Discover data key

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4D v18

Discover data key


Discover data key -> Function result

Parameter	Type	Description
Function result	Boolean	True if a valid encryption key for the currently open data file has been found, else False

Description

The Discover data key command searches for a valid encryption key corresponding to the currently opened data file at the root level of all connected devices and returns True if successful.

Connected devices to be searched include USB keys or external disks. A valid encryption key is necessary to allow read/write access to an encrypted database. This command can be called, for example, at database startup, after the user has been invited to connect a USB key.

Key files (".4DKeyChain" extension files) must be stored at the top level of connected devices (the search will not go through the folder hierarchy). Encryption keys must be saved in JSON format (see Storing data encryption keys in files in the 4D Design Reference).

Returned value

True if a valid encryption key is found for the current opened data file, in which case:
- the encryption key is applied if necessary so that encrypted data is usable (access to read / write operations).
- the encryption key is added to the 4D keychain.

False if no valid encryption key is found for the current opened data file, thus access to the data is not possible.

Example

 C_OBJECT($status)

 C_BOOLEAN($keyFound)

 

 $status:=ds.encryptionStatus()

 

 If(($status.isEncrypted) & (Not($status.keyProvided))) //no key is available

  // thus access to encrypted data is not allowed

    $keyFound:=Discover data key

    If($keyFound=True)

       ALERT("A valid encryption key has been found.")

    End if

 End if