JavaCard OS

Hello

I locked the applet via GPSystem.SetCardContentState (GPSystem.APPLICATION_LOCK)

But I do not know how to unlock the applet again.

Some people ask you to use ISD, but I do not know how to choose ISD.

Please tell me how to unlock the locked applet

Thank you

What's the model of your card?

1 Select the ISD; (Ask your card provider for the ISD AID value, or try to send SELECT command without ISD AID: "00 A4 04 00 00")
2 GP auth;
3 Send SET STATUS command: "80 F0 40 XX LC YY YY YY YY ...", XX is the new status value according to the definition "Application Life Cycle Coding", YY is the AID of your applet instance.

thank you for your answer

but i still don't know how to get gp auth

please explain gp auth using apdu

thank you

1 pyApdutool

2 GPShell
open_sc command
3 pyResMan

4 GlobalPlatformPro
gp.exe --unlock-applet <AID>
Note: Use gp.exe -h for usage informations.
5 Commands:

Note: For the details, see GlobalPlatform specification.
6 Write code:
Refer to the code of opensource tools: GPShell(C lanaguage)/GlobalPlatformPro(java language)/pyResMan(python language)/....

thank you for your answer

i only use number 5

but i don't know how to use

i send command

0x80, 0x50, 0x00, 0x00, 0x08, 0xF2, 0xA5, 0xFA, 0x8B, 0xEF, 0x9F, 0x8A, 0x51, 0x00
and
0x84, 0x82, 0x03, 0x00, 0x10 ,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00

first command receive 9000

but second receive 69 85

so please explain how to use second command using apdu

thank you for your help

This command needs "Host cryptogram and MAC". Both these datas can be calculated following globalplatform specification. this process is cumbersome, and the value can be used once.
The steps:
1 Send INITIALIZE UPDATE command with host challenge, the card challenge got;
2 Calculate Host cryptogram with host challenge + card challenge + other data and the command MAC;
3 Send EXTERNAL AUTHENTICATE command with Host cryptogram and MAC;

It is recommanded that use one tool to send these commands.