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write and read data from NVM
Posted: Thu Jan 05, 2017 10:34 pm
by RexLi
Can we write data on a java card's NVM without using java card applet? For example, write raw data into card NVM directly.
Is it possible to read card's NVM data without any authentication?
Re: write and read data from NVM
Posted: Fri Jan 06, 2017 5:08 am
by marjkbadboy
RexLi wrote:Can we write data on a java card's NVM without using java card applet? For example, write raw data into card NVM directly.
If you write data into NVM, you can only store a very limited amount of data. This is the GlobalPlatform Issuer and Card identifiers. You should not use these for application data.
RexLi wrote:Is it possible to read card's NVM data without any authentication?
Just implement an applet that does not require authentication.
Re: write and read data from NVM
Posted: Sat Jan 07, 2017 4:25 am
by RexLi
Can I make file on card's NVM ?
And if an applet is stored in NVM, which components the installer should insert to DF and when to insert to EF?
Re: write and read data from NVM
Posted: Sat Jan 07, 2017 5:58 am
by marjkbadboy
RexLi wrote:Can I make file on card's NVM ?
Yes, store the raw bytes in your applet.
RexLi wrote:And if an applet is stored in NVM, which components the installer should insert to DF and when to insert to EF?
A Java Card complies with the APDU messaging of ISO7816-4 and command can be implemented to support the part 4 commands but the card does not have to store the applet on a file system.