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Search found 39 matches

by Crawford
Thu Aug 30, 2018 5:06 am
Forum: Communication
Topic: How to determine the type of Keyfob card?
Replies: 1
Views: 1398

How to determine the type of Keyfob card?

Hello,

I have a Keyfob Card, but I don't know what types of card it is. a Mifare Card or an ID Card?
Are there any commands can be sent?

can anybody tell me, please?
by Crawford
Mon Oct 16, 2017 4:55 am
Forum: Questions & Answers
Topic: SW_ILLEGAL_USE returned by cipher.dofinal()
Replies: 3
Views: 1646

Re: SW_ILLEGAL_USE returned by cipher.dofinal()

Input data must have a multiple of 8 for decryption.

input='112233....BB' -> 11 bytes
after ISO9797_M2 padding='112233....BB8000000000' -> 16 bytes
after encryption='xxxx...xx' -> 16 bytes

So if you want to get correctly decrypted value, you have to give 16 bytes of encrypted data.
by Crawford
Mon Aug 21, 2017 5:13 am
Forum: Questions & Answers
Topic: Issue about generating 2048 bytes keys with RSA
Replies: 2
Views: 1416

Re: Issue about generating 2048 bytes keys with RSA

A status word of 0x6F00 is an Unknown Error.

You could try inserting debug code to see what line of code is failing. Add the following line of code near the start and keep moving/redploying and see when you start getting 6F00 instead of 1234.

Code: Select all

ISOException.throwIt((short)0x1234);
by Crawford
Mon Jul 24, 2017 11:12 pm
Forum: Questions & Answers
Topic: Generate random number
Replies: 1
Views: 1016

Re: Generate random number

If you remove the setSeeed call, you will get a different result from the random number generator, since you are seeding the generator with the same value.
by Crawford
Mon Jun 19, 2017 2:11 am
Forum: Questions & Answers
Topic: How to send int
Replies: 1
Views: 1014

Re: How to send int

You can convert int to byte[] to solve your problem.
To convert an int to a byte array, keep in mind that an int is 4 bytes. Then this is a straight Java problem that is not specific to Java Card.
by Crawford
Sun Jun 11, 2017 11:33 pm
Forum: Questions & Answers
Topic: BP tools crashed once running
Replies: 3
Views: 1337

BP tools crashed once running

I saw someone mentioned BP tools in this post https://javacardos.com/javacardforum/viewtopic.php?f=15&t=1154&start=10#p3773 . I also downloaded this tool. And it can work after the installation, but when I restart my computer, BP tools always crashed once starting. Does anyone experience thi...
by Crawford
Mon May 08, 2017 5:56 am
Forum: Questions & Answers
Topic: JCOP card chip speed
Replies: 3
Views: 1399

Re: JCOP card chip speed

I check it from the JCOP datasheet. If the card you bought is J3D081 from this online store. In contact mode, the following communication speeds are supported: - 9600 bit/s [Default] - 19200 bit/s - 38400 bit/s - 57600 bit/s - 115200 bit/s - 223200 bit/s In contactless mode,the following communicati...
by Crawford
Fri Mar 10, 2017 1:19 am
Forum: Questions & Answers
Topic: Specify the right interface for my code
Replies: 2
Views: 1217

Re: Specify the right interface for my code

Maybe this code helps: byte protocolMedia = (byte) (apdu.getProtocol() & APDU.PROTOCOL_MEDIA_MASK); if ((protocolMedia == APDU.PROTOCOL_MEDIA_CONTACTLESS_TYPE_A) || (protocolMedia == APDU.PROTOCOL_MEDIA_CONTACTLESS_TYPE_B)) { // Contactless interface; switch (buf[ISO7816.OFFSET_INS]) { case INS_...
by Crawford
Fri Feb 10, 2017 6:17 am
Forum: Questions & Answers
Topic: DES decryption implementation in java and java card
Replies: 3
Views: 1473

Re: DES decryption implementation in java and java card

IMO, there is no advantage or dis-advantage in this case. You should not rely on intermediate results of update anyway because the operation is not completed until doFinal(...) method is called.
by Crawford
Fri Feb 10, 2017 3:15 am
Forum: Questions & Answers
Topic: DES decryption implementation in java and java card
Replies: 3
Views: 1473

Re: DES decryption implementation in java and java card

mose05 wrote:- In java, it need to have at least 16 bytes input to have output data.


Have you got 8 bytes in the response? If you have 8 bytes only, you should call doFinal().
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