SIM Card PIN Not Handled via Modem Interface

[andrescera]

❗️SIM Card PIN Not Handled via Modem Interface (mmcli / ModemManager)

Describe the bug

The application currently does not handle SIM card PINs via the modem interface (mmcli / ModemManager). It assumes the SIM is always unlocked. When a SIM requires a PIN, the app fails to detect this and provides no prompt or mechanism for unlocking it. This leads to silent connection failures and confusing behavior for the user.

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Expected behavior

• Detect when the modem reports the SIM is in a locked or pin-required state.

• Prompt the user to enter the SIM PIN.

• Unlock the SIM using the mmcli command:

  mmcli -i <SIM-ID> --pin=<PIN>

• Upon successful unlock, resume modem initialization and connection.

• Additionally (optional):

  • Track incorrect PIN attempts and display remaining retries.

  • Detect puk-required state and optionally allow PUK entry.

  • Support enabling/disabling SIM PIN lock via:

    mmcli -i <SIM-ID> --enable-pin=<PIN>
    mmcli -i <SIM-ID> --disable-pin=<PIN>

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Current behavior

• No check for SIM lock status is performed.
• SIM PIN is never requested or submitted.
• App incorrectly assumes the SIM is ready and tries to connect.
• Resulting modem connection fails silently.
• Using mmcli -m <modem> manually reveals that the SIM is locked.

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To Reproduce

1. Insert a SIM card with a PIN enabled into a modem.

2. Start the application.

3. Observe that no prompt or notification is shown.

4. Check SIM status with:

   mmcli -m 0

   and note the SIM state is locked.

5. Attempt to connect via the app — it fails without explanation.

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Proposed Solution

• On initialization, query the modem’s SIM status via:

  mmcli -m <modem>

• If the SIM is locked (PIN required), prompt the user to enter their PIN.

• Unlock the SIM via:

  mmcli -i <SIM-ID> --pin=<PIN>

• On success:

  • Refresh modem state.
  • Continue with normal network connection flow.

• Add handling for:

  • Incorrect PIN entries (track retry counts).
  • PUK unlock flow (if supported).
  • SIM PIN configuration (enable/disable via user request).