Implemented interface authentication and virtual network segmentation

RNS/Reticulum.py

@@ -21,6 +21,11 @@
 # SOFTWARE.
 
 from .vendor.platformutils import get_platform
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.kdf.hkdf import HKDF
+from cryptography.hazmat.backends import default_backend
+
+cio_default_backend = default_backend()
 
 if get_platform() == "android":
     from .Interfaces import Interface
@@ -122,6 +127,7 @@ class Reticulum:
     HEADER_MINSIZE = 2+1+(TRUNCATED_HASHLENGTH//8)*1
     HEADER_MAXSIZE = 2+1+(TRUNCATED_HASHLENGTH//8)*2
     IFAC_MIN_SIZE  = 1
+    IFAC_SALT      = bytes.fromhex("adf54d882c9a9b80771eb4995d702d4a3e733391b2a0f53f416d9f907e55cff8")
     
     MDU            = MTU - HEADER_MAXSIZE - IFAC_MIN_SIZE
 
@@ -186,6 +192,8 @@ class Reticulum:
         self.share_instance       = True
         self.rpc_listener         = None
 
+        self.ifac_salt = Reticulum.IFAC_SALT
+
         self.requested_loglevel = loglevel
         if self.requested_loglevel != None:
             if self.requested_loglevel > RNS.LOG_EXTREME:
@@ -356,14 +364,20 @@ class Reticulum:
                             ifac_size = c.as_int("ifac_size")
                             
                     ifac_netname = None
-                    if "ifac_netname" in c:
+                    if "networkname" in c:
-                        if c.as_int("ifac_netname") >= Reticulum.IFAC_MIN_SIZE:
+                        if c["networkname"] != "":
-                            ifac_netname = c.as_int("ifac_netname")
+                            ifac_netname = c["networkname"]
+                    if "network_name" in c:
+                        if c["network_name"] != "":
+                            ifac_netname = c["network_name"]
 
                     ifac_netkey = None
-                    if "ifac_netkey" in c:
+                    if "passphrase" in c:
-                        if c.as_int("ifac_netkey") >= Reticulum.IFAC_MIN_SIZE:
+                        if c["passphrase"] != "":
-                            ifac_netkey = c.as_int("ifac_netkey")
+                            ifac_netkey = c["passphrase"]
+                    if "pass_phrase" in c:
+                        if c["pass_phrase"] != "":
+                            ifac_netkey = c["pass_phrase"]
                             
                     configured_bitrate = None
                     if "bitrate" in c:
@@ -406,8 +420,6 @@ class Reticulum:
 
                                     interface.mode = interface_mode
 
-                                    RNS.Transport.interfaces.append(interface)
-
                                     interface.announce_cap = announce_cap
                                     if configured_bitrate:
                                         interface.bitrate = configured_bitrate
@@ -452,8 +464,6 @@ class Reticulum:
 
                                 interface.mode = interface_mode
 
-                                RNS.Transport.interfaces.append(interface)
-
                                 interface.announce_cap = announce_cap
                                 if configured_bitrate:
                                     interface.bitrate = configured_bitrate
@@ -492,8 +502,6 @@ class Reticulum:
                                 
                                 interface.mode = interface_mode
 
-                                RNS.Transport.interfaces.append(interface)
-
                                 interface.announce_cap = announce_cap
                                 if configured_bitrate:
                                     interface.bitrate = configured_bitrate
@@ -529,8 +537,6 @@ class Reticulum:
                                 
                                 interface.mode = interface_mode
 
-                                RNS.Transport.interfaces.append(interface)
-
                                 interface.announce_cap = announce_cap
                                 if configured_bitrate:
                                     interface.bitrate = configured_bitrate
@@ -562,8 +568,6 @@ class Reticulum:
                                 
                                 interface.mode = interface_mode
 
-                                RNS.Transport.interfaces.append(interface)
-
                                 interface.announce_cap = announce_cap
                                 if configured_bitrate:
                                     interface.bitrate = configured_bitrate
@@ -599,8 +603,6 @@ class Reticulum:
 
                                 interface.mode = interface_mode
 
-                                RNS.Transport.interfaces.append(interface)
-
                                 interface.announce_cap = announce_cap
                                 if configured_bitrate:
                                     interface.bitrate = configured_bitrate
@@ -650,8 +652,6 @@ class Reticulum:
 
                                 interface.mode = interface_mode
 
-                                RNS.Transport.interfaces.append(interface)
-
                                 interface.announce_cap = announce_cap
                                 if configured_bitrate:
                                     interface.bitrate = configured_bitrate
@@ -702,8 +702,6 @@ class Reticulum:
 
                                 interface.mode = interface_mode
 
-                                RNS.Transport.interfaces.append(interface)
-
                                 interface.announce_cap = announce_cap
                                 if configured_bitrate:
                                     interface.bitrate = configured_bitrate
@@ -748,8 +746,6 @@ class Reticulum:
 
                                 interface.mode = interface_mode
 
-                                RNS.Transport.interfaces.append(interface)
-
                                 interface.announce_cap = announce_cap
                                 if configured_bitrate:
                                     interface.bitrate = configured_bitrate
@@ -762,6 +758,27 @@ class Reticulum:
                                 interface.ifac_netname = ifac_netname
                                 interface.ifac_netkey = ifac_netkey
 
+                                if interface.ifac_netname != None or interface.ifac_netkey != None:
+                                    ifac_origin = b""
+
+                                    if interface.ifac_netname != None:
+                                        ifac_origin += RNS.Identity.full_hash(interface.ifac_netname.encode("utf-8"))
+
+                                    if interface.ifac_netkey != None:
+                                        ifac_origin += RNS.Identity.full_hash(interface.ifac_netkey.encode("utf-8"))
+
+                                    ifac_origin_hash = RNS.Identity.full_hash(ifac_origin)
+                                    interface.ifac_key = HKDF(
+                                        algorithm=hashes.SHA256(),
+                                        length=64,
+                                        salt=self.ifac_salt,
+                                        info=None,
+                                        backend=cio_default_backend,
+                                    ).derive(ifac_origin_hash)
+
+                                    interface.ifac_identity = RNS.Identity.from_bytes(interface.ifac_key)
+                                    interface.ifac_signature = interface.ifac_identity.sign(RNS.Identity.full_hash(interface.ifac_key))
+
                                 RNS.Transport.interfaces.append(interface)
 
                         else:
@@ -859,6 +876,15 @@ class Reticulum:
                     else:
                         ifstats["peers"] = None
 
+                if hasattr(interface, "ifac_signature"):
+                    ifstats["ifac_signature"] = interface.ifac_signature
+                    ifstats["ifac_size"] = interface.ifac_size
+                    ifstats["ifac_netname"] = interface.ifac_netname
+                else:
+                    ifstats["ifac_signature"] = None
+                    ifstats["ifac_size"] = None
+                    ifstats["ifac_netname"] = None
+
                 if hasattr(interface, "announce_queue"):
                     if interface.announce_queue != None:
                         ifstats["announce_queue"] = len(interface.announce_queue)

RNS/Transport.py

@@ -474,7 +474,23 @@ class Transport:
 
     @staticmethod
     def transmit(interface, raw):
-        interface.processOutgoing(raw)
+        try:
+            if hasattr(interface, "ifac_identity") and interface.ifac_identity != None:
+                # Calculate packet access code
+                ifac       = interface.ifac_identity.sign(raw)[-interface.ifac_size:]
+
+                # Set IFAC flag
+                new_header = bytes([raw[0] | 0x80, raw[1]])
+
+                # Assemble new payload with IFAC and send it
+                new_raw    = new_header+ifac+raw[2:]
+                interface.processOutgoing(new_raw)
+
+            else:
+                interface.processOutgoing(raw)
+
+        except Exception as e:
+            RNS.log("Error while transmitting on "+str(interface)+". The contained exception was: "+str(e), RNS.LOG_ERROR)
 
     @staticmethod
     def outbound(packet):
@@ -704,6 +720,44 @@ class Transport:
 
     @staticmethod
     def inbound(raw, interface=None):
+        # If interface access codes are enabled,
+        # we must authenticate each packet.
+        if interface != None and hasattr(interface, "ifac_identity") and interface.ifac_identity != None:
+            # Check that IFAC flag is set
+            if raw[0] & 0x80 == 0x80:
+                if len(raw) > 2+interface.ifac_size:
+                    # Extract IFAC
+                    ifac = raw[2:2+interface.ifac_size]
+
+                    # Unset IFAC flag
+                    new_header = bytes([raw[0] & 0x7f, raw[1]])
+
+                    # Re-assemble packet
+                    new_raw = new_header+raw[2+interface.ifac_size:]
+
+                    # Calculate expected IFAC
+                    expected_ifac = interface.ifac_identity.sign(new_raw)[-interface.ifac_size:]
+
+                    # Check it
+                    if ifac == expected_ifac:
+                        # TODO: Remove log statements
+                        RNS.log("Packet IFAC match, allowing", RNS.LOG_EXTREME)
+                        raw = new_raw
+                    else:
+                        # TODO: Remove log statements
+                        RNS.log("Packet IFAC mismatch, dropping packet", RNS.LOG_EXTREME)
+                        return
+
+                else:
+                    return
+
+            else:
+                # If the IFAC flag is not set, but should be,
+                # we drop the packet.
+                # TODO: Remove log statements
+                RNS.log(str(interface)+" with IFAC enabled received packet without access code, dropping.", RNS.LOG_EXTREME)
+                return
+
         while (Transport.jobs_running):
             sleep(0.01)
 

RNS/Utilities/rnstatus.py

@@ -92,6 +92,10 @@ def program_setup(configdir, dispall=False, verbosity = 0):
                     clients = None
 
                 print(" {n}".format(n=ifstat["name"]))
+
+                if "ifac_netname" in ifstat and ifstat["ifac_netname"] != None:
+                    print("    Network : {nn}".format(nn=ifstat["ifac_netname"]))
+
                 print("    Status  : {ss}".format(ss=ss))
 
                 if clients != None:
@@ -106,6 +110,10 @@ def program_setup(configdir, dispall=False, verbosity = 0):
                 if "peers" in ifstat and ifstat["peers"] != None:
                     print("    Peers   : {np} reachable".format(np=ifstat["peers"]))
 
+                if "ifac_signature" in ifstat and ifstat["ifac_signature"] != None:
+                    sigstr = "<…"+RNS.hexrep(ifstat["ifac_signature"][-5:], delimit=False)+">"
+                    print("    Access  : {nb}-bit IFAC by {sig}".format(nb=ifstat["ifac_size"]*8, sig=sigstr))
+                
                 if "i2p_b32" in ifstat and ifstat["i2p_b32"] != None:
                     print("    I2P B32 : {ep}".format(ep=str(ifstat["i2p_b32"])))
 

RNS/__init__.py

@@ -60,7 +60,8 @@ logfile      = None
 logdest      = LOG_STDOUT
 logtimefmt   = "%Y-%m-%d %H:%M:%S"
 
-random.seed(os.urandom(10))
+instance_random = random.Random()
+instance_random.seed(os.urandom(10))
 
 _always_override_destination = False
 
@@ -130,7 +131,7 @@ def log(msg, level=3, _override_destination = False):
                 
 
 def rand():
-    result = random.random()
+    result = instance_random.random()
     return result
 
 def hexrep(data, delimit=True):