All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.bouncycastle.crypto.generators.PKCS5S2ParametersGenerator Maven / Gradle / Ivy

Go to download

The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.5 to JDK 1.8 with debug enabled.

There is a newer version: 1.70
Show newest version
package org.bouncycastle.crypto.generators;

import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.Mac;
import org.bouncycastle.crypto.PBEParametersGenerator;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.params.ParametersWithIV;
import org.bouncycastle.crypto.util.DigestFactory;
import org.bouncycastle.util.Arrays;

/**
 * Generator for PBE derived keys and ivs as defined by PKCS 5 V2.0 Scheme 2.
 * This generator uses a SHA-1 HMac as the calculation function.
 * 

* The document this implementation is based on can be found at * * RSA's PKCS5 Page */ public class PKCS5S2ParametersGenerator extends PBEParametersGenerator { private Mac hMac; private byte[] state; /** * construct a PKCS5 Scheme 2 Parameters generator. */ public PKCS5S2ParametersGenerator() { this(DigestFactory.createSHA1()); } public PKCS5S2ParametersGenerator(Digest digest) { hMac = new HMac(digest); state = new byte[hMac.getMacSize()]; } private void F( byte[] S, int c, byte[] iBuf, byte[] out, int outOff) { if (c == 0) { throw new IllegalArgumentException("iteration count must be at least 1."); } if (S != null) { hMac.update(S, 0, S.length); } hMac.update(iBuf, 0, iBuf.length); hMac.doFinal(state, 0); System.arraycopy(state, 0, out, outOff, state.length); for (int count = 1; count < c; count++) { hMac.update(state, 0, state.length); hMac.doFinal(state, 0); for (int j = 0; j != state.length; j++) { out[outOff + j] ^= state[j]; } } } private byte[] generateDerivedKey( int dkLen) { int hLen = hMac.getMacSize(); int l = (dkLen + hLen - 1) / hLen; byte[] iBuf = new byte[4]; byte[] outBytes = new byte[l * hLen]; int outPos = 0; CipherParameters param = new KeyParameter(password); hMac.init(param); for (int i = 1; i <= l; i++) { // Increment the value in 'iBuf' int pos = 3; while (++iBuf[pos] == 0) { --pos; } F(salt, iterationCount, iBuf, outBytes, outPos); outPos += hLen; } return outBytes; } /** * Generate a key parameter derived from the password, salt, and iteration * count we are currently initialised with. * * @param keySize the size of the key we want (in bits) * @return a KeyParameter object. */ public CipherParameters generateDerivedParameters( int keySize) { keySize = keySize / 8; byte[] dKey = Arrays.copyOfRange(generateDerivedKey(keySize), 0, keySize); return new KeyParameter(dKey, 0, keySize); } /** * Generate a key with initialisation vector parameter derived from * the password, salt, and iteration count we are currently initialised * with. * * @param keySize the size of the key we want (in bits) * @param ivSize the size of the iv we want (in bits) * @return a ParametersWithIV object. */ public CipherParameters generateDerivedParameters( int keySize, int ivSize) { keySize = keySize / 8; ivSize = ivSize / 8; byte[] dKey = generateDerivedKey(keySize + ivSize); return new ParametersWithIV(new KeyParameter(dKey, 0, keySize), dKey, keySize, ivSize); } /** * Generate a key parameter for use with a MAC derived from the password, * salt, and iteration count we are currently initialised with. * * @param keySize the size of the key we want (in bits) * @return a KeyParameter object. */ public CipherParameters generateDerivedMacParameters( int keySize) { return generateDerivedParameters(keySize); } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy