Test if database is open

[piegamesde]

I use a variation of the test.py script to retrieve some passwords. But when the database is closed, it simply throws a generic keepassxc_browser.protocol.ProtocolError: Database not opened somewhere in the code.

I'd like to have the ability to cleanly check if the database is open before starting to retrieve passwords (ideally without requiring identification).

[hrehfeld]

Thanks for the report! Can you provide a minimal example?

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On 8 May 2019 10:50:26 CEST, Piegames ***@***.***> wrote: I use a variation of the `test.py` script to retrieve some passwords. But when the database is closed, it simply throws a generic `keepassxc_browser.protocol.ProtocolError: Database not opened` somewhere in the code. I'd like to have the ability to cleanly check if the database is open before starting to retrieve passwords (ideally without requiring identification). -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: #5

[piegamesde]

test.py is already pretty minimal (note that I commented out line 18).

If I run it when the database is closed c.test_associate(id) in line 20 will return false. This will cause c.associate(id) in line 21 to throw a protocol error.

I'd like to add something like if c.is_open(): to abort the whole process if the database is locked.

[Phidica]

You can use get_database_hash() to test if the database is open. ie,

try:
    c.get_database_hash(id)
except ProtocolError as ex:
    print(ex) # "Database not opened"
    exit(1)

[piegamesde]

Hm, I commented the database hash part out because when I run this and the database is open, I get

>>> c.get_database_hash(id)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.7/site-packages/keepassxc_browser/protocol.py", line 198, in get_database_hash
    resp_message = self.send_encrypted_command(identity, command)
  File "/usr/lib/python3.7/site-packages/keepassxc_browser/protocol.py", line 172, in send_encrypted_command
    resp = self.send_command(identity, command, nonce, next_nonce)
  File "/usr/lib/python3.7/site-packages/keepassxc_browser/protocol.py", line 166, in send_command
    raise ProtocolError(resp['error'])
keepassxc_browser.protocol.ProtocolError: Cannot decrypt message

Don't know if this is related.

[Phidica]

Hm, I haven't seen that error before. Even if the access key hasn't been associated to the database we should be able to read the response to this request. What version of KeePassXC are you using?

[piegamesde]

KeePassXC - Version 2.4.1
Revision: 7bafe65

Qt 5.12.3
Debugging mode is disabled.

Operating system: Antergos Linux
CPU architecture: x86_64
Kernel: linux 5.0.13-arch1-1-ARCH

Enabled extensions:
- Auto-Type
- Browser Integration
- SSH Agent
- KeeShare (signed and unsigned sharing)
- YubiKey

Cryptographic libraries:
 libgcrypt 1.8.4

[Phidica]

Ah, you're using a much newer version of KeePassXC than I am. Perhaps the interface has changed... It looks like that error message actually means KeePassXC couldn't decrypt the message we had sent, not that we couldn't read its response.

As a workaround, you can also put the try / except block on the associate() command:

if not c.test_associate(id):
    try:
        associated_name = c.associate(id)
    except ProtocolError as ex:
        print(ex)
        exit(1)

[piegamesde]

I think

try:
    c.get_database_hash(id)
except ProtocolError as ex:
    print(ex) # "Database not opened"
    exit(1)

solves my issue, but I'd be happy to have a convenience method to do this for me.

[piegamesde]

I cannot import ProtocolError:

Traceback (most recent call last):
  File "keepassxc.py", line 2, in <module>
    from keepassxc_browser import Connection, Identity, ProtocolError
ImportError: cannot import name 'ProtocolError' from 'keepassxc_browser' (~/.local/lib/python3.7/site-packages/keepassxc_browser/__init__.py)

My code:

try:
    print(c.get_database_hash(id))
except ProtocolError as ex:
    print("Database not opened")

[Phidica]

Ah, right, ProtocolError isn't available in the same way the classes are. You need a separate import line:

 from keepassxc_browser.protocol import ProtocolError

[piegamesde]

It works now as expected, thanks.