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the encrypted file is cutted shortter  RSS feed

 
zb cong
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hello
my code as following:


public class EncryptHandler {

public EncryptHandler() {
}

public SecretKey genKey() {
try {
KeyGenerator kg = KeyGenerator.getInstance("DESede");
kg.init(168);
SecretKey key = kg.generateKey();
return key;
} catch (Exception e) {
e.printStackTrace();
System.exit(-1);
return null;
}
}

public SecretKey readKey(String path) {
try {
FileInputStream fin = new FileInputStream(path);
int num = fin.available();
byte[] keykb = new byte[num];
fin.read(keykb);

SecretKeySpec key = new SecretKeySpec(keykb, "DESede");
return key;

} catch (Exception e) {
e.printStackTrace();
System.exit(-1);
return null;
}
}

public void saveKeyAsObject(SecretKey key, String destPath) {
try {
ObjectOutputStream o = new ObjectOutputStream(new FileOutputStream(
destPath));
o.writeObject(key);
} catch (Exception e) {
System.exit(-1);
e.printStackTrace();
}

}

public void saveKeyAsByte(SecretKey key, String destPath) {
try {
byte[] kb = key.getEncoded();
FileOutputStream fo = new FileOutputStream(destPath);
fo.write(kb);
} catch (Exception e) {
e.printStackTrace();
System.exit(-1);
}

}

public void encryptFile(String srcPath, String destPath, SecretKey key) {
try {

Cipher cp = Cipher.getInstance("DESede");
cp.init(Cipher.ENCRYPT_MODE, key);

BufferedReader reader = new BufferedReader(new InputStreamReader(
new FileInputStream(srcPath)));
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(
new CipherOutputStream(new FileOutputStream(destPath), cp)));

String tmpStr = "";
while ((tmpStr = reader.readLine()) != null) {

writer.write(tmpStr + "\n");
writer.flush();
}
} catch (Exception e) {
e.printStackTrace();
System.exit(-1);
}
}

public void decryptFile(String srcPath, String destPath, SecretKey key) {
try {
Cipher cp = Cipher.getInstance("DESede");
cp.init(Cipher.DECRYPT_MODE, key);
BufferedReader reader = new BufferedReader(new InputStreamReader(
new CipherInputStream(new FileInputStream(srcPath), cp)));
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(
new FileOutputStream(destPath)));
String tmpStr = "";
while ((tmpStr = reader.readLine()) != null) {
writer.write(tmpStr + "\n");
writer.flush();
}
} catch (Exception e) {
e.printStackTrace();
System.exit(-1);
}

}

public static void main(String[] argv) {
String s = "Hello world!!!";
EncryptHandler c = new EncryptHandler();
SecretKey key = c.genKey();
c.saveKeyAsByte(key, "c:\\temp\\testkey1");
SecretKey k = c.readKey("c:\\temp\\testkey1");
c.encryptFile("c:\\temp\\newpasswords", "c:\\temp\\oooo", key);
c.decryptFile("c:\\temp\\oooo", "c:\\temp\\ttttt", key);

}
}




i use symetrical key encrypt text firle the flow as follow:
1 generate key
2 save the key to the disk
3 read the key from disk
4 encrypt a text file
5 decrypt the file generated in step 4

but i find the final text file is cutted shortter then the original one, and i think the such problem result from "encryptFile" method, i guess it maybe result from the "padding" problem, but i don't know how to solve it, i am a beginner, who can help me?

thank you very much!!
 
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