Warn user if imported key has derivation path different from xpub's d…

…epth

src/cryptoadvance/specter/key.py

@@ -1,8 +1,10 @@
+import logging
 from collections import OrderedDict
 from binascii import hexlify
 from embit import base58
 from .util.xpub import get_xpub_fingerprint
 
+logger = logging.getLogger(__name__)
 
 purposes = OrderedDict(
  {
@@ -135,9 +137,16 @@ def parse_xpub(cls, xpub, purpose=""):
  elif derivation_path[4] == "2h":
  key_type = "wsh"
 
+ # warn user if imported key has derivation path different from xpub's depth
+ depth = xpub_bytes[4]
+ if derivation != "" and depth != len(derivation_path):
+ logger.warning(
+ f"xpup has a depth of {depth} while derivation path "
+ f"indicates the key is {len(derivation_path)} levels deep"
+ )
+
  # infer fingerprint and derivation if depth == 0 or depth == 1
  xpub_bytes = base58.decode_check(xpub)
- depth = xpub_bytes[4]
  if depth == 0:
  fingerprint = hexlify(get_xpub_fingerprint(xpub)).decode()
  derivation = "m"