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Search found 14 matches

by roundtable
Mon May 21, 2018 4:12 am
Forum: Questions & Answers
Topic: PIN_TRY_COUNTER
Replies: 5
Views: 651

Re: PIN_TRY_COUNTER

please read documemt of javacard API: javacard.framework.OwnerPIN to decrease try count, just call check(..) with wrong PIN, follwoing is fragment of method check (): ublic boolean check(byte[] pin, short offset, byte length) throws ArrayIndexOutOfBoundsException, NullPointerException Compares pin a...
by roundtable
Tue May 15, 2018 8:34 am
Forum: Applets Development Guide
Topic: Encryption using secure element/domain keys
Replies: 1
Views: 722

Re: Encryption using secure element/domain keys

Yes, you may misunderstand the purpose of key-enc (DEK key), which is used to establish secure Communication channel between SE and external entity to loading or personalizing application instead of general purpose cipher. If you want to use SE to encrypt or decrypt data for you, you should write yo...
by roundtable
Tue May 15, 2018 8:25 am
Forum: Questions & Answers
Topic: Want to know how unwrap send command works.
Replies: 3
Views: 599

Re: Want to know how unwrap send command works.

The PUT Key command shall run on established secure channel, so you applet must proess the 'initialize update ' and 'external authenticate' commands first just like below : switch (ins) case INITIALIZE_UPDATE: apdu.setOutgoingAndSend((short) 5, GPSystem.getSecureChannel().processSecurity(apdu)); bre...
by roundtable
Tue May 15, 2018 2:08 am
Forum: Questions & Answers
Topic: How to calculate baud rate OR speed of CARD from ETU and ATR ?
Replies: 3
Views: 1004

Re: How to calculate baud rate OR speed of CARD from ETU and ATR ?

HI, you can refer below table: frequency was set to 3.571200 MHz +--------+----------+--------+------------+----------------+-----------------+-----------------+ | TA1 | Fi | Di | f(max) MHz | periods of ETU | duration of ETU | Baud rate | +========+==========+========+============+================+...
by roundtable
Wed Apr 18, 2018 10:14 pm
Forum: Questions & Answers
Topic: Multiply big numbers
Replies: 8
Views: 1166

Re: Multiply big numbers

You should know something important about javacard: 1. javacard is the mini subset of standard Java, so most of features, packages and classes are not supported in javacard. For example , class BigInterger, it is only available on standard Java (JDK) , if you use it on javacad, you can't build it su...
by roundtable
Wed Apr 18, 2018 5:00 am
Forum: Questions & Answers
Topic: Multiply big numbers
Replies: 8
Views: 1166

Re: Multiply big numbers

HI, guy, are you sure your javacard provide those special API for big integer modular arithmetic ? the standard javacard API can't support your requirements. you may need special javacard equipped with non-standard API to support big integer operation, such as modular add/sub/multiply/GCD and so on....
by roundtable
Thu Dec 07, 2017 11:52 pm
Forum: Applets Development Guide
Topic: Javacard kit 3.0.4 & crypto algorithm
Replies: 2
Views: 1062

Re: Javacard kit 3.0.4 & crypto algorithm

For signature builder call Signature. getInstance (MessageDigest. ALG_NULL, Signature. SIG_CIPHER_ECDSA, Cipher. PAD_NULL, false); infact , it is failed as expected, since ECDSA is signature standard specified In ANSI X9.62-1998, for this scheme, only message digest and Private key are needed withou...
by roundtable
Tue Nov 21, 2017 5:23 am
Forum: Questions & Answers
Topic: Error 68 81 when sending apdu(BFDEP1P2..)to card
Replies: 5
Views: 1330

Re: Error 68 81 when sending apdu(BFDEP1P2..)to card

Maybe you should select your applet again on logical channel 3 again,
03 A4 04 00 XXXXX
then send the command and check if SW is still 6D00
by roundtable
Tue Nov 21, 2017 5:19 am
Forum: Reader
Topic: The Square card reader
Replies: 2
Views: 934

Re: The Square card reader

maybe your card has been locked, you can get help from cad issuer, such as bank or credit card company.
by roundtable
Tue Nov 21, 2017 5:08 am
Forum: Questions & Answers
Topic: Geting Error on getIncomingLength() and getOffsetCdata()
Replies: 2
Views: 770

Re: Geting Error on getIncomingLength() and getOffsetCdata()

You should add following statement at beginning of your code:
import javacard.framework.*;

Try it
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