How to open and read .pfx file?

[titothetitan]

I want to sign a String for my app using a .pfx A1 Certificate but Android Studio isn't reading the file. The iteration below* works on Netbeans just fine but in Android Studio returns false as it was not reading the .pfx file at all.

public String signApp(String input) throws NoSuchAlgorithmException, InvalidKeyException, SignatureException, KeyStoreException, IOException, CertificateException, UnrecoverableEntryException {
String signedString = "";
InputStream certificado;
char[] password = null;
KeyStore keystore = null;
Enumeration<String> aliases;
String alias = "";
//Open the .pfx file
certificado = getClass().getResourceAsStream("imediata.pfx");

password = "1234".toCharArray();
keystore = KeyStore.getInstance("PKCS12");
keystore.load(certificado, password );
//Get the alias
KeyStore.PrivateKeyEntry pkEntry = null;
PrivateKey pk = null;
try {
aliases = keystore.aliases();
while(aliases.hasMoreElements()) { //* problem: it's returning false as it not reading at
// all!!
alias = aliases.nextElement();
if (keystore.isKeyEntry(alias)) {
pkEntry = (KeyStore.PrivateKeyEntry) keystore.getEntry(alias, new
KeyStore.PasswordProtection(password ));
pk = pkEntry.getPrivateKey();
}
}
} catch (KeyStoreException e) {
throw new RuntimeException("CATCH", e);
}

//Keystore

Key key = (PrivateKey) keystore.getKey(alias, password );
java.security.cert.Certificate cert = keystore.getCertificate(alias);
PublicKey publicKey = cert.getPublicKey();
KeyPair kPair = new KeyPair(publicKey, (PrivateKey) key);

byte[] buffer = chave.getBytes();
// Signature
Signature signatureProvider = Signature.getInstance("SHA1withRSA");
signatureProvider.initSign(kPair.getPrivate());
signatureProvider.initSign(pk);
signatureProvider.update(buffer, 0, buffer.length);
byte[] signature = signatureProvider.sign();
signedString = Base64.getEncoder().encodeToString(signature);
return signedString;
}