How to instantiate public key

hi,
I have a problem when I try to instanciate a RSAPublicKey from javacard with this code :
publicKey = (RSAPublicKey) KeyBuilder.buildKey(KeyBuilder.TYPE_RSA_PUBLIC, KeyBuilder.LENGTH_RSA_1024, false);
this returns the error code 6f 00.
please help again!

the first problem have been already fixed and the value returned by getReason is 1
here my public exponent and modulus arrays
private static final byte[] exponentPublicKey = {1, 0, 1};
private static final byte[] modulusPublicKey = {
          0, -48, -96, -44, -25, 111, 122, 92, 11, -79,
          124, -63, 97, -126, -60, -10, -44, -99, -20, 40,
          60, 82, -25, -85, -96, 46, 119, 91, -4, 122,
          -33, 88, 1, 51, 113, 20, 122, 101, -79, 59,
          -127, 53, 90, 64, -94, -44, -94, 18, 74, 89,
          62, 33, -66, 0, 0, -89, -11, -111, 10, 48,
          -27, 73, 88, 12, 89};

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Hi Friends..
Sorry, i have a little doubt regarding the Public Key Remainder..
What is Public Key Remainder used for?.. is it a part of Public Key?.. How to get it from Public Key, especially in Java?
As far as i know that the Public Key is constructed with Modulus and Exponent, and with this we can Encrypt and Verify data was signed by Private Key..
In Java, we can expose Public Key's modulus and public exponent using RSAPublicKey, there's no method to expose Public Key's Remainder..
Please help me regarding this..
Thanks

Leonardo Carreira wrote:
Hi Shane,
Thanks for your reply.. :)
safarmer wrote:
In that case the exponent and remainder are you public key (exponent and modulus) and the certificate is defined in the definitions section of Book 3. It is a secure way of verifying the public key and it's owner through a trusted certification authority.
EMV Book 3 tends to use Remainder and Modulus interchangeably.You mean, the Issuer (in this case one of E,M, and V) should provide 2 certificates for 1 card?..
This is implemented on SDA or DDA?..
Sorry, i'm still have no idea..
The Remainder and Modulus should be used interchangeably?..
How the Host and Card can decides in each transaction whether it will use Remainder or Modulus?..I mean that the terminology is used interchangeably. They refer to the same thing as far as the actual key is concerned.
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Hi all
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try {
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import java.security.KeyPair;
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public static void main(String[] args) throws Exception {
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/*i want to get the private and public key in this method ,but i found the result was not
the one i expected to get,how to solve the problem?
thanks in advance!
System.out.println("private key:" + key.getPrivate().toString());
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thanks in advance!

System.out.println("private key:" +
" + key.getPrivate().toString());
System.out.println("public key:" +
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key.getPrivate() returns an instance of PrivateKey and key.getPublic() returns an instance of PublicKey. Since PublicKey and PrivateKey are interfaces then they will return one of the concrete implementations. Check out the Javadoc for PublicKey and PrivateKey.
When you know which concreate implemenation you have then you can use the methods on that object (by appropriate casting) to find the information you want.

How does a public/private key encrypt and decrypt each other?

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I did the following code:
import java.security.*;
class keypair
public static void main(String args[])
try {
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catch (java.security.NoSuchAlgorithmException e) {
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E:\java>java keypair
Sun RSA public key, 1024 bits
modulus: 104598424699919432698042124865237006532583108525971624656815039032375
*68185931249899603942873174007833898125332457427834491991685017307342129730049040*
*85039266578793603162921901877391682504673766949037045217194339504369288262569809*
*64618725280325930282787918761626276736975012559809247463223114702205350103039131*
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How to parse modulus(n) and public exponent(e) from this output?
Similarly when i print private key, it produces the following output:
E:\java>java keypair
Sun RSA private CRT key, 1024 bits
modulus:          124578817060208658480856678950235831207402457067036419284514
*60119309486714863949162442643168408523979997168613499493638925829235693238993015*
*36861462235708805467117179894466762970147852286192228334073408407380525883650965*
*26200137024900438305422984852314541271126647102071346646999343089444655087519613*
*147762713*
public exponent: 65537
private exponent: 938527844532658207604152892230342202756165450473898580852699
*91069268853864683730106242370135012901790500054313488639918623825755509450966957*
*25996151023641565209086629652161258725723528561744214714448113895688480371394495*
*69970533766968335232379493089928062691491508442909468663624841001227918721233934*
*90451285*
prime p:          128112715803862066344339615342766575233634768887073748611821
*70613165835421234259251719401979554816266892921739504796026180704477109334458578*
*924582228715587*
prime q:          972415706579323990162180646771186062588725555167352041581263
*11833654947284058644791019214876691698044764118648637510099163830088827138987158*
*06445271350899*
prime exponent p: 102053075991522697645186596252261651077210381075096084960080
*01572103324900452503753532555651687424478224695551102238145517644352533224205327*
*850477437666141*
prime exponent q: 668659136319899226645386130685620335239039277715133737489656
*56694442226518700929665796129185316864860876985624927131126216000167126890435269*
*81971346772483*
crt coefficient: 337801534982286124613379128447816812903646302193598735486466
*78634104811105616496519276355880320340688935923186965279527763125244878069735173*
*60542121091569*
E:\java>
From this output how to parse n and d, where d is the secret exponent or decryption exponent? Thanks in advance. Apologies, for posting in this forum instead of cryptography forum.
Edited by: sowndar on Nov 28, 2009 3:12 AM

sowndar wrote:
From this output how to parse n and d, where d is the secret exponent or decryption exponent? Why do you think you need to parse anything? Why do you need the modulus and exponents?
P.S. Extract the public and private keys from the key pair, cast them to RSAPublicKey and RSAPrivateKey as appropriate then look at the methods of classes RSAPublicKey and RSAPrivateKey to see how to get modulus and exponents.

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Message was edited by:
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