A user provided an invoice that requires feature bit 30. (That bit is not in the spec)
To test:
```
lnbc1p324a66pp5tundykxx3q5kztsr8x00eknpn2uwe3394cnky3j9a0fswm568wnsdp9facx2mj5d9kk2um5v9khqueqv3hkuct5d9hkucqzpgxq9z0rgqsp5l73jgfgctzc92juer5rk2mqcrkj8teng53dr9vfxj4n8lulu4jmq9q8pqqqssq4gacn859tpzz99hkusnh7m93d5ncpx3t4zns8ynca7akmljpl5vh504qjz7dqwewqjh4md7xagaz5wg85knvxywrhp0sp2t09yta7lcq3qs6fy
lntb1p324a66pp5tundykxx3q5kztsr8x00eknpn2uwe3394cnky3j9a0fswm568wnssp5l73jgfgctzc92juer5rk2mqcrkj8teng53dr9vfxj4n8lulu4jmqdp9facx2mj5d9kk2um5v9khqueqv3hkuct5d9hkuxq9z0rgq9q8pqqqssqdte0z9dy7ur7fagsk7r3mtfj6upq88xfylhufys87zqpamklcfgn2f3xeq3nlhvn3qy9tdgg42vq9eq99qz6rz6tzqezfhzuv6zsr5qp7cgel4
```
In commit 9bba65199e,
the QRCodeWidget was put inside a BoxLayout as a workaround to avoid the "copy to clipboard" and
"save as file" functionality grabbing extra whitespace/stretch/padding and putting it into the
exported image.
However, in turn that commit introduced a bug, where making the dialog larger does not make the
QRCodeWidget larger (which worked prior).
This commit tries to fix the regression and also the original bug.
If keystore.check_password is called with some pw on a keystore that does not have a password set,
it now raises better exceptions: it should now always raise InvalidPassword, and with a nicer msg.
Previously the exc type would depend on the ks type.
Examples before change:
```
>>> wallet.keystore.check_password("asd")
Traceback (most recent call last):
File "/home/user/wspace/electrum/electrum/keystore.py", line 580, in check_password
xprv = pw_decode(self.xprv, password, version=self.pw_hash_version)
File "/home/user/wspace/electrum/electrum/crypto.py", line 311, in pw_decode
plaintext_bytes = pw_decode_bytes(data, password, version=version)
File "/home/user/wspace/electrum/electrum/crypto.py", line 270, in pw_decode_bytes
data_bytes = bytes(base64.b64decode(data))
File "/usr/lib/python3.10/base64.py", line 87, in b64decode
return binascii.a2b_base64(s)
binascii.Error: Incorrect padding
```
```
>>> wallet.keystore.check_password("asd")
Traceback (most recent call last):
s = aes_decrypt_with_iv(secret, iv, e)
File "/home/user/wspace/electrum/electrum/crypto.py", line 157, in aes_decrypt_with_iv
data = decryptor.update(data) + decryptor.finalize()
File "/usr/lib/python3/dist-packages/cryptography/hazmat/primitives/ciphers/base.py", line 148, in finalize
data = self._ctx.finalize()
File "/usr/lib/python3/dist-packages/cryptography/hazmat/backends/openssl/ciphers.py", line 193, in finalize
raise ValueError(
ValueError: The length of the provided data is not a multiple of the block length.
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/user/wspace/electrum/electrum/gui/qt/console.py", line 254, in exec_command
result = eval(command, self.namespace, self.namespace)
File "<string>", line 1, in <module>
File "/home/user/wspace/electrum/electrum/keystore.py", line 248, in check_password
self.get_private_key(pubkey, password)
File "/home/user/wspace/electrum/electrum/keystore.py", line 267, in get_private_key
sec = pw_decode(self.keypairs[pubkey], password, version=self.pw_hash_version)
File "/home/user/wspace/electrum/electrum/crypto.py", line 311, in pw_decode
plaintext_bytes = pw_decode_bytes(data, password, version=version)
File "/home/user/wspace/electrum/electrum/crypto.py", line 271, in pw_decode_bytes
return _pw_decode_raw(data_bytes, password, version=version)
File "/home/user/wspace/electrum/electrum/crypto.py", line 255, in _pw_decode_raw
raise InvalidPassword() from e
electrum.util.InvalidPassword: Incorrect password
```
-----
Examples after change:
```
>>> wallet.keystore.check_password("asd")
Traceback (most recent call last):
return binascii.a2b_base64(s)
binascii.Error: Incorrect padding
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "...\electrum\keystore.py", line 68, in wrapper
return check_password_fn(self, password)
File "...\electrum\keystore.py", line 605, in check_password
xprv = pw_decode(self.xprv, password, version=self.pw_hash_version)
File "...\electrum\crypto.py", line 311, in pw_decode
plaintext_bytes = pw_decode_bytes(data, password, version=version)
File "...\electrum\crypto.py", line 267, in pw_decode_bytes
raise CiphertextFormatError("ciphertext not valid base64") from e
electrum.crypto.CiphertextFormatError: ciphertext not valid base64
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "...\electrum\gui\qt\console.py", line 254, in exec_command
result = eval(command, self.namespace, self.namespace)
File "<string>", line 1, in <module>
File "...\electrum\keystore.py", line 76, in wrapper
raise InvalidPassword("password given but keystore has no password") from e
electrum.util.InvalidPassword: password given but keystore has no password
```
```
>>> wallet.keystore.check_password("asd")
Traceback (most recent call last):
s = aes_decrypt_with_iv(secret, iv, e)
File "...\electrum\crypto.py", line 158, in aes_decrypt_with_iv
data = cipher.decrypt(data)
File "...\Python310\site-packages\Cryptodome\Cipher\_mode_cbc.py", line 246, in decrypt
raise ValueError("Data must be padded to %d byte boundary in CBC mode" % self.block_size)
ValueError: Data must be padded to 16 byte boundary in CBC mode
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "...\electrum\keystore.py", line 68, in wrapper
return check_password_fn(self, password)
File "...\electrum\keystore.py", line 272, in check_password
self.get_private_key(pubkey, password)
File "...\electrum\keystore.py", line 291, in get_private_key
sec = pw_decode(self.keypairs[pubkey], password, version=self.pw_hash_version)
File "...\electrum\crypto.py", line 311, in pw_decode
plaintext_bytes = pw_decode_bytes(data, password, version=version)
File "...\electrum\crypto.py", line 268, in pw_decode_bytes
return _pw_decode_raw(data_bytes, password, version=version)
File "...\electrum\crypto.py", line 249, in _pw_decode_raw
raise InvalidPassword() from e
electrum.util.InvalidPassword: Incorrect password
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "...\electrum\gui\qt\console.py", line 254, in exec_command
result = eval(command, self.namespace, self.namespace)
File "<string>", line 1, in <module>
File "...\electrum\keystore.py", line 76, in wrapper
raise InvalidPassword("password given but keystore has no password") from e
electrum.util.InvalidPassword: password given but keystore has no password
```
