# Open Password Protected Container Files

This section describes how to extract password-protected container files by using the C API. The following guidelines apply to specific file types.

- Lotus Notes NSF files. If you are running a Notes client with an active user connected to a Domino server, you must specify the user’s password as a credential regardless of whether the NSF files you are opening are protected. This enables KeyView to access the Notes client and the Lotus Notes API. If the Notes client is not running with an active user, KeyView does not require credentials to access the client.
- PST files. To open password-protected PST files that use high encryption (Microsoft Outlook 2003 only), you must use the MAPI-based PST reader (`pstsr`). The native PST readers (`pstxsr` and `pstnsr`) do not support files that use high encryption and return the error message `KVERR_PasswordProtected` if a PST file is encrypted with high encryption.

To open container files

1. Define the credential information in the `KVOpenFileArg` data structure.
2. Pass `KVOpenFileArg` to the `fpOpenFile()` function.
3. Call `fpCloseFile()`.

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