Example usage for org.bouncycastle.crypto.generators KDFCounterBytesGenerator generateBytes

Introduction

In this page you can find the example usage for org.bouncycastle.crypto.generators KDFCounterBytesGenerator generateBytes.

Prototype

public int generateBytes(byte[] out, int outOff, int len) throws DataLengthException, IllegalArgumentException 

Source Link

Usage

From source file:com.github.horrorho.inflatabledonkey.crypto.NISTKDF.java

License:Open Source License

public static byte[] ctrHMac(byte[] keyDerivationKey, byte[] label, Supplier<Digest> digestSupplier,
        int keyLengthBytes) {

    logger.trace("<< ctrHMac() - keyDerivationKey: 0x{} label: {} digestSupplier: {} length: {}",
            Hex.toHexString(keyDerivationKey), Hex.toHexString(label), digestSupplier, keyLengthBytes);

    byte[] derivedKey = new byte[keyLengthBytes];

    // fixedInputData = label || 0x00 || dkLen in bits as 4 bytes big endian
    ByteBuffer buffer = ByteBuffer.allocate(label.length + 5);
    buffer.put(label);//  ww w  .  ja va  2s .  c om
    buffer.put((byte) 0);
    buffer.putInt(keyLengthBytes * 8);
    byte[] fixedInputData = buffer.array();
    logger.debug("-- ctrHMac() - fixed input data: 0x{}", Hex.toHexString(fixedInputData));

    HMac hMac = new HMac(digestSupplier.get());
    KDFCounterBytesGenerator generator = new KDFCounterBytesGenerator(hMac);
    generator.init(new KDFCounterParameters(keyDerivationKey, fixedInputData, R));
    generator.generateBytes(derivedKey, 0, derivedKey.length);

    logger.trace(">> ctrHMac() - derivedKey: 0x{}", Hex.toHexString(derivedKey));
    return derivedKey;
}

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