edges hardening

paranoia.py

@@ -0,0 +1,122 @@
+# Run-time hardening to detect unexpected inputs at the edges
+from loguru import logger
+
+ENABLE_HARDENING = True
+
+def panic(reason:str):
+    if not ENABLE_HARDENING:
+        return
+    logger.error(f"hardening error:  {reason}")
+    raise ValueError(f"hardening error:  {reason}")
+    
+# Throw if string contains any non-printable characters
+def assert_printable(v:str):
+    if not ENABLE_HARDENING:
+        return
+    if not isinstance(v, str):
+        panic("not a string "+str(v))
+    if not v.isprintable():
+        panic("string contains non-printable characters")
+    
+# Check if number is valid int and not NaN
+def assert_valid_int(v:int):
+    if not ENABLE_HARDENING:
+        return
+    if not isinstance(v, int):
+        panic("number is not a valid int")
+    
+# Check if number is valid positive int
+def assert_valid_positive_int(v:int):
+    if not ENABLE_HARDENING:
+        return
+    assert_valid_int(v)
+    if v < 0:
+        panic("number is not positive")
+    
+# Check if number is a valid sats amount
+def assert_valid_sats(v:int):
+    if not ENABLE_HARDENING:
+        return
+    assert_valid_positive_int(v)
+    max_sats_value = 10_000_000 
+    if v >= max_sats_value:
+        panic("sats amount looks too high")
+    
+# Check if number is a valid msats amount
+def assert_valid_msats(v:int):
+    if not ENABLE_HARDENING:
+        return
+    assert_valid_positive_int(v)
+    max_msats_value = 10_000_000 * 1000
+    if v >= max_msats_value:
+        panic("msats amount looks too high")
+    
+
+# Check if string is a valid sha256 hash
+def assert_valid_sha256(v:str):
+    if not ENABLE_HARDENING:
+        return
+    assert_printable(v)
+    if len(v) != 64 or not all(c in "0123456789abcdef" for c in v):
+        panic("string is not a valid sha256 hash")
+    
+# Check if valid nostr pubkey
+def assert_valid_pubkey(v:str):
+    if not ENABLE_HARDENING:
+        return
+    assert_valid_sha256(v)
+    
+
+# Check if valid wallet id
+def assert_valid_wallet_id(v:str):
+    if not ENABLE_HARDENING:
+        return
+    assert_printable(v)
+    if not v.isalnum():
+        panic("string is not a valid wallet id")
+
+
+# Check if valid timestamp in seconds
+def assert_valid_timestamp_seconds(v:int):
+    if not ENABLE_HARDENING:
+        return
+    assert_valid_int(v)
+    if v < 0:
+        panic("timestamp is negative")
+    if v > 2**31:
+        panic("timestamp is too high")
+
+# Check if string is within sane parameters
+def assert_sane_string(v:str):
+    if not ENABLE_HARDENING:
+        return
+    assert_printable(v)
+    if len(v) > 1024:
+        panic("string is too long")
+    
+
+# Check if string is a non-empty string
+def assert_non_empty_string(v:str):
+    if not ENABLE_HARDENING:
+        return
+    assert_printable(v)
+    if len(v.strip()) == 0:
+        panic("string is empty")
+    
+# Assert valid json
+def assert_valid_json(v:str):
+    if not ENABLE_HARDENING:
+        return
+    assert_non_empty_string(v)
+    try:
+        import json
+        json.loads(v)
+    except:
+        panic("string is not valid json")
+
+# Check if string is a valid bolt11 invoice
+def assert_valid_bolt11(invoice:str):
+    if not ENABLE_HARDENING:
+        return
+    assert_printable(invoice)
+