CODEWITHSUNDEEP
javaandroid
King
King

Reputation: 234

Encrypting a zip

I want to Encrypt Zip file that I generate, which contains a files inside it. I want to encrypt it with password.

Its my first time to work with Encryption. I did my own research, I seem to understand but not clearly on how it works.

Can anyone help with a clear example, and a good way of encrypting by explain to me and how do I implement it or maybe give an example.

Your help will be appreciated.

Upvotes: 2

Views: 2934

Answers (2)

Oleg Cherednik
Oleg Cherednik

Reputation: 18245

You can try zip4jvm

char[] password = "password".toCharArray();
ZipEntrySettings entrySettings =
             ZipEntrySettings.builder()
                             .encryption(Encryption.AES_256, password)
                             .build();
ZipSettings settings =
                  ZipSettings.builder()
                             .entrySettingsProvider(fileName -> entrySettings)
                             .build();

Path zip = Paths.get("dest.zip");
Path srcDir = Paths.get("/srcDir");
ZipIt.zip(zip).settings(settings).add(srcDir);

Upvotes: 2

Evripidis Drakos
Evripidis Drakos

Reputation: 870

I use CipherOutputStream like this:

public static void encryptAndClose(FileInputStream fis, FileOutputStream fos) 
        throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {

    // Length is 16 byte
    SecretKeySpec sks = new SecretKeySpec("1234567890123456".getBytes(), "AES");
    // Create cipher
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.ENCRYPT_MODE, sks);      

    // Wrap the output stream for encoding
    CipherOutputStream cos = new CipherOutputStream(fos, cipher);       

    //wrap output with buffer stream
    BufferedOutputStream bos = new BufferedOutputStream(cos);     

    //wrap input with buffer stream
    BufferedInputStream bis = new BufferedInputStream(fis); 

    // Write bytes
    int b;
    byte[] d = new byte[8];
    while((b = bis.read(d)) != -1) {
        bos.write(d, 0, b);
    }
    // Flush and close streams.
    bos.flush();
    bos.close();
    bis.close();
}


public static void decryptAndClose(FileInputStream fis, FileOutputStream fos) 
        throws IOException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {

    SecretKeySpec sks = new SecretKeySpec("1234567890123456".getBytes(), "AES");
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.DECRYPT_MODE, sks);

    CipherInputStream cis = new CipherInputStream(fis, cipher);

    //wrap input with buffer stream
    BufferedInputStream bis = new BufferedInputStream(cis); 

    //wrap output with buffer stream
    BufferedOutputStream bos = new BufferedOutputStream(fos);       

    int b;
    byte[] d = new byte[8];
    while((b = bis.read(d)) != -1) {
        bos.write(d, 0, b);
    }
    bos.flush();
    bos.close();
    bis.close();
}

I use it like this:

File output= new File(outDir, outFilename);

File input= new File(inDir, inFilename);

if (input.exists()) {

FileInputStream inStream = new FileInputStream(input);
FileOutputStream outStream = new FileOutputStream(output);

encryptAndClose(inStream, outStream);   
}

Upvotes: 2

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