Example usage for org.bouncycastle.crypto.modes GCMBlockCipher GCMBlockCipher

Introduction

In this page you can find the example usage for org.bouncycastle.crypto.modes GCMBlockCipher GCMBlockCipher.

Prototype

public GCMBlockCipher(BlockCipher c, GCMMultiplier m) 

Source Link

Usage

From source file:COSE.EncryptCommon.java

private void AES_GCM_Decrypt(AlgorithmID alg, byte[] rgbKey) throws CoseException, InvalidCipherTextException {
    GCMBlockCipher cipher = new GCMBlockCipher(new AESFastEngine(), new BasicGCMMultiplier());

    CBORObject cn = FindAttribute(HeaderKeys.IV);
    if (cn == null)
        throw new CoseException("Missing IV during decryption");
    if (cn.getType() != CBORType.ByteString)
        throw new CoseException("IV is incorrectly formed");
    if (cn.GetByteString().length != 96 / 8)
        throw new CoseException("IV size is incorrect");

    if (rgbKey.length != alg.getKeySize() / 8)
        throw new CoseException("Missing IV during decryption");
    KeyParameter contentKey = new KeyParameter(rgbKey);
    AEADParameters parameters = new AEADParameters(contentKey, 128, cn.GetByteString(), getAADBytes());

    cipher.init(false, parameters);/*from  w  w w .j a va2s  .  co  m*/
    byte[] C = new byte[cipher.getOutputSize(rgbEncrypt.length)];
    int length = cipher.processBytes(rgbEncrypt, 0, rgbEncrypt.length, C, 0);
    length += cipher.doFinal(C, length);

    rgbContent = C;
}

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From source file:COSE.EncryptCommon.java

private void AES_GCM_Encrypt(AlgorithmID alg, byte[] rgbKey)
        throws CoseException, IllegalStateException, InvalidCipherTextException {
    GCMBlockCipher cipher = new GCMBlockCipher(new AESFastEngine(), new BasicGCMMultiplier());

    if (rgbKey.length != alg.getKeySize() / 8)
        throw new CoseException("Key Size is incorrect");
    KeyParameter contentKey = new KeyParameter(rgbKey);

    CBORObject cn = FindAttribute(HeaderKeys.IV);
    byte[] IV;//from  ww  w.  j  av  a2  s  .c  om

    if (cn == null) {
        IV = new byte[96 / 8];
        random.nextBytes(IV);
        AddUnprotected(HeaderKeys.IV, CBORObject.FromObject(IV));
    } else {
        if (cn.getType() != CBORType.ByteString)
            throw new CoseException("IV is incorrectly formed");
        if (cn.GetByteString().length != 96 / 8)
            throw new CoseException("IV size is incorrect");
        IV = cn.GetByteString();
    }

    AEADParameters parameters = new AEADParameters(contentKey, 128, IV, getAADBytes());

    cipher.init(true, parameters);
    byte[] C = new byte[cipher.getOutputSize(rgbContent.length)];
    int length = cipher.processBytes(rgbContent, 0, rgbContent.length, C, 0);
    length += cipher.doFinal(C, length);

    rgbEncrypt = C;
}

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From source file:org.openmuc.jdlms.internal.security.CipheringGcm.java

License:Open Source License

public static byte[] encrypt(byte[] plaintext, int off, int len, byte[] systemTitle, int frameCounter,
        byte[] encryptionKey, byte[] authenticationKey, byte tag) throws IOException {

    byte[] frameCounterBytes = intToByteArray(frameCounter);

    byte[] iv = concat(systemTitle, frameCounterBytes);

    byte[] associatedData = new byte[authenticationKey.length + 1];
    associatedData[0] = SECURITY_CONTROL_BYTES_AUTH_CIPH;
    System.arraycopy(authenticationKey, 0, associatedData, 1, authenticationKey.length);

    AEADParameters parameters = new AEADParameters(new KeyParameter(encryptionKey), 96, iv, associatedData);

    GCMBlockCipher encCipher = new GCMBlockCipher(new AESFastEngine(), new BasicGCMMultiplier());
    encCipher.init(true, parameters);/* w w  w .  j  a v  a2s .co  m*/

    byte[] enc = new byte[encCipher.getOutputSize(len)];
    int length = encCipher.processBytes(plaintext, off, len, enc, 0);
    try {
        length += encCipher.doFinal(enc, length);
    } catch (IllegalStateException e) {
        throw new IOException("Unable to cipher/encrypt xDLMS pdu", e);
    } catch (InvalidCipherTextException e) {
        throw new IOException("Unable to cipher/encrypt xDLMS pdu", e);
    }

    byte[] result = new byte[enc.length + 7];
    result[0] = tag;
    result[1] = (byte) (enc.length + 5);
    result[2] = SECURITY_CONTROL_BYTES_AUTH_CIPH;
    System.arraycopy(frameCounterBytes, 0, result, 3, 4);
    System.arraycopy(enc, 0, result, 7, enc.length);

    return result;
}

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From source file:org.openmuc.jdlms.internal.security.CipheringGcm.java

License:Open Source License

public static byte[] decrypt(byte[] ciphertext, byte[] systemTitle, byte[] encryptionKey,
        byte[] authenticationKey) throws IOException {

    byte[] iv = new byte[12];
    System.arraycopy(systemTitle, 0, iv, 0, systemTitle.length);
    // copy frame counter
    System.arraycopy(ciphertext, 1, iv, 8, 4);

    byte[] associatedData = new byte[authenticationKey.length + 1];
    associatedData[0] = SECURITY_CONTROL_BYTES_AUTH_CIPH;
    System.arraycopy(authenticationKey, 0, associatedData, 1, authenticationKey.length);

    AEADParameters parameters = new AEADParameters(new KeyParameter(encryptionKey), 96, iv, associatedData);

    GCMBlockCipher decCipher = new GCMBlockCipher(new AESFastEngine(), new BasicGCMMultiplier());
    decCipher.init(false, parameters);// www .  j a va 2  s  . com

    byte[] dec = new byte[decCipher.getOutputSize(ciphertext.length - 5)];
    int len = decCipher.processBytes(ciphertext, 5, ciphertext.length - 5, dec, 0);
    try {
        len += decCipher.doFinal(dec, len);
    } catch (IllegalStateException e) {
        throw new IOException("Unable to decipher/decrypt xDLMS pdu", e);
    } catch (InvalidCipherTextException e) {
        throw new IOException("Unable to decipher/decrypt xDLMS pdu", e);
    }

    return dec;
}

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