added basic cryptography, advertising, and forwarding functionality to the LoRa handler. Also added a UUID class for generating unique IDs for each device.

also, i have 2 radios now! :D

relay/crypt_random.py

@@ -0,0 +1,39 @@
+from machine import ADC
+import utime
+import uhashlib
+
+adc = ADC(26)
+
+
+def get_entropy(samples: int = 512):
+    entropy = bytearray()
+    
+    for _ in range(samples):
+
+        value = adc.read_u16()
+        
+        mixed = (
+            value ^
+            (value >> 2) ^
+            (value >> 5) ^
+            utime.ticks_cpu()
+        ) & 0xFF
+        
+        entropy.append(mixed)
+        
+        utime.sleep_us(5)
+        
+    return entropy
+
+def secure_random(num_bytes: int = 32):
+    entropy = get_entropy()
+    
+    digest = uhashlib.sha256(entropy).digest()
+    
+    output = bytearray()
+    
+    while len(output) < num_bytes:
+        digest = uhashlib.sha256(digest).digest()
+        output.extend(digest)
+        
+    return bytes(output[:num_bytes])