed_uri=self.URSULA_SEEDNODE_URI,
federated_only=True,
minimum_stake=0)
bob_enc_keypair = DecryptingKeypair(
private_key=UmbralPrivateKey.from_bytes(
bytes.fromhex(recipient_privkeys["enc"])))
bob_sig_keypair = SigningKeypair(
private_key=UmbralPrivateKey.from_bytes(
bytes.fromhex(recipient_privkeys["sig"])))
enc_power = DecryptingPower(keypair=bob_enc_keypair)
sig_power = SigningPower(keypair=bob_sig_keypair)
power_ups = [enc_power, sig_power]
authorizedRecipient = Bob(
is_me=True,
federated_only=True,
crypto_power_ups=power_ups,
start_learning_now=True,
abort_on_learning_error=True,
known_nodes=[ursula],
save_metadata=False,
network_middleware=RestMiddleware(),
)
policy_pubkey = UmbralPublicKey.from_bytes(
bytes.fromhex(policy_info["policy_pubkey"]))
enrico_as_understood = Enrico.from_public_keys(
{
SigningPower:
UmbralPublicKey.from_bytes(
bytes.fromhex(receipt['data_source_public_key']))
},
#{SigningPower: data_source_public_key},
policy_encrypting_key=policy_pubkey)
alice_pubkey_restored = UmbralPublicKey.from_bytes(
(policy_info['alice_sig_pubkey']))
authorizedRecipient.join_policy(policy_info['label'].encode(),
alice_pubkey_restored)
kit = UmbralMessageKit.from_bytes(input)
delivered_cleartexts = authorizedRecipient.retrieve(
message_kit=kit,
data_source=enrico_as_understood,
alice_verifying_key=alice_pubkey_restored,
label=(policy_info['label'].encode()))
#delivered_cleartexts = authorizedRecipient.retrieve(message_kit=kit,data_source=data_source,alice_verifying_key=alice_pubkey_restored, label=(policy_info['label'].encode()) )
data = base64.b64decode(delivered_cleartexts[0])
output = open('./' + downloadFilename, 'wb')
output.write(data)
output.close()