Example usage for javax.crypto Cipher DECRYPT_MODE

Introduction

In this page you can find the example usage for javax.crypto Cipher DECRYPT_MODE.

Prototype

int DECRYPT_MODE

To view the source code for javax.crypto Cipher DECRYPT_MODE.

Click Source Link

Document

Constant used to initialize cipher to decryption mode.

Usage

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    byte[] input = "input".getBytes();
    byte[] keyBytes = new byte[] { 0x01, 0x23, 0x45, 0x67, (byte) 0x89, (byte) 0xab, (byte) 0xcd, (byte) 0xef };
    byte[] ivBytes = new byte[] { 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00 };

    SecretKeySpec key = new SecretKeySpec(keyBytes, "DES");
    IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
    Cipher cipher = Cipher.getInstance("DES/CBC/PKCS7Padding", "BC");

    cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);

    byte[] cipherText = new byte[cipher.getOutputSize(input.length)];

    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);

    ctLength += cipher.doFinal(cipherText, ctLength);

    cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);

    byte[] plainText = new byte[cipher.getOutputSize(ctLength)];

    int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);

    ptLength += cipher.doFinal(plainText, ptLength);

    System.out.println("plain : " + new String(plainText));

}

---

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
    generator.init(128);//  w  ww. ja  va2s. c  om
    Key keyToBeWrapped = generator.generateKey();
    System.out.println("input    : " + new String(keyToBeWrapped.getEncoded()));

    // create a wrapper and do the wrapping
    Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding", "BC");
    KeyGenerator keyGen = KeyGenerator.getInstance("AES", "BC");
    keyGen.init(256);
    Key wrapKey = keyGen.generateKey();
    cipher.init(Cipher.ENCRYPT_MODE, wrapKey);
    byte[] wrappedKey = cipher.doFinal(keyToBeWrapped.getEncoded());
    System.out.println("wrapped  : " + new String(wrappedKey));

    // unwrap the wrapped key
    cipher.init(Cipher.DECRYPT_MODE, wrapKey);
    Key key = new SecretKeySpec(cipher.doFinal(wrappedKey), "AES");
    System.out.println("unwrapped: " + new String(key.getEncoded()));
}

---

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    byte[] input = "input".getBytes();
    byte[] keyBytes = "input123".getBytes();
    byte[] ivBytes = "12345123".getBytes();

    SecretKeySpec key = new SecretKeySpec(keyBytes, "DES");
    IvParameterSpec ivSpec = new IvParameterSpec(new byte[8]);
    Cipher cipher = Cipher.getInstance("DES/CBC/PKCS7Padding", "BC");

    cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);

    byte[] cipherText = new byte[cipher.getOutputSize(ivBytes.length + input.length)];

    int ctLength = cipher.update(ivBytes, 0, ivBytes.length, cipherText, 0);

    ctLength += cipher.update(input, 0, input.length, cipherText, ctLength);

    ctLength += cipher.doFinal(cipherText, ctLength);

    cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);

    byte[] buf = new byte[cipher.getOutputSize(ctLength)];

    int bufLength = cipher.update(cipherText, 0, ctLength, buf, 0);

    bufLength += cipher.doFinal(buf, bufLength);

    byte[] plainText = new byte[bufLength - ivBytes.length];

    System.arraycopy(buf, ivBytes.length, plainText, 0, plainText.length);

    System.out.println("plain : " + new String(plainText));
}

---

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA", "BC");
    keyGen.initialize(512, new SecureRandom());
    KeyPair keyPair = keyGen.generateKeyPair();

    Signature signature = Signature.getInstance("SHA256withRSA", "BC");
    signature.initSign(keyPair.getPrivate());

    byte[] message = "abc".getBytes();
    signature.update(message);/*from w ww  .  ja va2  s .c o m*/

    byte[] sigBytes = signature.sign();
    Cipher cipher = Cipher.getInstance("RSA/None/PKCS1Padding", "BC");
    cipher.init(Cipher.DECRYPT_MODE, keyPair.getPublic());

    byte[] decSig = cipher.doFinal(sigBytes);
    ASN1InputStream aIn = new ASN1InputStream(decSig);
    ASN1Sequence seq = (ASN1Sequence) aIn.readObject();

    System.out.println(ASN1Dump.dumpAsString(seq));

    MessageDigest hash = MessageDigest.getInstance("SHA-256", "BC");
    hash.update(message);

    ASN1OctetString sigHash = (ASN1OctetString) seq.getObjectAt(1);
    System.out.println(MessageDigest.isEqual(hash.digest(), sigHash.getOctets()));
}

---

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    byte[] input = "www.java2s.com".getBytes();
    byte[] keyBytes = new byte[] { 0x01, 0x23, 0x45, 0x67, (byte) 0x89, (byte) 0xab, (byte) 0xcd, (byte) 0xef };

    SecretKeySpec key = new SecretKeySpec(keyBytes, "DES");
    Cipher cipher = Cipher.getInstance("DES/ECB/PKCS7Padding", "BC");
    System.out.println("input : " + new String(input));

    // encryption pass
    cipher.init(Cipher.ENCRYPT_MODE, key);
    byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
    ctLength += cipher.doFinal(cipherText, ctLength);
    System.out.println("cipher: " + new String(cipherText) + " bytes: " + ctLength);

    // decryption pass

    cipher.init(Cipher.DECRYPT_MODE, key);
    byte[] plainText = new byte[cipher.getOutputSize(ctLength)];
    int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
    ptLength += cipher.doFinal(plainText, ptLength);
    System.out.println("plain : " + new String(plainText) + " bytes: " + ptLength);
}

---

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    byte[] input = "java2s.com".getBytes();
    byte[] keyBytes = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c,
            0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 };

    SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
    Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");

    System.out.println(new String(input));

    // encryption pass
    cipher.init(Cipher.ENCRYPT_MODE, key);

    byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
    ctLength += cipher.doFinal(cipherText, ctLength);
    System.out.println(new String(cipherText));
    System.out.println(ctLength);

    // decryption pass
    cipher.init(Cipher.DECRYPT_MODE, key);
    byte[] plainText = new byte[cipher.getOutputSize(ctLength)];
    int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
    ptLength += cipher.doFinal(plainText, ptLength);
    System.out.println(new String(plainText));
    System.out.println(ptLength);

}

---

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    byte[] input = "www.java2s.com".getBytes();
    byte[] keyBytes = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c,
            0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 };

    SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");

    Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");

    System.out.println(new String(input));

    // encryption pass
    cipher.init(Cipher.ENCRYPT_MODE, key);

    byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
    ctLength += cipher.doFinal(cipherText, ctLength);
    System.out.println(new String(cipherText));
    System.out.println(ctLength);

    // decryption pass
    cipher.init(Cipher.DECRYPT_MODE, key);
    byte[] plainText = new byte[cipher.getOutputSize(ctLength)];
    int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
    ptLength += cipher.doFinal(plainText, ptLength);
    System.out.println(new String(plainText));
    System.out.println(ptLength);
}

---

From source file:Main.java

public static void main(String[] args) throws Exception {
    // Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    byte[] input = "input".getBytes();
    byte[] ivBytes = "1234567812345678".getBytes();

    Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
    KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
    generator.init(128);//from w  w  w .  jav  a2s  .  c o m
    Key encryptionKey = generator.generateKey();
    System.out.println("key : " + new String(encryptionKey.getEncoded()));

    cipher.init(Cipher.ENCRYPT_MODE, encryptionKey, new IvParameterSpec(ivBytes));
    byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
    ctLength += cipher.doFinal(cipherText, ctLength);
    Key decryptionKey = new SecretKeySpec(encryptionKey.getEncoded(), encryptionKey.getAlgorithm());

    cipher.init(Cipher.DECRYPT_MODE, decryptionKey, new IvParameterSpec(ivBytes));
    byte[] plainText = new byte[cipher.getOutputSize(ctLength)];
    int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
    ptLength += cipher.doFinal(plainText, ptLength);
    System.out.println("plain : " + new String(plainText));
}

---

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    byte[] input = " www.java2s.com ".getBytes();
    byte[] keyBytes = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c,
            0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 };

    SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
    Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding", "BC");
    System.out.println("input text : " + new String(input));

    // encryption pass

    byte[] cipherText = new byte[input.length];
    cipher.init(Cipher.ENCRYPT_MODE, key);
    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
    ctLength += cipher.doFinal(cipherText, ctLength);
    System.out.println("cipher text: " + new String(cipherText) + " bytes: " + ctLength);

    // decryption pass

    byte[] plainText = new byte[ctLength];
    cipher.init(Cipher.DECRYPT_MODE, key);
    int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
    ptLength += cipher.doFinal(plainText, ptLength);
    System.out.println("plain text : " + new String(plainText) + " bytes: " + ptLength);
}

---

From source file:MainClass.java

public static void main(String args[]) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    SecretKey key = KeyGenerator.getInstance("DES").generateKey();

    // for CBC; must be 8 bytes
    byte[] initVector = new byte[] { 0x10, 0x10, 0x01, 0x04, 0x01, 0x01, 0x01, 0x02 };

    AlgorithmParameterSpec algParamSpec = new IvParameterSpec(initVector);
    Cipher m_encrypter = Cipher.getInstance("DES/CBC/PKCS5Padding");
    Cipher m_decrypter = Cipher.getInstance("DES/CBC/PKCS5Padding");

    m_encrypter.init(Cipher.ENCRYPT_MODE, key, algParamSpec);
    m_decrypter.init(Cipher.DECRYPT_MODE, key, algParamSpec);

    FileInputStream fis = new FileInputStream("cipherTest.in");
    FileOutputStream fos = new FileOutputStream("cipherTest.out");
    int dataInputSize = fis.available();

    byte[] inputBytes = new byte[dataInputSize];
    fis.read(inputBytes);/*from w  w w.ja  va  2 s.c  om*/
    write(inputBytes, fos);
    fos.flush();
    fis.close();
    fos.close();

    String inputFileAsString = new String(inputBytes);
    System.out.println("INPUT FILE CONTENTS\n" + inputFileAsString + "\n");

    System.out.println("File encrypted and saved to disk\n");

    fis = new FileInputStream("cipherTest.out");

    byte[] decrypted = new byte[dataInputSize];
    read(decrypted, fis);

    fis.close();
    String decryptedAsString = new String(decrypted);

    System.out.println("DECRYPTED FILE:\n" + decryptedAsString + "\n");

}

---

• «
• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• 42
• 43
• 44
• 45
• 46
• 47
• 48
• 49
• 50
• »