AlgorithmParameters implGetParameters() {
AlgorithmParameters params = null;
if (salt == null) {
// Cipher is not initialized with parameters;
// follow the recommendation in PKCS12 v1.0
// section B.4 to generate salt and iCount.
salt = new byte[DEFAULT_SALT_LENGTH];
SunJCE.getRandom().nextBytes(salt);
iCount = DEFAULT_COUNT;
}
PBEParameterSpec pbeSpec = new PBEParameterSpec(salt, iCount);
try {
params = AlgorithmParameters.getInstance(pbeAlgo, "SunJCE");
} catch (GeneralSecurityException gse) {
// should never happen
throw new RuntimeException("SunJCE provider is not configured properly");
}
try {
params.init(pbeSpec);
} catch (InvalidParameterSpecException ipse) {
// should never happen
throw new RuntimeException("PBEParameterSpec not supported");
}
return params;
}
void implInit(
int opmode, Key key, AlgorithmParameterSpec params, SecureRandom random, CipherSpi cipherImpl)
throws InvalidKeyException, InvalidAlgorithmParameterException {
char[] passwdChars = null;
salt = null;
iCount = 0;
if (key instanceof javax.crypto.interfaces.PBEKey) {
javax.crypto.interfaces.PBEKey pbeKey = (javax.crypto.interfaces.PBEKey) key;
passwdChars = pbeKey.getPassword();
salt = pbeKey.getSalt(); // maybe null if unspecified
iCount = pbeKey.getIterationCount(); // maybe 0 if unspecified
} else if (key instanceof SecretKey) {
byte[] passwdBytes = key.getEncoded();
if ((passwdBytes == null) || !(key.getAlgorithm().regionMatches(true, 0, "PBE", 0, 3))) {
throw new InvalidKeyException("Missing password");
}
passwdChars = new char[passwdBytes.length];
for (int i = 0; i < passwdChars.length; i++) {
passwdChars[i] = (char) (passwdBytes[i] & 0x7f);
}
} else {
throw new InvalidKeyException("SecretKey of PBE type required");
}
if (((opmode == Cipher.DECRYPT_MODE) || (opmode == Cipher.UNWRAP_MODE))
&& ((params == null) && ((salt == null) || (iCount == 0)))) {
throw new InvalidAlgorithmParameterException("Parameters missing");
}
if (params == null) {
// generate default for salt and iteration count if necessary
if (salt == null) {
salt = new byte[DEFAULT_SALT_LENGTH];
if (random != null) {
random.nextBytes(salt);
} else {
SunJCE.getRandom().nextBytes(salt);
}
}
if (iCount == 0) iCount = DEFAULT_COUNT;
} else if (!(params instanceof PBEParameterSpec)) {
throw new InvalidAlgorithmParameterException("PBEParameterSpec type required");
} else {
PBEParameterSpec pbeParams = (PBEParameterSpec) params;
// make sure the parameter values are consistent
if (salt != null) {
if (!Arrays.equals(salt, pbeParams.getSalt())) {
throw new InvalidAlgorithmParameterException(
"Inconsistent value of salt between key and params");
}
} else {
salt = pbeParams.getSalt();
}
if (iCount != 0) {
if (iCount != pbeParams.getIterationCount()) {
throw new InvalidAlgorithmParameterException(
"Different iteration count between key and params");
}
} else {
iCount = pbeParams.getIterationCount();
}
}
// salt is recommended to be ideally as long as the output
// of the hash function. However, it may be too strict to
// force this; so instead, we'll just require the minimum
// salt length to be 8-byte which is what PKCS#5 recommends
// and openssl does.
if (salt.length < 8) {
throw new InvalidAlgorithmParameterException("Salt must be at least 8 bytes long");
}
if (iCount <= 0) {
throw new InvalidAlgorithmParameterException("IterationCount must be a positive number");
}
byte[] derivedKey = derive(passwdChars, salt, iCount, keySize, CIPHER_KEY);
SecretKey cipherKey = new SecretKeySpec(derivedKey, algo);
if (cipherImpl != null && cipherImpl instanceof ARCFOURCipher) {
((ARCFOURCipher) cipherImpl).engineInit(opmode, cipherKey, random);
} else {
byte[] derivedIv = derive(passwdChars, salt, iCount, 8, CIPHER_IV);
IvParameterSpec ivSpec = new IvParameterSpec(derivedIv, 0, 8);
// initialize the underlying cipher
cipher.init(opmode, cipherKey, ivSpec, random);
}
}