444 lines
16 KiB
Python
444 lines
16 KiB
Python
import base64
|
|
import math
|
|
import os
|
|
import RNS
|
|
import time
|
|
import atexit
|
|
from .vendor import umsgpack as umsgpack
|
|
from cryptography.hazmat.primitives import hashes
|
|
from cryptography.hazmat.backends import default_backend
|
|
from cryptography.hazmat.primitives import serialization
|
|
from cryptography.hazmat.primitives.serialization import load_der_public_key
|
|
from cryptography.hazmat.primitives.serialization import load_der_private_key
|
|
from cryptography.hazmat.primitives.asymmetric import rsa
|
|
from cryptography.hazmat.primitives.asymmetric import padding
|
|
|
|
class Identity:
|
|
"""
|
|
This class is used to manage identities in Reticulum. It provides methods
|
|
for encryption, decryption, signatures and verification, and is the basis
|
|
for all encrypted communication over Reticulum networks.
|
|
|
|
:param public_only: Specifies whether this destination only holds a public key.
|
|
"""
|
|
KEYSIZE = 1024
|
|
"""
|
|
RSA key size in bits.
|
|
"""
|
|
DERKEYSIZE = KEYSIZE+272
|
|
|
|
# Non-configurable constants
|
|
PADDINGSIZE = 336 # In bits
|
|
HASHLENGTH = 256 # In bits
|
|
SIGLENGTH = KEYSIZE
|
|
|
|
ENCRYPT_CHUNKSIZE = (KEYSIZE-PADDINGSIZE)//8
|
|
DECRYPT_CHUNKSIZE = KEYSIZE//8
|
|
|
|
TRUNCATED_HASHLENGTH = 80 # In bits
|
|
"""
|
|
Constant specifying the truncated hash length (in bits) used by Reticulum
|
|
for addressable hashes. Non-configurable.
|
|
"""
|
|
|
|
# Storage
|
|
known_destinations = {}
|
|
|
|
@staticmethod
|
|
def remember(packet_hash, destination_hash, public_key, app_data = None):
|
|
Identity.known_destinations[destination_hash] = [time.time(), packet_hash, public_key, app_data]
|
|
|
|
|
|
@staticmethod
|
|
def recall(destination_hash):
|
|
"""
|
|
Recall identity for a destination hash.
|
|
|
|
:param destination_hash: Destination hash as *bytes*.
|
|
:returns: An :ref:`RNS.Identity<api-identity>` instance that can be used to create an outgoing :ref:`RNS.Destination<api-destination>`, or *None* if the destination is unknown.
|
|
"""
|
|
RNS.log("Searching for "+RNS.prettyhexrep(destination_hash)+"...", RNS.LOG_EXTREME)
|
|
if destination_hash in Identity.known_destinations:
|
|
identity_data = Identity.known_destinations[destination_hash]
|
|
identity = Identity(public_only=True)
|
|
identity.load_public_key(identity_data[2])
|
|
identity.app_data = identity_data[3]
|
|
RNS.log("Found "+RNS.prettyhexrep(destination_hash)+" in known destinations", RNS.LOG_EXTREME)
|
|
return identity
|
|
else:
|
|
RNS.log("Could not find "+RNS.prettyhexrep(destination_hash)+" in known destinations", RNS.LOG_EXTREME)
|
|
return None
|
|
|
|
@staticmethod
|
|
def recall_app_data(destination_hash):
|
|
"""
|
|
Recall last heard app_data for a destination hash.
|
|
|
|
:param destination_hash: Destination hash as *bytes*.
|
|
:returns: *Bytes* containing app_data, or *None* if the destination is unknown.
|
|
"""
|
|
RNS.log("Searching for app_data for "+RNS.prettyhexrep(destination_hash)+"...", RNS.LOG_EXTREME)
|
|
if destination_hash in Identity.known_destinations:
|
|
app_data = Identity.known_destinations[destination_hash][3]
|
|
RNS.log("Found "+RNS.prettyhexrep(destination_hash)+" app_data in known destinations", RNS.LOG_EXTREME)
|
|
return app_data
|
|
else:
|
|
RNS.log("Could not find "+RNS.prettyhexrep(destination_hash)+" app_data in known destinations", RNS.LOG_EXTREME)
|
|
return None
|
|
|
|
@staticmethod
|
|
def save_known_destinations():
|
|
RNS.log("Saving known destinations to storage...", RNS.LOG_VERBOSE)
|
|
file = open(RNS.Reticulum.storagepath+"/known_destinations","wb")
|
|
umsgpack.dump(Identity.known_destinations, file)
|
|
file.close()
|
|
RNS.log("Done saving known destinations to storage", RNS.LOG_VERBOSE)
|
|
|
|
@staticmethod
|
|
def load_known_destinations():
|
|
if os.path.isfile(RNS.Reticulum.storagepath+"/known_destinations"):
|
|
try:
|
|
file = open(RNS.Reticulum.storagepath+"/known_destinations","rb")
|
|
Identity.known_destinations = umsgpack.load(file)
|
|
file.close()
|
|
RNS.log("Loaded "+str(len(Identity.known_destinations))+" known destination from storage", RNS.LOG_VERBOSE)
|
|
except:
|
|
RNS.log("Error loading known destinations from disk, file will be recreated on exit", RNS.LOG_ERROR)
|
|
else:
|
|
RNS.log("Destinations file does not exist, so no known destinations loaded", RNS.LOG_VERBOSE)
|
|
|
|
@staticmethod
|
|
def full_hash(data):
|
|
"""
|
|
Get a SHA-256 hash of passed data.
|
|
|
|
:param data: Data to be hashed as *bytes*.
|
|
:returns: SHA-256 hash as *bytes*
|
|
"""
|
|
digest = hashes.Hash(hashes.SHA256(), backend=default_backend())
|
|
digest.update(data)
|
|
|
|
return digest.finalize()
|
|
|
|
@staticmethod
|
|
def truncated_hash(data):
|
|
"""
|
|
Get a truncated SHA-256 hash of passed data.
|
|
|
|
:param data: Data to be hashed as *bytes*.
|
|
:returns: Truncated SHA-256 hash as *bytes*
|
|
"""
|
|
return Identity.full_hash(data)[:(Identity.TRUNCATED_HASHLENGTH//8)]
|
|
|
|
@staticmethod
|
|
def get_random_hash():
|
|
"""
|
|
Get a random SHA-256 hash.
|
|
|
|
:param data: Data to be hashed as *bytes*.
|
|
:returns: Truncated SHA-256 hash of random data as *bytes*
|
|
"""
|
|
return Identity.truncated_hash(os.urandom(10))
|
|
|
|
@staticmethod
|
|
def validate_announce(packet):
|
|
if packet.packet_type == RNS.Packet.ANNOUNCE:
|
|
RNS.log("Validating announce from "+RNS.prettyhexrep(packet.destination_hash), RNS.LOG_DEBUG)
|
|
destination_hash = packet.destination_hash
|
|
public_key = packet.data[10:Identity.DERKEYSIZE//8+10]
|
|
random_hash = packet.data[Identity.DERKEYSIZE//8+10:Identity.DERKEYSIZE//8+20]
|
|
signature = packet.data[Identity.DERKEYSIZE//8+20:Identity.DERKEYSIZE//8+20+Identity.KEYSIZE//8]
|
|
app_data = b""
|
|
if len(packet.data) > Identity.DERKEYSIZE//8+20+Identity.KEYSIZE//8:
|
|
app_data = packet.data[Identity.DERKEYSIZE//8+20+Identity.KEYSIZE//8:]
|
|
|
|
signed_data = destination_hash+public_key+random_hash+app_data
|
|
|
|
if not len(packet.data) > Identity.DERKEYSIZE//8+20+Identity.KEYSIZE//8:
|
|
app_data = None
|
|
|
|
announced_identity = Identity(public_only=True)
|
|
announced_identity.load_public_key(public_key)
|
|
|
|
if announced_identity.pub != None and announced_identity.validate(signature, signed_data):
|
|
RNS.Identity.remember(packet.get_hash(), destination_hash, public_key, app_data)
|
|
RNS.log("Stored valid announce from "+RNS.prettyhexrep(destination_hash), RNS.LOG_DEBUG)
|
|
del announced_identity
|
|
return True
|
|
else:
|
|
RNS.log("Received invalid announce", RNS.LOG_DEBUG)
|
|
del announced_identity
|
|
return False
|
|
|
|
@staticmethod
|
|
def exit_handler():
|
|
Identity.save_known_destinations()
|
|
|
|
|
|
@staticmethod
|
|
def from_file(path):
|
|
"""
|
|
Create a new :ref:`RNS.Identity<api-identity>` instance from a file.
|
|
Can be used to load previously created and saved identities into Reticulum.
|
|
|
|
:param path: The full path to the saved :ref:`RNS.Identity<api-identity>` data
|
|
:returns: A :ref:`RNS.Identity<api-identity>` instance, or *None* if the loaded data was invalid.
|
|
"""
|
|
identity = Identity(public_only=True)
|
|
if identity.load(path):
|
|
return identity
|
|
else:
|
|
return None
|
|
|
|
|
|
def __init__(self,public_only=False):
|
|
# Initialize keys to none
|
|
self.prv = None
|
|
self.pub = None
|
|
self.prv_bytes = None
|
|
self.pub_bytes = None
|
|
self.hash = None
|
|
self.hexhash = None
|
|
|
|
if not public_only:
|
|
self.create_keys()
|
|
|
|
def create_keys(self):
|
|
self.prv = rsa.generate_private_key(
|
|
public_exponent=65537,
|
|
key_size=Identity.KEYSIZE,
|
|
backend=default_backend()
|
|
)
|
|
self.prv_bytes = self.prv.private_bytes(
|
|
encoding=serialization.Encoding.DER,
|
|
format=serialization.PrivateFormat.PKCS8,
|
|
encryption_algorithm=serialization.NoEncryption()
|
|
)
|
|
self.pub = self.prv.public_key()
|
|
self.pub_bytes = self.pub.public_bytes(
|
|
encoding=serialization.Encoding.DER,
|
|
format=serialization.PublicFormat.SubjectPublicKeyInfo
|
|
)
|
|
|
|
self.update_hashes()
|
|
|
|
RNS.log("Identity keys created for "+RNS.prettyhexrep(self.hash), RNS.LOG_VERBOSE)
|
|
|
|
def get_private_key(self):
|
|
"""
|
|
:returns: The private key as *bytes*
|
|
"""
|
|
return self.prv_bytes
|
|
|
|
def get_public_key(self):
|
|
"""
|
|
:returns: The public key as *bytes*
|
|
"""
|
|
return self.pub_bytes
|
|
|
|
def load_private_key(self, prv_bytes):
|
|
"""
|
|
Load a private key into the instance.
|
|
|
|
:param prv_bytes: The private key as *bytes*.
|
|
:returns: True if the key was loaded, otherwise False.
|
|
"""
|
|
try:
|
|
self.prv_bytes = prv_bytes
|
|
self.prv = serialization.load_der_private_key(
|
|
self.prv_bytes,
|
|
password=None,
|
|
backend=default_backend()
|
|
)
|
|
self.pub = self.prv.public_key()
|
|
self.pub_bytes = self.pub.public_bytes(
|
|
encoding=serialization.Encoding.DER,
|
|
format=serialization.PublicFormat.SubjectPublicKeyInfo
|
|
)
|
|
self.update_hashes()
|
|
|
|
return True
|
|
|
|
except Exception as e:
|
|
RNS.log("Failed to load identity key", RNS.LOG_ERROR)
|
|
RNS.log("The contained exception was: "+str(e), RNS.LOG_ERROR)
|
|
return False
|
|
|
|
def load_public_key(self, key):
|
|
"""
|
|
Load a public key into the instance.
|
|
|
|
:param prv_bytes: The public key as *bytes*.
|
|
:returns: True if the key was loaded, otherwise False.
|
|
"""
|
|
try:
|
|
self.pub_bytes = key
|
|
self.pub = load_der_public_key(self.pub_bytes, backend=default_backend())
|
|
self.update_hashes()
|
|
except Exception as e:
|
|
RNS.log("Error while loading public key, the contained exception was: "+str(e), RNS.LOG_ERROR)
|
|
|
|
def update_hashes(self):
|
|
self.hash = Identity.truncated_hash(self.pub_bytes)
|
|
self.hexhash = self.hash.hex()
|
|
|
|
def to_file(self, path):
|
|
"""
|
|
Saves the identity to a file. This will write the private key to disk,
|
|
and anyone with access to this file will be able to decrypt all
|
|
communication for the identity. Be very careful with this method.
|
|
|
|
:param path: The full path specifying where to save the identity.
|
|
:returns: True if the file was saved, otherwise False.
|
|
"""
|
|
try:
|
|
with open(path, "wb") as key_file:
|
|
key_file.write(self.prv_bytes)
|
|
return True
|
|
return False
|
|
except Exception as e:
|
|
RNS.log("Error while saving identity to "+str(path), RNS.LOG_ERROR)
|
|
RNS.log("The contained exception was: "+str(e))
|
|
|
|
def load(self, path):
|
|
try:
|
|
with open(path, "rb") as key_file:
|
|
prv_bytes = key_file.read()
|
|
return self.load_private_key(prv_bytes)
|
|
return False
|
|
except Exception as e:
|
|
RNS.log("Error while loading identity from "+str(path), RNS.LOG_ERROR)
|
|
RNS.log("The contained exception was: "+str(e))
|
|
|
|
def encrypt(self, plaintext):
|
|
"""
|
|
Encrypts information for the identity.
|
|
|
|
:param plaintext: The plaintext to be encrypted as *bytes*.
|
|
:returns: Ciphertext as *bytes*.
|
|
:raises: *KeyError* if the instance does not hold a public key
|
|
"""
|
|
if self.pub != None:
|
|
chunksize = Identity.ENCRYPT_CHUNKSIZE
|
|
chunks = int(math.ceil(len(plaintext)/(float(chunksize))))
|
|
|
|
ciphertext = b"";
|
|
for chunk in range(chunks):
|
|
start = chunk*chunksize
|
|
end = (chunk+1)*chunksize
|
|
if (chunk+1)*chunksize > len(plaintext):
|
|
end = len(plaintext)
|
|
|
|
ciphertext += self.pub.encrypt(
|
|
plaintext[start:end],
|
|
padding.OAEP(
|
|
mgf=padding.MGF1(algorithm=hashes.SHA1()),
|
|
algorithm=hashes.SHA1(),
|
|
label=None
|
|
)
|
|
)
|
|
return ciphertext
|
|
else:
|
|
raise KeyError("Encryption failed because identity does not hold a public key")
|
|
|
|
|
|
def decrypt(self, ciphertext):
|
|
"""
|
|
Decrypts information for the identity.
|
|
|
|
:param ciphertext: The ciphertext to be decrypted as *bytes*.
|
|
:returns: Plaintext as *bytes*, or *None* if decryption fails.
|
|
:raises: *KeyError* if the instance does not hold a private key
|
|
"""
|
|
if self.prv != None:
|
|
plaintext = None
|
|
try:
|
|
chunksize = Identity.DECRYPT_CHUNKSIZE
|
|
chunks = int(math.ceil(len(ciphertext)/(float(chunksize))))
|
|
|
|
plaintext = b"";
|
|
for chunk in range(chunks):
|
|
start = chunk*chunksize
|
|
end = (chunk+1)*chunksize
|
|
if (chunk+1)*chunksize > len(ciphertext):
|
|
end = len(ciphertext)
|
|
|
|
plaintext += self.prv.decrypt(
|
|
ciphertext[start:end],
|
|
padding.OAEP(
|
|
mgf=padding.MGF1(algorithm=hashes.SHA1()),
|
|
algorithm=hashes.SHA1(),
|
|
label=None
|
|
)
|
|
)
|
|
except:
|
|
RNS.log("Decryption by "+RNS.prettyhexrep(self.hash)+" failed", RNS.LOG_VERBOSE)
|
|
|
|
return plaintext;
|
|
else:
|
|
raise KeyError("Decryption failed because identity does not hold a private key")
|
|
|
|
|
|
def sign(self, message):
|
|
"""
|
|
Signs information by the identity.
|
|
|
|
:param message: The message to be signed as *bytes*.
|
|
:returns: Signature as *bytes*.
|
|
:raises: *KeyError* if the instance does not hold a private key
|
|
"""
|
|
if self.prv != None:
|
|
signature = self.prv.sign(
|
|
message,
|
|
padding.PSS(
|
|
mgf=padding.MGF1(hashes.SHA256()),
|
|
salt_length=padding.PSS.MAX_LENGTH
|
|
),
|
|
hashes.SHA256()
|
|
)
|
|
return signature
|
|
else:
|
|
raise KeyError("Signing failed because identity does not hold a private key")
|
|
|
|
def validate(self, signature, message):
|
|
"""
|
|
Validates the signature of a signed message.
|
|
|
|
:param signature: The signature to be validated as *bytes*.
|
|
:param message: The message to be validated as *bytes*.
|
|
:returns: True if the signature is valid, otherwise False.
|
|
:raises: *KeyError* if the instance does not hold a public key
|
|
"""
|
|
if self.pub != None:
|
|
try:
|
|
self.pub.verify(
|
|
signature,
|
|
message,
|
|
padding.PSS(
|
|
mgf=padding.MGF1(hashes.SHA256()),
|
|
salt_length=padding.PSS.MAX_LENGTH
|
|
),
|
|
hashes.SHA256()
|
|
)
|
|
return True
|
|
except Exception as e:
|
|
return False
|
|
else:
|
|
raise KeyError("Signature validation failed because identity does not hold a public key")
|
|
|
|
def prove(self, packet, destination=None):
|
|
signature = self.sign(packet.packet_hash)
|
|
if RNS.Reticulum.should_use_implicit_proof():
|
|
proof_data = signature
|
|
else:
|
|
proof_data = packet.packet_hash + signature
|
|
|
|
if destination == None:
|
|
destination = packet.generate_proof_destination()
|
|
|
|
proof = RNS.Packet(destination, proof_data, RNS.Packet.PROOF, attached_interface = packet.receiving_interface)
|
|
proof.send()
|
|
|
|
def __str__(self):
|
|
return RNS.prettyhexrep(self.hash)
|