如何使 TAG_ALPHA_IDENTIFIER 为空而不要求用户确认

Question

My wallet applet requires to perform actions like PLAY TONE etc. But it requires a prompt "Yes or No?" from user. AFAIK, it is TAG_ALPHA_IDENTIFIER which is responsible for that. However, if I try this code below, it still asks user confirmation but now with "@" text. How to get rid of user confirmation at all?

Attempt 1. Failed with NullPtrException

proHdlr.appendTLV(ToolkitConstants.TAG_ALPHA_IDENTIFIER, null, (short)0, (short)0);
proHdlr.send();

Attempt 2. Prompts '@@'

proHdlr.appendTLV(ToolkitConstants.TAG_ALPHA_IDENTIFIER, (byte)0, (byte)0);
proHdlr.send();

Attempt 3. Prompts '@'

proHdlr.appendTLV(ToolkitConstants.TAG_ALPHA_IDENTIFIER, (byte)0);
proHdlr.send();

Attempt 4. Prompts Default Text

byte[] ALPHA_MSG = {};
proHdlr.appendTLV(ToolkitConstants.TAG_ALPHA_IDENTIFIER, ALPHA_MSG, (short)0, (short)ALPHA_MSG.length);
proHdlr.send();

According to ETSI 102.223 , "8.2 Alpha identifier" section, it should be:

Description	Length
Alpha identifier tag	1
Length(X)	Y
Alpha identifier	X

And there is also "Default text" in documentation, however since "5.3.7 Text attributes" requires Alpha Identifier to be present, Default text should not bother, right?

In this document "6.4.5 PLAY TONE" section, page 45 it says:

if the alpha identifier is provided by the UICC and is a null data object (ie length = '00' and no value part), the terminal should not give any information to the user;

That's what I need. How should I do it Java with ProactiveHandler? All my Google searches end up with some text/menu title for Alpha Identifier.

How to get rid of user confirmation and perform the proactive action without it?

Answer 1

a) Try to pass no data at all, ie leave out the proHdlr.appendTLV(ToolkitConstants.TAG_ALPHA_IDENTIFIER line.

b) The behavior might be phone-related or more specific modem-related. Check out a MediaTek based one, a Qualcomm based one and an iPhone and compare the results.