/** * generate a PBE based key suitable for a MAC algorithm, the key size is chosen according the * MAC size, or the hashing algorithm, whichever is greater. */ public static CipherParameters makePBEMacParameters( BCPBEKey pbeKey, AlgorithmParameterSpec spec) { if ((spec == null) || !(spec instanceof PBEParameterSpec)) { throw new IllegalArgumentException("Need a PBEParameter spec with a PBE key."); } PBEParameterSpec pbeParam = (PBEParameterSpec) spec; PBEParametersGenerator generator = makePBEGenerator(pbeKey.getType(), pbeKey.getDigest()); byte[] key = pbeKey.getEncoded(); CipherParameters param; if (pbeKey.shouldTryWrongPKCS12()) { key = new byte[2]; } generator.init(key, pbeParam.getSalt(), pbeParam.getIterationCount()); param = generator.generateDerivedMacParameters(pbeKey.getKeySize()); for (int i = 0; i != key.length; i++) { key[i] = 0; } return param; }
/** construct a key and iv (if necessary) suitable for use with a Cipher. */ public static CipherParameters makePBEParameters( BCPBEKey pbeKey, AlgorithmParameterSpec spec, String targetAlgorithm) { if ((spec == null) || !(spec instanceof PBEParameterSpec)) { throw new IllegalArgumentException("Need a PBEParameter spec with a PBE key."); } PBEParameterSpec pbeParam = (PBEParameterSpec) spec; PBEParametersGenerator generator = makePBEGenerator(pbeKey.getType(), pbeKey.getDigest()); byte[] key = pbeKey.getEncoded(); CipherParameters param; if (pbeKey.shouldTryWrongPKCS12()) { key = new byte[2]; } generator.init(key, pbeParam.getSalt(), pbeParam.getIterationCount()); if (pbeKey.getIvSize() != 0) { param = generator.generateDerivedParameters(pbeKey.getKeySize(), pbeKey.getIvSize()); } else { param = generator.generateDerivedParameters(pbeKey.getKeySize()); } if (targetAlgorithm.startsWith("DES")) { if (param instanceof ParametersWithIV) { KeyParameter kParam = (KeyParameter) ((ParametersWithIV) param).getParameters(); DESParameters.setOddParity(kParam.getKey()); } else { KeyParameter kParam = (KeyParameter) param; DESParameters.setOddParity(kParam.getKey()); } } for (int i = 0; i != key.length; i++) { key[i] = 0; } return param; }