Cryptage d'un fichier en Blowfich
Bonsoir,j'ai un problème au moment de décryptage d'un fichier.voila mon code
package application;
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import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
public class DecrypBlowfish {
private static String strkey ="Blowfish";
private static Base64 base64 = new Base64(true);
//encrypt using blowfish algorithm
public static byte[] encrypt(byte[] Data)throws Exception{
SecretKeySpec key = new SecretKeySpec(strkey.getBytes("UTF8"), "Blowfish");
Cipher cipher = Cipher.getInstance("Blowfish");
cipher.init(Cipher.ENCRYPT_MODE, key);
return base64.encode(Data);
}
//decrypt using blow fish algorithm
public static byte[] decrypt(byte[] encrypted)throws Exception{
byte[] encryptedData = base64.decodeBase64(encrypted);
SecretKeySpec key = new SecretKeySpec(strkey.getBytes("UTF8"), "Blowfish");
Cipher cipher = Cipher.getInstance("Blowfish");
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] decrypted = cipher.doFinal(encryptedData);
return decrypted;
}
private static String LireString() {
String ligne_lue=null;
try{
InputStreamReader lecteur=new InputStreamReader(System.in);
BufferedReader entree=new BufferedReader(lecteur);
ligne_lue=entree.readLine();
}
catch(IOException err){
System.exit(0);
}
return ligne_lue;
}
public static void main(String[] args) throws Exception {
String fichier;
System.out.println("Donner le nom du fichier a decrypter: ");
fichier = LireString();
File f = new File(fichier);
byte[] tab =java.nio.file.Files.readAllBytes(f.toPath());
byte[] decoded = decrypt(tab);
FileWriter fw = new FileWriter("bh.txt",true);
fw.write(new String(decoded));
fw.close();
}
} |
voila l'exeption
Citation:
Exception in thread "main" javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:750)
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:676)
at com.sun.crypto.provider.BlowfishCipher.engineDoFinal(BlowfishCipher.java:319)
at javax.crypto.Cipher.doFinal(Cipher.java:2087)
at application.DecrypBlowfish.decrypt(DecrypBlowfish.java:38)
at application.DecrypBlowfish.main(DecrypBlowfish.java:61)
Pouvez vous m'aider?
