/**
* Returns the key associated with the given alias, using the given password to recover it.
*
* @param alias the alias name
* @param password the password for recovering the key. This password is used internally as the
* key is exported in a PKCS12 format.
* @return the requested key, or null if the given alias does not exist or does not identify a
* <i>key entry</i>.
* @exception NoSuchAlgorithmException if the algorithm for recovering the key cannot be found
* @exception UnrecoverableKeyException if the key cannot be recovered (e.g., the given password
* is wrong).
*/
public Key engineGetKey(String alias, char[] password)
throws NoSuchAlgorithmException, UnrecoverableKeyException {
permissionCheck();
// An empty password is rejected by MacOS API, no private key data
// is exported. If no password is passed (as is the case when
// this implementation is used as browser keystore in various
// deployment scenarios like Webstart, JFX and applets), create
// a dummy password so MacOS API is happy.
if (password == null || password.length == 0) {
// Must not be a char array with only a 0, as this is an empty
// string.
if (random == null) {
random = new SecureRandom();
}
password = Long.toString(random.nextLong()).toCharArray();
}
Object entry = entries.get(alias.toLowerCase());
if (entry == null || !(entry instanceof KeyEntry)) {
return null;
}
// This call gives us a PKCS12 bag, with the key inside it.
byte[] exportedKeyInfo = _getEncodedKeyData(((KeyEntry) entry).keyRef, password);
if (exportedKeyInfo == null) {
return null;
}
PrivateKey returnValue = null;
try {
byte[] pkcs8KeyData = fetchPrivateKeyFromBag(exportedKeyInfo);
byte[] encryptedKey;
AlgorithmParameters algParams;
ObjectIdentifier algOid;
try {
// get the encrypted private key
EncryptedPrivateKeyInfo encrInfo = new EncryptedPrivateKeyInfo(pkcs8KeyData);
encryptedKey = encrInfo.getEncryptedData();
// parse Algorithm parameters
DerValue val = new DerValue(encrInfo.getAlgorithm().encode());
DerInputStream in = val.toDerInputStream();
algOid = in.getOID();
algParams = parseAlgParameters(in);
} catch (IOException ioe) {
UnrecoverableKeyException uke =
new UnrecoverableKeyException(
"Private key not stored as " + "PKCS#8 EncryptedPrivateKeyInfo: " + ioe);
uke.initCause(ioe);
throw uke;
}
// Use JCE to decrypt the data using the supplied password.
SecretKey skey = getPBEKey(password);
Cipher cipher = Cipher.getInstance(algOid.toString());
cipher.init(Cipher.DECRYPT_MODE, skey, algParams);
byte[] decryptedPrivateKey = cipher.doFinal(encryptedKey);
PKCS8EncodedKeySpec kspec = new PKCS8EncodedKeySpec(decryptedPrivateKey);
// Parse the key algorithm and then use a JCA key factory to create the private key.
DerValue val = new DerValue(decryptedPrivateKey);
DerInputStream in = val.toDerInputStream();
// Ignore this -- version should be 0.
int i = in.getInteger();
// Get the Algorithm ID next
DerValue[] value = in.getSequence(2);
AlgorithmId algId = new AlgorithmId(value[0].getOID());
String algName = algId.getName();
// Get a key factory for this algorithm. It's likely to be 'RSA'.
KeyFactory kfac = KeyFactory.getInstance(algName);
returnValue = kfac.generatePrivate(kspec);
} catch (Exception e) {
UnrecoverableKeyException uke =
new UnrecoverableKeyException("Get Key failed: " + e.getMessage());
uke.initCause(e);
throw uke;
}
return returnValue;
}