java.security.NoSuchAlgorithmException need Help!!!!!!!!!!

[Dorj Galaa]

this is Encrypt/Decrypt example but clause
import java.io.*;
import java.security.*;
import javax.crypto.*;
class EncryptDecrypt {
public static void main(String args[])
{
try
{
// generate Cipher objects for encoding and decoding
Cipher itsocipher1 = Cipher.getInstance("DES");
Cipher itsocipher2 = Cipher.getInstance("DES");
// generate a KeyGenerator object
KeyGenerator KG = KeyGenerator.getInstance("DES");
System.out.println("Using algorithm " + KG.getAlgorithm());
// generate a DES key
Key mykey = KG.generateKey();
// initialize the Cipher objects
System.out.println("Initializing ciphers...");
itsocipher1.init(Cipher.ENCRYPT_MODE, mykey);
itsocipher2.init(Cipher.DECRYPT_MODE, mykey);
// creating the encrypting cipher stream
System.out.println("Creating the encrypting cipher stream...");
FileInputStream fis = new FileInputStream("b.txt");
CipherInputStream cis1 = new CipherInputStream(fis, itsocipher1);
// creating the decrypting cipher stream
System.out.println("Creating the decrypting cipher stream...");
CipherInputStream cis2 = new CipherInputStream(cis1, itsocipher2);
// writing the decrypted data to output file
System.out.println("Writing the decrypted data to output file " + args[1]);
FileOutputStream fos = new FileOutputStream("c.txt");
byte[] b2 = new byte[1024];
int i2 = cis2.read(b2);
while (i2 != -1)
{
fos.write(b2, 0, i2);
i2 = cis2.read(b2);
}
fos.close();
cis1.close();
cis2.close();
}
catch (Exception e)
{
System.out.println("Caught exception: " + e);
}
}
}
may me i not registered provider how to add provider or algorithm

[Shreya Menon]

Dorj,
I haven't worked on this cryptography yet.
But if you can go to google groups and enter the exception, you can find a lot of links.
I used to do like that, I copy my errors in the groups and will read the comments from others with the same/similiar postings. I have got many valuable information from this.
Thanks,
Maya

[Dorj Galaa]

Hi maya?
this is encode sample. working correctly. But i can't decode
do you now how to decode? I no any idea. u can download javax.crypto package from <a href="http://jsecom15.sun.com/servlet/EComActionServlet?StoreId=8&PartDetailId=JCE-1_2_1-G-F&TransactionId=Try&LMLoadBalanced=&LMLoadBalanced=" target="_blank">http://jsecom15.sun.com/servlet/EComActionServlet?StoreId=8&PartDetailId=JCE-1_2_1-G-F&TransactionId=Try&LMLoadBalanced=&LMLoadBalanced=</a>;
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.io.*;
import com.sun.crypto.provider.*;
import java.util.*;
public class Encode
{
public static void main(String args[])
{
try
{
Provider sunJce = new SunJCE();
Security.addProvider(sunJce);
Cipher cipher1 = Cipher.getInstance("DES");
KeyGenerator KG1 = KeyGenerator.getInstance("DES");
KG1.init(56);
Key mykey = KG1.generateKey();
cipher1.init(Cipher.ENCRYPT_MODE, mykey);
FileInputStream fis=new FileInputStream("B.txt");
FileOutputStream fos=new FileOutputStream("C.txt");
byte[] input=new byte[5];
int a=-1;
String Line=null;
while ((a=fis.read(input))!=-1)
{
byte output[]=cipher1.doFinal(input);
System.out.println(Integer.toString(cipher1.getOutputSize(5)));
fos.write(output);
fos.flush();
}
fis.close();
fos.flush();
fos.close();
}
catch(Exception e)
{
System.out.println(e.getMessage());
}
}
}
this progarm convert 5 bytes to 8 byte. but i can't convert 8 byte to 5 byte. try this. i think
on line 20 change
cipher1.init(Cipher.ENCRYPT_MODE, mykey);

[Shreya Menon]

Dorj,
I haven't done any encoding or decoding. But I started my research on the topic.
Will this help you by any chance ?
http://developer.java.sun.com/developer/onlineTraining/Programming/BasicJava2/crypto.html
Please have a look at the algorithm ..
Thanks,
Maya

[David Bejjam]

Modify U'r program based on the following lines.
1. Install the Provider
2. Generate a key
3. Generate a Secret Key
4. Create a Cipher Instance
5. Initialize the Cipher(encrypt)
6. Use dofinal() to generate cipher text.
7. Initialize the same Cipher instance to decrypt.
Note - There is no need to create 2 Cipher instances for like U did in U'r program.
All the best

Originally posted by Dorj Galaa:
this is Encrypt/Decrypt example but clause
import java.io.*;
import java.security.*;
import javax.crypto.*;
class EncryptDecrypt {
public static void main(String args[])
{
try
{
// generate Cipher objects for encoding and decoding
Cipher itsocipher1 = Cipher.getInstance("DES");
Cipher itsocipher2 = Cipher.getInstance("DES");
// generate a KeyGenerator object
KeyGenerator KG = KeyGenerator.getInstance("DES");
System.out.println("Using algorithm " + KG.getAlgorithm());
// generate a DES key
Key mykey = KG.generateKey();
// initialize the Cipher objects
System.out.println("Initializing ciphers...");
itsocipher1.init(Cipher.ENCRYPT_MODE, mykey);
itsocipher2.init(Cipher.DECRYPT_MODE, mykey);
// creating the encrypting cipher stream
System.out.println("Creating the encrypting cipher stream...");
FileInputStream fis = new FileInputStream("b.txt");
CipherInputStream cis1 = new CipherInputStream(fis, itsocipher1);
// creating the decrypting cipher stream
System.out.println("Creating the decrypting cipher stream...");
CipherInputStream cis2 = new CipherInputStream(cis1, itsocipher2);
// writing the decrypted data to output file
System.out.println("Writing the decrypted data to output file " + args[1]);
FileOutputStream fos = new FileOutputStream("c.txt");
byte[] b2 = new byte[1024];
int i2 = cis2.read(b2);
while (i2 != -1)
{
fos.write(b2, 0, i2);
i2 = cis2.read(b2);
}
fos.close();
cis1.close();
cis2.close();
}
catch (Exception e)
{
System.out.println("Caught exception: " + e);
}
}
}
may me i not registered provider how to add provider or algorithm

[Dorj Galaa]

David Bejjam
can you send me example code of encrypt and decrypt

[David Bejjam]

Hi Dorj,
Pl.s send me U'r email address so that I can send the code.
David

[Dorj Galaa]

[e-mail]

[David Bejjam]

Dorj,
Hope U got the code.
All the best.