How Signature Files Authenticate Target Files; Determine Successful Authentication; Digital Certificates And The File Authentication Process - VeriFone V200c Reference Manual

How Signature Files
Authenticate Target
Files
Determine
Successful
Authentication
Digital Certificates
and the File
Authentication
Process
The terminal supports the following download mechanisms:
Download Mechanism
Serial Direct
USB/SD
Netloader
NFS
All content, regardless of download mechanism, is downloaded to /mnt/flash/
install/dl. Content is not usable until it is actually installed by the Secure
Installer. The Secure Installer authenticates all downloaded content and then
installs it. At this point the content becomes usable. For example, the Secure
Installer installs authenticated downloaded application content to the application
user's home directory.
Signature files are downloaded together with their target application files in the
same data transfer operation. When an attempt is made to install an application
executable or data file, a matching signature and certificate must be present. The
operating system compares the application file's signature against the values
stored in the application file's calculated signature.
All downloaded files must have an associated signature as part of the download.
Otherwise, the installation fails. To ensure a target file successfully authenticated
after a download, confirm that all downloaded files are installed. If an application
file is not successfully authenticated, the operating system does not allow it to
install and run, either following the initial download or on subsequent terminal
restarts.
The file authentication module always processes certificates before it processes
signature files. Digital certificates (*.crt files) generated by the Verifone CA
have two important functions in the file authentication process:
•
They define the rules for file location and usage (for example, the valid file
group, replaceable *.crt files, parent *.crt files, whether child
*.crt files can exist, and so on).
•
They convey the public cryptographic keys generated for terminal sponsors
and signers that are the required inputs to the VeriShield File Signing Tool to
verify file signatures.
Planning for File Authentication
Description
Supported over all serial ports (COM1/
COM2/COM3 and USB Serial Gadget
Supported over USB memory devices and
micro SD memory
Verifone proprietary TCP-IP file transfer
Network File System
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