User's Manual Part 4

FILE AUTHENTICATION
Introduction to File Authentication
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MNI 3600 REFERENCE MANUAL 113
Because each application is responsible for verifying its own data and prompt
files, the other application files should have their own matching signature files.
The master .OUT file should validate that these additional signature files are
authenticate before the signature files are used.
• If two or more applications are to run on the same terminal, the signature files
for the respective applications must be downloaded, together with the
corresponding target files, into the specific file group(s) for which the
applications are authorized. If an application is downloaded into a group for
which is it not authorized, file authentication for that application fails.
If, for example, Application B is downloaded into GID4, where it is authorized
to run, but the signature files for all Application B executable files are
downloaded into GID7, file authentication for Application B fails and it is not
allowed to run.
• Each certificate contains an attribute to verify if an application is valid for a
particular group.
Authenticate Files Stored in the RAM or Flash of a File Group
All *.p7s files are loaded into RAM and contain flags that indicate if the file to verify
is stored in flash or RAM. A signature file must know if its matching application file
is stored in flash or RAM. If a signature file cannot locate its matching application
file, the application file is not authenticated.
If the signature file authenticates its target file, and if the *FA variable is present in
the CONFIG.SYS file of the target file group and is set to 1, the signature file is
retained in memory and is automatically moved, if necessary, into the same file
system as the target file it authenticates. That is, if the target file is stored in the
flash, the signature file is also stored in the flash; if the target file is stored in RAM,
the signature file is also stored in RAM.
If the signature file authenticates its target file and the *FA variable is present in
the CONFIG.SYS file of the target file group and is set to 0, the signature file is
erased when its target file is authenticated.
If you intend to perform back-to-back downloads, as described in Chapter 4, all
signature files must be retained in the Omni 3600 terminal’s application memory,
together with the target application files they authenticate.
NOTE
To control if signature files are retained or deleted when they are processed by the
file authentication module, you must use the protected CONFIG.SYS variable *FA
as documented in the Verix Operating System Programmer’s Manual.