Java Spongy Castle: Encryption Helper Functions.java

public static PublicKey getRSAPublicKeyFromString(String apiKey) throws Exception{
	KeyFactory keyFactory = KeyFactory.getInstance("RSA", "SC"); 
	byte[] publicKeyBytes = Base64.decode(apiKey.getBytes("UTF-8"), Base64.DEFAULT); 
	X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(publicKeyBytes); 
	return keyFactory.generatePublic(x509KeySpec);
} 

public static PrivateKey getRSAPrivateKeyFromString(String key) throws Exception {
	byte [] clear = Base64.decode(key, Base64.DEFAULT); 
	PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(clear); 
	KeyFactory fact = KeyFactory.getInstance("RSA", "SC"); 
	PrivateKey priv = fact.generatePrivate(keySpec); 
	Arrays.fill(clear, (byte) 0); 
	return priv;
}

public static String stripPublicKeyHeaders(String key) {
        //strip the headers from the key string
        StringBuilder strippedKey = new StringBuilder();
        String lines[] = key.split("\n");
        for(String line : lines) {
            if(!line.contains("BEGIN PUBLIC KEY") && !line.contains("END PUBLIC KEY")) {
                strippedKey.append(line.trim());
            }
        }
        return strippedKey.toString().trim();
}