The Geodetic Datasource file exists as an XML database file called geodata.xml. Because XML files are human readable and editable, given the right software, it is possible for a user to open the file and manually edit the contents in an attempt to bypass restrictions placed on the application via the Administrative Settings. Directly editing the datasource file was somewhat commonplace in older versions of the Calculator applications but is not recommended in newer versions, due to the complexity of the file structure. To prevent this, the geodata.xml file contains a digital signature that uniquely identifies the contents of the entire XML file. If the geodetic datasource is edited outside of the dialogs in the Calculator, the digital signature will not match. This can be used to validate the datasource on start up.
Several other files used by the datasource are also signed and will be validated along with it. These include the custom.xml file, the view file, and any change log files. Any warnings displayed will specify which of these files has an invalid signature.
An Administrative user can set an installation of the Calculator to validate the geodetic data source when the application is started up and alert the user if the signature does not match. To set the Calculator to validate the datasource:
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Go to Options>Administrative Settings and click onto the General tab.
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To validate the data source immediately, click the Validate Datasource button. If valid, a popup will open stating that the signature is valid.
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To set validation when loading a data source, such as at application startup, enable the check-box labeled Validate datasource when loaded. This will enable the validation options.
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There are two options available for when the datasource is not able to validate the signature. The Calculator can be forced to close down, or the user can simply be alerted that there may be a problem with the datasource and allowed to continue using the application. Select the appropriate setting for your needs and click OK.
- Once set, these settings are application-wide and apply to any workspace. For more information on how administrative users may lock the settings, see Password Access.