VeriFone DUET Vx810, Справочное руководство

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F
ILE
A
UTHENTICATION
Introduction to File Authentication
V X 810 R
EFERENCE
G
UIDE
75
It is not mandatory to always download a signature file and its target application
file at the same time. For example, you can download the corresponding signature
file in a separate operation. A non-authenticated application can reside in the
device’s memory, but is not authenticated or allowed to run on the device until the
signature files for the application executable files are processed by the file
authentication module after a subsequent download procedure and device restart.
Determine Successful Authentication
To ensure the V
x
810’s logical security, never assume that a target file was
authenticated simply because it downloaded onto the V
x
810 together with its
signature file.
There are several ways to ensure a target file is successfully authenticated after a
download:
•
Confirm if all downloaded executable files run. If an executable code file is
not successfully authenticated, the operating system does not allow it to
execute and run, either following the initial download or on subsequent device
restarts. The effect of this rule depends on whether or not all executable files
are successfully authenticated.
•
If the executable file that failed to authenticate is the main application
(*.out) specified in the CONFIG.SYS *GO variable, the main application is
not allowed to run.
•
If the executable that failed to authenticate is a secondary executable
(*.out) or shared library (*.lib) used by the main application, the
CONFIG.SYS *GO application executes and runs until it issues a function
call to that library. When the main application attempts to access a non-
authenticated executable, the main application may crash.
•
Visually (and audibly) confirm file authentication during the process.
When the file authentication module is invoked at device restart and detects a
new signature file, it displays status information on the screen indicating
success or failure of the authentication of each target file based on its
corresponding signature file. (A similar status display also appears on the
screen when you download digital certificates.)
You can watch the screen display following the download to see if a specific
target file fails authentication. If this happens,
FAILED
is displayed for five
seconds on the screen below the filenames of the target and signature files,
and the device beeps as an alert.
An application can issue a function call to read the ATTR_NOT_AUTH bit’s
current value for all relevant files to verify they were successfully
authenticated. If the ATTR_NOT_AUTH bit’s binary value is 1, the file did not
authenticate; if 0, the file did authenticate.