keystore: fail sooner if unsupported version

follow-up #4937

electrum/crypto.py

@@ -31,7 +31,7 @@
 
 import pyaes
 
-from .util import assert_bytes, InvalidPassword, to_bytes, to_string
+from .util import assert_bytes, InvalidPassword, to_bytes, to_string, WalletFileException
 from .i18n import _
 
 
@@ -123,7 +123,7 @@ def DecodeAES_bytes(secret: bytes, ciphertext: bytes) -> bytes:
 assert PW_HASH_VERSION_LATEST in SUPPORTED_PW_HASH_VERSIONS
 
 
-class UnexpectedPasswordHashVersion(InvalidPassword):
+class UnexpectedPasswordHashVersion(InvalidPassword, WalletFileException):
     def __init__(self, version):
         self.version = version
 
@@ -134,7 +134,7 @@ def __str__(self):
             instruction=_('You are most likely using an outdated version of Electrum. Please update.'))
 
 
-class UnsupportedPasswordHashVersion(InvalidPassword):
+class UnsupportedPasswordHashVersion(InvalidPassword, WalletFileException):
     def __init__(self, version):
         self.version = version
 

electrum/keystore.py

@@ -35,7 +35,8 @@
                     bip32_private_key, bip32_derivation, BIP32_PRIME,
                     is_xpub, is_xprv)
 from .ecc import string_to_number, number_to_string
-from .crypto import (pw_decode, pw_encode, sha256d, PW_HASH_VERSION_LATEST)
+from .crypto import (pw_decode, pw_encode, sha256d, PW_HASH_VERSION_LATEST,
+                     SUPPORTED_PW_HASH_VERSIONS, UnsupportedPasswordHashVersion)
 from .util import (PrintError, InvalidPassword, hfu, WalletFileException,
                    BitcoinException, bh2u, bfh, print_error, inv_dict)
 from .mnemonic import Mnemonic, load_wordlist
@@ -95,6 +96,8 @@ class Software_KeyStore(KeyStore):
     def __init__(self, d):
         KeyStore.__init__(self)
         self.pw_hash_version = d.get('pw_hash_version', 1)
+        if self.pw_hash_version not in SUPPORTED_PW_HASH_VERSIONS:
+            raise UnsupportedPasswordHashVersion(self.pw_hash_version)
 
     def may_have_password(self):
         return not self.is_watching_only()

electrum/storage.py

@@ -575,6 +575,11 @@ def convert_version_18(self):
         self.put('verified_tx3', None)
         self.put('seed_version', 18)
 
+    # def convert_version_19(self):
+    #     TODO for "next" upgrade:
+    #       - move "pw_hash_version" from keystore to storage
+    #     pass
+
     def convert_imported(self):
         if not self._is_upgrade_method_needed(0, 13):
             return